Science.gov

Sample records for aerosol imager cai

  1. Deriving High Resolution UV Aerosol Optical Depth over East Asia using CAI-OMI Joint Retrieval

    NASA Astrophysics Data System (ADS)

    Go, S.; Kim, J.; KIM, M.; Lee, S.

    2015-12-01

    Monitoring aerosols using near UV spectral region have been successfully performed over decades by Ozong Monitoring Instruments (OMI) with benefit of strong aerosol signal over continuous dark surface reflectance, both land and ocean. However, because of big foot print of OMI, the cloud contamination error was a big issue in the UV aerosol algorithm. In the present study, high resolution UV aerosol optical depth (AOD) over East Asia was derived by collaborating the Greenhouse gases Observing SATellite/Thermal And Near infrared Sensor for carbon Observation (GOSAT/TANSO)-Cloud and Aerosol Imager (CAI) and OMI together. AOD of 0.1 degree grid resolution was retrieved using CAI band 1 (380nm) by bring OMI lv.2 aerosol type, single scattering albedo, and aerosol layer peak height in 1 degree grid resolution. Collocation of the two dataset within the 0.5 degree grid with time difference of OMI and CAI less than 5 minute was selected. Selected region becomes wider as it goes to the higher latitude. Also, calculated degradation factor of 1.57 was applied to CAI band1 (380nm) by comparing normalized radiance and Lambertian Equivalent Reflectivity (LER) of both sensors. The calculated degradation factor was reasonable over dark scene, but inconsistent over cirrus cloud and bright area. Then, surface reflectance was developed by compositing CAI LER minimum data over three month period, since the infrequent sampling rate associated with the three-day recursion period of GOSAT and the narrow CAI swath of 1000 km. To retrieve AOD, look up table (LUT) was generated using radiative transfer model VLIDORT NGST. Finally, the retrieved AOD was validated with AERONET ground based measurement data during the Dragon-NE Asia campaign in 2012.

  2. GOSAT CO2 retrieval results using TANSO-CAI aerosol information over East Asia

    NASA Astrophysics Data System (ADS)

    KIM, M.; Kim, W.; Jung, Y.; Lee, S.; Kim, J.; Lee, H.; Boesch, H.; Goo, T. Y.

    2015-12-01

    In the satellite remote sensing of CO2, incorrect aerosol information could induce large errors as previous studies suggested. Many factors, such as, aerosol type, wavelength dependency of AOD, aerosol polarization effect and etc. have been main error sources. Due to these aerosol effects, large number of data retrieved are screened out in quality control, or retrieval errors tend to increase if not screened out, especially in East Asia where aerosol concentrations are fairly high. To reduce these aerosol induced errors, a CO2 retrieval algorithm using the simultaneous TANSO-CAI aerosol information is developed. This algorithm adopts AOD and aerosol type information as a priori information from the CAI aerosol retrieval algorithm. The CO2 retrieval algorithm based on optimal estimation method and VLIDORT, a vector discrete ordinate radiative transfer model. The CO2 algorithm, developed with various state vectors to find accurate CO2 concentration, shows reasonable results when compared with other dataset. This study concentrates on the validation of retrieved results with the ground-based TCCON measurements in East Asia and the comparison with the previous retrieval from ACOS, NIES, and UoL. Although, the retrieved CO2 concentration is lower than previous results by ppm's, it shows similar trend and high correlation with previous results. Retrieved data and TCCON measurements data are compared at three stations of Tsukuba, Saga, Anmyeondo in East Asia, with the collocation criteria of ±2°in latitude/longitude and ±1 hours of GOSAT passing time. Compared results also show similar trend with good correlation. Based on the TCCON comparison results, bias correction equation is calculated and applied to the East Asia data.

  3. Developments of global greenhouse gas retrieval algorithm using Aerosol information from GOSAT-CAI

    NASA Astrophysics Data System (ADS)

    Kim, Woogyung; kim, Jhoon; Jung, Yeonjin; lee, Hanlim; Boesch, Hartmut

    2014-05-01

    Human activities have resulted in increasing atmospheric CO2 concentration since the beginning of Industrial Revolution to reaching CO2 concentration over 400 ppm at Mauna Loa observatory for the first time. (IPCC, 2007). However, our current knowledge of carbon cycle is still insufficient due to lack of observations. Satellite measurement is one of the most effective approaches to improve the accuracy of carbon source and sink estimates by monitoring the global CO2 distributions with high spatio-temporal resolutions (Rayner and O'Brien, 2001; Houweling et al., 2004). Currently, GOSAT has provided valuable information to observe global CO2 trend, enables our extended understanding of CO2 and preparation for future satellite plan. However, due to its physical limitation, GOSAT CO2 retrieval results have low spatial resolution and cannot cover wide area. Another obstruction of GOSAT CO2 retrieval is low data availability mainly due to contamination by clouds and aerosols. Especially, in East Asia, one of the most important aerosol source areas, it is hard to have successful retrieval result due to high aerosol concentration. The main purpose of this study is to improve data availability of GOSAT CO2 retrieval. In this study, current state of CO2 retrieval algorithm development is introduced and preliminary results are shown. This algorithm is based on optimal estimation method and utilized VLIDORT the vector discrete ordinate radiative transfer model. This proto type algorithm, developed from various combinations of state vectors to find accurate CO2 concentration, shows reasonable result. Especially the aerosol retrieval algorithm using GOSAT-CAI measurements, which provide aerosol information for the same area with GOSAT-FTS measurements, are utilized as input data of CO2 retrieval. Other CO2 retrieval algorithms use chemical transport model result or climatologically expected values as aerosol information which is the main reason of low data availability. With

  4. Retrieval and Validation of Aerosol Optical Properties over East Asia from TANSO-Cloud and Aerosol Imager

    NASA Astrophysics Data System (ADS)

    Lee, Sanghee; Kim, Jhoon; Kim, Mijin; Choi, Myungje; Go, Sujung; Lim, HyunKwang; Ou, Mi-Lim; Goo, Tae-Young; Yokota, Tatsuya

    2015-04-01

    Aerosol is a significant component on air quality and climate change. In particular, spatial and temporal distribution of aerosol shows large variability over East Asia, thus has large effect in retrieving carbon dioxide from Greenhouse Gases Observing Satellite (GOSAT) Thermal And Near infrared Sensor for carbon Observation Fourier Transform Spectrometer (TANSO-FTS). An aerosol retrieval algorithm was developed from TANSO- Cloud and Aerosol Imager (CAI) onboard the GOSAT. The algorithm retrieves aerosol optical depth (AOD), size distribution of aerosol, and aerosol type in 0.1 degree grid resolution and surface reflectance was estimated using the clear sky composite method. To test aerosol absorptivity, the reflectance difference method was considered using channels of TANSO-CAI. In this study, the retrieved aerosol optical depth (AOD) was compared with those of Aerosol Robotic NETwork (AERONET) and MODerate resolution Imaging Sensor (MODIS) dataset from September 2011 and August 2014. Comparisons of AODs between AERONET and CAI show the reasonably good correlation with correlation coefficient of 0.77 and regression slope of 0.87 for the whole period. Moreover, those between MODIS and CAI for the same period show correlations with correlation coefficient of 0.7 ~ 0.9 and regression slope of 0.7 ~ 1.2, depending on season and comparison regions however, the largest error source in aerosol retrieval has been surface reflectance. Over ocean and some Land, surface reflectance tends to be overestimated, and thereby CAI-AOD tends to be underestimated. Based on the results with CAI algorithm developed, the algorithm is continuously improved for better performance.

  5. Validation of Retrieved Aerosol Optical Properties over Northeast Asia for Five Years from GOSAT TANSO-Cloud and Aerosol Imager

    NASA Astrophysics Data System (ADS)

    Kim, J.; Lee, S.; KIM, M.; Choi, M.; Go, S.; Lim, H.; Goo, T. Y.; Nakajima, T.; Kuze, A.; Shiomi, K.; Yokota, T.

    2015-12-01

    An aerosol retrieval algorithm was developed from Thermal And Near infrared Sensor for carbon Observation-Cloud and Aerosol Imager (TANSO-CAI) onboard the Greenhouse Gases Observing Satellite (GOSAT). The algorithm retrieves aerosol optical depth (AOD), size distribution of aerosol, and aerosol type in 0.1 degree grid resolution by look-up tables, which is used in retrieving optical properties of aerosol using inversion products from Aerosol Robotic NETwork (AERONET) sun-photometer observation. To improve the accuracy of aerosol algorithm, first, this algorithm considered the annually estimated radiometric degradation factor of TANSO-CAI suggested by Kuze et al. (2014). Second, surface reflectance was determined by two methods: one using the clear sky composite method from CAI measurements and the other the database from MODerate resolution Imaging Sensor (MODIS) surface reflectance data. At a given pixel, the surface reflectance is selected by using normalized difference vegetation index (NDVI) depending on season (Hsu et al., 2013). In this study, the retrieved AODs were compared with those of AERONET and MODIS dataset for different season over five years. Comparisons of AODs between AERONET and CAI show reasonable agreement with correlation coefficients of 0.65 ~ 0.97 and regression slopes between 0.7 and 1.2 for the whole period, depending on season and sites. Moreover, those between MODIS and CAI for the same period show agreements with correlation coefficients of 0.7 ~ 0.9 and regression slopes between 0.7 and 1.0, depending on season and regions. The results show reasonably good correlation, however, the largest error source in aerosol retrieval has been surface reflectance of TANSO-CAI due to its 3-days revisit orbit characteristics.

  6. Skinner and CAI.

    ERIC Educational Resources Information Center

    Chandler, Harry N.

    1984-01-01

    The author cites comments of B.F. Skinner supporting the benefits of carefully constructed computer assisted instruction (CAI) programs. Preliminary studies on military populations suggesting the value of CAI are discussed, as is the collection of information about software. (CL)

  7. Developing Large CAI Packages.

    ERIC Educational Resources Information Center

    Reed, Mary Jac M.; Smith, Lynn H.

    1983-01-01

    When developing large computer-assisted instructional (CAI) courseware packages, it is suggested that there be more attentive planning to the overall package design before actual lesson development is begun. This process has been simplified by modifying the systems approach used to develop single CAI lessons, followed by planning for the…

  8. Current Issues in CAI.

    ERIC Educational Resources Information Center

    Hansen, Duncan N.

    A great deal of research has been done on instructional strategies and concepts of individualized instruction in computer-assisted instruction (CAI). Individualizing instruction within CAI can be defined in terms of an input output process which includes a stimulus array, cognitive processes, and response requirements. Research in these areas of…

  9. CAI Terminal Characteristics.

    ERIC Educational Resources Information Center

    Braun, Peter

    The bewildering number of available terminals which are offered to CAI users presents a rather formidable problem of which one to choose. This article surveys what appear to be evolving standards for terminals. The usefulness of these terminals for CAI purposes is discussed, together with the best known prototype exhibiting the particular feature.…

  10. Experience with the CAIS

    NASA Technical Reports Server (NTRS)

    Tighe, Michael F.

    1986-01-01

    Intermetrics' experience is that the Ada package construct, which allows separation of specification and implementation allows specification of a CAIS that is transportable across varying hardware and software bases. Additionally, the CAIS is an excellent basis for providing operating system functionality to Ada applications. By allowing the Byron APSE to be moved easily from system to system, and allowing significant re-writes of underlying code. Ada and the CAIS provide portability as well as transparency to change at the application operating system interface level.

  11. Carbon, CAIs and chondrules

    NASA Technical Reports Server (NTRS)

    Ash, R. D.; Russell, S. S.

    1994-01-01

    It has been shown that C is present in CAI's and chondrules. It can be distinguished from matrix C both by its thermal stability and isotopic composition, which implies that it was not introduced after parent body accretion. It is concluded that C must have been present in the chondrule and CAI precursor material. Therefore any models of chondrule and CAI formation and inferences drawn about solar system conditions during these events must take into account the consequences of the presence of C on inclusion chemistry, mineralogy, and oxidation state.

  12. The CAIS 2 Project

    NASA Technical Reports Server (NTRS)

    Legrand, Sue; Thall, Richard

    1986-01-01

    The Common APSE Interface Set (CAIS) is a proposed MIL-STD intended to promote the portability of Ada Programming Support Environment (APSE) tools written in Ada. The standardized interfaces define a virtual operating system, from which portable tools derive their basic services, e.g., file management, input/output, communications, and process control. In the Ada world, such a virtual operating system is called a Kernel Ada Programming Support Environment (KAPSE). The CAIS is a standardized interface between KAPSEs and tools. The CAIS has been proposed as a starting point for standard interfaces to be used in the NASA Software Support Environment (SSE) for the Space Station Program. The status of the CAIS standardization effort and plans for further development are described.

  13. Verification of new cloud discrimination algorithm using GOSAT TANSO-CAI in the Amazon

    NASA Astrophysics Data System (ADS)

    Oishi, Y.; Ishida, H.; Nakajima, T. Y.

    2015-12-01

    Greenhouse gases Observing SATellite (GOSAT) was launched in 2009 to measure the global atmospheric CO2 and CH4 concentrations. GOSAT is equipped with two sensors: the Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) and the Cloud and Aerosol Imager (TANSO-CAI). The presence of clouds in the instantaneous field-of-view (IFOV) of the FTS leads to incorrect estimates of the concentrations. Thus, the FTS data which are suspected to be cloud-contaminated must be identified using a CAI cloud discrimination algorithm and rejected. Conversely, overestimation of clouds leads to reduce the amount of the FTS data which can be used to estimate the greenhouse gases concentrations. It becomes a serious problem in the region of tropical rainforest such as the Amazon, where there are very few remaining FTS data by cloud cover. The preparation for the launch of the GOSAT-2 in fiscal 2017 has been progressing. To improve the accuracy of estimates of the greenhouse gases concentrations, we need to refine the existing CAI cloud discrimination algorithm. For the reason, a new cloud discrimination algorithm using support vector machines (SVM) was developed. Visual inspections can use the locally optimized thresholds, though the existing CAI cloud discrimination algorithm uses the common thresholds all over the world. Thus, it is certain that the accuracy of visual inspections is better than these algorithms in the limited region without areas such as ice and snow, where it is difficult to discriminate between clouds and ground surfaces. In this study we evaluated the accuracy of the new cloud discrimination algorithm by comparing with the existing CAI cloud discrimination algorithm and visual inspections of the same CAI images in the Amazon. We will present our latest results.

  14. CAI Update: So You Want to Do CAI?

    ERIC Educational Resources Information Center

    Bagley, Carole

    1979-01-01

    Provides necessary characteristics to consider when selecting a CAI system plus a list of costs and capabilities available with the better known CAI systems. Characteristics of major CAI systems are presented in three categories--large/maxi, mini, and micro systems--in chart form. (JEG)

  15. Skill Specific CAI Techniques.

    ERIC Educational Resources Information Center

    Lavine, Roberta Z.; Fechter, Sharon Ahern

    Advantages of computer-assisted instruction (CAI) for grammar-oriented exercises are considered, and a learning module to help the student prepare for the Test of English as a Foreign Language (TOEFL) exam is described. The exercises are modeled on the TOEFL exam: the student is given a sentence, one part of which is incorrect and is asked to…

  16. Development of a generalized algorithm of satellite remote sensing using multi-wavelength and multi-pixel information (MWP method) for aerosol properties by satellite-borne imager

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Nakajima, T.; Morimoto, S.; Takenaka, H.

    2014-12-01

    We have developed a new satellite remote sensing algorithm to retrieve the aerosol optical characteristics using multi-wavelength and multi-pixel information of satellite imagers (MWP method). In this algorithm, the inversion method is a combination of maximum a posteriori (MAP) method (Rodgers, 2000) and the Phillips-Twomey method (Phillips, 1962; Twomey, 1963) as a smoothing constraint for the state vector. Furthermore, with the progress of computing technique, this method has being combined with the direct radiation transfer calculation numerically solved by each iteration step of the non-linear inverse problem, without using LUT (Look Up Table) with several constraints.Retrieved parameters in our algorithm are aerosol optical properties, such as aerosol optical thickness (AOT) of fine and coarse mode particles, a volume soot fraction in fine mode particles, and ground surface albedo of each observed wavelength. We simultaneously retrieve all the parameters that characterize pixels in each of horizontal sub-domains consisting the target area. Then we successively apply the retrieval method to all the sub-domains in the target area.We conducted numerical tests for the retrieval of aerosol properties and ground surface albedo for GOSAT/CAI imager data to test the algorithm for the land area. The result of the experiment showed that AOTs of fine mode and coarse mode, soot fraction and ground surface albedo are successfully retrieved within expected accuracy. We discuss the accuracy of the algorithm for various land surface types. Then, we applied this algorithm to GOSAT/CAI imager data, and we compared retrieved and surface-observed AOTs at the CAI pixel closest to an AERONET (Aerosol Robotic Network) or SKYNET site in each region. Comparison at several sites in urban area indicated that AOTs retrieved by our method are in agreement with surface-observed AOT within ±0.066.Our future work is to extend the algorithm for analysis of AGEOS-II/GLI and GCOM/C-SGLI data.

  17. Comparison of Gosat CAI and SPOT Vgt Ndvi Data with Different Season and Land Cover in East Asia

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Wang, X.; Guo, M.; Tani, H.

    2011-08-01

    The Normalized Difference Vegetation Index (NDVI) has become one of the most widely used indices in remote sensing applications in a variety of fields. Many studies have compared the NDVI values for different satellite sensors. Nowadays, the Greenhouse Gases Observing Satellite (GOSAT) was successfully launched on January 23, 2009. It is used to monitor greenhouse gases on the Earth's surface and also has a sensor, the Cloud Aerosol Imager (CAI), that senses red and near infrared spectrums. It can also process NDVI data. Therefore, we are first compare GOSAT CAI and SPOT VGT NDVI data in different seasonal and land cover in East Asian, to explore the relationship between the two types of datasets, and to discuss the possibility of extending SPOT VGT data using GOSAT CAI NDVI data for the same area. We used GOSAT CAI Level 3 data to derive 10-day composite NDVI values for the East Asia region for November 2009 and January, April and July 2010 using the maximum value composite (MVC) method. We compared these values with 10-day composite SPOT VGT NDVI data for the same period. The results show that the correlation coefficients of regression analysis generally revealed a strong correlation between NDVI from the two sensors in November 2009 and January, April and July 2010 (0.88, 0.85, 0.77 and 0.74, respectively). The differences place may be affected by cloud cover. From the combined analysis of seasonal changes and land cover, we found that the correlations between the SPOT VGT and the GOSAT CAI NDVI data are less affected by seasonal change and the SPOT VGT data is more sensitive to high vegetation coverage than the GOSAT CAI data. In the future, through continued monitoring and processing by cloud removal technology, the accuracy of GOSAT CAI NDVI data will be further improved and thus be more widely used.

  18. Feasibility of polarized all-sky imaging for aerosol characterization

    NASA Astrophysics Data System (ADS)

    Kreuter, A.; Blumthaler, M.

    2012-12-01

    Polarized all-sky distribution measurements contain radiative information about aerosol properties. We investigate the method of all-sky imaging for aerosol property retrieval and propose a technical frame work for image processing and analysis. Using Zernike polynomials, we decompose the relative Stokes parameter distributions, which efficiently captures the information content. The resulting feature vector is well suited for all-sky imaging, independent of calibration and robust against noise. It can be directly used in existing algorithms or alternative types of retrieval methods of aerosol optical properties in the future. By modeling possible aerosol scenarios we investigate the influence of different aerosol types in terms of the first two principal components describing the maximal variances. In this representation we show that the feature vector from a polarized all-sky imager is suitable for aerosol classification with respect to size and single scatter albedo.

  19. The Aerosol Limb Imager: acousto-optic imaging of limb scattered sunlight for stratospheric aerosol profiling

    NASA Astrophysics Data System (ADS)

    Elash, B. J.; Bourassa, A. E.; Loewen, P. R.; Lloyd, N. D.; Degenstein, D. A.

    2015-12-01

    The Aerosol Limb Imager (ALI) is an optical remote sensing instrument designed to image scattered sunlight from the atmospheric limb. These measurements are used to retrieve spatially resolved information of the stratospheric aerosol distribution, including spectral extinction coefficient and particle size. Here we present the design, development and test results of an ALI prototype instrument. The long term goal of this work is the eventual realization of ALI on a satellite platform in low earth orbit, where it can provide high spatial resolution observations, both in the vertical and cross-track. The instrument design uses a large aperture Acousto-Optic Tunable Filter (AOTF) to image the sunlit stratospheric limb in a selectable narrow wavelength band ranging from the visible to the near infrared. The ALI prototype was tested on a stratospheric balloon flight from the Canadian Space Agency (CSA) launch facility in Timmins, Canada, in September 2014. Preliminary analysis of the hyperspectral images indicate that the radiance measurements are of high quality, and we have used these to retrieve vertical profiles of stratospheric aerosol extinction coefficient from 650-1000 nm, along with one moment of the particle size distribution. Those preliminary results are promising and development of a satellite prototype of ALI within the Canadian Space Agency is ongoing.

  20. Maxi CAI with a Micro.

    ERIC Educational Resources Information Center

    Gerhold, George; And Others

    This paper describes an effective microprocessor-based CAI system which has been repeatedly tested by a large number of students and edited accordingly. Tasks not suitable for microprocessor based systems (authoring, testing, and debugging) were handled on larger multi-terminal systems. This approach requires that the CAI language used on the…

  1. Impact of atmospheric aerosols on long range image quality

    NASA Astrophysics Data System (ADS)

    LeMaster, Daniel A.; Eismann, Michael T.

    2012-06-01

    Image quality in high altitude long range imaging systems can be severely limited by atmospheric absorption, scattering, and turbulence. Atmospheric aerosols contribute to this problem by scattering target signal out of the optical path and by scattering in unwanted light from the surroundings. Target signal scattering may also lead to image blurring though, in conventional modeling, this effect is ignored. The validity of this choice is tested in this paper by developing an aerosol modulation transfer function (MTF) model for an inhomogeneous atmosphere and then applying it to real-world scenarios using MODTRAN derived scattering parameters. The resulting calculations show that aerosol blurring can be effectively ignored.

  2. MAPTIP experiment, marine aerosol properties and thermal imager performance

    SciTech Connect

    Eijk, A.M.J. van; Leeuw, G. de; Jensen, D.R.

    1994-12-31

    During the fall of 1993, a field experimental study on Marine Aerosol Properties and Thermal Imager Performance (MAPTIP) was conducted in the Dutch coastal waters. The objectives of the MAPTIP trial were: (1) to improve and validate vertical marine aerosol models by providing an extensive set of aerosol and meteorological measurements, within a coastal environment, at different altitudes and for a range of meteorological conditions; (2) to make aerosol and meteorological observations in the first 10 m above the ocean surface with a view to extending existing aerosol models to incorporate near-surface effects; (3) to assess marine boundary layer effects on thermal imaging systems. Aerosol and meteorological instruments, as well as thermal imagers and calibrated targets, were used at several platforms and locations. Measurements have been made of atmospheric turbulence and refractivity effects at wavelengths in the IR and visible, to assess the marine boundary layer effects on the degradation of thermal images. Calibrated targets at different altitudes were observed to the maximum observable range under a wide variety of conditions in both the 3--5 and 8--12 gm bands, These data will be used for the development and validation of IRST models and IR ship signature models with the view of determining the effects of marine-generated aerosols, turbulence and meteorological profiles on their performance.

  3. CAI: VS CBE Languages. Authoring, How Soon?

    ERIC Educational Resources Information Center

    Bagley, Carole A.

    This paper gives a view of CAI (computer assisted instruction), computers in education, CAI author languages, and concepts for authoring. Distinctions are drawn among CAI, CBE (computer based education), CMI (computer managed instruction), and CGM (computer managed materials), and the functions of each are described. CAI has been slow in coming…

  4. A CAI in the Ivuna CI1 Chondrite

    NASA Technical Reports Server (NTRS)

    Frank, David R.; Zolensky, M.; Martinez, J.; Mikouchi, T.; Ohsumi, K.; Hagiya, K.; Satake, W.; Le, L.; Ross, D.; Peslier, A.

    2011-01-01

    We have recently discovered the first well-preserved calcium aluminum-rich inclusion (CAI) in a CI1 chondrite (Ivuna). Previously, all CI1 chondrites were thought to be devoid of preserved CAI and chondrules due to the near total aqueous alteration to which their parent body (bodies) have been subjected. The CAI is roughly spherical, but with a slight teardrop geometry and a maximum diameter of 170 microns (fig. 1). It lacks any Wark-Lovering Rim. Incipient aqueous alteration, and probably shock, have rendered large portions of the CAI poorly crystalline. It is extremely fine-grained, with only a few grains exceeding 10 microns. We have performed electron microprobe analyses (EPMA), FEG-SEM imaging and element mapping, as well as electron back-scattered diffraction (EBSD) and synchrotron X-ray diffraction (SXRD) in order to determine the fundamental characteristics of this apparently unique object.

  5. Estimation of aerosol optical properties from all-sky imagers

    NASA Astrophysics Data System (ADS)

    Kazantzidis, Andreas; Tzoumanikas, Panagiotis; Salamalikis, Vasilios; Wilbert, Stefan; Prahl, Christoph

    2015-04-01

    Aerosols are one of the most important constituents in the atmosphere that affect the incoming solar radiation, either directly through absorbing and scattering processes or indirectly by changing the optical properties and lifetime of clouds. Under clear skies, aerosols become the dominant factor that affect the intensity of solar irradiance reaching the ground. It has been shown that the variability in direct normal irradiance (DNI) due to aerosols is more important than the one induced in global horizontal irradiance (GHI), while the uncertainty in its calculation is dominated by uncertainties in the aerosol optical properties. In recent years, all-sky imagers are used for the detection of cloud coverage, type and velocity in a bouquet of applications including solar irradiance resource and forecasting. However, information about the optical properties of aerosols could be derived with the same instrumentation. In this study, the aerosol optical properties are estimated with the synergetic use of all-sky images, complementary data from the Aerosol Robotic Network (AERONET) and calculations from a radiative transfer model. The area of interest is Plataforma Solar de Almería (PSA), Tabernas, Spain and data from a 5 month period are analyzed. The proposed methodology includes look-up-tables (LUTs) of diffuse sky radiance of Red (R), Green (G) and Blue (B) channels at several zenith and azimuth angles and for different atmospheric conditions (Angström α and β, single scattering albedo, precipitable water, solar zenith angle). Based on the LUTS, results from the CIMEL photometer at PSA were used to estimate the RGB radiances for the actual conditions at this site. The methodology is accompanied by a detailed evaluation of its robustness, the development and evaluation of the inversion algorithm (derive aerosol optical properties from RGB image values) and a sensitivity analysis about how the pre-mentioned atmospheric parameters affect the results.

  6. Airflow measurement inaccuracies in aerosol imaging

    SciTech Connect

    Sirr, S.A.; Miltz-Miller, S.; Notman, D.N.; Boyle, M.J.; Boudreau, R.J.; Loken, M.K.

    1986-04-01

    Aerosol production using inclined compressed air tanks may be subject to error caused by airflow meter variability and by the degree of inclination of the air-flow meter. Since most of these tanks are used in an inclined position, it is important for clinicians to be aware of these errors.

  7. Airflow measurement inaccuracies in aerosol imaging.

    PubMed

    Sirr, S A; Miltz-Miller, S; Notman, D N; Boyle, M J; Boudreau, R J; Loken, M K

    1986-04-01

    Aerosol production using inclined compressed air tanks may be subject to error caused by airflow meter variability and by the degree of inclination of the air-flow meter. Since most of these tanks are used in an inclined position, it is important for clinicians to be aware of these errors. PMID:3952316

  8. CAI in Thermodynamics at the USAF Academy.

    ERIC Educational Resources Information Center

    Byerley, Aaron R.; Winn, Robert C.

    1986-01-01

    Illustrates computer assisted instruction (CAI) at the United States Air Force (USAF) academy by presenting a sample CAI session involving thermodynamics. Comments on evaluation of the program. Future plans are included. (JN)

  9. CAI in Advanced Literature Class.

    ERIC Educational Resources Information Center

    Hinton, Norman

    1981-01-01

    Ways that computer assisted instruction (CAI) can be useful in teaching English at upperclass and graduate levels are considered, with illustrations from PLATO lessons that have been composed and programmed. One lesson takes advantage of PLATO's graphic design capabilities, which enabled the teacher to design the runic figures and to show them in…

  10. Teacher's Handbook for CAI Courses.

    ERIC Educational Resources Information Center

    Suppes, Patrick; And Others

    The handbooks for the most widely used computer-assisted instruction (CAI) courses now available on computer terminals at the Institute for Mathematical Studies in the Social Sciences at Stanford University are presented. Handbooks are included for the following courses: Strands Drill-and-practice (arithmetic fundamentals for fourth grade), Logic…

  11. Flexible Teaching Methods for CAI Systems.

    ERIC Educational Resources Information Center

    Hammel, D. G.

    Although much progress has been made in the ten years that computer-assisted instruction (CAI) has been researched, two major problems still exist. One is the high cost of CAI; the other is its lack of flexibility. The former problem will abate with improved technology and the creation of educational CAI utility systems. One possible solution to…

  12. Atmospheric aerosol profiling with a bistatic imaging lidar system.

    PubMed

    Barnes, John E; Sharma, N C Parikh; Kaplan, Trevor B

    2007-05-20

    Atmospheric aerosols have been profiled using a simple, imaging, bistatic lidar system. A vertical laser beam is imaged onto a charge-coupled-device camera from the ground to the zenith with a wide-angle lens (CLidar). The altitudes are derived geometrically from the position of the camera and laser with submeter resolution near the ground. The system requires no overlap correction needed in monostatic lidar systems and needs a much smaller dynamic range. Nighttime measurements of both molecular and aerosol scattering were made at Mauna Loa Observatory. The CLidar aerosol total scatter compares very well with a nephelometer measuring at 10 m above the ground. The results build on earlier work that compared purely molecular scattered light to theory, and detail instrument improvements. PMID:17514239

  13. The Aerosol Limb Imager: acousto-optic imaging of limb-scattered sunlight for stratospheric aerosol profiling

    NASA Astrophysics Data System (ADS)

    Elash, B. J.; Bourassa, A. E.; Loewen, P. R.; Lloyd, N. D.; Degenstein, D. A.

    2016-03-01

    The Aerosol Limb Imager (ALI) is an optical remote sensing instrument designed to image scattered sunlight from the atmospheric limb. These measurements are used to retrieve spatially resolved information of the stratospheric aerosol distribution, including spectral extinction coefficient and particle size. Here we present the design, development and test results of an ALI prototype instrument. The long-term goal of this work is the eventual realization of ALI on a satellite platform in low earth orbit, where it can provide high spatial resolution observations, both in the vertical and cross-track. The instrument design uses a large-aperture acousto-optic tunable filter (AOTF) to image the sunlit stratospheric limb in a selectable narrow wavelength band ranging from the visible to the near infrared. The ALI prototype was tested on a stratospheric balloon flight from the Canadian Space Agency (CSA) launch facility in Timmins, Canada, in September 2014. Preliminary analysis of the hyperspectral images indicates that the radiance measurements are of high quality, and we have used these to retrieve vertical profiles of stratospheric aerosol extinction coefficient from 650 to 1000 nm, along with one moment of the particle size distribution. Those preliminary results are promising and development of a satellite prototype of ALI within the Canadian Space Agency is ongoing.

  14. The Evolutionary Development of CAI Hardware.

    ERIC Educational Resources Information Center

    Stifle, John E.

    After six years of research in computer assisted instruction (CAI) using PLATO III, a decision was made at the University of Illinois to develop a larger system as a national CAI resource. This document describes the design specifications and problems in the development of PLATO IV, a system which is capable of accomodating up to 4,000 terminals…

  15. Computers for Your Classroom: CAI and CMI.

    ERIC Educational Resources Information Center

    Thomas, David B.; Bozeman, William C.

    1981-01-01

    The availability of compact, low-cost computer systems provides a means of assisting classroom teachers in the performance of their duties. Computer-assisted instruction (CAI) and computer-managed instruction (CMI) are two applications of computer technology with which school administrators should become familiar. CAI is a teaching medium in which…

  16. CAI Systems Past, Present, and Future.

    ERIC Educational Resources Information Center

    Feingold, Samuel L.

    In considering the development of computer-assisted instruction (CAI) systems over the past eleven years, one can see a pattern of interaction between advances in computer hardware and software and continuing efforts to solve the basic problems of CAI: problems of achieving a natural-language capability, of keeping the cost low, and of making…

  17. A risk management approach to CAIS development

    NASA Technical Reports Server (NTRS)

    Hart, Hal; Kerner, Judy; Alden, Tony; Belz, Frank; Tadman, Frank

    1986-01-01

    The proposed DoD standard Common APSE Interface Set (CAIS) was developed as a framework set of interfaces that will support the transportability and interoperability of tools in the support environments of the future. While the current CAIS version is a promising start toward fulfilling those goals and current prototypes provide adequate testbeds for investigations in support of completing specifications for a full CAIS, there are many reasons why the proposed CAIS might fail to become a usable product and the foundation of next-generation (1990'S) project support environments such as NASA's Space Station software support environment. The most critical threats to the viability and acceptance of the CAIS include performance issues (especially in piggybacked implementations), transportability, and security requirements. To make the situation worse, the solution to some of these threats appears to be at conflict with the solutions to others.

  18. Fluorescence lifetime imaging of optically levitated aerosol: a technique to quantitatively map the viscosity of suspended aerosol particles.

    PubMed

    Fitzgerald, C; Hosny, N A; Tong, H; Seville, P C; Gallimore, P J; Davidson, N M; Athanasiadis, A; Botchway, S W; Ward, A D; Kalberer, M; Kuimova, M K; Pope, F D

    2016-08-21

    We describe a technique to measure the viscosity of stably levitated single micron-sized aerosol particles. Particle levitation allows the aerosol phase to be probed in the absence of potentially artefact-causing surfaces. To achieve this feat, we combined two laser based techniques: optical trapping for aerosol particle levitation, using a counter-propagating laser beam configuration, and fluorescent lifetime imaging microscopy (FLIM) of molecular rotors for the measurement of viscosity within the particle. Unlike other techniques used to measure aerosol particle viscosity, this allows for the non-destructive probing of viscosity of aerosol particles without interference from surfaces. The well-described viscosity of sucrose aerosol, under a range of relative humidity conditions, is used to validate the technique. Furthermore we investigate a pharmaceutically-relevant mixture of sodium chloride and salbutamol sulphate under humidities representative of in vivo drug inhalation. Finally, we provide a methodology for incorporating molecular rotors into already levitated particles, thereby making the FLIM/optical trapping technique applicable to real world aerosol systems, such as atmospheric aerosols and those generated by pharmaceutical inhalers. PMID:27430158

  19. Exploring Atmospheric Aerosol Chemistry with Advanced High-Resolution Mass Spectrometry and Particle Imaging Methods

    NASA Astrophysics Data System (ADS)

    Nizkorodov, S.

    2014-12-01

    Physical and chemical complexity of atmospheric aerosols presents significant challenges both to experimentalists working on aerosol characterization and to modelers trying to parameterize critical aerosol properties. Multi-modal approaches that combine state-of-the-art experimental, theoretical, and modeling methods are becoming increasingly important in aerosol research. This presentation will discuss recent applications of unique high-resolution mass spectrometry and particle imaging tools developed at two Department of Energy's user facilities, the Environmental Molecular Science Laboratory (EMSL) and Advanced Light Source (ALS), to studies of molecular composition, photochemical aging, and properties of laboratory-generated and field aerosols. Specifically, this presentation will attempt to address the following questions: (a) how do NO2, SO2, and NH3 affect molecular level composition of anthropogenic aerosols?; (b) what factors determine viscosity/surface tension of organic aerosol particles?; (c) how does photolysis affect molecular composition and optical properties of organic aerosols?

  20. Spectropolarimetric Imaging of Aerosols Using Tandem Photoelastic Modulators

    NASA Astrophysics Data System (ADS)

    Davis, A.; Diner, D. J.; Gutt, G.; Hancock, B.; Wang, Y.; Chipman, R.; Hirschy, L.

    2006-12-01

    Passive multiangular, multispectral, and polarimetric sensing approaches each have unique strengths for the measurement of tropospheric aerosol column abundances and microphysical properties. Current spaceborne multispectral and multiangular aerosol sensors (e.g., MISR and MODIS) operate at spatial resolutions of ~1 km. Under NASA's Instrument Incubator Program, we are developing an electro-optic imaging approach that will supplement such observations with high-accuracy imaging polarimetry. Polarization adds sensitivity to particle real refractive index and size distribution. To achieve a degree of linear polarization (DOLP) uncertainty of 0.5%, our approach temporally modulates the linear-polarization component of incoming light at a rapid rate, enabling each detector within a focal-plane array, combined with polarization analyzers, to measure the relative proportions of the linear Stokes components Q or U to the total intensity. This results in a "self- calibrating" approach that is independent of detector gain variations or changes in optical transmittance. Our system uses tandem photoelastic modulators (PEMs) within a reflective camera design. The two PEMs vibrate at slightly different resonant frequencies, leading to modulation of the polarized light at a heterodyne frequency of ~25 Hz. High-speed (1 kHz) readout of the detector arrays samples the output waveforms from which Q/I and U/I are derived. We report on experimental and theoretical analyses of PEM and optical system performance, along with plans for developing ruggedized PEMs capable of withstanding launch and on-orbit stresses.

  1. Multiangle Imaging Spectroradiometer (MISR) Global Aerosol Optical Depth Validation Based on 2 Years of Coincident Aerosol Robotic Network (AERONET) Observations

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.; Gaitley, Barbara J.; Martonchik, John V.; Diner, David J.; Crean, Kathleen A.; Holben, Brent

    2005-01-01

    Performance of the Multiangle Imaging Spectroradiometer (MISR) early postlaunch aerosol optical thickness (AOT) retrieval algorithm is assessed quantitatively over land and ocean by comparison with a 2-year measurement record of globally distributed AERONET Sun photometers. There are sufficient coincident observations to stratify the data set by season and expected aerosol type. In addition to reporting uncertainty envelopes, we identify trends and outliers, and investigate their likely causes, with the aim of refining algorithm performance. Overall, about 2/3 of the MISR-retrieved AOT values fall within [0.05 or 20% x AOT] of Aerosol Robotic Network (AERONET). More than a third are within [0.03 or 10% x AOT]. Correlation coefficients are highest for maritime stations (approx.0.9), and lowest for dusty sites (more than approx.0.7). Retrieved spectral slopes closely match Sun photometer values for Biomass burning and continental aerosol types. Detailed comparisons suggest that adding to the algorithm climatology more absorbing spherical particles, more realistic dust analogs, and a richer selection of multimodal aerosol mixtures would reduce the remaining discrepancies for MISR retrievals over land; in addition, refining instrument low-light-level calibration could reduce or eliminate a small but systematic offset in maritime AOT values. On the basis of cases for which current particle models are representative, a second-generation MISR aerosol retrieval algorithm incorporating these improvements could provide AOT accuracy unprecedented for a spaceborne technique.

  2. Summary of the marine aerosol properties and thermal imager performance trial (MAPTIP). Professional paper

    SciTech Connect

    Leeuw, G. de; Eijik, A.M. van

    1995-08-01

    This paper describes a 1993 field experiment entitled Marine Aerosol Properties and Thermal Imager Performance Trial (MAPTIP) conducted by NATO AC/243 Panel 04/RSG.8 and 04/RSG.5 in the Dutch coastal waters. Objectives were: to improve and validate vertical marine aerosol models by providing an extensive set of aerosol and meteorological measurements, within a coastal environment at different altitudes and for a range of meteorological conditions; make aerosol and meteorological observations in the first 10 m of the ocean surface with a view to extending existing aerosol models to incorporate near-surface effects; and to assess marine boundary layer effects on thermal Imaging systems. Aerosol and meteorological instruments, as well as thermal imagers and calibrated targets, were utilized. This network of instrumentation has provided a comprehensive database of aerosol size distribution profiles and relevant meteorological variables throughout the marine atmospheric boundary layer. Thermal imagery was included to provide ground truth for assessing the low-level propagation effects near the ocean surface. Measurements were made of atmospheric turbulence and refractivity effects in the IR and RF bands to assess the marine boundary layer effects on the degradation of thermal images. Calibrated targets at different altitudes were observed and these data will be used for development and validation of IRST models and IR ship signature models for determining the effects of marine-generated aerosols turbulence and meteorological profiles on their performance.

  3. The Sensitivity of Multiangle Imaging to Natural Mixes of Aerosols Over Ocean

    NASA Technical Reports Server (NTRS)

    Kahn, R.; Banerjee, P.; McDonald, D.

    1999-01-01

    Multiangle, multispectral remote sensing observations, such as those anticipated from the Earth Observing System (EOS) Multi-angle Imaging SpectroRadiomenter (MISR), can significantly improve our ability to constrain aerosol properties based on a generic retrieval approach; top-of-atmosphere radiances were interpreted in terms of a single, average aerosol population having unimodal size distribution and uniform composition.

  4. CAIs in Semarkona (LL3.0)

    NASA Technical Reports Server (NTRS)

    Mishra, R. K.; Simon, J. I.; Ross, D. K.; Marhas, K. K.

    2016-01-01

    Calcium, Aluminum-rich inclusions (CAIs) are the first forming solids of the Solar system. Their observed abundance, mean size, and mineralogy vary quite significantly between different groups of chondrites. These differences may reflect the dynamics and distinct cosmochemical conditions present in the region(s) of the protoplanetary disk from which each type likely accreted. Only about 11 such objects have been found in L and LL type while another 57 have been found in H type ordinary chondrites, compared to thousands in carbonaceous chondrites. At issue is whether the rare CAIs contained in ordinary chondrites truly reflect a distinct population from the inclusions commonly found in other chondrite types. Semarkona (LL3.00) (fall, 691 g) is the most pristine chondrite available in our meteorite collection. Here we report petrography and mineralogy of 3 CAIs from Semarkona

  5. Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight (CXIDB ID 16)

    DOE Data Explorer

    Loh, N. Duane

    2012-06-20

    This deposition includes the aerosol diffraction images used for phasing, fractal morphology, and time-of-flight mass spectrometry. Files in this deposition are ordered in subdirectories that reflect the specifics.

  6. Instrument Status and Level 1 Data Processing of TANSO-FTS and CAI on GOSAT

    NASA Astrophysics Data System (ADS)

    Kuze, Akihiko; Nakajima, Masakatsu; Suto, Hiroshi; Shiomi, Kei

    The Greenhouse gases Observing SATellite (GOSAT) observes carbon dioxide (CO2 ) and methane (CH4 ) globally from space. It was launched on January 23, 2009 from Tanegashima Space Cen-ter. Since February 7, 2009, the Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) and Cloud and Aerosol Imager (TANSO-CAI) have been continuously operated. They acquire global data every three days. For the first six months after the launch, on-orbit function, performance, calibration, and validation have been checked-out. The brief summary of instrument design, pre-launch test results, observation plan (grid and sun glint observation and special target mode), onboard calibration schemes, and the initial on-orbit results of radiometric, geometric and spectroscopic performances are presented. TANSO-FTS Level 1A and 1B data processing algorithm and its updates on the ground are also presented. In addition we will show recent on-orbit instrument status such as pointing accuracy, interferogram quality, and radiometric accuracy and vicarious calibration results.

  7. Simplified Tutorial Programming for Interactive CAI.

    ERIC Educational Resources Information Center

    Jelden, D. L.

    A validated instructional model generated on a large mainframe computer by the military was modified to a microcomputer format for use in programming tutorial computer assisted instruction (CAI) materials, and a simplified, compatible system of generating programs was identified--CP/M and MP/M from Digital Research Corporation. In order to…

  8. The Relevance of AI Research to CAI.

    ERIC Educational Resources Information Center

    Kearsley, Greg P.

    This article provides a tutorial introduction to Artificial Intelligence (AI) research for those involved in Computer Assisted Instruction (CAI). The general theme is that much of the current work in AI, particularly in the areas of natural language understanding systems, rule induction, programming languages, and socratic systems, has important…

  9. Man-Computer Communications and CAI.

    ERIC Educational Resources Information Center

    Hunka, S.

    A variety of direct and indirect instructional activities during the last ten years have employed computers. Within Computer Assisted Instruction (CAI) programs, the following broad classes of instructional strategies have been generally accepted: tutorial, drill and practice, review, testing, remediation and diagnosis, problem solving, and…

  10. Aerosol Properties From Multi-angle Satellite Imaging

    NASA Astrophysics Data System (ADS)

    Kahn, R. A.; Martonchik, J. V.; Diner, D. J.; Chen, W. A.; Gaitley, B. J.; Kalashnikova, O. V.; Liu, Y.; Team, T.

    2005-12-01

    Based on pre-launch simulations, we expected that data from the multi-angle, multi-spectral MISR instrument aboard NASA's Terra satellite would contain, in addition to aerosol optical depth (AOT), information about particle size, shape, and single-scattering albedo (SSA). Such information would add a great deal to the global aerosol picture that satellites provide, allowing more meaningful assessments of aerosol direct radiative impact, source attribution, material fluxes, and possibly indirect effects of aerosols on clouds. But particle micro-physical property retrievals are much more difficult to validate than AOT, since there are significant uncertainties in aerosol size, and especially shape and SSA, retrieved from surface-based sun photometers, whereas instrumented aircraft must fly complex patterns to adequately sample all aerosol layers in the entire column seen simultaneously by MISR. Our multi-faceted validation effort, which makes use of ground-based AERONET sun photometers as well as coincident satellite and intensive field observations, has allowed us to quantify MISR data sensitivity to these aerosol micro-physical properties over dark water, and in a few situations, over land. In broad terms, over dark water MISR can distinguish three-to-five aerosol size bins between about 0.1 and 2.5 microns effective diameter, spherical vs. non-spherical particle shapes, plates from grains from spheroids at least in some cases, and two-to-four SSA groupings between 0.75 and 1.0. MISR can also identify several aerosol modes within the column, provided each contributes more than about 20% to the total column mid-visible AOT. These sensitivities diminish for column AOT below about 0.15, and for brighter underlying surfaces. This talk will summarize the current status of the MISR Standard Aerosol Product, the latest MISR Research Aerosol Retrieval validation study results, and our plans for completing aerosol micro-physical property formal validation for the MISR

  11. Magnesium Isotopic Composition of CAIs and Chondrules from CBb Chondrites

    NASA Astrophysics Data System (ADS)

    Gounelle, M.; Young, E. D.; Shahar, A.; Kearsley, A.

    2006-03-01

    We measured magnesium isotope ratios in 17 chondrules and 3 CAIs from the CBb chondrites HH 237 and QUE 94411 by LA-MC-ICPMS. We find no detectable 26Al excesses in the three CAIs and approximately normal (chondritic) d25Mg in CAIs and chondrules.

  12. Aerosol Imaging with a Soft X-ray Free Electron Laser

    SciTech Connect

    Bogan, Michael J.; Boutet, Sebastien; Chapman, Henry N.; Marchesini, Stefano; Barty, Anton; Benner, W.Henry Rohner, Urs; Frank, Matthias; Hau-Riege, Stefan P.; Bajt, Sasa; Woods, Bruce; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; Hajdu, Janos; Schulz, Joachim; /DESY

    2011-08-22

    Lasers have long played a critical role in the advancement of aerosol science. A new regime of ultrafast laser technology has recently be realized, the world's first soft xray free electron laser. The Free electron LASer in Hamburg, FLASH, user facility produces a steady source of 10 femtosecond pulses of 7-32 nm x-rays with 10{sub 12} photons per pulse. The high brightness, short wavelength, and high repetition rate (>500 pulses per second) of this laser offers unique capabilities for aerosol characterization. Here we use FLASH to perform the highest resolution imaging of single PM2.5 aerosol particles in flight to date. We resolve to 35 nm the morphology of fibrous and aggregated spherical carbonaceous nanoparticles that existed for less than two milliseconds in vacuum. Our result opens the possibility for high spatialand time-resolved single particle aerosol dynamics studies, filling a critical technological need in aerosol science.

  13. Quantitative Models of CAI Rim Layer Growth

    NASA Astrophysics Data System (ADS)

    Ruzicka, A.; Boynton, W. V.

    1995-09-01

    Many hypotheses have been proposed to account for the ~50 micrometer-thick layer sequences (Wark-Lovering rims) that typically surround coarse-grained Ca,Al-rich inclusions (CAIs), but to date no consensus has emerged on how these rims formed. A two-step process-- flash heating of CAIs to produce a refractory residue on the margins of CAIs [1,2,3], followed by reaction and diffusion between CAIs or the refractory residue and an external medium rich in Mg, Si and other ferromagnesian and volatile elements to form the layers [3,4,5]-- may have formed the rims. We have tested the second step of this process quantitatively, and show that many, but not all, of the layering characteristics of CAI rims in the Vigarano, Leoville, and Efremovka CV3 chondrites can be explained by steady-state reaction and diffusion between CAIs and an external medium rich in Mg and Si. Moreover, observed variations in the details of the layering from one CAI to another can be explained primarily by differences in the identity and composition of the external medium, which appears to have included vapor alone, vapor + olivine, and olivine +/- clinopyroxene +/- vapor. An idealized layer sequence for CAI rims in Vigarano, Leoville, and Efremovka can be represented as MSF|S|AM|D|O, where MSF = melilite (M) + spinel (S) + fassaite (F) in the interior of CAIs; S = spinel-rich layer; AM = a layer consisting either of anorthite (A) alone, or M alone, or both A and M; D = a clinopyroxene layer consisting mainly of aluminous diopside (D) that is zoned to fassaite towards the CAI; and O = olivine-rich layer, composed mainly of individually zoned olivine grains that apparently pre-existed layer formation [3]. A or M are absent between the S and D layers in roughly half of the rims. The O layer varies considerably in thickness (0-60 micrometers thick) and in porosity from rim to rim, with olivine grains either tightly intergrown to form a compact layer or arranged loosely on the outer surfaces of the CAIs

  14. On-orbit performance and level 1 data processing of TANSO-FTS and CAI on GOSAT

    NASA Astrophysics Data System (ADS)

    Kuze, Akihiko; Suto, Hiroshi; Shiomi, Kei; Nakajima, Masakatsu; Hamazaki, Takashi

    2009-09-01

    The Greenhouse gases Observing SATellite (GOSAT) monitors carbon dioxide (CO2) and methane (CH4) globally from space. It is a joint project of Japan Aerospace Exploration Agency (JAXA), Ministry of the Environment (MOE) and National Institute for Environmental Studies (NIES). GOSAT is placed in a sun-synchronous orbit of 666km and 12:48 local time, with an inclination angle of 98 deg. It was launched on January 23, 2009 from Tanegashima Space Center. There are two instruments on GOSAT. The Thermal And Near infrared Sensor for carbon Observation Fourier- Transform Spectrometer (TANSO-FTS) detects the Short wave infrared (SWIR) reflected on the earth's surface as well as the thermal infrared (TIR) radiated from the ground and the atmosphere. TANSO-FTS is capable of detecting wide spectral coverage; three narrow bands (0.76, 1.6, and 2 μm) and a wide band (5.5-14.3 μm) with 0.27 cm-1 spectral resolution. The TANSO Cloud and Aerosol Imager (TANSO-CAI) is a radiometer of ultraviolet (UV), visible, and SWIR to correct cloud and aerosol interference. For three months after the launch, the on-orbit function and performance have been checked out. Now level 1A (raw interferogram) and level 2B (spectra) are now being processed and provided regularly with calibration data.

  15. Aerosol Source Plume Physical Characteristics from Space-based Multiangle Imaging

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.; Li, W.-H.; Moroney, Catherine; Diner, David J.; Martonchik, John V.; Fishbein, Evan

    2007-01-01

    Models that assess aerosol effects on regional air quality and global climate parameterize aerosol sources in terms of amount, type, and injection height. The multiangle imaging spectroradiometer (MISR) aboard NASA's Terra satellite retrieves total column aerosol optical thickness (AOT), and aerosol type over cloud-free land and water. A stereo-matching algorithm automatically retrieves reflecting-layer altitude wherever clouds or aerosol plumes have discernable spatial contrast, with about 500-m accuracy, at 1.1-km horizontal resolution. Near-source biomass burning smoke, volcanic effluent, and desert dust plumes are observed routinely, providing information about aerosol amount, particle type, and injection height useful for modeling applications. Compared to background aerosols, the plumes sampled have higher AOT, contain particles having expected differences in Angstrom exponent, size, single-scattering albedo, and for volcanic plume and dust cloud cases, particle shape. As basic thermodynamics predicts, thin aerosol plumes lifted only by regional winds or less intense heat sources are confined to the boundary layer. However, when sources have sufficient buoyancy, the representative plumes studied tend to concentrate within discrete, high-elevation layers of local stability; the aerosol is not uniformly distributed up to a peak altitude, as is sometimes assumed in modeling. MISR-derived plume heights, along with meteorological profile data from other sources, make it possible to relate radiant energy flux observed by the moderate resolution imaging spectroradiometer (MODIS), also aboard the Terra spacecraft, to convective heat flux that plays a major role in buoyant plume dynamics. A MISR climatology of plume behavior based on these results is being developed.

  16. Sensitivity of Multiangle Imaging to the Optical and Microphysical Properties of Biomass Burning Aerosols

    NASA Technical Reports Server (NTRS)

    Chen, Wei-Ting; Kahn, Ralph A.; Nelson, David; Yau, Kevin; Seinfeld, John H.

    2008-01-01

    The treatment of biomass burning (BB) carbonaceous particles in the Multiangle Imaging SpectroRadiometer (MISR) Standard Aerosol Retrieval Algorithm is assessed, and algorithm refinements are suggested, based on a theoretical sensitivity analysis and comparisons with near-coincident AERONET measurements at representative BB sites. Over the natural ranges of BB aerosol microphysical and optical properties observed in past field campaigns, patterns of retrieved Aerosol Optical Depth (AOD), particle size, and single scattering albedo (SSA) are evaluated. On the basis of the theoretical analysis, assuming total column AOD of 0.2, over a dark, uniform surface, MISR can distinguish two to three groups in each of size and SSA, except when the assumed atmospheric particles are significantly absorbing (mid-visible SSA approx.0.84), or of medium sizes (mean radius approx.0.13 pin); sensitivity to absorbing, medium-large size particles increases considerably when the assumed column AOD is raised to 0.5. MISR Research Aerosol Retrievals confirm the theoretical results, based on coincident AERONET inversions under BB-dominated conditions. When BB is externally mixed with dust in the atmosphere, dust optical model and surface reflection uncertainties, along with spatial variability, contribute to differences between the Research Retrievals and AERONET. These results suggest specific refinements to the MISR Standard Aerosol Algorithm complement of component particles and mixtures. They also highlight the importance for satellite aerosol retrievals of surface reflectance characterization, with accuracies that can be difficult to achieve with coupled surface-aerosol algorithms in some higher AOD situations.

  17. Chemometric analysis of multi-sensor hyperspectral images of coarse mode aerosol particles for the image-based investigation on aerosol particles

    NASA Astrophysics Data System (ADS)

    Ofner, Johannes; Kamilli, Katharina A.; Eitenberger, Elisabeth; Friedbacher, Gernot; Lendl, Bernhard; Held, Andreas; Lohninger, Hans

    2015-04-01

    Multi-sensor hyperspectral imaging is a novel technique, which allows the determination of composition, chemical structure and pure components of laterally resolved samples by chemometric analysis of different hyperspectral datasets. These hyperspectral datasets are obtained by different imaging methods, analysing the same sample spot and superimposing the hyperspectral data to create a single multi-sensor dataset. Within this study, scanning electron microscopy (SEM), Raman and energy-dispersive X-ray spectroscopy (EDX) images were obtained from size-segregated aerosol particles, sampled above Western Australian salt lakes. The particles were collected on aluminum foils inside a 2350 L Teflon chamber using a Sioutas impactor, sampling aerosol particles of sizes between 250 nm and 10 µm. The complex composition of the coarse-mode particles can be linked to primary emissions of inorganic species as well as to oxidized volatile organic carbon (VOC) emissions. The oxidation products of VOC emissions are supposed to form an ultra-fine nucleation mode, which was observed during several field campaigns between 2006 and 2013. The aluminum foils were analysed using chemical imaging and electron microscopy. A Horiba LabRam 800HR Raman microscope was used for vibrational mapping of an area of about 100 µm x 100 µm of the foils at a resolution of about 1 µm. The same area was analysed using a Quanta FEI 200 electron microscope (about 250 nm resolution). In addition to the high-resolution image, the elemental composition could be investigated using energy-dispersive X-ray spectroscopy. The obtained hyperspectral images were combined into a multi-sensor dataset using the software package Imagelab (Epina Software Labs, www.imagelab.at). After pre-processing of the images, the multi-sensor hyperspectral dataset was analysed using several chemometric methods such as principal component analysis (PCA), hierarchical cluster analysis (HCA) and other multivariate methods. Vertex

  18. NALDA (Naval Aviation Logistics Data Analysis) CAI (computer aided instruction)

    SciTech Connect

    Handler, B.H. ); France, P.A.; Frey, S.C.; Gaubas, N.F.; Hyland, K.J.; Lindsey, A.M.; Manley, D.O. ); Hunnum, W.H. ); Smith, D.L. )

    1990-07-01

    Data Systems Engineering Organization (DSEO) personnel developed a prototype computer aided instruction CAI system for the Naval Aviation Logistics Data Analysis (NALDA) system. The objective of this project was to provide a CAI prototype that could be used as an enhancement to existing NALDA training. The CAI prototype project was performed in phases. The task undertaken in Phase I was to analyze the problem and the alternative solutions and to develop a set of recommendations on how best to proceed. The findings from Phase I are documented in Recommended CAI Approach for the NALDA System (Duncan et al., 1987). In Phase II, a structured design and specifications were developed, and a prototype CAI system was created. A report, NALDA CAI Prototype: Phase II Final Report, was written to record the findings and results of Phase II. NALDA CAI: Recommendations for an Advanced Instructional Model, is comprised of related papers encompassing research on computer aided instruction CAI, newly developing training technologies, instructional systems development, and an Advanced Instructional Model. These topics were selected because of their relevancy to the CAI needs of NALDA. These papers provide general background information on various aspects of CAI and give a broad overview of new technologies and their impact on the future design and development of training programs. The paper within have been index separately elsewhere.

  19. Determining Aerosol Plume Height from Two GEO Imagers: Lessons from MISR and GOES

    NASA Technical Reports Server (NTRS)

    Wu, Dong L.

    2012-01-01

    Aerosol plume height is a key parameter to determine impacts of particulate matters generated from biomass burning, wind-blowing dust, and volcano eruption. Retrieving cloud top height from stereo imageries from two GOES (Geostationary Operational Environmental Satellites) have been demonstrated since 1970's and the principle should work for aerosol plumes if they are optically thick. The stereo technique has also been used by MISR (Multiangle Imaging SpectroRadiometer) since 2000 that has nine look angles along track to provide aerosol height measurements. Knowing the height of volcano aerosol layers is as important as tracking the ash plume flow for aviation safety. Lack of knowledge about ash plume height during the 2010 Eyja'rjallajokull eruption resulted in the largest air-traffic shutdown in Europe since World War II. We will discuss potential applications of Asian GEO satellites to make stereo measurements for dust and volcano plumes.

  20. Aerosol modulation transfer function model for passive long-range imaging over a nonuniform atmospheric path

    NASA Astrophysics Data System (ADS)

    Eismann, Michael T.; LeMaster, Daniel A.

    2013-04-01

    An aerosol modulation transfer function (MTF) model is developed to assess the impact of aerosol scattering on passive long-range imaging sensors. The methodology extends from previous work to explicitly address imaging scenarios with a nonuniform distribution of scattering characteristics over the propagation path and incorporates the moderate resolution transfer code database of aerosol cross-section and phase function characteristics in order to provide an empirical foundation for realistic quantitative MTF assessments. The resulting model is compared with both predictions from a Monte-Carlo scattering simulation and a scene-derived MTF estimate from an empirical image, with reasonable agreement in both cases. Application to long-range imaging situations at both visible and infrared wavelengths indicates that the magnitude and functional form of the aerosol MTF differ significantly from other contributors to the composite system MTF. Furthermore, the image-quality impact is largely radiometric in the sense that the contrast reduction is approximately independent of spatial frequency, and image blur is practically negligible.

  1. Comparison of Coincident Multiangle Imaging Spectroradiometer and Moderate Resolution Imaging Spectroradiometer Aerosol Optical Depths over Land and Ocean Scenes Containing Aerosol Robotic Network Sites

    NASA Technical Reports Server (NTRS)

    Abdou, Wedad A.; Diner, David J.; Martonchik, John V.; Bruegge, Carol J.; Kahn, Ralph A.; Gaitley, Barbara J.; Crean, Kathleen A.; Remer, Lorraine A.; Holben, Brent

    2005-01-01

    The Multiangle Imaging Spectroradiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS), launched on 18 December 1999 aboard the Terra spacecraft, are making global observations of top-of-atmosphere (TOA) radiances. Aerosol optical depths and particle properties are independently retrieved from these radiances using methodologies and algorithms that make use of the instruments corresponding designs. This paper compares instantaneous optical depths retrieved from simultaneous and collocated radiances measured by the two instruments at locations containing sites within the Aerosol Robotic Network (AERONET). A set of 318 MISR and MODIS images, obtained during the months of March, June, and September 2002 at 62 AERONET sites, were used in this study. The results show that over land, MODIS aerosol optical depths at 470 and 660 nm are larger than those retrieved from MISR by about 35% and 10% on average, respectively, when all land surface types are included in the regression. The differences decrease when coastal and desert areas are excluded. For optical depths retrieved over ocean, MISR is on average about 0.1 and 0.05 higher than MODIS in the 470 and 660 nm bands, respectively. Part of this difference is due to radiometric calibration and is reduced to about 0.01 and 0.03 when recently derived band-to-band adjustments in the MISR radiometry are incorporated. Comparisons with AERONET data show similar patterns.

  2. Research on TRIZ and CAIs Application Problems for Technology Innovation

    NASA Astrophysics Data System (ADS)

    Li, Xiangdong; Li, Qinghai; Bai, Zhonghang; Geng, Lixiao

    In order to realize application of invent problem solve theory (TRIZ) and computer aided innovation software (CAIs) , need to solve some key problems, such as the mode choice of technology innovation, establishment of technology innovation organization network(TION), and achievement of innovative process based on TRIZ and CAIs, etc.. This paper shows that the demands for TRIZ and CAIs according to the characteristics and existing problem of the manufacturing enterprises. Have explained that the manufacturing enterprises need to set up an open TION of enterprise leading type, and achieve the longitudinal cooperation innovation with institution of higher learning. The process of technology innovation based on TRIZ and CAIs has been set up from researching and developing point of view. Application of TRIZ and CAIs in FY Company has been summarized. The application effect of TRIZ and CAIs has been explained using technology innovation of the close goggle valve product.

  3. Retrieval of aerosol optical thickness from PROBA-CHRIS images acquired over a coniferous forest

    NASA Astrophysics Data System (ADS)

    Maffei, Carmine; Leone, Antonio P.; Menenti, Massimo; Pippi, Ivan; Maselli, Fabio; Antonelli, Paolo

    2005-10-01

    In the present work we show the potential of multiangular hyperspectral PROBA-CHRIS data to estimate aerosol optical properties over dense dark vegetation. Data acquired over San Rossore test site (Pisa, Italy) have been used together with simultaneous ground measurements. Additionally, spectral measurement over the canopy have been performed to describe the directional behavior of a Pinus pinaster canopy. Determination of aerosol properties from optical remote sensing images over land is an under-determined problem, and some assumptions have to be made on both the aerosol and the surface being imaged. Radiance measured on multiple directions add extra information that help in reducing retrieval ambiguity. Nevertheless, multiangular observations don't allow to ignore directional spectral properties of vegetation canopies. Since surface reflectivity is the parameter we wish to determine with remote sensing after atmospheric correction, at least the shape of the bi-directional reflectance factor has to be assumed. We have adopted a Rahman BRF, and have estimated its geometrical parameters from ground spectral measurements. The inversion of measured radiance to obtain aerosol optical properties has been performed, allowing simultaneous retrieval of aerosol model and optical thickness together with the vegetation reflectivity parameter of the Rahman model.

  4. Physical properties of CAI-rich asteroids

    NASA Astrophysics Data System (ADS)

    Tanga, P.; Devogele, M.; Cellino, A.; Pinilla-Alonso, N.; Campins, H.; Bus, S. J.

    2015-12-01

    Some L-type asteroids (collectively called "Barbarians") are known to exhibit an anomalous polarimetric behavior, whose origin - still to be elucidated - can be related to compositional and/or scattering effects. The fact that these asteroids belong to the same taxonomic class (following the De Meo 2009 classification, including NIR) implies that composition must play a role. Sunshine et al. 2008 showed that these asteroids contain high amounts of CAIs, possibly hinting to a formation in an early proto-planetary environment, very rich in refractory material. On the base of this evidence, we started an observational campaign to increase the data coverage of these objects, by obtaining new NIR spectra, photometric and polarimetric measurements. Our first results show that the peculiar features are not restricted to polarimetry. In particular we show the existence of an anomalous distribution of the rotation periods, and a possible relation between CAI abundance and albedos determined by WISE. We tentatively discuss a possible scenario justifying the different observed features.

  5. Influence of aerosol estimation on coastal water products retrieved from HICO images

    NASA Astrophysics Data System (ADS)

    Patterson, Karen W.; Lamela, Gia

    2011-06-01

    The Hyperspectral Imager for the Coastal Ocean (HICO) is a hyperspectral sensor which was launched to the International Space Station in September 2009. The Naval Research Laboratory (NRL) has been developing the Coastal Water Signatures Toolkit (CWST) to estimate water depth, bottom type and water column constituents such as chlorophyll, suspended sediments and chromophoric dissolved organic matter from hyperspectral imagery. The CWST uses a look-up table approach, comparing remote sensing reflectance spectra observed in an image to a database of modeled spectra for pre-determined water column constituents, depth and bottom type. In order to successfully use this approach, the remote sensing reflectances must be accurate which implies accurately correcting for the atmospheric contribution to the HICO top of the atmosphere radiances. One tool the NRL is using to atmospherically correct HICO imagery is Correction of Coastal Ocean Atmospheres (COCOA), which is based on Tafkaa 6S. One of the user input parameters to COCOA is aerosol optical depth or aerosol visibility, which can vary rapidly over short distances in coastal waters. Changes to the aerosol thickness results in changes to the magnitude of the remote sensing reflectances. As such, the CWST retrievals for water constituents, depth and bottom type can be expected to vary in like fashion. This work is an illustration of the variability in CWST retrievals due to inaccurate aerosol thickness estimation during atmospheric correction of HICO images.

  6. Titanium Isotopes in CAIs -- Heterogeneities in the Early Solar System

    NASA Astrophysics Data System (ADS)

    Leya, I.; Schönbächler, M.; Halliday, A. N.

    2009-03-01

    We present Ti isotope data for CAIs from Allende and Efremovka. The new data demonstrate that n-rich isotopes, e.g., 50Ti, 62Ni, and 96Zr, are correlated in CAIs and that the n-rich addition was heteogeneously distributed in the early solar system.

  7. E-CAI: a novel server to estimate an expected value of Codon Adaptation Index (eCAI)

    PubMed Central

    Puigbò, Pere; Bravo, Ignacio G; Garcia-Vallvé, Santiago

    2008-01-01

    Background The Codon Adaptation Index (CAI) is a measure of the synonymous codon usage bias for a DNA or RNA sequence. It quantifies the similarity between the synonymous codon usage of a gene and the synonymous codon frequency of a reference set. Extreme values in the nucleotide or in the amino acid composition have a large impact on differential preference for synonymous codons. It is thence essential to define the limits for the expected value of CAI on the basis of sequence composition in order to properly interpret the CAI and provide statistical support to CAI analyses. Though several freely available programs calculate the CAI for a given DNA sequence, none of them corrects for compositional biases or provides confidence intervals for CAI values. Results The E-CAI server, available at , is a web-application that calculates an expected value of CAI for a set of query sequences by generating random sequences with G+C and amino acid content similar to those of the input. An executable file, a tutorial, a Frequently Asked Questions (FAQ) section and several examples are also available. To exemplify the use of the E-CAI server, we have analysed the codon adaptation of human mitochondrial genes that codify a subunit of the mitochondrial respiratory chain (excluding those genes that lack a prokaryotic orthologue) and are encoded in the nuclear genome. It is assumed that these genes were transferred from the proto-mitochondrial to the nuclear genome and that its codon usage was then ameliorated. Conclusion The E-CAI server provides a direct threshold value for discerning whether the differences in CAI are statistically significant or whether they are merely artifacts that arise from internal biases in the G+C composition and/or amino acid composition of the query sequences. PMID:18230160

  8. Dust and Pollution Aerosol Air Mass Mapping from Satellite Multi-angle Imaging

    NASA Astrophysics Data System (ADS)

    Kahn, R. A.; Nelson, D. L.; Yau, K. S.; Martonchik, J.; Diner, D. J.; Gaitley, B. J.; Russell, P.; Livingston, J.; Redemann, J.; Quinn, P. R.; Clarke, A. R.; Howell, S.; McNaughton, C.; Reid, J.; Holben, B.; Wendisch, M.; Petzold, A.

    2006-12-01

    One objective of the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) is to map aerosol air mass types, based on retrieved column-average particle microphysical properties. Early results demonstrated the ability to distinguish three-to-five bins over the 0.1 to 2.5 micron aerosol size range, about two-to-four groupings of single-scattering albedo, and to separate spherical from randomly oriented non- spherical particles, under good but not ideal viewing conditions. These results relied heavily on the MISR Research Aerosol Retrieval algorithm, which allows flexibility in choosing retrieval patch size and location, component aerosol properties and mixtures, and mixture acceptance criteria, compared to early versions of the MISR Standard algorithm, designed to routinely process the entire global data set. Early mid-visible column aerosol optical depth results were validated against surface-based sun photometer measurements. The corresponding particle property results appeared qualitatively promising, but formal validation requires quantitative constraints on component particle properties and mixtures in a range of natural settings, available mainly from the combination of height-resolved and total column data collected by surface and airborne instruments during field campaigns. This presentation will highlight the latest detailed, multi-platform case studies, as well as MISR regional mapping, of smoke, Saharan dust, and mixtures of pollution aerosol and desert dust collected during the INTEX, SAMUM, and UAE-2 campaigns, respectively. The broader implications of these results for global, and especially regional, aerosol climate and air quality studies will also be discussed. This work is performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  9. Metamorphism of an Efremovka Type B CAI and Comparison with Other Settings of Alteration

    NASA Astrophysics Data System (ADS)

    Fagan, T. J.; Aragane, H.; Enokido, Y.; Brearley, A. J.

    2015-07-01

    Primary minerals in a type B CAI from Efremovka are partially altered to feldspathoids, Fe-spinel and secondary anorthite. The extent of recrystallization is not as great as in typical Allende CAIs, but metamorphism has affected Efremovka CAIs.

  10. Seasonal Variation of Aerosol Particle Size Using MER/Pancam Sky Imaging

    NASA Astrophysics Data System (ADS)

    Smith, M. D.; Wolff, M. J.

    2013-12-01

    Imaging of the sky taken by the Pancam cameras on-board the Mars Exploration Rovers (MER) provide a useful tool for determining the optical depth and physcial properties of aerosols above the rover. Specifically, the brightness of the sky as a function of angle away from the Sun provides a powerful constraint on the size distribution and shape of dust and water ice aerosols. More than 100 Pancam "sky surveys" were taken by each of the two MER rovers covering a time span of several Mars years and a wide range of dust loading conditions including the planet-encirclind dust storm during Mars Year 28 (Earth year 2007). These sky surveys enable the time evolution of aerosol particle size to be determined including its relation to dust loading. Radiative transfer modeling is used to model the observations. Synthetic Pancam sky brightness is computed using a discrete-ordinates radiative transfer code that accounts for multiple scattering from aerosols and spherical geometry by integrating the source functions along curved paths in that coordinate system. We find that Mie scattering from spheres is not a good approximation for describing the angular variation of sky brightness far from the Sun (at scattering angles greater than 45 degrees). Significant seasonal variations are seen in the retrieved effective radius of the aerosols with higher optical depth strongly correlated with larger particle size.

  11. Retrieval of aerosol optical thickness fort he EarthCARE Multi-Spectral Imager (MSI)

    NASA Astrophysics Data System (ADS)

    von Hoyningen-Huene, Wolfgang; Kokhanovsky, Alexander; Burrows, John P.; Hesselmans, Gerard; Gale, Leslie; Wandinger, Ulla; Bouvet, Marc; Eisinger, Michael

    2010-05-01

    The future EarthCARE mission is a cloud - aerosol mission and is composed of 4 scientific instruments: a) the HSRL lidar - ATLID, providing vertical profiles of backscatter-, extinction- and depolarization profiles, b) the cloud - precipitation radar - CPR, giving vertical profiles of cloud and precipitation parameters, c) the multi-spectral imager - MSI as an imager with a swath width of 150 km and 0.5 km scene resolution, delivering the cloud and aerosol conditions in the vicinity of the lidar and radar beams and d) the broad band radiometer - BBR, measuring up-welling broad band radiation fluxes. The mission intends to use synergies between the vertical profiles from ATLID and CPR and the area and columnar information on clouds and aerosols from the MSI and the combination of all in the BBR up-welling fluxes. The use of the MSI instrument as imager for aerosol optical thickness (AOT) requires retrieval methods for AOT over ocean and land, which are in development within projects (AMARSI and IRMA), supported by ESA. The algorithm development for the AOT retrieval consists of a target discrimination, the estimation of the surface reflectance and determination of aerosol reflectance, which is used for AOT determination, applying look-up-tables. The algorithms are tested with synthetic data from radiative modelling and MODIS measurements with a selection of the subset of MSI VIS and NIR channels (0.659, 0.865, 1.61 and 2.1 µm). For the instrument performance of MODIS the algorithms developed provide quite comparable AOT with AERONET observations.

  12. Evaluation of Aerosol Properties over Ocean from Moderate Resolution Imaging Spectroradiometer (MODIS) during ACE-Asia

    NASA Technical Reports Server (NTRS)

    Chu, D. A.; Remer, L. A.; Kaufman, Y. J.; Schmid, B.; Redemann, J.; Knobelspiesse, K.; Chern, J.-D.; Livingston, J.; Russell, P. B.; Xiong, X.; Ridgway, W.

    2005-01-01

    The Aerosol Characterization Experiment-Asia (ACE-Asia) was conducted in March-May 2001 in the western North Pacific in order to characterize the complex mix of dust, smoke, urban/industrial pollution, and background marine aerosol that is observed in that region in springtime. The Moderate Resolution Imaging Spectroradiometer (MODIS) provides a large-scale regional view of the aerosol during the ACE-Asia time period. Focusing only on aerosol retrievals over ocean, MODIS data show latitudinal and longitudinal variation in the aerosol characteristics. Typically, aerosol optical depth (tau(sub a)) values at 0.55 micrometers are highest in the 30 deg. - 50 deg. latitude band associated with dust outbreaks. Monthly mean tau(sub a) in this band ranges approx. 0.40-70, although large differences between monthly mean and median values indicate the periodic nature of these dust outbreaks. The size parameters, fine mode fraction (eta), and effective radius (r(sub eff)) vary between monthly mean values of eta = 0.47 and r(sub eff)= 0.75 micrometers in the cleanest regions far offshore to approximately eta = 0.85 and r(sub eff) =.30 micrometers in near-shore regions dominated by biomass burning smoke. The collocated MODIS retrievals with airborne, ship-based, and ground-based radiometers measurements suggest that MODIS retrievals of spectral optical depth fall well within expected error (DELTA tau(sub a) = plus or minus 0.03 plus or minus 0.05 tau(sub a)) except in situations dominated by dust, in which cases MODIS overestimate both the aerosol loading and the aerosol spectral dependence. Such behavior is consistent with issues related to particle nonsphericity. Comparisons of MODIS-derived r(sub eff) with AERONET retrievals at the few occurrences of collocations show MODIS systematically underestimates particle size by 0.2 micrometers. Multiple-year analysis of MODIS aerosol size parameters suggests systematic differences between the year 2001 and the years 2000 and 2002

  13. Progress in Developing a Multiangle SpectroPolarimetric Imager (MSPI) for Aerosol Remote Sensing from Space

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Davis, A.; Geier, S.; Gutt, G.; Hancock, B.; Raouf, N.; Chipman, R. A.; Mahler, A.; McClain, S.; Smith, P.; Smith, G.; Cairns, B.; Torres, O.

    2007-12-01

    The National Research Council's Earth Sciences Decadal Survey identifies a multiangle, multispectral, high- accuracy polarization imager as one component of its notional Aerosol-Cloud-Ecosytem (ACE) mission. Under NASA's Instrument Incubator Program (IIP) and internal JPL funding, we have been developing a candidate instrument approach, the Multiangle SpectroPolarimetric Imager (MSPI). The MSPI architecture is conceptually similar to the Terra Multi-angle Imaging SpectroRadiometer (MISR), but the new camera design incorporates features of other aerosol instruments by extending the spectral range to the ultraviolet and shortwave infrared, increasing the image swath to achieve more rapid global coverage, and adding high-accuracy polarimetry in selected spectral bands. UV intensity observations are sensitive to aerosol absorption and height; the longer wavelengths provide improved particle size discrimination; and multiangle acquisition provides sensitivity to particle shape and helps separate aerosol backscatter and extinction from surface reflectance. The 0.5% DOLP uncertainty specification allows for the simultaneous retrieval of aerosol optical depth and particle size when combined with accurate radiance measurements, and provides sensitivity to the real part of the aerosol refractive index, thus providing unique information related to particle composition. Many factors can affect polarimetric accuracy for an imager, including polarization sensitivity of the optics, gain differences among the different detectors whose signals are combined to measure polarization, and spatial displacements on the ground of the locations where different polarization orientations are measured. The MSPI camera design deals with these issues by: (a) using a reflective optical design with optimized mirror coatings to minimize instrument-induced polarization, (b) introducing a rapid, time-variable retardance into the optical path, which has the effect of modulating the polarized

  14. Comparison of Multi-angle Imaging SpectroRadiometer (MISR) joint aerosol product with high-resolution model output

    NASA Astrophysics Data System (ADS)

    Kalashnikova, O.; Lee, H.; Suzuki, K.; Braverman, A. J.

    2014-12-01

    The Multi-angle Imaging SpectroRadiometer (MISR) Level 3 Joint Aerosol product (JOINT_AS) provides global, descriptive summary of MISR Level 2 aerosol optical thickness (AOT) for eight different types of aerosols at 5 x 5 degrees of horizontal resolution in each month between March 2000 and present. Using Version 22 JOINT_AS, this study analyzed characteristics of the observed AOT distributions and compared various statistical moments of aerosol optical thickness derived from JOINT_AS with the results from Nonhydrostatic Icosahedral Atmospheric Model (NICAM) simulation. Overall, marginal distributions of AOT show highly positive skewness at many grid points. Some of the large skewness values are related to the problems in MISR's retrieval algorithm. For example, the positive skewness in AOT for strongly absorbing aerosols at mid- and high latitudes in winter results from few outlier values is due to cloud contamination over a wide area. Combined AOT for multiple MISR aerosol types is comparable to the AOT for carbonaceous, sulfate aerosols and dust particles from the NICAM simulation implemented with aerosol transport processes. NICAM's carbonaceous aerosols in the Southwest Africa show good agreement with MISR's strongly absorbing aerosols. The AOT of dust particles in MISR and NICAM exhibit similar spatial patterns over the Sahara desert. The AOT of nonabsorbing aerosols in MISR well represents spatial distributions of the sulfate aerosols originating from industrial complex over the Shandong Peninsula in China. Our results indicate that MISR's AOT for each aerosol type may be useful for monitoring biomass burning, dust storms and air pollution and evaluating chemistry climate models.

  15. Creation and Distribution of CAIs in the Protoplanetary Nebula

    NASA Technical Reports Server (NTRS)

    Cuzzi, J. N.; Davis, S. S.; Dobrovolskis, A. R.

    2003-01-01

    CaAl rich refractory mineral inclusions (CAIs) found at 1 - 10% mass fraction in primitive chondrites appear to be several million years older than the dominant (chondrule) components in the same parent bodies. A prevalent concern is that it is difficult to retain CAIs for this long against gas-drag-induced radial drift into the sun. We assess a hot inner (turbulent) nebula context for CAI formation, using analytical models of nebula evolution and particle diffusion. We show that outward radial diffusion in a weakly turbulent nebula can prevent significant numbers of CAI-size particles from being lost into the sun for times of 1 - 3 x 10(exp 6) years. To match the CAI abundances quantitatively, we advocate an enhancement of the inner hot nebula in silicate-forming material, due to rapid inward migration of very primitive, silicate and carbon rich, meter-sized objects. 'Combustion' of the carbon into CO would make the CAI formation environment more reduced than solar, as certain observations imply. Abundant CO might also play a role in mass-independent chemical fractionation of oxygen isotopes as seen in CAIs and associated primitive, high-temperature condensates.

  16. New Titanium Isotope Data for Allende and Efremovka CAIs

    NASA Astrophysics Data System (ADS)

    Leya, Ingo; Schönbächler, Maria; Krähenbühl, Urs; Halliday, Alex N.

    2009-09-01

    We measured the titanium (Ti) isotope composition, i.e., 50Ti/47Ti, 48Ti/47Ti, and 46Ti/47Ti, in five calcium-rich-aluminum-rich refractory inclusions (CAIs) from the oxidized CV3 chondrite Allende and in two CAIs from the reduced CV3 chondrite Efremovka. Our data indicate that CAIs are enriched in 50Ti/47Ti and 46Ti/47Ti and are slightly depleted in 48Ti/47Ti compared to normal Ti defined by ordinary chondrites, eucrites, ureilites, mesosiderites, Earth, Moon, and Mars. Some CAIs have an additional 50Ti excess of ~8ɛ relative to bulk carbonaceous chondrites, which are enriched in 50Ti by ~2ɛ relative to terrestrial values, leading to a total excess of ~10ɛ. This additional 50Ti excess is correlated with nucleosynthetic anomalies found in 62Ni and 96Zr, all indicating an origin from a neutron-rich stellar source. Bulk carbonaceous chondrites show a similar trend, however, the extent of the anomalies is either less than or similar to the smallest anomalies seen in CAIs. Mass balance calculations suggest that bulk Allende Ti possibly consists of a mixture of at least two Ti components, anomalous Ti located in CAIs and a normal component possibly for matrix and chondrules. This argues for a heterogeneous distribution of Ti isotopes in the solar system. The finding that anomalous Ti is concentrated in CAIs suggests that CAIs formed in a specific region of the solar system and were, after their formation, not homogeneously redistributed within the solar system. Combining the CAI data with improved model predictions for early solar system irradiation effects indicates that a local production scenario for the relatively short lived radionuclides can be excluded, because the production of, e.g., 10Be, 26Al, and 41Ca, would result in a significant collateral shift in Ti isotopes, which is not seen in the measured data.

  17. FIB-NanoSIMS-TEM Coordinated Study of a Wark-Lovering Rim in a Vigarano Type A CAI

    NASA Technical Reports Server (NTRS)

    Cai, A.; Ito, M.; Keller, L. P.; Ross, D. K.; Nakamura-Messenger, K.

    2010-01-01

    Wark-Lovering (WL) rims are thin multi layered mineral sequences that surround most Ca, Al-rich inclusions (CAIs). Unaltered WL rims are composed of the same primary high temperature minerals as CAIs, such as melilite, spinel, pyroxene, hibonite, perovskite, anorthite and olivine. It is still unclear whether the rim minerals represent a different generation formed by a separate event from their associated CAIs or are a byproduct of CAI formation. Several models have been proposed for the origins of WL rims including condensation, flashheating, reaction of a CAI with a Mg-Si-rich reservoir (nebular gas or solid); on the basis of mineralogy, abundances of trace elements, O and Mg isotopic studies. Detailed mineralogical characterizations of WL rims at micrometer to nanometer scales have been obtained by TEM observations, but so far no coordinated isotopic - mineralogical studies have been performed. Thus, we have applied an O isotopic imaging technique by NanoSIMS 50L to investigate heterogeneous distributions of O isotopic ratios in minerals within a cross section of a WL rim prepared using a focused ion beam (FIB) instrument. After the isotopic measurements, we determine the detailed mineralogy and microstructure of the same WL FIB section to gain insight into its petrogenesis. Here we present preliminary results from O isotopic and elemental maps by NanoSIMS and mineralogical analysis by FE-SEM of a FIB section of a WL rim in the Vigarano reduced CV3 chondrite.

  18. Polarized Imaging Nephelometer for in situ airborne measurements of aerosol light scattering.

    PubMed

    Dolgos, Gergely; Martins, J Vanderlei

    2014-09-01

    Global satellite remote sensing of aerosols requires in situ measurements to enable the calibration and validation of algorithms. In order to improve our understanding of light scattering by aerosol particles, and to enable routine in situ airborne measurements of aerosol light scattering, we have developed an instrument, called the Polarized Imaging Nephelometer (PI-Neph). We designed and built the PI-Neph at the Laboratory for Aerosols, Clouds and Optics (LACO) of the University of Maryland, Baltimore County (UMBC). This portable instrument directly measures the ambient scattering coefficient and phase matrix elements of aerosols, in the field or onboard an aircraft. The measured phase matrix elements are the P(11), phase function, and P(12). Lasers illuminate the sampled ambient air and aerosol, and a wide field of view camera detects scattered light in a scattering angle range of 3° to 176°. The PI-Neph measures an ensemble of particles, supplying the relevant quantity for satellite remote sensing, as opposed to particle-by-particle measurements that have other applications. Comparisons with remote sensing measurements will have to consider aircraft inlet effects. The PI-Neph first measured at a laser wavelength of 532nm, and was first deployed successfully in 2011 aboard the B200 aircraft of NASA Langley during the Development and Evaluation of satellite ValidatiOn Tools by Experimenters (DEVOTE) project. In 2013, we upgraded the PI-Neph to measure at 473nm, 532nm, and 671nm nearly simultaneously. LACO has deployed the PI-Neph on a number of airborne field campaigns aboard three different NASA aircraft. This paper describes the PI-Neph measurement approach and validation by comparing measurements of artificial spherical aerosols with Mie theory. We provide estimates of calibration uncertainties, which show agreement with the small residuals between measurements of P(11) and -P(12)/P(11) and Mie theory. We demonstrate the capability of the PI-Neph to measure

  19. Astrophysics of CAI formation as revealed by silicon isotope LA-MC-ICPMS of an igneous CAI

    NASA Astrophysics Data System (ADS)

    Shahar, Anat; Young, Edward D.

    2007-05-01

    Silicon isotope ratios of a typical CAI from the Leoville carbonaceous chondrite, obtained in situ by laser ablation MC-ICPMS, together with existing 25Mg/ 24Mg data, reveal a detailed picture of the astrophysical setting of CAI melting and subsequent heating. Models for the chemical and isotopic effects of evaporation of the molten CAI are used to produce a univariant relationship between PH 2 and time during melting. The result shows that this CAI was molten for a cumulative time of no more than 70 days and probably less than 15 days depending on temperature. The object could have been molten for an integrated time of just a few hours if isotope ratio zoning was eliminated after melting by high subsolidus temperatures (e.g., > 1300 K) for ˜ 500 yr. In all cases subsolidus heating sufficient to produce diffusion-limited isotope fractionation at the margin of the solidified CAI is required. These stable isotope data point to a two-stage history for this igneous CAI involving melting for a cumulative timescale of hours to months followed by subsolidus heating for years to hundreds of years. The thermobarometric history deduced from combining Si and Mg isotope ratio data implicates thermal processing in the disk, perhaps by passage through shockwaves, following melting. This study underscores the direct link between the meaning of stable isotope ratio zoning, or lack thereof, and the inferred astrophysical setting of melting and subsequent processing of CAIs.

  20. Dust aerosol retrieval results from MISR (multi-angle imaging spectro-radiometer)

    NASA Technical Reports Server (NTRS)

    Kalashnikova, Olga V.; Diner, David J.; Kahn, Ralph; Gaitley, Barbara

    2004-01-01

    Satellite measurements provide important tools for understanding the effect of mineral dust aerosols on past and present climate and climate predictions. Multi-angle instruments such as Multi-angle Imaging Spectro- Radiometer (MISR) provide independent constraints on aerosol properties based on their sensitivity to the shape of aerosol scattering phase functions. The current MISR operational retrieval algorithm (version 16 and higher) was modified by incorporating new non-spherical dust models that account for naturally occurring dust shapes and compositions. We present selected examples of MISR version 16 retrievals over AERONET sunphotometer land and ocean sites during the passage of dust fronts. Our analysis shows that during such events MISR retrieves Angstrom exponents characteristic of large particles, having little spectral variation in extinction over the MISR wavelength range (442, 550, 672 and 866 nm channels), as expected. The retrieved fraction of non-spherical particles is also very high. This quantity is not retrieved by satellite instruments having only nadir-viewing cameras. Our comparison of current (version 16) MISR-retrieved aerosol optical thickness (AOT) with AERONET instantaneous AOT shows better coverage and stronger correlations than when making identical comparisons with previous AOT retrievals (version 15). The MISR algorithm successful mixtures include a non-spherical dust component with high frequency in retrievals over dark water and slightly lower frequency over land. Selection frequencies of non-spherical dust models also decrease in dusty regions affected by pollution.

  1. Aerosol mobility imaging for rapid size distribution measurements

    DOEpatents

    Wang, Jian; Hering, Susanne Vera; Spielman, Steven Russel; Kuang, Chongai

    2016-07-19

    A parallel plate dimensional electrical mobility separator and laminar flow water condensation provide rapid, mobility-based particle sizing at concentrations typical of the remote atmosphere. Particles are separated spatially within the electrical mobility separator, enlarged through water condensation, and imaged onto a CCD array. The mobility separation distributes particles in accordance with their size. The condensation enlarges size-separated particles by water condensation while they are still within the gap of the mobility drift tube. Once enlarged the particles are illuminated by a laser. At a pre-selected frequency, typically 10 Hz, the position of all of the individual particles illuminated by the laser are captured by CCD camera. This instantly records the particle number concentration at each position. Because the position is directly related to the particle size (or mobility), the particle size spectra is derived from the images recorded by the CCD.

  2. Effect of the aerosol type uncertainty on the surface reflectance retrieval using CHRIS/PROBA hyperspectral images over land.

    NASA Astrophysics Data System (ADS)

    Tirelli, C.; Manzo, C.; Curci, G.; Bassani, C.

    2014-12-01

    The surface reflectance is crucial for the quantitative analysis of land surface properties in geological, agricultural and urban studies. The first requirement for a reliable surface reflectance estimation is an accurate atmospheric correction obtained by an appropriate selection of aerosol loading and type. The aerosol optical thickness at 550nm is widely used to describe the aerosol loading. Recent works have highlighted the relevant role of the aerosol types on the atmospheric correction process defined by their micro-physical properties. The aim of this work is to evaluate the radiative impact of the aerosol type on the surface reflectance obtained from CHRIS (Compact High Resolution Imaging Spectrometer) hyperspectral data over land. CHRIS on PROBA satellite is an high resolution multi-angular imaging spectrometer, operating in the visible near-infrared spectral domain (400 to 1000 nm). As test case the urban site of Brussels has been selected. The physically-based algorithm CHRIS@CRI (CHRIS Atmospherically Corrected Reflectance Imagery) has been developed specifically for CHRIS data by using the vector version of 6S (6SV) radiative transfer model. The atmospheric data needed for the atmospheric correction were obtained from CIMEL CE-318 of the Brussels AERONET station. CHRIS images were selected if simultaneous AERONET data were available. Other specific requirements for imagery acquisition were high aerosol loading and high solar irradiation. The aerosol radiative impact has been investigated comparing the reflectance obtained by applying the CHRIS@CRI algorithm with different aerosol types: the three aerosol standard of 6SV and two characterized by specific microphysical properties provided by the AERONET station and calculated with FlexAOD code (a post-processing tool of the chemical transport model GEOS-Chem), respectively. The results show a clear dependence of the atmospheric correction results on the aerosol absorption properties.

  3. Micron Scale Oxygen Isotope Heterogeneity in Anorthite of A Forsterite-bearing Type B CAI E60 from Efremovka

    NASA Astrophysics Data System (ADS)

    Nagashima, K.; Krot, A. N.; Huss, G. R.; Yurimoto, H.

    2010-03-01

    Oxygen isotope imaging with UH Cameca ims 1280+SCAPS isotope microscope of a Fo-B CAI E60 from Efremovka revealed complex distributions of O-isotopes in anorthite supporting isotopic exchange with 16O-poor gas during remelting and recrystallization.

  4. Daytime Variation of Shortwave Direct Radiative Forcing of Biomass Burning Aerosols from GOES-8 Imager.

    NASA Astrophysics Data System (ADS)

    Christopher, Sundar A.; Zhang, Jianglong

    2002-02-01

    Hourly Geostationary Operational Environmental Satellite-8 (GOES-8) imager data (1344-1944 UTC) from 20 July-31 August 1998 were used to study the daytime variation of shortwave direct radiative forcing (SWARF) of smoke aerosols over biomass burning regions in South America (4°-16°S, 51°-65°W). Vicarious calibration procedures were used to adjust the GOES visible channel reflectance values for the degradation in signal response. Using Mie theory and discrete ordinate radiative transfer (DISORT) calculations, smoke aerosol optical thickness (AOT) was estimated at 0.67 m. The GOES-retrieved AOT was then compared against ground-based AOT retrieved values. Using the retrieved GOES-8 AOT, a four-stream broadband radiative transfer model was used to compute shortwave fluxes for smoke aerosols at the top of the atmosphere (TOA). The daytime variation of smoke AOT and SWARF was examined for the study area. For selected days, the Clouds and the Earth's Radiant Energy System (CERES) TOA shortwave (SW) fluxes are compared against the model-derived SW fluxes.Results of this study show that the GOES-derived AOT is in excellent agreement with Aerosol Robotic Network (AERONET)-derived AOT values with linear correlation coefficient of 0.97. The TOA CERES-estimated SW fluxes compare well with the model-calculated SW fluxes with linear correlation coefficient of 0.94. For August 1998 the daytime diurnally averaged AOT and SWARF for the study area is 0.63 ± 0.39 and 45.8 ± 18.8 W m2, respectively. This is among the first studies to estimate the daytime diurnal variation of SWARF of smoke aerosols using satellite data.

  5. Aerosol Airmass Type Mapping Over the Urban Mexico City Region From Space-based Multi-angle Imaging

    NASA Technical Reports Server (NTRS)

    Patadia, F.; Kahn, R. A.; Limbacher, J. A.; Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.

    2013-01-01

    Using Multi-angle Imaging SpectroRadiometer (MISR) and sub-orbital measurements from the 2006 INTEX-B/MILAGRO field campaign, in this study we explore MISR's ability to map different aerosol air mass types over the Mexico City metropolitan area. The aerosol air mass distinctions are based on shape, size and single scattering albedo retrievals from the MISR Research Aerosol Retrieval algorithm. In this region, the research algorithm identifies dust-dominated aerosol mixtures based on non-spherical particle shape, whereas spherical biomass burning and urban pollution particles are distinguished by particle size. Two distinct aerosol air mass types based on retrieved particle microphysical properties, and four spatially distributed aerosol air masses, are identified in the MISR data on 6 March 2006. The aerosol air mass type identification results are supported by coincident, airborne high-spectral-resolution lidar (HSRL) measurements. Aerosol optical depth (AOD) gradients are also consistent between the MISR and sub-orbital measurements, but particles having single-scattering albedo of approx. 0.7 at 558 nm must be included in the retrieval algorithm to produce good absolute AOD comparisons over pollution-dominated aerosol air masses. The MISR standard V22 AOD product, at 17.6 km resolution, captures the observed AOD gradients qualitatively, but retrievals at this coarse spatial scale and with limited spherical absorbing particle options underestimate AOD and do not retrieve particle properties adequately over this complex urban region. However, we demonstrate how AOD and aerosol type mapping can be accomplished with MISR data over complex urban regions, provided the retrieval is performed at sufficiently high spatial resolution, and with a rich enough set of aerosol components and mixtures.

  6. Variability of Marine Aerosol Fine-Mode Fraction and Estimates of Anthropogenic Aerosol Component Over Cloud-Free Oceans from the Moderate Resolution Imaging Spectroradiometer (MODIS)

    NASA Technical Reports Server (NTRS)

    Yu, Hongbin; Chin, Mian; Remer, Lorraine A.; Kleidman, Richard G.; Bellouin, Nicolas; Bian, Huisheng; Diehl, Thomas

    2009-01-01

    In this study, we examine seasonal and geographical variability of marine aerosol fine-mode fraction (f(sub m)) and its impacts on deriving the anthropogenic component of aerosol optical depth (tau(sub a)) and direct radiative forcing from multispectral satellite measurements. A proxy of f(sub m), empirically derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 5 data, shows large seasonal and geographical variations that are consistent with the Goddard Chemistry Aerosol Radiation Transport (GOCART) and Global Modeling Initiative (GMI) model simulations. The so-derived seasonally and spatially varying f(sub m) is then implemented into a method of estimating tau(sub a) and direct radiative forcing from the MODIS measurements. It is found that the use of a constant value for fm as in previous studies would have overestimated Ta by about 20% over global ocean, with the overestimation up to 45% in some regions and seasons. The 7-year (2001-2007) global ocean average tau(sub a) is 0.035, with yearly average ranging from 0.031 to 0.039. Future improvement in measurements is needed to better separate anthropogenic aerosol from natural ones and to narrow down the wide range of aerosol direct radiative forcing.

  7. Reflections on current and future applications of multiangle imaging to aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, David

    2010-05-01

    The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global Earth data from NASA's Terra satellite since February 2000. With its 9 along-track view angles, 4 spectral bands, intrinsic spatial resolution of 275 m, and stable radiometric and geometric calibration, no instrument that combines MISR's attributes has previously flown in space, nor is there is a similar capability currently available on any other satellite platform. Multiangle imaging offers several tools for remote sensing of aerosol and cloud properties, including bidirectional reflectance and scattering measurements, stereoscopic pattern matching, time lapse sequencing, and potentially, optical tomography. Current data products from MISR employ several of these techniques. Observations of the intensity of scattered light as a function of view angle and wavelength provide accurate measures of aerosol optical depths (AOD) over land, including bright desert and urban source regions. Partitioning of AOD according to retrieved particle classification and incorporation of height information improves the relationship between AOD and surface PM2.5 (fine particulate matter, a regulated air pollutant), constituting an important step toward a satellite-based particulate pollution monitoring system. Stereoscopic cloud-top heights provide a unique metric for detecting interannual variability of clouds and exceptionally high quality and sensitivity for detection and height retrieval for low-level clouds. Using the several-minute time interval between camera views, MISR has enabled a pole-to-pole, height-resolved atmospheric wind measurement system. Stereo imagery also makes possible global measurement of the injection heights and advection speeds of smoke plumes, volcanic plumes, and dust clouds, for which a large database is now available. To build upon what has been learned during the first decade of MISR observations, we are evaluating algorithm updates that not only refine retrieval

  8. Bistatic imaging lidar measurements of aerosols, fogs, and clouds in the lower atmosphere

    NASA Astrophysics Data System (ADS)

    Lin, Jinming; Mishima, Hidetsugu; Kawahara, Takuya D.; Saito, Yasunori; Nomura, Akio; Yamaguchi, Kenji; Morikawa, Kimio

    1998-08-01

    We have been developing a bistatic imaging lidar using a high sensitive CCD camera with an image intensifier as a high speed shutter for measuring spatial distributions of aerosols, fogs and clouds in the lower atmosphere at daytime as well as at nighttime. The bistatic imaging lidar was applied to two field observation campaigns. One was made cooperatively with a wind profiler and a radiosonde at Moriya (36 km north of Tokyo) for five days from May 26 to 30, 1997 and another cooperatively with a monostatic lidar at Hakuba alpine ski area of Nagano for 10 days from February 7 to 16, 1998 during the period of the 18th Winter Olympic Games in Japan. We report the results obtained at both campaigns and discuss the ability of this system in measuring the meteorological features of the local lower atmosphere under different conditions.

  9. An Integrated Multiangle, Multispectral, and Polarimetric Imaging Concept for Aerosol Remote Sensing from Space

    NASA Technical Reports Server (NTRS)

    Diner, David J.; Chipman, Russell A.; Beaudry, Neil; Cairns, Brian; Foo, Leslie D.; Macenka, Steven A.; Cunningham, Thomas J.; Seshadri, Suresh; Keller, Christoph

    2004-01-01

    Techniques for passive remote sensing of aerosol optical and microphysical properties from space include visible, near and shortwave-infrared imaging (e.g., from MODIS), multiangle intensity imaging (e.g., ATSR-2, AATSR, MISR), near-ultraviolet mapping (e.g., TOMSIOMI), and polarimetry (e.g., POLDER, APS). Each of these methods has unique strengths. In this paper, we present a concept for integrating these approaches into a unified sensor. Design goals include spectral coverage from the near-UV to the shortwave infrared; intensity and polarimetric imaging simultaneously at multiple view angles; global coverage within a few days; kilometer to sub-kilometer spatial resolution; and measurement of the degree of linear polarization (DOLP) for a subset of the spectral complement with an uncertainty of 0.5% or less.

  10. Liquid-liquid phase separation in aerosol particles: Imaging at the Nanometer Scale

    SciTech Connect

    O'Brien, Rachel; Wang, Bingbing; Kelly, Stephen T.; Lundt, Nils; You, Yuan; Bertram, Allan K.; Leone, Stephen R.; Laskin, Alexander; Gilles, Mary K.

    2015-04-21

    Atmospheric aerosols can undergo phase transitions including liquid-liquid phase separation (LLPS) while responding to changes in the ambient relative humidity (RH). Here, we report results of chemical imaging experiments using environmental scanning electron microscopy (ESEM) and scanning transmission x-ray microscopy (STXM) to investigate the LLPS of micron sized particles undergoing a full hydration-dehydration cycle. Internally mixed particles composed of ammonium sulfate (AS) and either: limonene secondary organic carbon (LSOC), a, 4-dihydroxy-3-methoxybenzeneaceticacid (HMMA), or polyethylene glycol (PEG-400) were studied. Events of LLPS with apparent core-shell particle morphology were observed for all samples with both techniques. Chemical imaging with STXM showed that both LSOC/AS and HMMA/AS particles were never homogeneously mixed for all measured RH’s above the deliquescence point and that the majority of the organic component was located in the shell. The shell composition was estimated as 65:35 organic: inorganic in LSOC/AS and as 50:50 organic: inorganic for HMMA/AS. PEG-400/AS particles showed fully homogeneous mixtures at high RH and phase separated below 89-92% RH with an estimated 50:50% organic to inorganic mix in the shell. These two chemical imaging techniques are well suited for in-situ analysis of the hygroscopic behavior, phase separation, and surface composition of collected ambient aerosol particles.

  11. Aerosol Plume Detection Algorithm Based on Image Segmentation of Scanning Atmospheric Lidar Data

    DOE PAGESBeta

    Weekley, R. Andrew; Goodrich, R. Kent; Cornman, Larry B.

    2016-04-06

    An image-processing algorithm has been developed to identify aerosol plumes in scanning lidar backscatter data. The images in this case consist of lidar data in a polar coordinate system. Each full lidar scan is taken as a fixed image in time, and sequences of such scans are considered functions of time. The data are analyzed in both the original backscatter polar coordinate system and a lagged coordinate system. The lagged coordinate system is a scatterplot of two datasets, such as subregions taken from the same lidar scan (spatial delay), or two sequential scans in time (time delay). The lagged coordinatemore » system processing allows for finding and classifying clusters of data. The classification step is important in determining which clusters are valid aerosol plumes and which are from artifacts such as noise, hard targets, or background fields. These cluster classification techniques have skill since both local and global properties are used. Furthermore, more information is available since both the original data and the lag data are used. Performance statistics are presented for a limited set of data processed by the algorithm, where results from the algorithm were compared to subjective truth data identified by a human.« less

  12. NEW TITANIUM ISOTOPE DATA FOR ALLENDE AND EFREMOVKA CAIs

    SciTech Connect

    Leya, Ingo; Schoenbaechler, Maria; Kraehenbuehl, Urs; Halliday, Alex N.

    2009-09-10

    We measured the titanium (Ti) isotope composition, i.e., {sup 50}Ti/{sup 47}Ti, {sup 48}Ti/{sup 47}Ti, and {sup 46}Ti/{sup 47}Ti, in five calcium-rich-aluminum-rich refractory inclusions (CAIs) from the oxidized CV3 chondrite Allende and in two CAIs from the reduced CV3 chondrite Efremovka. Our data indicate that CAIs are enriched in {sup 50}Ti/{sup 47}Ti and {sup 46}Ti/{sup 47}Ti and are slightly depleted in {sup 48}Ti/{sup 47}Ti compared to normal Ti defined by ordinary chondrites, eucrites, ureilites, mesosiderites, Earth, Moon, and Mars. Some CAIs have an additional {sup 50}Ti excess of {approx}8{epsilon} relative to bulk carbonaceous chondrites, which are enriched in {sup 50}Ti by {approx}2{epsilon} relative to terrestrial values, leading to a total excess of {approx}10{epsilon}. This additional {sup 50}Ti excess is correlated with nucleosynthetic anomalies found in {sup 62}Ni and {sup 96}Zr, all indicating an origin from a neutron-rich stellar source. Bulk carbonaceous chondrites show a similar trend, however, the extent of the anomalies is either less than or similar to the smallest anomalies seen in CAIs. Mass balance calculations suggest that bulk Allende Ti possibly consists of a mixture of at least two Ti components, anomalous Ti located in CAIs and a normal component possibly for matrix and chondrules. This argues for a heterogeneous distribution of Ti isotopes in the solar system. The finding that anomalous Ti is concentrated in CAIs suggests that CAIs formed in a specific region of the solar system and were, after their formation, not homogeneously redistributed within the solar system. Combining the CAI data with improved model predictions for early solar system irradiation effects indicates that a local production scenario for the relatively short lived radionuclides can be excluded, because the production of, e.g., {sup 10}Be, {sup 26}Al, and {sup 41}Ca, would result in a significant collateral shift in Ti isotopes, which is not seen in the

  13. 3D Aerosol-Cloud Radiative Interaction Observed in Collocated MODIS and ASTER Images of Cumulus Cloud Fields

    NASA Technical Reports Server (NTRS)

    Wen, Guoyong; Marshak, Alexander; Cahalan, Robert F.; Remer, Lorraine A.; Kleidman, Richard G.

    2007-01-01

    3D aerosol-cloud interaction is examined by analyzing two images containing cumulus clouds in biomass burning regions in Brazil. The research consists of two parts. The first part focuses on identifying 3D clo ud impacts on the reflectance of pixel selected for the MODIS aerosol retrieval based purely on observations. The second part of the resea rch combines the observations with radiative transfer computations to identify key parameters in 3D aerosol-cloud interaction. We found that 3D cloud-induced enhancement depends on optical properties of nearb y clouds as well as wavelength. The enhancement is too large to be ig nored. Associated biased error in 1D aerosol optical thickness retrie val ranges from 50% to 140% depending on wavelength and optical prope rties of nearby clouds as well as aerosol optical thickness. We caution the community to be prudent when applying 1D approximations in comp uting solar radiation in dear regions adjacent to clouds or when usin g traditional retrieved aerosol optical thickness in aerosol indirect effect research.

  14. Evaluation of the Aerosol Type Effect on the Surface Reflectance Retrieval Using Chris/proba Images Over Land

    NASA Astrophysics Data System (ADS)

    Tirelli, C.; Manzo, C.; Curci, G.; Bassani, C.

    2015-04-01

    Surface reflectance has a central role in the analysis of land surface for a broad variety of agricultural, geological and urban studies. An accurate atmospheric correction, obtained by an appropriate selection of aerosol type and loading, is the first requirement for a reliable surface reflectance estimation. The aerosol type is defined by its micro-physical properties, while the aerosol loading is described by optical thickness at 550 nm. The aim of this work is to evaluate the radiative impact of the aerosol model on the surface reflectance obtained from CHRIS (Compact High Resolution Imaging Spectrometer) hyperspectral data over land by using the specifically developed algorithm CHRIS@CRI (CHRIS Atmospherically Corrected Reflectance Imagery) based on the 6SV radiative transfer model. Five different aerosol models have been used: one provided by the AERONET inversion products (used as reference), three standard aerosol models in 6SV, and one obtained from the output of the GEOS-Chem global chemistry-transport model (CTM). As test case the urban site of Bruxelles and the suburban area of Rome Tor Vergata have been considered. The results obtained encourages the use of CTM in operational retrieval and provides an evaluation of the role of the aerosol model in the atmospheric correction process, considering the different microphysical properties impact.

  15. Case studies of aerosol remote sensing with the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI)

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Xu, F.; Garay, M. J.; Martonchik, J. V.; Kalashnikova, O. V.; Davis, A. B.; Rheingans, B.; Geier, S.; Jovanovic, V.; Bull, M.

    2012-12-01

    The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) is an 8-band (355, 380, 445, 470, 555, 660, 865, 935 nm) pushbroom camera, measuring polarization in the 470, 660, and 865 nm bands, mounted on a gimbal to acquire multiangular observations over a ±67° along-track range with 10-m spatial resolution across an 11-km wide swath. Among the instrument objectives are exploration of methodologies for combining multiangle, multispectral, polarimetric, and imaging observations to retrieve the optical depth and microphysical properties of tropospheric aerosols. AirMSPI was integrated on NASA's ER-2 high-altitude aircraft in 2010 and has successfully completed a number of flights over land and ocean targets in the Southern California vicinity. In this paper, we present case studies of AirMSPI imagery, interpreted using vector radiative transfer theory. AirMSPI observations over California's Central Valley are compared with model calculations using aerosol properties reported by the Fresno AERONET sunphotometer. Because determination of the radiative impact of different types of aerosols requires accurate attribution of the source of the reflected light along with characterization of the aerosol optical and microphysical properties, we explore the sensitivity of the Fresno measurements to variations in different aerosol properties, demonstrating the value of combining intensity and polarimetry at multiple view angles and spectral bands for constraining particle microphysical properties. Images over ocean to be presented include scenes over nearly cloud-free skies and scenes containing scattered clouds. It is well known that imperfect cloud screening confounds the determination of aerosol impact on radiation; it is perhaps less well appreciated that the effect of cloud reflections in the water can also be problematic. We calculate the magnitude of this effect in intensity and polarization and discuss its potential impact on aerosol retrievals, underscoring the value

  16. Handheld hyperspectral imager for standoff detection of chemical and biological aerosols

    NASA Astrophysics Data System (ADS)

    Hinnrichs, Michele; Jensen, James O.; McAnally, Gerard

    2004-02-01

    Pacific Advanced Technology has developed a small hand held imaging spectrometer, Sherlock, for gas leak and aerosol detection and imaging. The system is based on a patent technique that uses diffractive optics and image processing algorithms to detect spectral information about objects in the scene of the camera (IMSS Image Multi-spectral Sensing). This camera has been tested at Dugway Proving Ground and Dstl Porton Down facility looking at Chemical and Biological agent simulants. The camera has been used to investigate surfaces contaminated with chemical agent simulants. In addition to Chemical and Biological detection the camera has been used for environmental monitoring of green house gases and is currently undergoing extensive laboratory and field testing by the Gas Technology Institute, British Petroleum and Shell Oil for applications for gas leak detection and repair. The camera contains an embedded Power PC and a real time image processor for performing image processing algorithms to assist in the detection and identification of gas phase species in real time. In this paper we will present an over view of the technology and show how it has performed for different applications, such as gas leak detection, surface contamination, remote sensing and surveillance applications. In addition a sampling of the results form TRE field testing at Dugway in July of 2002 and Dstl at Porton Down in September of 2002 will be given.

  17. Measurement of Aerosol and Cloud Particles with PACS and HARP Hyperangular Imaging Polarimeters

    NASA Astrophysics Data System (ADS)

    Martins, J.; Fernandez-Borda, R.; Remer, L. A.; Sparr, L.; Buczkowski, S.; Munchak, L. A.

    2013-12-01

    PACS is new hyper-angular imaging polarimeter for aeorosol and cloud measurerents designed to meet the requirements of the proposed ACE decadal survey mission. The full PACS system consists of three wide field of view (110deg cross track) telescopes covering the UV, VNIR, and SWIR spectral ranges with angular coverage between +55 deg forward to -55deg backwards. The angular density can be selected to cover up to 100 different viewing angles at selected wavelengths. PACS_VNIR is a prototype airborne instrument designed to demonstrate PACS capability by deploying just one of the three wavelength modules of the full PACS. With wavelengths at 470, 550, 675, 760 and 875nm, PACS_VNIR flew for the first time during the PODEX experiment in January/February 2013 aboard the NASA ER-2 aircraft. PACS SWIR (1.64, 1.88, 2.1, and 2.25um) is currently under construction and should be operational in the lab by Fall/2013. PACS_ UV has been fully designed, but is not yet under construction. During the PODEX flights PACS_VNIR collected data for aerosol and clouds over variable surface types including, water, vegetation, urban areas, and snow. The data is currently being calibrated, geolocated and prepared for the inversion of geophysical parameters including water cloud size distribution and aerosol microphysical parameters. The large density of angles in PACS allows for the characterization of cloudbow features in relatively high spatial resolution in a pixel to pixel basis. This avoids the need for assumptions of cloud homogeneity over any distance. The hyperangle capability also allows detailed observation of cloud ice particles, surface characterization, and optimum selection of the number of angles desired for aerosol retrievals. The aerosol and cloud retrieval algorithms under development for the retrieval of particle microphysical properties from the PACS data will be discussed in this presentation. As an extension of the PACS concept we are currently developing the HARP (Hyper

  18. Numerical simulation and validation of SI-CAI hybrid combustion in a CAI/HCCI gasoline engine

    NASA Astrophysics Data System (ADS)

    Wang, Xinyan; Xie, Hui; Xie, Liyan; Zhang, Lianfang; Li, Le; Chen, Tao; Zhao, Hua

    2013-02-01

    SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In this study, a SI-CAI hybrid combustion model (HCM) has been constructed on the basis of the 3-Zones Extended Coherent Flame Model (ECFM3Z). An ignition model is included to initiate the ECFM3Z calculation and induce the flame propagation. In order to precisely depict the subsequent auto-ignition process of the unburned fuel and air mixture independently after the initiation of flame propagation, the tabulated chemistry concept is adopted to describe the auto-ignition chemistry. The methodology for extracting tabulated parameters from the chemical kinetics calculations is developed so that both cool flame reactions and main auto-ignition combustion can be well captured under a wider range of thermodynamic conditions. The SI-CAI hybrid combustion model (HCM) is then applied in the three-dimensional computational fluid dynamics (3-D CFD) engine simulation. The simulation results are compared with the experimental data obtained from a single cylinder VVA engine. The detailed analysis of the simulations demonstrates that the SI-CAI hybrid combustion process is characterised with the early flame propagation and subsequent multi-site auto-ignition around the main flame front, which is consistent with the optical results reported by other researchers. Besides, the systematic study of the in-cylinder condition reveals the influence mechanism of the early flame propagation on the subsequent auto-ignition.

  19. Aerosol-induced lung injuries observed by synchrotron radiation X-ray phase-contrast imaging technique

    NASA Astrophysics Data System (ADS)

    Yue, Weisheng; Zhang, Guilin; Liu, Ping; Sun, Jianqi; Hwu, Yeukuang; Je, Jung Ho; Tan, Mingguang; Li, Yan

    2007-09-01

    Adverse health effects are associated with the inhalation of a variety of atmospheric particles. To study the lung injuries caused by aerosol PM2.5, synchrotron radiation (SR) X-ray phase-contrast imaging technique was used. Nude mice were inoculated with PM2.5 samples collected from suburban area (JD), industrial area (BS) and traffic tunnel (DPQ) of Shanghai. From X-ray phase-contrast images of lung tissues, apart from blood vessels and structures of alveoli, even hemorrhage spots of several microns caused by the inflammation were clearly observed. The studies showed that the PM2.5 samples collected from the traffic tunnel (DPQ) produced higher level of lung injury, followed by the aerosol samples collected from industrial area (BS) and suburban area (JD). Our studies also helped us to understand the process of lung injuries caused by aerosol particles.

  20. Chemical Imaging of Ambient Aerosol Particles: Observational Constraints on Mixing State Parameterization

    SciTech Connect

    O'Brien, Rachel; Wang, Bingbing; Laskin, Alexander; Riemer, Nicole; West, Matthew; Zhang, Qi; Sun, Yele; Yu, Xiao-Ying; Alpert, Peter A.; Knopf, Daniel A.; Gilles, Mary K.; Moffet, Ryan

    2015-09-28

    A new parameterization for quantifying the mixing state of aerosol populations has been applied for the first time to samples of ambient particles analyzed using spectro-microscopy techniques. Scanning transmission x-ray microscopy/near edge x-ray absorption fine structure (STXM/NEXAFS) and computer controlled scanning electron microscopy/energy dispersive x-ray spectroscopy (CCSEM/EDX) were used to probe the composition of the organic and inorganic fraction of individual particles collected on June 27th and 28th during the 2010 Carbonaceous Aerosols and Radiative Effects (CARES) study in the Central Valley, California. The first field site, T0, was located in downtown Sacramento, while T1 was located near the Sierra Nevada Mountains. Mass estimates of the aerosol particle components were used to calculate mixing state metrics, such as the particle-specific diversity, bulk population diversity, and mixing state index, for each sample. Both microscopy imaging techniques showed more changes over these two days in the mixing state at the T0 site than at the T1 site. The STXM data showed evidence of changes in the mixing state associated with a build-up of organic matter confirmed by collocated measurements and the largest impact on the mixing state was due to an increase in soot dominant particles during this build-up. The CCSEM/EDX analysis showed the presence of two types of particle populations; the first was dominated by aged sea salt particles and had a higher mixing state index (indicating a more homogeneous population), the second was dominated by carbonaceous particles and had a lower mixing state index.

  1. The Earth Clouds and Radiation Explorer (EarthCARE) Mission: Cloud and Aerosol Lidar and Imager algorithms.

    NASA Astrophysics Data System (ADS)

    Donovan, David; van Zadelhoff, Gerd-Jan; Wandinger, Ulla; Hünerbein, Anjah; Fischer, Jurgen; von Bismarck, Jonas; Eisinger, Michael; Lajas, Dulce; Wehr, Tobias

    2015-04-01

    The value of multi-sensor remote sensing applied to clouds and aerosol has become clear in recent years. For example, combinations of instruments including passive radiometers, lidars and cloud radars have proved invaluable for their ability to retrieve profiles of cloud macrophysical and microphysical properties. This is amply illustrated by various results from the US-DoE ARM (and similar) surface sites as well as results from data collected by sensors aboard the A-train satellites CloudSat, CALIPSO, and Terra. The Earth Clouds Aerosol and Radiation Explorer (EarthCARE) mission is a combined ESA/JAXA mission to be launched in 2018 which has been designed with sensor-synergy playing a key role. The mission consists of a cloud-profiling radar (CPR), a high-spectral resolution cloud/aerosol lidar (ATLID), a cloud/aerosol multi-spectral imager (MSI), and a three-view broad-band radiometer (BBR). The mission will deliver cloud, aerosol and radiation products focusing on horizontal scales ranging from 1 km to 10 km. EarthCARE data will be used in multiple ways ranging from model evaluation studies, to GCM-orientated cloud microphysical property parameterization development, to data assimilation activities. Recently a number of activities, funded by ESA, have kicked-off which will ultimately deliver operational algorithms for EarthCARE. One of these activities is the "Atmospheric Products from Imager and Lidar" (APRIL) project which focuses on the development of lidar, imager and combined lidar-imager cloud and aerosol algorithms. In this presentation an overview of the APRIL algorithms within the wider context of the planned EarthCARE processing chain will be given.

  2. Use of Selected Computer Assisted Instruction (CAI) in Health Classes.

    ERIC Educational Resources Information Center

    Poehler, David L.

    A pilot project examined the effectiveness of computer assisted instruction (CAI) in teaching selected concepts of health and fitness: coronary risk, lifestyle, and nutrition as related to weight control. A convenience sample of 58 students from two Concepts of Health and Fitness classes were randomly assigned to two groups, both of which used…

  3. Effects of Logo and CAI Environments on Cognition and Creativity.

    ERIC Educational Resources Information Center

    Clements, Douglas H.

    1986-01-01

    This study assessed the effects of learning logo computer programing and computer-assisted instruction (CAI) on specific cognitive skills, metacognitive skills, creativity, and achievement. The programing group scored significantly higher on measures of operational competence, two of three measures of metacognitive skills, and a measure of…

  4. MONIFORMS as Authoring Aids for the PLATO IV CAI System.

    ERIC Educational Resources Information Center

    Schulz, Russel E.

    An analysis of portions of the HumRRO (Human Resources Research Organization) developed computer-assisted instruction (CAI) course in COBOL programing, and a survey of representatives from Advanced Research Project Agency (ARPA) PLATO IV installations indicated a need for authoring aids that could be prepared and programed easily and quickly. The…

  5. Introductory CAI Dialogue in Differential Calculus for Freshman Physics

    ERIC Educational Resources Information Center

    Kalman, C. S.; And Others

    1974-01-01

    A project on computer based dialogue for freshmen is described and evaluated. The dialogue utilizes a CAI language written in Fortran that allows a designer to easily write and edit questions at his own desk without the use of a terminal. (Author/DT)

  6. An Intelligent CAI Monitor and Generative Tutor. Interim Report.

    ERIC Educational Resources Information Center

    Koffman, Elliot B.; And Others

    Design techniques for generative computer-assisted-instructional (CAI) systems are described in this report. These are systems capable of generating problems for students and of deriving and monitoring solutions; problem difficulty, instructional pace, and depth of monitoring are all individually tailored and parts of the solution algorithms can…

  7. CAI for the Developmentally Handicapped: Nine Years of Progress.

    ERIC Educational Resources Information Center

    Hallworth, H. J.; Brebner, Ann

    Initiated nine years ago by the University of Calgary Faculty of Education Computer Applications Unit in cooperation with the nearby Vocational and Rehabilitation Research Institute (VRRI), this project uses computer assisted instruction (CAI) to teach social and vocational skills to developmentally handicapped young adults, many of whom also have…

  8. High-accuracy Multiangle Spectropolarimetric Imaging Concept for Aerosol Remote Sensing from Space

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Chipman, R. A.; Cairns, B.; Foo, L. D.; Keller, C. U.; Macenka, S. A.; Bruce, C. F.

    2004-05-01

    Satellite remote sensing has a key role in measuring the distribution, radiative impact, and regional and global spatial context of tropospheric aerosols. A synergistic combination of multispectral, multiangle, and polarimetric approaches would improve the accuracies of aerosol optical depth and particle property characterizations compared to what is achievable using each method by itself. In this paper we discuss the science benefits and technical feasibility of combining key attributes of multiple aerosol remote sensing instruments into a single instrument package. The features of the conceptual instrument are: spectral coverage from the near-UV to the shortwave infrared; global coverage within a few days; intensity and polarimetric imaging simultaneously at multiple view angles; kilometer to sub-kilometer spatial resolution; and measurement of the degree of linear polarization in one visible and one shortwave-infrared spectral band, i.e., a subset of the full spectral complement, with an uncertainty of 0.5% or less. The polarimetric accuracy is the driving requirement of the instrument design, and is stipulated in order to achieve uncertainty goals in optical depth (0.01) and single scattering albedo (0.03) that appear difficult to reach given the current state-of-the-art of the calibration of intensity-only measurements. Bispectral polarimetry is invoked to enable size-resolved retrievals of particle real refractive index. After examining many approaches and technologies for imaging polarimetry, we conclude that ultrafast time-multiplexing is the best option for meeting the instrument performance requirements. The approach is based upon innovative advances in high-precision imaging polarimetry developed for ground-based solar astronomy. Rapid modulation of the linear polarization Stokes components Q and U, coupled with synchronous demodulation in a charge-caching focal plane, provides two essential benefits: (1) the same detector is used to measure the relative

  9. Use of Photoelastic Modulators for High-accuracy Spectropolarimetric Imaging of Aerosols

    NASA Technical Reports Server (NTRS)

    Diner, David J.; Davis, Ab; Cunningham, Tom; Gutt, Gary; Hancock, Bruce; Raouf, Nasrat; Wang, Yu; Zan, Jason; Chipman, Russell; Beaudry, Neil; Hirschy, Linda

    2006-01-01

    Passive multiangular, multispectral, and polarimetric sensing approaches each have unique strengths for the measurement of tropospheric aerosol column abundances and microphysical properties. Current spaceborne multispectral and multiangular aerosols sensors operate at approximately 1 km resolution. Under NASA's Instrument Incubator Program, we are developing an electro-optic imaging approach that will enable adding high-accuracy polarimetry to such observations. To achieve a degree of linear polarization (DOLP) uncertainty of 0.5%, our approach temporally modulates the linear-polarization component of incoming light at a rapid rate, enabling each detector within a focal-plane array, combined with polarization analyzers, to measure the relative proportions of the linear Stokes components Q or U to the total intensity. Our system uses tandem photoelastic modulators (PEMs) within a high-reflectance, low diattenuation camera design. The two PEMs vibrate at slightly different resonant frequencies, leading to modulation of the polarized light at a heterodyne frequency of 25 Hz. High-speed (1 kHz) readout of the detector arrays samples the output waveforms from which Q/I and U/I are derived. We report on experimental and theoretical analyses of PEM and optical system performance, along with plans for developing ruggedized PEMs capable of withstanding launch and on-orbit stresses.

  10. Feasibility of anomaly occurrence in aerosols time series obtained from MODIS satellite images during hazardous earthquakes

    NASA Astrophysics Data System (ADS)

    Akhoondzadeh, Mehdi; Jahani Chehrebargh, Fatemeh

    2016-09-01

    Earthquake is one of the most devastating natural disasters that its prediction has not materialized comprehensive. Remote sensing data can be used to access information which is closely related to an earthquake. The unusual variations of lithosphere, atmosphere and ionosphere parameters before the main earthquakes are considered as earthquake precursors. To date the different precursors have been proposed. This paper examines one of the parameters which can be derived from satellite imagery. The mentioned parameter is Aerosol Optical Depth (AOD) that this article reviews its relationship with earthquake. Aerosol parameter can be achieved through various methods such as AERONET ground stations or using satellite images via algorithms such as the DDV (Dark Dense Vegetation), Deep Blue Algorithm and SYNTAM (SYNergy of Terra and Aqua Modis). In this paper, by analyzing AOD's time series (derived from MODIS sensor on the TERRA platform) for 16 major earthquakes, seismic anomalies were observed before and after earthquakes. Before large earthquakes, rate of AOD increases due to the pre-seismic changes before the strong earthquake, which produces gaseous molecules and therefore AOD increases. Also because of aftershocks after the earthquake there is a significant change in AOD due to gaseous molecules and dust. These behaviors suggest that there is a close relationship between earthquakes and the unusual AOD variations. Therefore the unusual AOD variations around the time of earthquakes can be introduced as an earthquake precursor.

  11. Distribution and Origin of 36Cl In Allende CAIs

    SciTech Connect

    Matzel, J P; Jacobsen, B; Hutcheon, I D; Krot, A N; Nagashima, K; Yin, Q; Ramon, E C; Weber, P; Wasserburg, G J

    2009-12-11

    The abundance of short-lived radionuclides (SLRs) in early solar system materials provide key information about their nucleosynthetic origin and can constrain the timing of early solar system events. Excesses of {sup 36}S ({sup 36}S*) correlated with {sup 35}Cl/{sup 34}S ratios provide direct evidence for in situ decay of {sup 36}Cl ({tau}{sub 1/2} {approx} 0.3 Ma) and have been reported in sodalite (Na{sub 8}Al{sub 6}Si{sub 6}O{sub 24}Cl{sub 2}) and wadalite (Ca{sub 6}Al{sub 5}Si{sub 2}O{sub 16}Cl{sub 3}) in CAIs and chondrules from the Allende and Ningqiang CV carbonaceous chondrites. While previous studies demonstrate unequivocally that {sup 36}Cl was extant in the early solar system, no consensus on the origin or initial abundance of {sup 36}Cl has emerged. Understanding the origin of {sup 36}Cl, as well as the reported variation in the initial {sup 36}Cl/{sup 35}Cl ratio, requires addressing when, where and how chlorine was incorporated into CAIs and chondrules. These factors are key to distinguishing between stellar nucleosynthesis or energetic particle irradiation for the origin of {sup 36}Cl. Wadalite is a chlorine-rich secondary mineral with structural and chemical affinities to grossular. The high chlorine ({approx}12 wt%) and very low sulfur content (<<0.01 wt%) make wadalite ideal for studies of the {sup 36}Cl-{sup 36}S system. Wadalite is present in Allende CAIs exclusively in the interior regions either in veins crosscutting melilite or in zones between melilite and anorthite associated with intergrowths of grossular, monticellite, and wollastonite. Wadalite and sodalite most likely resulted from open-system alteration of primary minerals with a chlorine-rich fluid phase. We recently reported large {sup 36}S* correlated with {sup 35}Cl/{sup 34}S in wadalite in Allende Type B CAI AJEF, yielding a ({sup 36}Cl/{sup 35}Cl){sub 0} ratio of (1.7 {+-} 0.3) x 10{sup -5}. This value is the highest reported {sup 36}Cl/{sup 35}Cl ratio and is {approx}5 times

  12. Handheld hyperspectral imager for standoff detection of chemical and biological aerosols

    NASA Astrophysics Data System (ADS)

    Hinnrichs, Michele; Jensen, James O.; McAnally, Gerard

    2004-08-01

    Pacific Advanced Technology has developed a small hand held imaging spectrometer, Sherlock, for gas leak and aerosol detection and imaging. The system is based on a patented technique, (IMSS Image Multi-spectral Sensing), that uses diffractive optics and image processing algorithms to detect spectral information about objects in the scene of the camera. This cameras technology has been tested at Dugway Proving Ground and Dstl Porton Down facilities looking at Chemical and Biological agent simulants. In addition to Chemical and Biological detection, the camera has been used for environmental monitoring of green house gases and is currently undergoing extensive laboratory and field testing by the Gas Technology Institute, British Petroleum and Shell Oil for applications for gas leak detection and repair. In this paper we will present some of the results from the data collection at the TRE test at Dugway Proving Ground during the summer of 2002 and laboratory testing at the Dstl facility at Porton Down in the UK in the fall of 2002.

  13. Impacts of Cross-Platform Vicarious Calibration on the Deep Blue Aerosol Retrievals for Moderate Resolution Imaging Spectroradiometer Aboard Terra

    NASA Technical Reports Server (NTRS)

    Jeong, Myeong-Jae; Hsu, N. Christina; Kwiatkowska, Ewa J.; Franz, Bryan A.; Meister, Gerhard; Salustro, Clare E.

    2012-01-01

    The retrieval of aerosol properties from spaceborne sensors requires highly accurate and precise radiometric measurements, thus placing stringent requirements on sensor calibration and characterization. For the Terra/Moderate Resolution Imaging Spedroradiometer (MODIS), the characteristics of the detectors of certain bands, particularly band 8 [(B8); 412 nm], have changed significantly over time, leading to increased calibration uncertainty. In this paper, we explore a possibility of utilizing a cross-calibration method developed for characterizing the Terral MODIS detectors in the ocean bands by the National Aeronautics and Space Administration Ocean Biology Processing Group to improve aerosol retrieval over bright land surfaces. We found that the Terra/MODIS B8 reflectance corrected using the cross calibration method resulted in significant improvements for the retrieved aerosol optical thickness when compared with that from the Multi-angle Imaging Spectroradiometer, Aqua/MODIS, and the Aerosol Robotic Network. The method reported in this paper is implemented for the operational processing of the Terra/MODIS Deep Blue aerosol products.

  14. Effectiveness of CAI Package on Achievement in Physics of IX Standard Students

    ERIC Educational Resources Information Center

    Maheswari, I. Uma; Ramakrishnan, N.

    2015-01-01

    The present study is an experimental one in nature, to find out the effectiveness of CAI package on in Physics of IX std. students. For this purpose a CAI package was developed and validated. The validated CAI package formed an independent variable of this study. The dependent variable is students' achievements in physics content. In order to find…

  15. Harvard University Computer-Aided Instruction (CAI) Laboratory. Technical Report Number 6.

    ERIC Educational Resources Information Center

    Stolurow, Lawrence M.; Peterson, Theodore I.

    This report is a detailed description of the Harvard CAI Laboratory, including its history, organization, functions, staffing, programs and support. Discussed are materials relating to CAI in general, such as psychological research, modes of instruction, advantages and implementation of CAI. Reviewed also are specific projects of this facility. A…

  16. Individual Particle TOF-SIMS Imaging Analysis of Aerosol Collected During the April 2001 Asian Dust Event.

    NASA Astrophysics Data System (ADS)

    Peterson, R. E.

    2002-12-01

    Time of Flight Secondary Ion Mass Spectroscopy can provide information regarding the surface chemistry, including both organic and inorganic compounds, of individual atmospheric aerosol in themicrometer size range. X-ray analysis has commonly been used to analyze the composition of single particles but has several important limitations. Principally, X-ray analysis cannot be used to study organic compounds in the aerosol, it offers low sensitivity for light elements common in crustal material and it cannot distinguish isotopes. TOF-SIMS has the potential to provide superior performance in these areas. We have developed statistical image processing methods to allow extraction of individual particle mass spectra from TOF-SIMS images. In mid April 2001 a strong Asian dust event was tracked by the NASA TOMS satellite across the Pacific Ocean and into the continental United States. While Asian dust deposition is common in Hawaii, strong events characterized by significant visibility degradation have been much less frequently reported in the Rocky Mountain west. Samples were taken during and after the event at the University of Utah in Salt Lake City, Utah (SLC). Size segregated samples were collected on Al substrates using an 8 stage cascade impactor and total aerosol samples were collected with 47 mm Fluoropore filters. Surface and depth profile analysis of the particles was performed using a Phi Trift I TOF-SIMS instrument. Statistical methods, including PCA, mixture models and neural networks, were used to extract spectra of individual particles from the TOF-SIMS images and to classify particles based on their surface chemistry and depth profiles. Differences in both the chemistry and size distribution of the particles could be seen between the aerosol collected during the Asian dust event and aerosol collected post-event at the University of Utah site. Positive TOF-SIMS spectra of SLC urban aerosol were dominated by sub-micrometer organics, and negative spectra

  17. Characterization of aerosol-containing chemical simulant clouds using a sensitive, thermal infrared imaging spectrometer

    NASA Astrophysics Data System (ADS)

    Hall, Jeffrey L.; D'Amico, Francis M.; Kolodzey, Steven J.; Qian, Jun; Polak, Mark L.; Westerberg, Karl; Chang, Clement S.

    2011-05-01

    A sensitive, ground-based thermal imaging spectrometer was deployed at the Army's Dugway Proving Ground to remotely monitor explosively released chemical-warfare-agent-simulant clouds from stand-off ranges of a few kilometers. The sensor has 128 spectral bands covering the 7.6 to 13.5 micron region. The measured cloud spectra clearly showed scattering of high-elevation-angle sky radiance by liquid aerosols or dust in the clouds: we present arguments that show why the scattering is most likely due to dust. This observation has significant implications for early detection of dust-laden chemical clouds. On one hand, detection algorithms must properly account for the scattered radiation component, which would include out-of-scene radiation components as well as a dust signature; on the other hand, this scattering gives rise to an enhanced "delta-T" for detection by a ground-based sensor.

  18. Remote sensing of cloud, aerosol and water vapor properties from the Moderate Resolution Imaging Spectrometer (MODIS)

    NASA Technical Reports Server (NTRS)

    King, M. D.

    1992-01-01

    The Moderate Resolution Imaging Spectrometer (MODIS) is an Earth-viewing sensor being developed as a facility instrument for the Earth Observing System (EOS) to be launched in the late 1990s. MODIS consists of two separate instruments that scan a swath width sufficient to provide nearly complete global coverage every two days from a polar-orbiting, Sun-synchronous, platform at an altitude of 705 km. Of primary interest for studies of atmospheric physics is the MODIS-N (nadir) instrument which will provide images in 36 spectral bands between 0.415 and 14.235 micrometers with spatial resoulutions of 250 m (2 bands), 500 m (5 bands) and 1000 m (29 bands). These bands have been carefully selected to enable advanced studies of land, ocean and atmosperhic processes. The intent of this lecture is to describe the current status of MODIS-N and its companion instrument MODIS-T (tilt), a tiltable cross-track scanning radiometer with 32 uniformly spaced channels between 0.410 and 0.875 micrometers, and to describe the physical principles behind the development of MODIS for the remote sensing of atmospheric properties. Primary emphasis will be placed on the main atmospheric applications of determining the optical, microphysical and physical properties of clouds and aerosol particles form spectral-reflection and thermal-emission measurements. In addition to cloud and aerosol properties, MODIS-N will be utilized for the determination of the total precipitable water vapor over land and atmospheric stability. The physical principles behind the determination of each of these atmospheric products will be described herein.

  19. Characterization of Meteorites by Focused Ion Beam Sectioning: Recent Applications to CAIs and Primitive Meteorite Matrices

    NASA Technical Reports Server (NTRS)

    Christoffersen, Roy; Keller, Lindsay P.; Han, Jangmi; Rahman, Zia; Berger, Eve L.

    2015-01-01

    Focused ion beam (FIB) sectioning has revolutionized preparation of meteorite samples for characterization by analytical transmission electron microscopy (TEM) and other techniques. Although FIB is not "non-destructive" in the purest sense, each extracted section amounts to no more than nanograms (approximately 500 cubic microns) removed intact from locations precisely controlled by SEM imaging and analysis. Physical alteration of surrounding material by ion damage, fracture or sputter contamination effects is localized to within a few micrometers around the lift-out point. This leaves adjacent material intact for coordinate geochemical analysis by SIMS, microdrill extraction/TIMS and other techniques. After lift out, FIB sections can be quantitatively analyzed by electron microprobe prior to final thinning, synchrotron x-ray techniques, and by the full range of state-of-the-art analytical field-emission scanning transmission electron microscope (FE-STEM) techniques once thinning is complete. Multiple meteorite studies supported by FIB/FE-STEM are currently underway at NASA-JSC, including coordinated analysis of refractory phase assemblages in CAIs and fine-grained matrices in carbonaceous chondrites. FIB sectioning of CAIs has uncovered epitaxial and other overgrowth relations between corundum-hibonite-spinel consistent with hibonite preceding corundum and/or spinel in non-equilibrium condensation sequences at combinations of higher gas pressures, dust-gas enrichments or significant nebular transport. For all of these cases, the ability of FIB to allow for coordination with spatially-associated isotopic data by SIMS provides immense value for constraining the formation scenarios of the particular CAI assemblage. For carbonaceous chondrites matrix material, FIB has allowed us to obtain intact continuous sections of the immediate outer surface of Murchison (CM2) after it has been experimentally ion processed to simulate solar wind space weathering. The surface

  20. Observations from a prototype implementation of the Common APSE Interface Set (CAIS)

    NASA Technical Reports Server (NTRS)

    Mcclimens, M.; Bowerman, R.; Howell, C.; Gill, H.; Hutchison, R.

    1985-01-01

    This paper presents an overview of the Common Ada Programming Support Environment (APSE) Interface Set (CAIS), its purpose, and its history. The paper describes an internal research and development effort at the Mitre Corporation to implement a prototype version of the current CAIS specification and to rehost existing Ada software development tools onto the CAIS prototype. Based on this effort, observations are made on the maturity and functionality of the CAIS. These observations support the government's current policy of publicizing the CAIS specification as a baseline for public review in support of its evolution into a standard which can be mandated for use as Ada is today.

  1. Bridging the Gap Between Science and Clinical Efficacy: Physiology, Imaging, and Modeling of Aerosols in the Lung.

    PubMed

    Darquenne, Chantal; Fleming, John S; Katz, Ira; Martin, Andrew R; Schroeter, Jeffry; Usmani, Omar S; Venegas, Jose; Schmid, Otmar

    2016-04-01

    Development of a new drug for the treatment of lung disease is a complex and time consuming process involving numerous disciplines of basic and applied sciences. During the 2015 Congress of the International Society for Aerosols in Medicine, a group of experts including aerosol scientists, physiologists, modelers, imagers, and clinicians participated in a workshop aiming at bridging the gap between basic research and clinical efficacy of inhaled drugs. This publication summarizes the current consensus on the topic. It begins with a short description of basic concepts of aerosol transport and a discussion on targeting strategies of inhaled aerosols to the lungs. It is followed by a description of both computational and biological lung models, and the use of imaging techniques to determine aerosol deposition distribution (ADD) in the lung. Finally, the importance of ADD to clinical efficacy is discussed. Several gaps were identified between basic science and clinical efficacy. One gap between scientific research aimed at predicting, controlling, and measuring ADD and the clinical use of inhaled aerosols is the considerable challenge of obtaining, in a single study, accurate information describing the optimal lung regions to be targeted, the effectiveness of targeting determined from ADD, and some measure of the drug's effectiveness. Other identified gaps were the language and methodology barriers that exist among disciplines, along with the significant regulatory hurdles that need to be overcome for novel drugs and/or therapies to reach the marketplace and benefit the patient. Despite these gaps, much progress has been made in recent years to improve clinical efficacy of inhaled drugs. Also, the recent efforts by many funding agencies and industry to support multidisciplinary networks including basic science researchers, R&D scientists, and clinicians will go a long way to further reduce the gap between science and clinical efficacy. PMID:26829187

  2. Evaluation of the Moderate-Resolution Imaging Spectroradiometer (MODIS) retrievals of dust aerosol over the ocean during PRIDE

    NASA Astrophysics Data System (ADS)

    Levy, Robert C.; Remer, Lorraine A.; Tanré, Didier; Kaufman, Yoram J.; Ichoku, Charles; Holben, Brent N.; Livingston, John M.; Russell, Philip B.; Maring, Hal

    2003-10-01

    The Puerto Rico Dust Experiment (PRIDE) took place in Roosevelt Roads, Puerto Rico from 26 June to 24 July 2000 to study the radiative and physical properties of African dust aerosol transported into the region. PRIDE had the unique distinction of being the first major field experiment to allow direct comparison of aerosol retrievals from the Moderate Imaging Spectroradiometer (MODIS) with Sun photometer and in situ aerosol measurements. Over the ocean the MODIS algorithm retrieves aerosol optical depth (AOD) as well as information about the aerosols' size distribution. During PRIDE, AODs derived by MODIS in the red wavelengths (0.66 μm) compare closely with Sun photometers. However, MODIS-derived AODs are too large in the blue and green wavelengths (0.47 and 0.55 μm) and too small in the near infrared (0.87 μm). This error in AOD spectral dependence results in retrieved particle size distributions that are small compared to in situ measurements and smaller still when compared to Sun photometer sky radiance inversions. The differences in size distributions may be, in part, associated with MODIS' simplification of dust as spherical particles. Analysis of this PRIDE data set is a first step toward derivation of realistic models for future MODIS retrievals.

  3. CAIs in CO3 Meteorites: Parent Body or Nebular Alteration?

    NASA Astrophysics Data System (ADS)

    Greenwood, R. C.; Hutchison, R.; Huss, G. R.; Hutcheon, I. D.

    1992-07-01

    It is widely held that alteration of Ca Al-rich inclusions (CAIs) in CV3 and CO3 meteorites occurred in the nebula (Hashimoto 1992). The CO3 chondrites, however, appear to define a metamorphic sequence dominated by parent body, and not nebular, metamorphic effects (Scott and Jones, 1990). To investigate the effects of metamorphism on CAIs we have studied inclusions from 4 CO chondrites: Colony (3.0), Felix (3.2), Lance (3.4), and Warrenton (3.6). In a section of Colony (74 mm^2) 81 CAIs, 30-870 micrometers long, comprise 52 nodular spinel-rich inclusions (fragments of Type-A CAI composed largely of spinel), 12 spinel-pyroxene inclusions, 10 melilite-rich inclusions, 2 hibonite-only inclusions, 2 CaAl4O7-bearing inclusions, and 3 spinel-pyroxene- olivine inclusions. Although a find, CAIs in Colony are relatively fresh, melilite in particular being little altered. In 79% of the spinel-bearing inclusions, spinel has <2wt% FeO, which otherwise ranges to 34.8%. Mg isotopic compositions were determined in 5 selected Colony inclusion; evidence of ^26Mg* from decay of ^26Al was found in 4 CAI. A hibonite-only inclusion has the largest ^26Mg* excess, delta^26Mg 32o/oo. Data show no evidence of isotopic disturbance and define a linear array with slope ^26Mg* /^27Al = (3.4+- 0.6) x 10^-5, like that obtained by Davis and Hinton (1986) in a hibonite-bearing spherule from Ornans. Despite Al/Mg ratios of up to 1500, CaAl4O7 in one inclusion shows no evidence of ^26Mg*; ^26Mg* < 4 x 10^-6. All three melilite-bearing inclusions from Colony C21 (angstrom k(sub)8.3-14.3), C56 (angstrom k(sub)10.5-16) and C62 (angstrom k(sub)15-21) show evidence of radiogenic ^26Mg*. Excess ^26Mg positively correlates with the Al/Mg ratios but the data do not define a unique initial value of ^26Al/^27Al. Data for melilite in C21, in particular, show evidence for disturbance of the Al-Mg system, as is common for Allende CAI (Podosek et al. 1991). Melilites in C56 in contrast show no evidence of

  4. Replacement textures in CAI and implications regarding planetary metamorphism

    NASA Technical Reports Server (NTRS)

    Meeker, G. P.; Wasserburg, G. J.; Armstrong, J. T.

    1983-01-01

    Formation by a secondary metamorphic event, rather than primary crystallization from a melt or a sequential nebular condensation, is indicated by textural and chemical features of five coarse grained, Ca- and Al-rich inclusions (CAI) from the Allende meteorite which contain embayed pyroxene surrounded by melilite. It is suggested that the most probable environment for a metamorphic process (requiring the addition of Ca derived from calcite or from the introduction of a fluid phase) is that of a small planetary body, rather than the solar nebula. These results are compatible with O isotopic heterogeneities within CAI, and offer a mechanism for the production of lower temperature alteration phases, together with the rim phases found in these inclusions.

  5. Oxygen Isotope Measurements of a Rare Murchison Type A CAI and Its Rim

    NASA Technical Reports Server (NTRS)

    Matzel, J. E. P.; Simon, J. I.; Hutcheon, I. D.; Jacobsen, B.; Simon, S. B.; Grossman, L.

    2013-01-01

    Ca-, Al-rich inclusions (CAIs) from CV chondrites commonly show oxygen isotope heterogeneity among different mineral phases within individual inclusions reflecting the complex history of CAIs in both the solar nebula and/or parent bodies. The degree of isotopic exchange is typically mineral-specific, yielding O-16-rich spinel, hibonite and pyroxene and O-16-depleted melilite and anorthite. Recent work demonstrated large and systematic variations in oxygen isotope composition within the margin and Wark-Lovering rim of an Allende Type A CAI. These variations suggest that some CV CAIs formed from several oxygen reservoirs and may reflect transport between distinct regions of the solar nebula or varying gas composition near the proto-Sun. Oxygen isotope compositions of CAIs from other, less-altered chondrites show less intra-CAI variability and 16O-rich compositions. The record of intra-CAI oxygen isotope variability in CM chondrites, which commonly show evidence for low-temperature aqueous alteration, is less clear, in part because the most common CAIs found in CM chondrites are mineralogically simple (hibonite +/- spinel or spinel +/- pyroxene) and are composed of minerals less susceptible to O-isotopic exchange. No measurements of the oxygen isotope compositions of rims on CAIs in CM chondrites have been reported. Here, we present oxygen isotope data from a rare, Type A CAI from the Murchison meteorite, MUM-1. The data were collected from melilite, hibonite, perovskite and spinel in a traverse into the interior of the CAI and from pyroxene, melilite, anorthite, and spinel in the Wark-Lovering rim. Our objectives were to (1) document any evidence for intra-CAI oxygen isotope variability; (2) determine the isotopic composition of the rim minerals and compare their composition(s) to the CAI interior; and (3) compare the MUM-1 data to oxygen isotope zoning profiles measured from CAIs in other chondrites.

  6. The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI): a new tool for aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Xu, F.; Garay, M. J.; Martonchik, J. V.; Rheingans, B. E.; Geier, S.; Davis, A.; Hancock, B. R.; Jovanovic, V. M.; Bull, M. A.; Capraro, K.; Chipman, R. A.; McClain, S. C.

    2013-08-01

    The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) is an eight-band (355, 380, 445, 470, 555, 660, 865, 935 nm) pushbroom camera, measuring polarization in the 470, 660, and 865 nm bands, mounted on a gimbal to acquire multiangular observations over a ±67° along-track range. The instrument has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. AirMSPI employs a photoelastic modulator-based polarimetric imaging technique to enable accurate measurements of the degree and angle of linear polarization in addition to spectral intensity. A description of the AirMSPI instrument and ground data processing approach is presented. Example images of clear, hazy, and cloudy scenes over the Pacific Ocean and California land targets obtained during flights between 2010 and 2012 are shown, and quantitative interpretations of the data using vector radiative transfer theory and scene models are provided to highlight the instrument's capabilities for determining aerosol and cloud microphysical properties and cloud 3-D spatial distributions. Sensitivity to parameters such as aerosol particle size distribution, ocean surface wind speed and direction, cloud-top and cloud-base height, and cloud droplet size is discussed. AirMSPI represents a major step toward realization of the type of imaging polarimeter envisioned to fly on NASA's Aerosol-Cloud-Ecosystem (ACE) mission in the next decade.

  7. The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI): a new tool for aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Xu, F.; Garay, M. J.; Martonchik, J. V.; Rheingans, B. E.; Geier, S.; Davis, A.; Hancock, B. R.; Jovanovic, V. M.; Bull, M. A.; Capraro, K.; Chipman, R. A.; McClain, S. C.

    2013-02-01

    The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) is an eight-band (355, 380, 445, 470, 555, 660, 865, 935 nm) pushbroom camera, measuring polarization in the 470, 660, and 865 nm bands, mounted on a gimbal to acquire multiangular observations over a ± 67° along-track range. The instrument has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. AirMSPI employs a photoelastic modulator-based polarimetric imaging technique to enable accurate measurements of the degree and angle of linear polarization in addition to spectral intensity. A description of the AirMSPI instrument and ground data processing approach is presented. Example images of clear, hazy, and cloudy scenes over the Pacific Ocean and California land targets obtained during flights between 2010 and 2012 are shown, and quantitative interpretations of the data using vector radiative transfer theory and scene models are provided to highlight the instrument's capabilities for determining aerosol and cloud microphysical properties and cloud 3-D spatial distributions. Sensitivity to parameters such as aerosol particle size distribution, ocean surface wind speed and direction, cloud-top and cloud-base height, and cloud droplet size is discussed. AirMSPI represents a major step toward realization of the type of imaging polarimeter envisioned to fly on NASA's Aerosol-Cloud-Ecosystem (ACE) mission in the next decade.

  8. Evaluation of applicability of high-resolution multiangle imaging photo-polarimetric observations for aerosol atmospheric correction

    NASA Astrophysics Data System (ADS)

    Kalashnikova, Olga; Garay, Michael; Xu, Feng; Diner, David; Seidel, Felix

    2016-07-01

    Multiangle spectro-polarimetric measurements have been advocated as an additional tool for better understanding and quantifying the aerosol properties needed for atmospheric correction for ocean color retrievals. The central concern of this work is the assessment of the effects of absorbing aerosol properties on remote sensing reflectance measurement uncertainty caused by neglecting UV-enhanced absorption of carbonaceous particles and by not accounting for dust nonsphericity. In addition, we evaluate the polarimetric sensitivity of absorbing aerosol properties in light of measurement uncertainties achievable for the next generation of multi-angle polarimetric imaging instruments, and demonstrate advantages and disadvantages of wavelength selection in the UV/VNIR range. In this work a vector Markov Chain radiative transfer code including bio-optical models was used to quantitatively evaluate in water leaving radiances between atmospheres containing realistic UV-enhanced and non-spherical aerosols and the SEADAS carbonaceous and dust-like aerosol models. The phase matrices for the spherical smoke particles were calculated using a standard Mie code, while those for non-spherical dust particles were calculated using the numerical approach developed for modeling dust for the AERONET network of ground-based sunphotometers. As a next step, we have developed a retrieval code that employs a coupled Markov Chain (MC) and adding/doubling radiative transfer method for joint retrieval of aerosol properties and water leaving radiance from Airborne Multiangle SpectroPolarimetric Imager-1 (AirMSPI-1) polarimetric observations. The AirMSPI-1 instrument has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. AirMSPI typically acquires observations of a target area at 9 view angles between ±67° at 10 m resolution. AirMSPI spectral channels are centered at 355, 380, 445, 470, 555, 660, and 865 nm, with 470, 660, and 865 reporting linear polarization. We

  9. Silicon Isotopic Fractionation of CAI-like Vacuum Evaporation Residues

    SciTech Connect

    Knight, K; Kita, N; Mendybaev, R; Richter, F; Davis, A; Valley, J

    2009-06-18

    Calcium-, aluminum-rich inclusions (CAIs) are often enriched in the heavy isotopes of magnesium and silicon relative to bulk solar system materials. It is likely that these isotopic enrichments resulted from evaporative mass loss of magnesium and silicon from early solar system condensates while they were molten during one or more high-temperature reheating events. Quantitative interpretation of these enrichments requires laboratory determinations of the evaporation kinetics and associated isotopic fractionation effects for these elements. The experimental data for the kinetics of evaporation of magnesium and silicon and the evaporative isotopic fractionation of magnesium is reasonably complete for Type B CAI liquids (Richter et al., 2002, 2007a). However, the isotopic fractionation factor for silicon evaporating from such liquids has not been as extensively studied. Here we report new ion microprobe silicon isotopic measurements of residual glass from partial evaporation of Type B CAI liquids into vacuum. The silicon isotopic fractionation is reported as a kinetic fractionation factor, {alpha}{sub Si}, corresponding to the ratio of the silicon isotopic composition of the evaporation flux to that of the residual silicate liquid. For CAI-like melts, we find that {alpha}{sub Si} = 0.98985 {+-} 0.00044 (2{sigma}) for {sup 29}Si/{sup 28}Si with no resolvable variation with temperature over the temperature range of the experiments, 1600-1900 C. This value is different from what has been reported for evaporation of liquid Mg{sub 2}SiO{sub 4} (Davis et al., 1990) and of a melt with CI chondritic proportions of the major elements (Wang et al., 2001). There appears to be some compositional control on {alpha}{sub Si}, whereas no compositional effects have been reported for {alpha}{sub Mg}. We use the values of {alpha}Si and {alpha}Mg, to calculate the chemical compositions of the unevaporated precursors of a number of isotopically fractionated CAIs from CV chondrites whose

  10. Status of the Multi-Angle Imaging SpectroRadiometer Instrument for EOS-AM1 and Its Application to Remote Sensing of Aerosols

    NASA Technical Reports Server (NTRS)

    Diner, D. J.; Abdou, W. A.; Bruegge, C. J.; Conel, J. E.; Kahn, R. A.; Maronchik, J. V.; Paradise, S. R.; West, R. A.

    1995-01-01

    The Multi-Angle Imaging SpectroRadiometer (MISR) instrument is being developed at JPL for the EOS AM1 spacecraft, scheduled for launch in June 1998. The development status and strategy for observing atmospheric aerosols are described.

  11. Primary Reverse Oxygen-Isotope Evolution of Pyroxene in Compact Type A CAIs from the Efremovka and NWA-3118 CV3 Chondrites: Insights into Internal CAI Mixing Lines

    NASA Astrophysics Data System (ADS)

    MacPherson, G. J.; Nagashima, K.; Ivanova, M. A.; Krot, A. N.

    2012-03-01

    ^1^6O-depleted Ti-Al-rich pyroxenes in compact Type A CAIs reflect the composition of the perovsites from which they first formed. Perovsite apparently exchanged oxygen very early, prior to melilite exchange and to initial melting of the CAIs.

  12. Assessment of capabilities of multiangle imaging photo-polarimetry for atmospheric correction in presence of absorbing aerosols

    NASA Astrophysics Data System (ADS)

    Kalashnikova, O. V.; Garay, M. J.; Xu, F.; Seidel, F. C.; Diner, D. J.

    2015-12-01

    Satellite remote sensing of ocean color is a critical tool for assessing the productivity of marine ecosystems and monitoring changes resulting from climatic or environmental influences. Yet water-leaving radiance comprises less than 10% of the signal measured from space, making correction for absorption and scattering by the intervening atmosphere imperative. Traditional ocean color retrieval algorithms utilize a standard set of aerosol models and the assumption of negligible water-leaving radiance in the near-infrared. Modern improvements have been developed to handle absorbing aerosols such as urban particulates in coastal areas and transported desert dust over the open ocean, where ocean fertilization can impact biological productivity at the base of the marine food chain. Even so, imperfect knowledge of the absorbing aerosol optical properties or their height distribution results in well-documented sources of error. In the UV, the problem of UV-enhanced absorption and nonsphericity of certain aerosol types are amplified due to the increased Rayleigh and aerosol optical depth, especially at off-nadir view angles. Multi-angle spectro-polarimetric measurements have been advocated as an additional tool to better understand and retrieve the aerosol properties needed for atmospheric correction for ocean color retrievals. The central concern of the work to be described is the assessment of the effects of absorbing aerosol properties on water leaving radiance measurement uncertainty by neglecting UV-enhanced absorption of carbonaceous particles and by not accounting for dust nonsphericity. In addition, we evaluate the polarimetric sensitivity of absorbing aerosol properties in light of measurement uncertainties achievable for the next generation of multi-angle polarimetric imaging instruments, and demonstrate advantages and disadvantages of wavelength selection in the UV/VNIR range. The phase matrices for the spherical smoke particles were calculated using a standard

  13. Aerosol Particle Size Retrievals from the Compact Reconnaissance Imaging Spectrometer for Mars

    NASA Astrophysics Data System (ADS)

    Guzewich, S.; Smith, M. D.; Wolff, M. J.

    2013-12-01

    During the extended mission of the Mars Reconnaisance Orbiter, the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) has made periodic limb-viewing geometry observations of the Martian atmosphere. Sufficient radiance is typically available to produce a vertical distribution of dust and water ice aerosols from the surface to approximately 50 km altitude. Radiative transfer modeling is conducted to achieve a best fit between the observed and modeled spectrum. The spherical geometry of the limb-viewing geometry is handled using a pseudo-spherical approximation that is computationally efficient and accurate to within a few percent of a Monte Carlo method for the geometries observed. Different particle sizes of dust and water ice have unique extinction coefficients across the visible and near-infrared portion of the spectrum observed by CRISM. We use a wide range of wavelengths across the CRISM spectrum to conduct the retrieval. Here we provide initial results on the retrieval of dust and water ice particle sizes over the duration of the CRISM limb-viewing observations.

  14. Dual-Photoelastic-Modulator-Based Polarimetric Imaging Concept for Aerosol Remote Sensing

    NASA Technical Reports Server (NTRS)

    Diner, David J.; Davis, Ab; Hancock, Bruce; Gutt, Gary; Chipman, Russell A.; Cairns, Brian

    2007-01-01

    A dual-photoelastic-modulator- (PEM-) based spectropolarimetric camera concept is presented as an approach for global aerosol monitoring from space. The most challenging performance objective is to measure degree of linear polarization (DOLP) with an uncertainty of less than 0.5% in multiple spectral bands, at moderately high spatial resolution, over a wide field of view, and for the duration of a multiyear mission. To achieve this, the tandem PEMs are operated as an electro-optic circular retardance modulator within a high-performance reflective imaging system. Operating the PEMs at slightly different resonant frequencies generates a beat signal that modulates the polarized component of the incident light at a much lower heterodyne frequency. The Stokes parameter ratio q = Q/I is obtained from measurements acquired from each pixel during a single frame, providing insensitivity to pixel responsivity drift and minimizing polarization artifacts that conventionally arise when this quantity is derived from differences in the signals from separate detectors. Similarly, u = U/I is obtained from a different pixel; q and u are then combined to form the DOLP. A detailed accuracy and tolerance analysis for this polarimeter is presented.

  15. Wavelength dependence of dust aerosol single scattering albedo as observed by the Compact Reconnaissance Imaging Spectrometer

    NASA Astrophysics Data System (ADS)

    Wolff, M. J.; Smith, M. D.; Clancy, R. T.; Arvidson, R.; Kahre, M.; Seelos, F.; Murchie, S.; Savijärvi, H.

    2009-06-01

    Observations by the Compact Reconnaissance Imaging Spectrometer (CRISM) onboard the Mars Reconnaissance Orbiter (MRO) over the range 440-2920 nm of the very dusty Martian atmosphere of the 2007 planet-encircling dust event are combined with those made by both Mars Exploration Rovers (MERs) to better characterize the single scattering albedo (ω 0) of Martian dust aerosols. Using the diagnostic geometry of the CRISM emission phase function (EPF) sequences and the “ground truth” connection provided at both MER locations allows one to more effectively isolate the single scattering albedo (ω 0). This approach eliminates a significant portion of the type of uncertainty involved in many of the earlier radiative transfer analyses. Furthermore, the use of a “first principles” or microphysical representation of the aerosol scattering properties offers a direct path to produce a set of complex refractive indices (m = n + ik) that are consistent with the retrieved ω 0 values. We consider a family of effective particle radii: 1.2, 1.4, 1.6, and 1.8 μm. The resulting set of model data comparisons, ω 0, and m are presented along with an assessment of potential sources of error and uncertainty. We discuss our results within the context of previous work, including the apparent dichotomy of the literature values: “dark” (solar band ω 0 = 0.89-0.90) and “bright” (solar band ω 0 = 0.92-0.94). Previous work suggests that a mean radius of 1.8 μm is representative for the conditions sampled by the CRISM observations. Using the m for this case and a smaller effective particle radius more appropriate for diffuse dust conditions (1.4 μm), we examine EPF-derived optical depths relative to the MER 880 nm optical depths. Finally, we explore the potential impact of the resulting brighter solar band ω 0 of 0.94 to atmospheric temperatures in the planetary boundary layer.

  16. Oxygen Isotope Variations at the Margin of a CAI Records Circulation Within the Solar Nebula

    NASA Astrophysics Data System (ADS)

    Simon, Justin I.; Hutcheon, Ian D.; Simon, Steven B.; Matzel, Jennifer E. P.; Ramon, Erick C.; Weber, Peter K.; Grossman, Lawrence; DePaolo, Donald J.

    2011-03-01

    Micrometer-scale analyses of a calcium-, aluminum-rich inclusion (CAI) and the characteristic mineral bands mantling the CAI reveal that the outer parts of this primitive object have a large range of oxygen isotope compositions. The variations are systematic; the relative abundance of 16O first decreases toward the CAI margin, approaching a planetary-like isotopic composition, then shifts to extremely 16O-rich compositions through the surrounding rim. The variability implies that CAIs probably formed from several oxygen reservoirs. The observations support early and short-lived fluctuations of the environment in which CAIs formed, either because of transport of the CAIs themselves to distinct regions of the solar nebula or because of varying gas composition near the proto-Sun.

  17. Operational Retrieval of aerosol optical depth over Indian subcontinent and Indian Ocean using INSAT-3D/Imager product validation

    NASA Astrophysics Data System (ADS)

    Mishra, M. K.; Rastogi, G.; Chauhan, P.

    2014-11-01

    Aerosol optical depth (AOD) over Indian subcontinent and Indian Ocean region is derived operationally for the first time from the geostationary earth orbit (GEO) satellite INSAT-3D Imager data at 0.65 μm wavelength. Single visible channel algorithm based on clear sky composites gives larger retrieval error in AOD than other multiple channel algorithms due to errors in estimating surface reflectance and atmospheric property. However, since MIR channel signal is insensitive to the presence of most aerosols, therefore in present study, AOD retrieval algorithm employs both visible (centred at 0.65 μm) and mid-infrared (MIR) band (centred at 3.9 μm) measurements, and allows us to monitor transport of aerosols at higher temporal resolution. Comparisons made between INSAT-3D derived AOD (τI) and MODIS derived AOD (τM) co-located in space (at 1° resolution) and time during January, February and March (JFM) 2014 encompasses 1165, 1052 and 900 pixels, respectively. Good agreement found between τI and τM during JFM 2014 with linear correlation coefficients (R) of 0.87, 0.81 and 0.76, respectively. The extensive validation made during JFM 2014 encompasses 215 co-located AOD in space and time derived by INSAT 3D (τI) and 10 sun-photometers (τA) that includes 9 AERONET (Aerosol Robotic Network) and 1 handheld sun-photometer site. INSAT-3D derived AOD i.e. τI, is found within the retrieval errors of τI = ±0.07 ±0.15τA with linear correlation coefficient (R) of 0.90 and root mean square error equal (RMSE) to 0.06. Present work shows that INSAT-3D aerosol products can be used quantitatively in many applications with caution for possible residual clouds, snow/ice, and water contamination.

  18. Effects of Image Charges on the Scavenging of Aerosol Particles by Cloud Droplets and on Droplet Charging and Possible Ice Nucleation Processes.

    NASA Astrophysics Data System (ADS)

    Tinsley, B. A.; Rohrbaugh, R. P.; Hei, M.; Beard, K. V.

    2000-07-01

    Previous calculations of the rate at which falling droplets in clouds collide with aerosols have led to the conclusion that except in thunderclouds any electrical charges on the aerosols or droplets have little effect on the collision rate. However, it had been assumed that the aerosols would have only a few elementary charges on them, whereas it is now known that at the tops of nonthunderstorm clouds the evaporating droplets may have several hundred elementary charges on them and that much of this charge remains on the residual aerosol for 5 min or so after the evaporation. Also, most previous calculations neglected image charge forces that provide strong attraction at close range even when droplet and aerosol have charges of the same sign and of comparable magnitude.The authors present numerical calculations showing that electrical effects dominate collision rates for charged evaporation aerosols. The calculations are for the size range of 0.1- to 1.0-m radius with the collision efficiency compared to that for phoretic and Brownian effects being greater by up to a factor of 30 greater for droplets from 18.6- to 106-m radius with relative humidity in the range 95%-100% and only 50 elementary charges on the aerosol. The results imply that electrical effects can be important for the scavenging of evaporation aerosol particles in the size range of the Greenfield gap.The authors call this process `electroscavenging.' Electroscavenging of charged particles, when the particles are mostly of the same sign, is a previously unrecognized droplet charging process. Electroscavenging also provides a pathway for contact ice nucleation when charged aerosol particles from evaporated charged droplets collide with supercooled droplets. Ice nucleation can occur because aerosol particles from the evaporation of cloud droplets have been found to be more effective as ice forming nuclei than other aerosol particles that have not been processed through droplets.

  19. Climatology of the aerosol optical depth by components from the Multiangle Imaging SpectroRadiometer (MISR) and a high-resolution chemistry transport model

    NASA Astrophysics Data System (ADS)

    Lee, H.; Kalashnikova, O. V.; Suzuki, K.; Braverman, A.; Garay, M. J.; Kahn, R. A.

    2015-12-01

    The Multi-angle Imaging SpectroRadiometer (MISR) Joint Aerosol (JOINT_AS) Level 3 product provides a global, descriptive summary of MISR Level 2 aerosol optical depth (AOD) and aerosol type information for each month between March 2000 and the present. Using Version 1 of JOINT_AS, which is based on the operational (Version 22) MISR Level 2 aerosol product, this study analyzes, for the first time, characteristics of observed and simulated distributions of AOD for three broad classes of aerosols: non-absorbing, absorbing, and non-spherical - near or downwind of their major source regions. The statistical moments (means, standard deviations, and skewnesses) and distributions of AOD by components derived from the JOINT_AS are compared with results from the SPectral RadIatioN-TrAnSport (SPRINTARS) model, a chemistry transport model (CTM) with very high spatial and temporal resolution. Overall, the AOD distributions of combined MISR aerosol types show good agreement with those from SPRINTARS. Marginal distributions of AOD for each aerosol type in both MISR and SPRINTARS show considerable high positive skewness, which indicates the importance of including extreme AOD events when comparing satellite retrievals with models. The MISR JOINT_AS product will greatly facilitate comparisons between satellite observations and model simulations of aerosols by type.

  20. Climatology of the aerosol optical depth by components from the Multi-angle Imaging SpectroRadiometer (MISR) and chemistry transport models

    NASA Astrophysics Data System (ADS)

    Lee, Huikyo; Kalashnikova, Olga V.; Suzuki, Kentaroh; Braverman, Amy; Garay, Michael J.; Kahn, Ralph A.

    2016-06-01

    The Multi-angle Imaging SpectroRadiometer (MISR) Joint Aerosol (JOINT_AS) Level 3 product has provided a global, descriptive summary of MISR Level 2 aerosol optical depth (AOD) and aerosol type information for each month over 16+ years since March 2000. Using Version 1 of JOINT_AS, which is based on the operational (Version 22) MISR Level 2 aerosol product, this study analyzes, for the first time, characteristics of observed and simulated distributions of AOD for three broad classes of aerosols: spherical nonabsorbing, spherical absorbing, and nonspherical - near or downwind of their major source regions. The statistical moments (means, standard deviations, and skewnesses) and distributions of AOD by components derived from the JOINT_AS are compared with results from two chemistry transport models (CTMs), the Goddard Chemistry Aerosol Radiation and Transport (GOCART) and SPectral RadIatioN-TrAnSport (SPRINTARS). Overall, the AOD distributions retrieved from MISR and modeled by GOCART and SPRINTARS agree with each other in a qualitative sense. Marginal distributions of AOD for each aerosol type in both MISR and models show considerable high positive skewness, which indicates the importance of including extreme AOD events when comparing satellite retrievals with models. The MISR JOINT_AS product will greatly facilitate comparisons between satellite observations and model simulations of aerosols by type.

  1. Coordinated Oxygen Isotopic and Petrologic Studies of CAIS Record Varying Composition of Protosolar

    NASA Technical Reports Server (NTRS)

    Simon, Justin I.; Matzel, J. E. P.; Simon, S. B.; Weber, P. K.; Grossman, L.; Ross, D. K.; Hutcheon, I. D.

    2012-01-01

    Ca-, Al-rich inclusions (CAIs) record the O-isotope composition of Solar nebular gas from which they grew [1]. High spatial resolution O-isotope measurements afforded by ion microprobe analysis across the rims and margin of CAIs reveal systematic variations in (Delta)O-17 and suggest formation from a diversity of nebular environments [2-4]. This heterogeneity has been explained by isotopic mixing between the O-16-rich Solar reservoir [6] and a second O-16-poor reservoir (probably nebular gas) with a "planetary-like" isotopic composition [e.g., 1, 6-7], but the mechanism and location(s) where these events occur within the protoplanetary disk remain uncertain. The orientation of large and systematic variations in (Delta)O-17 reported by [3] for a compact Type A CAI from the Efremovka reduced CV3 chondrite differs dramatically from reports by [4] of a similar CAI, A37 from the Allende oxidized CV3 chondrite. Both studies conclude that CAIs were exposed to distinct, nebular O-isotope reservoirs, implying the transfer of CAIs among different settings within the protoplanetary disk [4]. To test this hypothesis further and the extent of intra-CAI O-isotopic variation, a pristine compact Type A CAI, Ef-1 from Efremovka, and a Type B2 CAI, TS4 from Allende were studied. Our new results are equally intriguing because, collectively, O-isotopic zoning patterns in the CAIs indicate a progressive and cyclic record. The results imply that CAIs were commonly exposed to multiple environments of distinct gas during their formation. Numerical models help constrain conditions and duration of these events.

  2. The Vibrio cholerae quorum-sensing autoinducer CAI-1: analysis of the biosynthetic enzyme CqsA

    SciTech Connect

    Kelly, R.; Bolitho, M; Higgins, D; Lu, W; Ng, W; Jeffrey, P; Rabinowitz, J; Semmelhack, M; Hughson, F; Bassler, B

    2009-01-01

    Vibrio cholerae, the bacterium that causes the disease cholera, controls virulence factor production and biofilm development in response to two extracellular quorum-sensing molecules, called autoinducers. The strongest autoinducer, called CAI-1 (for cholera autoinducer-1), was previously identified as (S)-3-hydroxytridecan-4-one. Biosynthesis of CAI-1 requires the enzyme CqsA. Here, we determine the CqsA reaction mechanism, identify the CqsA substrates as (S)-2-aminobutyrate and decanoyl coenzyme A, and demonstrate that the product of the reaction is 3-aminotridecan-4-one, dubbed amino-CAI-1. CqsA produces amino-CAI-1 by a pyridoxal phosphate-dependent acyl-CoA transferase reaction. Amino-CAI-1 is converted to CAI-1 in a subsequent step via a CqsA-independent mechanism. Consistent with this, we find cells release {ge}100 times more CAI-1 than amino-CAI-1. Nonetheless, V. cholerae responds to amino-CAI-1 as well as CAI-1, whereas other CAI-1 variants do not elicit a quorum-sensing response. Thus, both CAI-1 and amino-CAI-1 have potential as lead molecules in the development of an anticholera treatment.

  3. The Graphics Terminal Display System; a Powerful General-Purpose CAI Package.

    ERIC Educational Resources Information Center

    Hornbeck, Frederick W., Brock, Lynn

    The Graphic Terminal Display System (GTDS) was created to support research and development in computer-assisted instruction (CAI). The system uses an IBM 360/50 computer and interfaces with a large-screen graphics display terminal, a random-access slide projector, and a speech synthesizer. An authoring language, GRAIL, was developed for CAI, and…

  4. Knowledge-Based CAI: CINS for Individualized Curriculum Sequencing. Final Technical Report No. 290.

    ERIC Educational Resources Information Center

    Wescourt, Keith T.; And Others

    This report describes research on the Curriculum Information Network (CIN) paradigm for computer-assisted instruction (CAI) in technical subjects. The CIN concept was first conceived and implemented in the BASIC Instructional Program (BIP). The primary objective of CIN-based CAI and the BIP project has been to develop procedures for providing each…

  5. Less Equals More: Coaching/Prompting CAI as a Tool Technology.

    ERIC Educational Resources Information Center

    Cooper, Ted L.

    Recent reviews of computer-assisted instruction (CAI) in various journals suggest that the technological and economic barriers to its adoption and use may be overcome in the very near future, and that CAI will be feasible in a number of educational settings. Computer hardware costs have dropped dramatically in recent years, and a variety of…

  6. Learner Control of Instructional Sequencing within an Adaptive Tutorial CAI Environment. Technical Report 75-7.

    ERIC Educational Resources Information Center

    Seidel, Robert J.; And Others

    A study to test the effects of learner control of the sequencing of instructional tasks when using computer-assisted instruction (CAI) systems is described. Using a series of CAI modules to teach the COBOL programing language to military personnel, students were able to control various aspects of their learning environment. Among the research…

  7. Curricular and Computer System Compatibility of CAI Programs for Multi-University Use.

    ERIC Educational Resources Information Center

    Hall, Keith A.

    A brief introduction to developmental efforts in computer assisted instruction (CAI) at Pennsylvania State University is followed by a description of a program of mobile CAI facilities inaugurated in 1970 as part of the inservice continuing education program for teachers. The paper includes very brief descriptions of the graduate level courses…

  8. Audio-Tutorial and CAI Aids for Problem Solving in Introductory Chemistry

    ERIC Educational Resources Information Center

    Lower, Stephen K.

    1970-01-01

    Starting from a successful audio-tutorial program, the author initiated a computer assisted tutorial program in solving chemistry problems. Discusses the advantages of computer assisted instruction (CAI) over audiotapes and the advantages of both over conventional instructional methods. Presents a flow chart of a CAI program on a calorimetry…

  9. CAI-BASIC: A Program to Teach the Programming Language BASIC.

    ERIC Educational Resources Information Center

    Barry, Thomas Anthony

    A computer-assisted instruction (CAI) program was designed which fulfills the objectives of teaching a simple programing language, interpreting student responses, and executing and editing student programs. The CAI-BASIC program is written in FORTRAN IV and executes on IBM-2741 terminals while running under a time-sharing system on an IBM-360-70…

  10. Petrological Investigations of CAIs from Efremovka and NWA 3118 CV3 Chondrites

    NASA Astrophysics Data System (ADS)

    Ivanova, M. A.; Lorenz, C. A.; Korochantseva, E. V.; MacPherson, G. J.

    2010-03-01

    Several new big CAIs were extracted from the Efremovka and NWA 3118 CV3 chondrites to analyze petrology, chemistry and isotopic compositions. Here we report preliminary results on mineralogy, petrology and bulk chemistry of two CAIs, of Type B1 and of Type A.

  11. Learning with Computers: Implementation of an Integrated Learning System for Computer Assisted Instruction (CAI).

    ERIC Educational Resources Information Center

    Texas State Dept. of Criminal Justice, Huntsville. Windham School System.

    This publication provides information on implementation of an integrated learning system for computer-assisted instruction (CAI) in adult learning environments. The first of the document's nine chapters is an introduction to computer-delivered instruction that addresses the appropriateness of computers in instruction and types of CAI activities.…

  12. Effects of Computer Assisted Instruction (CAI) on Secondary School Students' Performance in Biology

    ERIC Educational Resources Information Center

    Yusuf, Mudasiru Olalere; Afolabi, Adedeji Olufemi

    2010-01-01

    This study investigated the effects of computer assisted instruction (CAI) on secondary school students' performance in biology. Also, the influence of gender on the performance of students exposed to CAI in individualised or cooperative learning settings package was examined. The research was a quasi experimental involving a 3 x 2 factorial…

  13. An Object-Oriented Architecture for a Web-Based CAI System.

    ERIC Educational Resources Information Center

    Nakabayashi, Kiyoshi; Hoshide, Takahide; Seshimo, Hitoshi; Fukuhara, Yoshimi

    This paper describes the design and implementation of an object-oriented World Wide Web-based CAI (Computer-Assisted Instruction) system. The goal of the design is to provide a flexible CAI/ITS (Intelligent Tutoring System) framework with full extendibility and reusability, as well as to exploit Web-based software technologies such as JAVA, ASP (a…

  14. Distribution of vanadium and melting of opaque assemblages in Efremovka CAI's

    NASA Astrophysics Data System (ADS)

    Casanova, I.; Grossman, L.

    1993-03-01

    A petrographic and chemical study of compact Type A CAI's from the Efremovka CV3 chondrite strongly suggests that the opaque assemblages (OA's) that they contain were molten at temperatures below the CAI silicate solidus, and that the V-rich magnetite presently observed in association with OA's formed by in situ oxidation of their FeNi.

  15. Computer-Aided Technical Training Using Electronic Equipment On-Line with the CAI System.

    ERIC Educational Resources Information Center

    Huggett, Geoffrey; And Others

    This report describes an experimental course in the operation and troubleshooting of a communications transceiver, the AN/URC-32, in which the transceiver is used as part of an instructional station in a CAI system. The transceiver and the CAI system are hard-wired together to form a single training system. The system is presently operating in the…

  16. Distribution of vanadium and melting of opaque assemblages in Efremovka CAI's

    NASA Technical Reports Server (NTRS)

    Casanova, I.; Grossman, L.

    1993-01-01

    A petrographic and chemical study of compact Type A CAI's from the Efremovka CV3 chondrite strongly suggests that the opaque assemblages (OA's) that they contain were molten at temperatures below the CAI silicate solidus, and that the V-rich magnetite presently observed in association with OA's formed by in situ oxidation of their FeNi.

  17. A Study of Effectiveness of Computer Assisted Instruction (CAI) over Classroom Lecture (CRL) at ICS Level

    ERIC Educational Resources Information Center

    Kaousar, Tayyeba; Choudhry, Bushra Naoreen; Gujjar, Aijaz Ahmed

    2008-01-01

    This study was aimed to evaluate the effectiveness of CAI vs. classroom lecture for computer science at ICS level. The objectives were to compare the learning effects of two groups with classroom lecture and computer-assisted instruction studying the same curriculum and the effects of CAI and CRL in terms of cognitive development. Hypotheses of…

  18. CAI in New York City: Report on the First Year's Operations

    ERIC Educational Resources Information Center

    Butler, Cornelius F.

    1969-01-01

    "The nation's largest CAI operation in a public school system concluded its first full year of operation in June, 1969. The results indicate a very definite success for education's most closely watched use of technology. Three major criteria for success of such a project are 1) acceptance of CAI by the schools and their pupils, 2) per pupil costs…

  19. A Multi-Media CAI Terminal Based upon a Microprocessor with Applications for the Handicapped.

    ERIC Educational Resources Information Center

    Brebner, Ann; Hallworth, H. J.

    The design of the CAI interface described is based on the microprocessor in order to meet three basic requirements for providing appropriate instruction to the developmentally handicapped: (1) portability, so that CAI can be taken into the customary learning environment; (2) reliability; and (3) flexibility, to permit use of new input and output…

  20. Nebular History of the Allende FoB CAI SJ101

    NASA Astrophysics Data System (ADS)

    Petaev, M. I.; Jacobsen, S. B.

    2009-03-01

    We compare petrologic and chemical characteristics of a unique FoB CAI SJ101 with the results of thermodynamic modeling of condensation of its precursors in a system of solar composition and speculate about nebular formation history of this CAI.

  1. INAA of CAIs from the Maralinga CK4 chondrite: Effects of parent body thermal metamorphism

    NASA Technical Reports Server (NTRS)

    Lindstrom, D. J.; Keller, L. P.; Martinez, R. R.

    1993-01-01

    Maralinga is an anomalous CK4 carbonaceous chondrite which contains numerous Ca-, Al-rich inclusions (CAI's) unlike the other members of the CK group. These CAI's are characterized by abundant green hercynitic spinel intergrown with plagioclase and high-Ca clinopyroxene, and a total lack of melilite. Instrumental Neutron Activation Analysis (INAA) was used to further characterize the meteorite, with special focus on the CAI's. High sensitivity INAA was done on eight sample disks about 100-150 microns in diameter obtained from a normal 30 micron thin section with a diamond microcoring device. The CAI's are enriched by 60-70X bulk meteorite values in Zn, suggesting that the substantial exchange of Fe for Mg that made the spinel in the CAI's hercynitic also allowed efficient scavenging of Zn from the rest of the meteorite during parent body thermal metamorphism. Less mobile elements appear to have maintained their initial heterogeneity.

  2. Compound CAIs Containing Zr-Y-Sc-Rich Inclusions from NWA 3118 and Efremovka CV3 Chondrites

    NASA Astrophysics Data System (ADS)

    Ivanova, M. A.; Krot, A. N.; Nagashima, K.; Lorenz, C. A.; Logan, M. A. V.; Kononkova, N. N.; MacPherson, G. J.

    2011-03-01

    CAIs enriched in Zr, Sc and Y provide important records of the refractory element fractionation in the early solar nebula. We discribed mineralogy, petrology and oxygen isotopes of two Zr-rich CAIs from NWA 3118 and from Efremovka.

  3. Observations and Modeling of 3-Dimensional Cloud and Aerosol Fields from the Multiangle SpectroPolarimetric Imager (MSPI)

    NASA Astrophysics Data System (ADS)

    Garay, M. J.; Diner, D. J.; Martonchik, J. V.; Davis, A. B.

    2011-12-01

    Knowledge of the detailed 3-dimensional structure of clouds and atmospheric aerosols is vital for correctly modeling their radiative effects and interpreting optical remote sensing measurements of scattered sunlight. We will describe a set of new observations made by the Multiangle SpectroPolarimetric Imager (MSPI) from the ground and from the NASA ER-2 aircraft. MSPI is being developed and tested at JPL as a payload for the preliminary Aerosol-Cloud-Ecosystems (PACE) satellite mission, which is expected to fly near the end of the decade. MSPI builds upon experience gained from the Multi-angle Imaging SpectroRadiometer (MISR) currently orbiting on NASA's Terra satellite. Ground-MSPI and Air-MSPI are two prototype cameras operating in the ultraviolet (UV) to the visible/near-infrared (VNIR) range mounted on gimbals that acquire imagery in a pushbroom fashion, including polarization in selected spectral bands with demonstrated high polarimetric accuracy (0.5% uncertainty in degree of linear polarization). The spatial resolution of Ground-MSPI is 1 m for objects at a distance of 3 km. From the operational altitude of the ER-2, Air-MSPI has a ground resolution of approximately 10 m at nadir. This resolution, coupled with good calibration and high polarimetric performance means that MSPI can be used to derive radiatively important parameters of aerosols and clouds using intensity and polarization information together. As part of the effort for developing retrieval algorithms for the instrument, we have employed an extremely flexible 3-dimensional vector radiative transfer code. We will show example imagery from both MSPI cameras and describe how these scenes are modeled using this code. We will also discuss some of the important unknowns and limitations of this observational approach.

  4. Mapping aerosol intrusion in Himalayan valleys using the Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)

    NASA Astrophysics Data System (ADS)

    Brun, Julien; Shrestha, Prabhakar; Barros, Ana P.

    2011-11-01

    Mapping the spatial and temporal distribution of aerosols along mountain ranges is an important step toward elucidating orographic aerosol-cloud-rainfall interactions. This requires high spatial resolution aerosol observations over complex topography, which are not currently available either from ground-based observing systems or from remote-sensing products. Here, a novel approach is presented that relies on visible channels from MODIS Rapid Response data at 250 m spatial resolution to extract the daytime aerosol run-up (intrusion length and height) from the Indo-Gangetic Plains to the High Himalaya. Intrusion length and height are determined from the intersection of topography with the MODIS-derived aerosol plume using an adaptive object-classification algorithm. The methodology is demonstrated for a case study of the Arun River in eastern Nepal. Results of run-up extraction are examined along with the Total Attenuated Backscatter (Level 1B at 532 nm) from CALIPSO to investigate the regional variability of aerosol. During the pre-monsoon season, CALIPSO nighttime profiles show the presence of a slanted dust layer following the envelope topography. This is consistent with upper level transport of aerosol by north-westerly winds associated with high-frequency dust storms. In the winter, the signal is weaker, and the nighttime elevated aerosol layer is flat and remains below the envelope orography consistent with blocking conditions. For both seasons, the daytime aerosol layer detected from MODIS observations is always below the ridges. This suggests that in addition to seasonal variability governed by synoptic conditions, there is a distinct diurnal cycle in the North-South transport of aerosol between the Himalayas and the IGP.

  5. Nanoscale Images of Airborne PM2.5: Aerosol Dynamics with the LCLS X-ray Laser

    NASA Astrophysics Data System (ADS)

    Bogan, M. J.

    2012-12-01

    It is now possible to capture images of individual airborne PM2.5 particles - including soot, NaCl particles and engineered nanoparticles - with 20-40 nm resolution (Loh et al Nature 2012). Ions released during the imaging process provide information on the chemical content of the isolated particles. The scattering signal used to compose the image also provides the fractal dimension of individual particles. This new paradigm of aerosol dynamics is enabled by the incredible brightness and ultrashort pulses available at X-ray free electron laser (FEL) facilities, such as the Linac Coherent Light Source (LCLS) and the FLASH FEL facility in Hamburg. Femtosecond long x-ray pulses deliver sufficient photons (10^12 per pulse) to detect scattered X-rays off individual particles injected at >100 m/s into vacuum through an aerodynamic lens stack. The intensity of the scattered X-rays measured by an area detector is fed into lensless imaging algorithms to reconstruct an image of the particle that caused the scattering. X-ray FELs can peer inside the individual airborne particles and are a sensitive probe of particle crystallinity. The development of this method and applications to imaging micron-sized soot, water droplets and biological aerosols will be discussed. A primary long-term goal of the research is to take snapshots of airborne particles as they change their size, shape and chemical make-up in response to their environment. "Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight" ND Loh, C Hampton, A Martin, D Starodub, R Sierra, A Barty, A Aquila, J Schulz, L Lomb, J Steinbrener, R Shoeman, S Kassemeyer, C Bostedt, J. Bozek, S Epp, B. Erk, R Hartmann, D Rolles, A Rudenko, B Rudek, L Foucar, N Kimmel, G Weidenspointner, G Hauser, P Holl, E. Pedersoli, M Liang, M Hunter, L Gumprecht, N Coppola, C Wunderer, H Graafsma, F Maia, T Ekeberg, M Hantke, H Fleckenstein, H. Hirsemann, K Nass, T White, H Tobias, G Farquar, W Benner, S Hau

  6. Simple convergent-nozzle aerosol injector for single-particle diffractive imaging with X-ray free-electron lasers.

    PubMed

    Kirian, R A; Awel, S; Eckerskorn, N; Fleckenstein, H; Wiedorn, M; Adriano, L; Bajt, S; Barthelmess, M; Bean, R; Beyerlein, K R; Chavas, L M G; Domaracky, M; Heymann, M; Horke, D A; Knoska, J; Metz, M; Morgan, A; Oberthuer, D; Roth, N; Sato, T; Xavier, P L; Yefanov, O; Rode, A V; Küpper, J; Chapman, H N

    2015-07-01

    A major challenge in high-resolution x-ray free-electron laser-based coherent diffractive imaging is the development of aerosol injectors that can efficiently deliver particles to the peak intensity of the focused X-ray beam. Here, we consider the use of a simple convergent-orifice nozzle for producing tightly focused beams of particles. Through optical imaging we show that 0.5 μm particles can be focused to a full-width at half maximum diameter of 4.2 μm, and we demonstrate the use of such a nozzle for injecting viruses into a micro-focused soft-X-ray FEL beam. PMID:26798816

  7. Simple convergent-nozzle aerosol injector for single-particle diffractive imaging with X-ray free-electron lasers

    PubMed Central

    Kirian, R. A.; Awel, S.; Eckerskorn, N.; Fleckenstein, H.; Wiedorn, M.; Adriano, L.; Bajt, S.; Barthelmess, M.; Bean, R.; Beyerlein, K. R.; Chavas, L. M. G.; Domaracky, M.; Heymann, M.; Horke, D. A.; Knoska, J.; Metz, M.; Morgan, A.; Oberthuer, D.; Roth, N.; Sato, T.; Xavier, P. L.; Yefanov, O.; Rode, A. V.; Küpper, J.; Chapman, H. N.

    2015-01-01

    A major challenge in high-resolution x-ray free-electron laser-based coherent diffractive imaging is the development of aerosol injectors that can efficiently deliver particles to the peak intensity of the focused X-ray beam. Here, we consider the use of a simple convergent-orifice nozzle for producing tightly focused beams of particles. Through optical imaging we show that 0.5 μm particles can be focused to a full-width at half maximum diameter of 4.2 μm, and we demonstrate the use of such a nozzle for injecting viruses into a micro-focused soft-X-ray FEL beam. PMID:26798816

  8. Two Generations of Sodic Metasomatism in an Allende Type B CAI

    NASA Technical Reports Server (NTRS)

    Ross, D. K.; Simon, J. I.; Simon, S. B.; Grossman, L.

    2015-01-01

    Calcium-Aluminum rich inclusions (CAI) in Allende, along with other chondritic compo-nents, experienced variable amounts and types of alter-ation of their mineralogy and chemistry. In CAIs, one of the principal types of alteration led to the depo-sition of nepheline and sodalite. Here we extend initial obervations of alteration in an Allende CAI, focus-ing on occurences of nepheline and a nepheline-like phase with unusally high Ca (referred to as "calcic nepheline" in this abstract). Detailed petrographic and microchemical observations of alteration phases in an Allende Type B CAI (TS4) show that two separate generations of "nepheline", with very distinct composi-tions, crystallized around the margins and in the interi-or of this CAI. We use observations of micro-faults as potential temporal markers, in order to place constraints on the timing of alteration events in Allende. These observa-tions of micro-faulting that truncate and offset one gen-eration of "nepheline" indicate that some "nepheline" crystallized before incorporation of the CAI into the Allende parent-body. Some of the sodic metasomatism in some Allende CAIs occurred prior to Allende par-ent-body assembly. The earlier generation of "calcic-nepheline" has a very distinctive, calcium-rich compo-sition, and the second generation is low in calcium, and matches the compositions of nephelines found in near-by altered chondrules, and in the Allende matrix.

  9. Transmission of 10 micron radiation over coastal waters: comparison of point-source image intensities with aerosol extinction and MODTRAN calculations

    NASA Astrophysics Data System (ADS)

    Schwering, Piet B.; de Leeuw, Gerrit; van Eijk, Alexander M.

    1996-10-01

    During the MAPTIP experiments in the Dutch coastal waters, 11 October - 5 November 1993, transmission curves were determined from the intensities of the image of a point source suspended from a helicopter at ranges between 0.5 and 6 NMi. The images were recorded with a 10 micrometer USFA 9092 camera from the MeetPost Noordwijk, a research tower in the North Sea at 9 km from the Dutch coast. The transmission determined from the point source intensities at several ranges is compared with calculated values. The transmission is determined by extinction due to aerosols and molecular species in the propagation path. Both contributions can be determined using code using measured size distributions. Also effects of path radiance and background on the image intensity are considered. In this coastal area, and the off- shore winds that were usually encountered during MAPTIP, the aerosol size distributions are known to be a complicated mixture of continental and marine aerosols. Hence the common aerosol models, that usually work well over the open ocean, are often not so reliable in a coastal environment. An attempt is made to assess the influence of marine and anthropogenic contributions to the aerosol on the detection range of point targets in a coastal atmosphere.

  10. Column-integrated aerosol optical properties from ground-based spectroradiometer measurements at Barrax (Spain) during the Digital Airborne Imaging Spectrometer Experiment (DAISEX) campaigns

    NASA Astrophysics Data System (ADS)

    Pedrós, Roberto; Martinez-Lozano, Jose A.; Utrillas, Maria P.; Gómez-Amo, José L.; Tena, Fernando

    2003-09-01

    The Digital Airborne Imaging Spectrometer Experiment (DAISEX) was carried out for the European Space Agency (ESA) in order to develop the potential of spaceborne imaging spectroscopy for a range of different scientific applications. DAISEX involved simultaneous data acquisitions using different airborne imaging spectrometers over test sites in southeast Spain (Barrax) and the Upper Rhine valley (Colmar, France, and Hartheim, Germany). This paper presents the results corresponding to the column-integrated aerosol optical properties from ground-based spectroradiometer measurements over the Barrax area during the DAISEX campaign days in the years 1998, 1999, and 2000. The instruments used for spectral irradiance measurements were two Licor 1800 and one Optronic OL-754 spectroradiometers. The analysis of the spectral aerosol optical depth in the visible range shows in all cases the predominance of the coarse-particle mode over the fine-particle mode. The analysis of the back trajectories of the air masses indicates a predominance of marine-type aerosols in the lower atmospheric layers in all cases. Overall, the results obtained show that during the DAISEX there was a combination of maritime aerosols with smaller continental aerosols.

  11. Effects of Computer-assisted Instruction (CAI) on 11th Graders' Attitudes to Biology and CAI and Understanding of Reproduction in Plants and Animals

    NASA Astrophysics Data System (ADS)

    Soyibo, Kola; Hudson, Ann

    2000-02-01

    This study investigated whether the use of the combination of the lecture, discussion and computer-assisted instruction (CAI) significantly improved the experimental students' attitudes to biology and the computer/CAI and their understanding of reproduction in plants and animals. The sample comprised 77 Jamaican grade 11 female students from two traditional high schools in Kingston. Attitudes to a biology questionnaire, attitudes to the computer/CAI questionnaire and a biology achievement test (BAT) were used for data collection. The results indicated that the experimental subjects' post-test attitudes to biology and the computer/CAI were significantly better than those of the control group subjects taught with the lecture and discussion methods; the experimental subjects significantly outscored the control group subjects on the post-test BAT; there were significant differences in their post-test BAT means based on their attitudes to biology in favour of experimental subjects with highly favourable attitudes to biology, but there were no significant differences in their means attributable to their post-test attitudes to the computer/CAI; there was a positive statistically significant but weak relationship between the experimental subjects' post-test attitudes to biology and their post-test BAT scores.

  12. Determination of the single scattering albedo and direct radiative forcing of biomass burning aerosol with data from the MODIS (Moderate Resolution Imaging Spectroradiometer) satellite instrument

    NASA Astrophysics Data System (ADS)

    Zhu, Li

    Biomass burning aerosols absorb and scatter solar radiation and therefore affect the energy balance of the Earth-atmosphere system. The single scattering albedo (SSA), the ratio of the scattering coefficient to the extinction coefficient, is an important parameter to describe the optical properties of aerosols and to determine the effect of aerosols on the energy balance of the planet and climate. Aerosol effects on radiation also depend strongly on surface albedo. Large uncertainties remain in current estimates of radiative impacts of biomass burning aerosols, due largely to the lack of reliable measurements of aerosol and surface properties. In this work we investigate how satellite measurements can be used to estimate the direct radiative forcing of biomass burning aerosols. We developed a method using the critical reflectance technique to retrieve SSA from the Moderate Resolution Imaging Spectroradiometer (MODIS) observed reflectance at the top of the atmosphere (TOA). We evaluated MODIS retrieved SSAs with AErosol RObotic NETwork (AERONET) retrievals and found good agreements within the published uncertainty of the AERONET retrievals. We then developed an algorithm, the MODIS Enhanced Vegetation Albedo (MEVA), to improve the representations of spectral variations of vegetation surface albedo based on MODIS observations at the discrete 0.67, 0.86, 0.47, 0.55, 1.24, 1.64, and 2.12 mu-m channels. This algorithm is validated using laboratory measurements of the different vegetation types from the Amazon region, data from the Johns Hopkins University (JHU) spectral library, and data from the U.S. Geological Survey (USGS) digital spectral library. We show that the MEVA method can improve the accuracy of flux and aerosol forcing calculations at the TOA compared to more traditional interpolated approaches. Lastly, we combine the MODIS retrieved biomass burning aerosol SSA and the surface albedo spectrum determined from the MEVA technique to calculate TOA flux and

  13. Remote sensing of cloud, aerosol, and water vapor properties from the moderate resolution imaging spectrometer (MODIS)

    NASA Technical Reports Server (NTRS)

    King, Michael D.; Kaufman, Yoram J.; Menzel, W. Paul; Tanre, Didier D.

    1992-01-01

    The authors describe the status of MODIS-N and its companion instrument MODIS-T (tilt), a tiltable cross-track scanning spectrometer with 32 uniformly spaced channels between 0.410 and 0.875 micron. They review the various methods being developed for the remote sensing of atmospheric properties using MODIS, placing primary emphasis on the principal atmospheric applications of determining the optical, microphysical, and physical properties of clouds and aerosol particles from spectral reflection and thermal emission measurements. In addition to cloud and aerosol properties, MODIS-N will be used for determining the total precipitable water vapor and atmospheric stability. The physical principles behind the determination of each of these atmospheric products are described, together with an example of their application to aircraft and/or satellite measurements.

  14. Microstructural Investigation of a Wark-Lovering Rim on a Vigarano CAI

    NASA Technical Reports Server (NTRS)

    Han, J.; Keller, L. P.; Needham, A. W.; Messenger, S.; Simon, J. I.

    2015-01-01

    Wark-Lovering (WL) rims are thin multi-layered mineral sequences that surround many CAIs. These rim layers consist of the primary minerals found in the CAI interiors, but vary in their mineralogy. Several models for their origin have been proposed including condensation, reaction with a nebular gas, evaporation, or combinations of these. However, there still is little consensus on how and when the rims formed. Here, we describe the microstructure and mineralogy of a WL rim on a type B CAI from the Vigarano CV(sub red) chondrite using FIB/TEM to better understand the astrophysical significance of WL rim formation.

  15. Passive multiangle imaging of clouds, aerosols, and atmospheric dynamics: Broadening our vision from MISR to WindCam and MSPI

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Wu, D. L.; Chipman, R.; Davis, A.; Misr Science Team

    2010-12-01

    The Multi-angle Imaging SpectroRadiometer (MISR) has been collecting global Earth data from NASA’s Terra satellite since February 2000. With its nine along-track view angles, four visible/near-infrared spectral bands, intrinsic spatial resolution of 275 m, and stable calibration, no instrument that combines MISR’s attributes has previously flown in space, nor is there is a similar capability currently available on any other satellite platform. The MISR data record provides unprecedented opportunities for characterizing long-term variability in aerosol and cloud structure and atmospheric dynamics, including measurements of the vertical distributions of clouds; aerosol (smoke, volcanic, and dust) plume heights and global optical depths and particle properties; and pole-to-pole height-resolved winds. To extend what has been learned during the first decade of MISR observations, we are developing the WindCam and Multiangle SpectroPolarimetric Imager (MSPI) instruments. WindCam will enable MISR-like stereo observations over a broader swath using a much more compact sensor design. MSPI expands MISR capabilities through broader spectral coverage (ultraviolet to shortwave infrared), wider swath (enabling more rapid global coverage), and incorporation of high-accuracy polarimetric imaging, which will provide greater sensitivity to particle microphysics. A ground-based prototype camera (GroundMSPI) with spectral coverage from 355-935 nm has been built and an airborne version (AirMSPI) is ready for flight on NASA’s ER-2 high-altitude aircraft. Algorithm developments and improvements enabled by increases in computational speed since Terra launch are being explored with MISR data, and will be needed to handle the rich information content of these MISR successor instruments.

  16. Desert Dust Aerosol Air Mass Mapping in the Western Sahara, Using Particle Properties Derived from Space-Based Multi-Angle Imaging

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Esselborn, Michael; Fiebig, Marcus; Heese, Birgit; Knippertz, Peter; Mueller, Detlef; Schladitz, Alexander; Von Hoyningen-Huene, Wolfgang

    2008-01-01

    Coincident observations made over the Moroccan desert during the Sahara mineral dust experiment (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from multi-angle imaging spectroradiometer (MISR) observations, and to place the suborbital aerosol measurements into the satellite s larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05 0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR s ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape and single-scattering albedo. For the three study days, the satellite observations (1) highlight regional gradients in the mix of dust and background spherical particles, (2) identify a dust plume most likely part of a density flow and (3) show an aerosol air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometres away.

  17. CFD modeling and image analysis of exhaled aerosols due to a growing bronchial tumor: Towards non-invasive diagnosis and treatment of respiratory obstructive diseases

    SciTech Connect

    Xi, Jinxiang; Kim, JongWon; Si, Xiuhua A.; Corley, Richard A.; Kabilan, Senthil; Wang, Shengyu

    2015-01-01

    Diagnosis and prognosis of tumorigenesis are generally performed with CT, PET, or biopsy. Such methods are accurate, but have the limitations of high cost and posing additional health risks to patients. In this study, we introduce an alternative computer aided diagnostic tool that can locate malignant sites caused by tumorigenesis in a non-invasive and low-cost way. Our hypothesis is that exhaled aerosol distribution is unique to lung structure and is sensitive to airway structure variations. With appropriate approaches, it is possible to locate the disease site, determine the disease severity, and subsequently formulate a targeted drug delivery plan to treat the disease. This study numerically evaluated the feasibility of the proposed breath test in an image-based lung model with varying pathological stages of a bronchial squamous tumor. Large eddy simulations and a Lagrangian tracking approach were used to model respiratory airflows and aerosol dynamics. Respirations of tracer aerosols of 1 μm at a flow rate of 20 L/min were simulated, with the distributions of exhaled aerosols recorded on a filter at the mouth exit. Aerosol patterns were quantified with multiple analytical techniques such as concentration disparity, spatial scanning and fractal analysis. We demonstrated that a growing bronchial tumor induced notable variations in both the airflow and exhaled aerosol distribution. These variations became more apparent with increasing tumor severity. The exhaled aerosols exhibited distinctive pattern parameters such as spatial probability, fractal dimension, and multifractal spectrum. Results of this study show that morphometric measures of the exhaled aerosol pattern can be used to detect and monitor the pathological states of respiratory diseases in the upper airway. The proposed breath test also has the potential to locate the site of the disease, which is critical in developing a personalized, site-specific drug delivery protocol.

  18. CFD modeling and image analysis of exhaled aerosols due to a growing bronchial tumor: Towards non-invasive diagnosis and treatment of respiratory obstructive diseases

    DOE PAGESBeta

    Xi, Jinxiang; Kim, JongWon; Si, Xiuhua A.; Corley, Richard A.; Kabilan, Senthil; Wang, Shengyu

    2015-01-01

    Diagnosis and prognosis of tumorigenesis are generally performed with CT, PET, or biopsy. Such methods are accurate, but have the limitations of high cost and posing additional health risks to patients. In this study, we introduce an alternative computer aided diagnostic tool that can locate malignant sites caused by tumorigenesis in a non-invasive and low-cost way. Our hypothesis is that exhaled aerosol distribution is unique to lung structure and is sensitive to airway structure variations. With appropriate approaches, it is possible to locate the disease site, determine the disease severity, and subsequently formulate a targeted drug delivery plan to treatmore » the disease. This study numerically evaluated the feasibility of the proposed breath test in an image-based lung model with varying pathological stages of a bronchial squamous tumor. Large eddy simulations and a Lagrangian tracking approach were used to model respiratory airflows and aerosol dynamics. Respirations of tracer aerosols of 1 μm at a flow rate of 20 L/min were simulated, with the distributions of exhaled aerosols recorded on a filter at the mouth exit. Aerosol patterns were quantified with multiple analytical techniques such as concentration disparity, spatial scanning and fractal analysis. We demonstrated that a growing bronchial tumor induced notable variations in both the airflow and exhaled aerosol distribution. These variations became more apparent with increasing tumor severity. The exhaled aerosols exhibited distinctive pattern parameters such as spatial probability, fractal dimension, and multifractal spectrum. Results of this study show that morphometric measures of the exhaled aerosol pattern can be used to detect and monitor the pathological states of respiratory diseases in the upper airway. The proposed breath test also has the potential to locate the site of the disease, which is critical in developing a personalized, site-specific drug delivery protocol.« less

  19. CFD Modeling and Image Analysis of Exhaled Aerosols due to a Growing Bronchial Tumor: towards Non-Invasive Diagnosis and Treatment of Respiratory Obstructive Diseases

    SciTech Connect

    Xi, Jinxiang; Kim, JongWon; Si, Xiuhua A.; Corley, Richard A.; Kabilan, Senthil; Wang, Shengyu

    2015-02-06

    Diagnosis and prognosis of tumorigenesis are generally performed with CT, PET, or biopsy. Such methods are accurate, but have the limitations of high cost and posing additional health risks to patients. In this study, we introduce an alternative computer aided diagnostic tool that can locate malignant sites caused by tumorigenesis in a non-invasive and low-cost way. Our hypothesis is that exhaled aerosol distribution is unique to lung structure and is sensitive to airway structure vari-ations. With appropriate approaches, it is possible to locate the disease site, determine the disease severity, and subsequently formulate a targeted drug delivery plan to treat the disease. This study numerically evaluated the feasibility of the proposed breath test in an image-based lung model with varying pathological stages of a bronchial squamous tumor. Large eddy simulations and a Lagran-gian tracking approach were used to model respiratory airflows and aerosol dynamics. Respira-tions of tracer aerosols of 1 µm at a flow rate of 20 L/min were simulated, with the distributions of exhaled aerosols recorded on a filter at the mouth exit. Aerosol patterns were quantified with multiple analytical techniques such as concentration disparity, spatial scanning and fractal analysis. We demonstrated that a growing bronchial tumor induced notable variations in both the airflow and exhaled aerosol distribution. These variations became more apparent with increasing tumor severity. The exhaled aerosols exhibited distinctive pattern parameters such as spatial probability, fractal dimension, and multifractal spectrum. Results of this study show that morphometric measures of the exhaled aerosol pattern can be used to detect and monitor the pathological states of respiratory diseases in the upper airway. The proposed breath test also has the potential to locate the site of the disease, which is critical in developing a personalized, site-specific drug de-livery protocol.

  20. CFD Modeling and Image Analysis of Exhaled Aerosols due to a Growing Bronchial Tumor: towards Non-Invasive Diagnosis and Treatment of Respiratory Obstructive Diseases

    PubMed Central

    Xi, Jinxiang; Kim, JongWon; Si, Xiuhua A.; Corley, Richard A.; Kabilan, Senthil; Wang, Shengyu

    2015-01-01

    Diagnosis and prognosis of tumorigenesis are generally performed with CT, PET, or biopsy. Such methods are accurate, but have the limitations of high cost and posing additional health risks to patients. In this study, we introduce an alternative computer aided diagnostic tool that can locate malignant sites caused by tumorigenesis in a non-invasive and low-cost way. Our hypothesis is that exhaled aerosol distribution is unique to lung structure and is sensitive to airway structure variations. With appropriate approaches, it is possible to locate the disease site, determine the disease severity, and subsequently formulate a targeted drug delivery plan to treat the disease. This study numerically evaluated the feasibility of the proposed breath test in an image-based lung model with varying pathological stages of a bronchial squamous tumor. Large eddy simulations and a Lagrangian tracking approach were used to model respiratory airflows and aerosol dynamics. Respirations of tracer aerosols of 1 µm at a flow rate of 20 L/min were simulated, with the distributions of exhaled aerosols recorded on a filter at the mouth exit. Aerosol patterns were quantified with multiple analytical techniques such as concentration disparity, spatial scanning and fractal analysis. We demonstrated that a growing bronchial tumor induced notable variations in both the airflow and exhaled aerosol distribution. These variations became more apparent with increasing tumor severity. The exhaled aerosols exhibited distinctive pattern parameters such as spatial probability, fractal dimension, and multifractal spectrum. Results of this study show that morphometric measures of the exhaled aerosol pattern can be used to detect and monitor the pathological states of respiratory diseases in the upper airway. The proposed breath test also has the potential to locate the site of the disease, which is critical in developing a personalized, site-specific drug delivery protocol. PMID:25767612

  1. CFD modeling and image analysis of exhaled aerosols due to a growing bronchial tumor: towards non-invasive diagnosis and treatment of respiratory obstructive diseases.

    PubMed

    Xi, Jinxiang; Kim, JongWon; Si, Xiuhua A; Corley, Richard A; Kabilan, Senthil; Wang, Shengyu

    2015-01-01

    Diagnosis and prognosis of tumorigenesis are generally performed with CT, PET, or biopsy. Such methods are accurate, but have the limitations of high cost and posing additional health risks to patients. In this study, we introduce an alternative computer aided diagnostic tool that can locate malignant sites caused by tumorigenesis in a non-invasive and low-cost way. Our hypothesis is that exhaled aerosol distribution is unique to lung structure and is sensitive to airway structure variations. With appropriate approaches, it is possible to locate the disease site, determine the disease severity, and subsequently formulate a targeted drug delivery plan to treat the disease. This study numerically evaluated the feasibility of the proposed breath test in an image-based lung model with varying pathological stages of a bronchial squamous tumor. Large eddy simulations and a Lagrangian tracking approach were used to model respiratory airflows and aerosol dynamics. Respirations of tracer aerosols of 1 µm at a flow rate of 20 L/min were simulated, with the distributions of exhaled aerosols recorded on a filter at the mouth exit. Aerosol patterns were quantified with multiple analytical techniques such as concentration disparity, spatial scanning and fractal analysis. We demonstrated that a growing bronchial tumor induced notable variations in both the airflow and exhaled aerosol distribution. These variations became more apparent with increasing tumor severity. The exhaled aerosols exhibited distinctive pattern parameters such as spatial probability, fractal dimension, and multifractal spectrum. Results of this study show that morphometric measures of the exhaled aerosol pattern can be used to detect and monitor the pathological states of respiratory diseases in the upper airway. The proposed breath test also has the potential to locate the site of the disease, which is critical in developing a personalized, site-specific drug delivery protocol. PMID:25767612

  2. First retrieval of data regarding spatial distribution of Asian dust aerosol from the Geostationary Ocean Color Imager

    NASA Astrophysics Data System (ADS)

    Lee, Kwon Ho; Ryu, Joo Hyung; Ahn, Jae Hyun; Kim, Young Joon

    2012-12-01

    Aerosol optical thickness (AOT) was retrieved from the Geostationary Ocean Color Imager (GOCI) on board the Communication, Ocean, and Meteorological Satellite (COMS) for the first time. AOT values were retrieved over the ocean at a spatial scale of 0.5 × 0.5 km2 by using the look-up table (LUT)-based separation technique. The radiative transfer model (RTM) was used for different models of atmosphere-ocean environmental conditions, taking into account the realistic variability of scattering and absorption. Ocean surface properties affected by whitecaps and pigment content were also taken into account. The results show that the radiance observed by the GOCI amounts to only 5% of the radiation that penetrated the ocean and, consequently, 95% of the radiation is scattered in the atmosphere or reflected at the ocean surface in the visible wavelengths longer than 0.6 ìm. Within these wavelengths, radiance variations at the top of atmosphere (TOA) due to pigment variations are within 10%, while the radiance variation due to wind speed is considerably higher. For verification of GOCI-retrieved AOTs, comparison between GOCI and ground-based sunphotometer measurement at Gosan, Korea (126.10°E, 33.23°N)) showed good correlation (r = 0.99). The GOCI observations obtained by using the proposed technique showed promising results for the daily monitoring of atmospheric aerosol loading as well as being useful for environmental supervisory authorities.

  3. MAPPING ANNUAL MEAN GROUND-LEVEL PM2.5 CONCENTRATIONS USING MULTIANGLE IMAGING SPECTRORADIOMETER AEROSOL OPTICAL THICKNESS OVER THE CONTIGUOUS UNITED STATES

    EPA Science Inventory

    We present a simple approach to estimating ground-level fine particle (PM2.5, particles smaller than 2.5 um in diameter) concentration using global atmospheric chemistry models and aerosol optical thickness (AOT) measurements from the Multi- angle Imaging SpectroRadiometer (MISR)...

  4. Further Investigations of Minor Element Distributions in Spinels in Type B CAIs

    NASA Astrophysics Data System (ADS)

    Taylor, D. J.; McKeegan, K. D.

    2004-03-01

    We have measured minor element concentrations in spinels from type B CAIs in Efremovka and Allende. We find a correlation of V and Ti that supports previous interpretations of additional remelting and crystallization events for these objects.

  5. Chemical imaging of ambient aerosol particles: Observational constraints on mixing state parameterization

    NASA Astrophysics Data System (ADS)

    O'Brien, Rachel E.; Wang, Bingbing; Laskin, Alexander; Riemer, Nicole; West, Matthew; Zhang, Qi; Sun, Yele; Yu, Xiao-Ying; Alpert, Peter; Knopf, Daniel A.; Gilles, Mary K.; Moffet, Ryan C.

    2015-09-01

    A new parameterization for quantifying the mixing state of aerosol populations has been applied for the first time to samples of ambient particles analyzed using spectro-microscopy techniques. Scanning transmission X-ray microscopy/near edge X-ray absorption fine structure (STXM/NEXAFS) and computer-controlled scanning electron microscopy/energy dispersive X-ray spectroscopy (CCSEM/EDX) were used to probe the composition of the organic and inorganic fraction of individual particles collected on 27 and 28 June during the 2010 Carbonaceous Aerosols and Radiative Effects study in the Central Valley, California. The first field site, T0, was located in downtown Sacramento, while T1 was located near the Sierra Nevada Mountains. Mass estimates of the aerosol particle components were used to calculate mixing state metrics, such as the particle-specific diversity, bulk population diversity, and mixing state index, for each sample. The STXM data showed evidence of changes in the mixing state associated with a buildup of organic matter confirmed by collocated measurements, and the largest impact on the mixing state was due to an increase in soot dominant particles during this buildup. The mixing state from STXM was similar between T0 and T1, indicating that the increased organic fraction at T1 had a small effect on the mixing state of the population. The CCSEM/EDX analysis showed the presence of two types of particle populations: the first was dominated by aged sea-salt particles and had a higher mixing state index (indicating a more homogeneous population); the second was dominated by carbonaceous particles and had a lower mixing state index.

  6. Aerosol optical properties derived from the DRAGON-NE Asia campaign, and implications for a single-channel algorithm to retrieve aerosol optical depth in spring from Meteorological Imager (MI) on-board the Communication, Ocean, and Meteorological Satellite (COMS)

    NASA Astrophysics Data System (ADS)

    Kim, M.; Kim, J.; Jeong, U.; Kim, W.; Hong, H.; Holben, B.; Eck, T. F.; Lim, J. H.; Song, C. K.; Lee, S.; Chung, C.-Y.

    2016-02-01

    An aerosol model optimized for northeast Asia is updated with the inversion data from the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-northeast (NE) Asia campaign which was conducted during spring from March to May 2012. This updated aerosol model was then applied to a single visible channel algorithm to retrieve aerosol optical depth (AOD) from a Meteorological Imager (MI) on-board the geostationary meteorological satellite, Communication, Ocean, and Meteorological Satellite (COMS). This model plays an important role in retrieving accurate AOD from a single visible channel measurement. For the single-channel retrieval, sensitivity tests showed that perturbations by 4 % (0.926 ± 0.04) in the assumed single scattering albedo (SSA) can result in the retrieval error in AOD by over 20 %. Since the measured reflectance at the top of the atmosphere depends on both AOD and SSA, the overestimation of assumed SSA in the aerosol model leads to an underestimation of AOD. Based on the AErosol RObotic NETwork (AERONET) inversion data sets obtained over East Asia before 2011, seasonally analyzed aerosol optical properties (AOPs) were categorized by SSAs at 675 nm of 0.92 ± 0.035 for spring (March, April, and May). After the DRAGON-NE Asia campaign in 2012, the SSA during spring showed a slight increase to 0.93 ± 0.035. In terms of the volume size distribution, the mode radius of coarse particles was increased from 2.08 ± 0.40 to 2.14 ± 0.40. While the original aerosol model consists of volume size distribution and refractive indices obtained before 2011, the new model is constructed by using a total data set after the DRAGON-NE Asia campaign. The large volume of data in high spatial resolution from this intensive campaign can be used to improve the representative aerosol model for East Asia. Accordingly, the new AOD data sets retrieved from a single-channel algorithm, which uses a precalculated look-up table (LUT) with the new aerosol model, show an

  7. Corrections in dose assessment of 99mTc radiolabeled aerosol particles targeted to central human airways using planar gamma camera imaging.

    PubMed

    Möller, Winfried; Felten, Kathrin; Meyer, Gabriele; Meyer, Peter; Seitz, Jürgen; Kreyling, Wolfgang G

    2009-03-01

    The dose of inhaled radiolabeled aerosols is usually assessed using gamma (GC) camera imaging. Because of the complex and inhomogeneous structure of the lung, consisting of soft tissue, the thoracic skeleton, blood vessels, and air spaces, proper attenuation correction coefficients are difficult to evaluate and the estimated doses bear high uncertainty. One hundred milliliters of aerosol boli composed of 100 nm diameter (99m)Tc radiolabeled carbon particles (Technegas) were targeted either to the airways (AW) or to 800-mL volumetric lung depth (alveoli, AL) in 11 healthy volunteers. In addition, 750-mL full breaths (FB) of aerosol were inhaled to a 800-mL lung depth. The deposited dose was measured by collecting aerosol from inhaled and exhaled air stream on filters, which were analyzed for radioactivity. Lung imaging was performed using a planar GC (posterior). Ratios of GC counts to deposited dose (GC/DD) were similar after FB and AL administration, but twofold lower after AW administration (p < 0.01). Associated attenuation correction factors (ACF) were 2.5 +/- 0.5 (FB), 2.2 +/- 0.4 (AL), and 5.5 +/- 1.6 (AW, p < 0.01). Both GC/DD and ACF were highly correlated to the aerosol distribution index (central to peripheral ratio, C/P). After shallow bolus administration there was a negative correlation between body mass index and GC/DD. Inhalation of radioaerosols used in medical diagnosis and therapy in combination with high central airway deposition results in an underestimation of the deposited dose based on planar GC imaging. The aerosol distribution index C/P may provide one suitable indicator for corrections, which should be confirmed in future studies by individual attenuation analysis based on radiotracer transmission measurements. PMID:18844481

  8. Cloud Retrieval Information Content Studies with the Pre-Aerosol, Cloud and ocean Ecosystem (PACE) Ocean Color Imager (OCI)

    NASA Astrophysics Data System (ADS)

    Coddington, Odele; Platnick, Steven; Pilewskie, Peter; Schmidt, Sebastian

    2016-04-01

    The NASA Pre-Aerosol, Cloud and ocean Ecosystem (PACE) Science Definition Team (SDT) report released in 2012 defined imager stability requirements for the Ocean Color Instrument (OCI) at the sub-percent level. While the instrument suite and measurement requirements are currently being determined, the PACE SDT report provided details on imager options and spectral specifications. The options for a threshold instrument included a hyperspectral imager from 350-800 nm, two near-infrared (NIR) channels, and three short wave infrared (SWIR) channels at 1240, 1640, and 2130 nm. Other instrument options include a variation of the threshold instrument with 3 additional spectral channels at 940, 1378, and 2250 nm and the inclusion of a spectral polarimeter. In this work, we present cloud retrieval information content studies of optical thickness, droplet effective radius, and thermodynamic phase to quantify the potential for continuing the low cloud climate data record established by the MOderate Resolution and Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) missions with the PACE OCI instrument (i.e., non-polarized cloud reflectances and in the absence of midwave and longwave infrared channels). The information content analysis is performed using the GEneralized Nonlinear Retrieval Analysis (GENRA) methodology and the Collection 6 simulated cloud reflectance data for the common MODIS/VIIRS algorithm (MODAWG) for Cloud Mask, Cloud-Top, and Optical Properties. We show that using both channels near 2 microns improves the probability of cloud phase discrimination with shortwave-only cloud reflectance retrievals. Ongoing work will extend the information content analysis, currently performed for dark ocean surfaces, to different land surface types.

  9. Tungsten and hafnium distribution in calcium aluminum inclusions (CAIs) from Allende and Efremovka

    NASA Astrophysics Data System (ADS)

    Humayun, Munir; Simon, Steven B.; Grossman, Lawrence

    2007-09-01

    Recent 182Hf- 182W age determinations on Allende Ca-, Al-rich refractory inclusions (CAIs) and on iron meteorites indicate that CAIs have initial ɛ182W (-3.47 ± 0.20, 2 σ) identical to that of magmatic iron meteorites after correction of cosmogenic 182W burn-out (-3.47 ± 0.35, 2 σ). Either the Allende CAIs were isotopically disturbed or the differentiation of magmatic irons (groups IIAB, IID, IIIAB, and IVB) all occurred <1 m.y. after CAI formation. To assess the extent of isotopic disturbance, we have analyzed the elemental distribution of Hf and W in two CAIs, Ef2 from Efremovka (CV3 reduced), and Golfball from Allende (CV3 oxidized). Fassaite is the sole host of Hf (10-25 ppm) and, therefore, of radiogenic W in CAIs, with 180Hf/ 184W > 10 3, which is lowered by the ubiquitous presence of metal inclusions to 180Hf/ 184W > 10 in bulk fassaite. Metal alloy (Ni ˜ 50%) is the sole host of W (˜500 ppm) in Ef2, while opaque assemblages (OAs) and secondary veins are the hosts of W in Golfball. A large metal alloy grain from Ef2, EM2, has 180Hf/ 184W < 0.006. Melilite has both Hf and W below detection limits (<0.01 ppm), but the presence of numerous metallic inclusions or OAs makes melilite a carrier for W, with 180Hf/ 184W < 1 in bulk melilite. Secondary processes had little impact on the 182Hf- 182W systematics of Ef2, but a vein cross-cutting fassaite in Golfball has >100 ppm W with no detectable Pt or S. This vein provides evidence for transport of oxidized W in the CAI. Because of the ubiquitous distribution of OAs, interpretations of the 182Hf- 182W isochron reported for Allende CAIs include: (i) all W in the OAs was derived by alteration of CAI metal, or (ii) at least some of the W in OAs may have been equilibrated with radiogenic W during metamorphism of Allende. Since (ii) cannot be ruled out, new 182Hf- 182W determinations on CAIs from reduced CV3 chondrites are needed to firmly establish the initial W isotopic composition of the solar system.

  10. Effects of Computer-Assisted Instruction (CAI) on 11th Graders' Attitudes to Biology and CAI and Understanding of Reproduction in Plants and Animals.

    ERIC Educational Resources Information Center

    Soyibo, Kola; Hudson, Ann

    2000-01-01

    Investigates whether the use of the combination of lecture, discussion, and computer-assisted instruction (CAI) significantly improved students' attitudes toward biology and their understanding of reproduction in plants and animals. Studies grade 11 Jamaican female students (n=77) from two traditional high schools in Kingston. (Contains 19…

  11. Correlates of aldosterone-induced increases in Cai2+ and Isc suggest that Cai2+ is the second messenger for stimulation of apical membrane conductance.

    PubMed Central

    Petzel, D; Ganz, M B; Nestler, E J; Lewis, J J; Goldenring, J; Akcicek, F; Hayslett, J P

    1992-01-01

    Studies were performed on monolayers of cultured A6 cells, grown on permeable filters, to determine the second messenger system involved in the aldosterone-induced increase in electrogenic sodium transport. Addition of aldosterone (1 microM) to the solution bathing the basal surface of cells caused both an increase in Isc and threefold transient rise in intracellular calcium Cai2+ after a delay of approximately 60 min. Because both events were inhibited by actinomycin D and cyclohexamide, they appeared to require transcriptional and translational processes. Addition of BAPTA to the bathing media to chelate Cai2+ reduced Isc and the delayed Cai2+ transient; 50 microM BAPTA inhibited Isc and the rise in Cai2+ by greater than 80%. Further studies suggested that the action of aldosterone to increase Isc may be dependent on a calcium/calmodulin-dependent protein kinase, because W-7 and trifluoperazine reduced the aldosterone-induced Isc in a dose-dependent manner. Taken together, these observations suggest that calcium is a second messenger for the action of aldosterone on sodium transport, and suggest, for the first time, that agonists which bind to intracellular receptors can utilize, via delayed processes dependent on de novo transcription and translation, intracellular second messenger systems to regulate target cell function. PMID:1729267

  12. An Improved Method for Estimating Aerosol Optical Thickness from Artificial Light Sources Observed by the Visible/Infrared Imaging Radiometer Suite Day/Night Band

    NASA Astrophysics Data System (ADS)

    McHardy, Theodore Mitchell

    Using Visible/Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) data, a method, dubbed the "variance method", is developed for retrieving nighttime aerosol optical thickness (AOT) values based on the dispersion of radiance values above an artificial light source. An improvement of a previous algorithm, this updated method derives a semi-quantitative indicator of nighttime AOT using artificial light sources. Nighttime AOT retrievals from the newly developed method are inter-compared with an interpolated value from late afternoon and early morning ground observations from four AErosol RObotic NETwork (AERONET) sites as well as column-integrated Aerosol Optical Depth (AOD) from one High Spectral Resolution LiDAR (HSRL) site at Huntsville, AL during the NASA Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign, providing full diel coverage. This method does not account for lunar reflectance from either the surface or the aerosol layer. Sensitivity tests do no indicate large systematic or random errors associated with lunar illumination. VIIRS AOT retrievals yield a coefficient of determination (r2) of 0.60 and a root-mean-squared-error (RMSE) of 0.18 when compared against straddling daytime-averaged AERONET AOT values. Preliminary results suggest that artificial light sources can be used for estimating regional and global nighttime aerosol distributions in the future.

  13. Search for extinct 36Cl: Vigarano CAIs, the Pink Angel from Allende, and a Ningqiang chondrule

    NASA Astrophysics Data System (ADS)

    Nakashima, Daisuke; Ott, Ulrich; Hoppe, Peter; El Goresy, Ahmed

    2008-12-01

    We have searched for excesses of 36S derived from the decay of extinct 36Cl in sodalite, a secondary Cl-rich mineral, in Ca-Al-rich inclusions (CAIs) from the Vigarano and Allende CV3 chondrites and in a chondrule from the Ningqiang carbonaceous chondrite. The presence of sodalite in two CAIs from Vigarano and its absence from surrounding CAI fragments suggests sodalite formation after CAI fragmentation. As for sodalite in the Allende Pink Angel CAI, oxygen isotopic compositions have been interpreted as indicative of high temperature interactions, thus suggesting formation prior to accretion to the parent body, probably in a nebular setting. Sodalite in the Ningqiang chondrule is considered to have formed via alkali-Ca exchange, which is believed to have occurred before accretion to the parent body. Sodalites in the Vigarano CAIs and in the Ningqiang chondrule show no clear evidence for the presence of radiogenic 36S. The inferred 2 σ upper limits for 36Cl/ 35Cl at the time of sodalite formation are 1.6 × 10 -6 (Vigarano CAIs) and 3.3 × 10 -6 (Ningqiang chondrule), respectively. In the Pink Angel CAI sodalite exhibits small 36S excesses which weakly correlate with 35Cl/ 34S ratios. The inferred 36Cl/ 35Cl ratio of (1.8 ± 2.2) × 10 -6 (2 σ error) is lower than that found by Hsu et al. [Hsu, W., Guan, Y., Leshin, L. A., Ushikubo, T. and Wasserburg, G. J. (2006) A late episode of irradiation in the early solar system: Evidence from extinct 36Cl and 26Al in meteorites. Astrophys. J. 640, 525-529], thus indicative of heterogeneous distribution of 36Cl in this CAI. Spallation reactions induced by energetic particles from the young Sun are suggested for the origin of 36Cl, similar to the case of 10Be. While 10Be appears to be present in roughly equal abundance in all studied CAIs, our study indicates the level of 36Cl abundances to be variable so that there seems to be no simple relationship between 10Be and 36Cl. This would be expected if trapped cosmic rays rather

  14. Comparison of Tc-99m DTPA aerosol with radioactive gas ventilation imaging in patients (pts) with suspected pulmonary embolism (PE)

    SciTech Connect

    Alderson, P.O.; Kroop, S.A.; Biello, D.R.; Siegel, B.A.; Gottschalk, A.; Hoffer, P.B.; Ramanna, L.; Waxman, A.D.

    1984-01-01

    The utility of Tc-99m labeled DTPA aerosol (A) as a ventilation agent was compared to that of Xe-133 (Xe) or Kr-81m (Kr) gases in a series of 100 pts (age range 20-83, 53% women) undergoing ventilation-perfusion (V-P) imaging for suspected PE. The majority of pts had A and Xe studies in conjunction with P scans; 26 had A and Kr studies. All A studies were comprised of multiple 100K ct views performed prior to P scanning. Conventional Xe or Kr studies were then performed in conjunction with a multiview P scan. The studies were later reviewed by four independent readers who evaluated 100 V-P studies (100 A-P pairs, 100 gas-P pairs) and the accompanying chest radiographs and determined the probability of PE as none, low, high, or nondiagnostic (NDX). The A scans showed central hot spots in 27% of pts, but poor peripheral penetration in only 5%. Prominent lower lobe deposition was seen in 19 of the 66 pts who inhaled A upright, but in none who inhaled in the supine position. The A-P and gas-P scans were either both diagnostic or both NDX 82% of the time. There were 77% agreement between probability categories for A-P and Kr-P studies, and 74% agreement with Xe-P. These results were better than the inter-observer agreement for gas-P studies alone. Angiography revealed that 3 A-P studies were true negatives, 3 were true positives (pos), and one was a false pos (also pos by gas-P). The results suggest that commercially available DTPA aerosols provide comparable results to gas-P studies in pts with suspected PE.

  15. Pushing back the limits of Raman imaging by coupling super-resolution and chemometrics for aerosols characterization

    PubMed Central

    Offroy, Marc; Moreau, Myriam; Sobanska, Sophie; Milanfar, Peyman; Duponchel, Ludovic

    2015-01-01

    The increasing interest in nanoscience in many research fields like physics, chemistry, and biology, including the environmental fate of the produced nano-objects, requires instrumental improvements to address the sub-micrometric analysis challenges. The originality of our approach is to use both the super-resolution concept and multivariate curve resolution (MCR-ALS) algorithm in confocal Raman imaging to surmount its instrumental limits and to characterize chemical components of atmospheric aerosols at the level of the individual particles. We demonstrate the possibility to go beyond the diffraction limit with this algorithmic approach. Indeed, the spatial resolution is improved by 65% to achieve 200 nm for the considered far-field spectrophotometer. A multivariate curve resolution method is then coupled with super-resolution in order to explore the heterogeneous structure of submicron particles for describing physical and chemical processes that may occur in the atmosphere. The proposed methodology provides new tools for sub-micron characterization of heterogeneous samples using far-field (i.e. conventional) Raman imaging spectrometer. PMID:26201867

  16. Pushing back the limits of Raman imaging by coupling super-resolution and chemometrics for aerosols characterization

    NASA Astrophysics Data System (ADS)

    Offroy, Marc; Moreau, Myriam; Sobanska, Sophie; Milanfar, Peyman; Duponchel, Ludovic

    2015-07-01

    The increasing interest in nanoscience in many research fields like physics, chemistry, and biology, including the environmental fate of the produced nano-objects, requires instrumental improvements to address the sub-micrometric analysis challenges. The originality of our approach is to use both the super-resolution concept and multivariate curve resolution (MCR-ALS) algorithm in confocal Raman imaging to surmount its instrumental limits and to characterize chemical components of atmospheric aerosols at the level of the individual particles. We demonstrate the possibility to go beyond the diffraction limit with this algorithmic approach. Indeed, the spatial resolution is improved by 65% to achieve 200 nm for the considered far-field spectrophotometer. A multivariate curve resolution method is then coupled with super-resolution in order to explore the heterogeneous structure of submicron particles for describing physical and chemical processes that may occur in the atmosphere. The proposed methodology provides new tools for sub-micron characterization of heterogeneous samples using far-field (i.e. conventional) Raman imaging spectrometer.

  17. Image-Processing Educator

    NASA Technical Reports Server (NTRS)

    Gunther, F. J.

    1986-01-01

    Apple Image-Processing Educator (AIPE) explores ability of microcomputers to provide personalized computer-assisted instruction (CAI) in digital image processing of remotely sensed images. AIPE is "proof-of-concept" system, not polished production system. User-friendly prompts provide access to explanations of common features of digital image processing and of sample programs that implement these features.

  18. Experimental Determination of Li, Be and B Partitioning During CAI Crystallization

    SciTech Connect

    Ryerson, F J; Brenan, J M; Phinney, D L

    2005-01-12

    The main focus of the work is to develop a better understanding of the distribution of the elements B, Be and Li in melilite, fassaitic clinop clinopy-roxene, anorthite and spinel, which are the primary constituents of calcium-aluminum-rich inclusions (CAIs). These elements are the parent or decay products of short-lived nuclides (specifically, {sup 7}Be and {sup 10}Be) formed by cosmic ray spallation reactions on silicon and oxygen. Recent observations suggest that some CAIs contain ''fossil'' {sup 7}Be and {sup 10}Be in the form of ''excess'' amounts of their decay products (B and Li). The exact timing of {sup 7}Be and {sup 10}Be production is unknown, but if it occurred early in CAI history, it could constrain the birthplace of CAIs to be within a limited region near the infant sun. Other interpretations are possible, however, and bear little significance to early CAI genesis. In order to interpret the anomalies as being ''primary'', and thus originating at high temperature, information on the intermineral partitioning of both parent and daughter elements is required.

  19. The ethnoecology of Caiçara metapopulations (Atlantic Forest, Brazil): ecological concepts and questions

    PubMed Central

    Begossi, Alpina

    2006-01-01

    The Atlantic Forest is represented on the coast of Brazil by approximately 7,5% of remnants, much of these concentrated on the country's SE coast. Within these southeastern remnants, we still find the coastal Caiçaras who descend from Native Indians and Portuguese Colonizers. The maintenance of such populations, and their existence in spite of the deforestation that occurred on the Atlantic Forest coast, deserves especial attention and analysis. In this study, I address, in particular, the Caiçaras who live on the coast of São Paulo and Rio de Janeiro States, illustrating with examples of coastal inhabitants from other areas, such as Bahia State (NE coast) and of other forested areas (riverine caboclos of the Amazon). The major focus of this study, based on previous research, performed since 1986 in several populations or villages of the Atlantic Forest coast, is to understand the resilience of the Caiçaras, which is analyzed using ecological concepts, such as metapopulation, resilience and adaptive cycles. The Caiçara populations are located on islands (Búzios, Comprida, Grande, Ilhabela, Jaguanum, Gipóia) and on the coast (Bertioga, Puruba, Picinguaba, among others). Information gathered about the Caiçaras regarding the economic cycles of the local regions, along with ecological, historical and economic data available, are used to understand such resilience, and are complemented with comparative examples from the Brazilian Amazon and with variables such as the local restrictions imposed by environmental governmental agencies. PMID:17010204

  20. The Formation Of The First Solids In The Solar System: An Investigation Of CAI Diversity

    NASA Astrophysics Data System (ADS)

    Taillifet, Esther; Baillié, K.; Charnoz, S.; Aléon, J.

    2012-10-01

    Chondritic meteorites are primitive bodies and therefore an important source of information on the first moments of planets formation. Chondrites contain several materials especially calcium and aluminum rich inclusions (CAIs), known to be the oldest objects of the solar system (4.567 Gyr - Amelin et al., 2002; Connelly et al., 2008) and thus the first solids to be formed. CAIs appear in various textures, sizes and compositions in chondrites. Though, all of them should have formed at high temperature (1300-1800 K) in the same region of the solar nebula by condensation from the gas (e.g. Grossman, 1972; Yoneda & Grossman, 1995; Petaev & Wood, 1998; Ebel & Grossman 2000). To answer this problem we study the CAI formation within the solar nebula using numerical simulations. For this work we developed a self consistent thermodynamical model of the solar nebula (see associated talk from Baillié et. al ) based on previous works (Calvet et. al, 1991; Hueso & Guillot, 2005; Dullemond, Dominik and Natta, 2001). Using this model, we simulate the young system with Lagrangian Implicit Disk Transport code (LIDT - Charnoz et. al, 2010). We will focus on the very first instants of the CAIs within the few years following their condensation. We will report our first results in terms of thermal history and investigate if turbulence-driven transport may explain the CAI diversity.

  1. Mineralogy and Petrology of EK-459-5-1, A Type B1 CAI from Allende

    NASA Technical Reports Server (NTRS)

    Jeffcoat, C. R.; Kerekgyarto, A. G.; Lapen, T. J.; Andreasen, R.; Righter, M.; Ross, D. K.

    2015-01-01

    Calcium-aluminum-rich inclusions (CAIs) are a type of coarse-grained clast composed of Ca-, Al-, and Mg-rich silicates and oxides found in chondrite meteorites. Type B (CAIs) are exclusively found in the CV chondrite meteorites and are the most well studied type of inclusion found in chondritic meteorites. Type B1 CAIs are distinguished by a nearly monomineralic rim of melilite that surrounds an interior predominantly composed of melilite, fassaite (Ti and Al-rich clinopyroxene), anorthite, and spinel with varying amounts of other minor primary and secondary phases. The formation of Type B CAIs has received considerable attention in the course of CAI research and quantitative models, experimental results and observations from Type B inclusions remain largely in disagreement. Recent experimental results and quantitative models have shown that the formation of B1 mantles could have occurred by the evaporative loss of Si and Mg during the crystallization of these objects. However, comparative studies suggest that the lower bulk SiO2 compositions in B1s result in more prior melilite crystallization before the onset of fassaite and anorthite crystallization leading to the formation of thick melilite rich rims in B1 inclusions. Detailed petrographic and cosmochemical studies of these inclusions will further our understanding of these complex objects.

  2. A FIB/TEM Study of a Complex Wark-Lovering Rim on a Vigarano CAI

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Needham, A. W.; Messenger, S.

    2013-01-01

    Wark-Lovering (WL) rims are thin multilayered mineral sequences that surround most Ca, Al-rich inclusions (CAIs). Several processes have been proposed for WL rim formation, including condensation, flash-heating or reaction with a nebular reservoir, or combinations of these [e.g. 1-7], but no consensus exists. Our previous coordinated transmission electron microscope (TEM) and NanoSIMS O isotopic measurements showed that a WL rim experienced flash heating events in a nebular environment with planetary O isotopic composition, distinct from the (16)O-rich formation environment [6]. Our efforts have focused on CAIs from the CV(sub red) chondrites, especially Vigarano, because these have escaped much of the parent body alteration effects that are common in CAIs from CV(sub ox) group.

  3. Arginine oscillation explains Na+ independence in the substrate/product antiporter CaiT

    PubMed Central

    Kalayil, Sissy; Schulze, Sabrina; Kühlbrandt, Werner

    2013-01-01

    Most secondary-active transporters transport their substrates using an electrochemical ion gradient. In contrast, the carnitine transporter (CaiT) is an ion-independent, l-carnitine/γ-butyrobetaine antiporter belonging to the betaine/carnitine/choline transporter family of secondary transporters. Recently determined crystal structures of CaiT from Escherichia coli and Proteus mirabilis revealed an inverted five-transmembrane-helix repeat similar to that in the amino acid/Na+ symporter LeuT. The ion independence of CaiT makes it unique in this family. Here we show that mutations of arginine 262 (R262) make CaiT Na+-dependent. The transport activity of R262 mutants increased by 30–40% in the presence of a membrane potential, indicating substrate/Na+ cotransport. Structural and biochemical characterization revealed that R262 plays a crucial role in substrate binding by stabilizing the partly unwound TM1′ helix. Modeling CaiT from P. mirabilis in the outward-open and closed states on the corresponding structures of the related symporter BetP reveals alternating orientations of the buried R262 sidechain, which mimic sodium binding and unbinding in the Na+-coupled substrate symporters. We propose that a similar mechanism is operative in other Na+/H+-independent transporters, in which a positively charged amino acid replaces the cotransported cation. The oscillation of the R262 sidechain in CaiT indicates how a positive charge triggers the change between outward-open and inward-open conformations as a unifying critical step in LeuT-type transporters. PMID:24101465

  4. High expression of CAI2, a 9p21-embedded long non-coding RNA, contributes to advanced stage neuroblastoma

    PubMed Central

    Barnhill, Lisa M.; Williams, Richard T.; Cohen, Olga; Kim, Youngjin; Batova, Ayse; Mielke, Jenna A.; Messer, Karen; Pu, Minya; Bao, Lei; Yu, Alice L.; Diccianni, Mitchell B.

    2014-01-01

    Neuroblastoma is a pediatric cancer with significant genomic and biological heterogeneity. p16 and ARF, two important tumor suppressor genes on chromosome 9p21, are inactivated commonly in most cancers but paradoxically overexpressed in neuroblastoma. Here we report that exon γ in p16 is also part of an undescribed long non-coding RNA (lncRNA) that we have termed CAI2 (CDKN2A/ARF Intron 2 lncRNA). CAI2 is a single exon gene with a poly A signal located in but independent of the p16/ARF exon 3. CAI2 is expressed at very low levels in normal tissue but is highly expressed in most tumor cell lines with an intact 9p21 locus. Concordant expression of CAI2 with p16 and ARF in normal tissue along with the ability of CAI2 to induce p16 expression suggested that CAI2 may regulate p16 and/or ARF. In neuroblastoma cells transformed by serial passage in vitro, leading to more rapid proliferation, CAI2, p16 and ARF expression all increased dramatically. A similar relationship was also observed in primary neuroblastomas where CAI2 expression was significantly higher in advanced stage neuroblastoma, independently of MYCN amplification. Consistent with its association with high risk disease, CAI2 expression was also significantly associated with poor clinical outcomes, although this effect was reduced when adjusted for MYCN amplification. Taken together, our findings suggested that CAI2 contributes to the paradoxical overexpression of p16 in neuroblastoma, where CAI2 may offer a useful biomarker of high-risk disease. PMID:25028366

  5. The effects of gender and cooperative learning with CAI on college students' computer science achievement and attitudes toward computers

    NASA Astrophysics Data System (ADS)

    Shen, Ching-Heng

    The purpose of this study was to examine the effects of gender and cooperative learning with CAI on college students' computer science achievement and attitudes toward computers, when the effects of computer ownership, prior computer instruction, previous software and programming experience were controlled. The participants were 155 undergraduates enrolled in introductory computer courses at two colleges in North Taiwan during the Fall 1996 semester. Before the treatment period, they were asked to fill out the Background Data Form, instructed with cooperative learning strategy, and trained on cooperative and individual learning with CAI. During the treatment period, they were randomly assigned to the treatment (78 students) or the control group (77 students). The treatment group students used a CAI program on computer numbering, encoding, and hardware systems with their partner throughout all six CAI sessions. The control group students used the same CAI program individually within the six CAI sessions. After the 6-week treatment period, both groups were posttested by a 40-item multiple-choice Computer Science Achievement Test (CSAT) and a 30-item Computer Attitude Scale (CAS). Data for both posttests were collected from 153 students (77 in the treatment, 76 in the control group; 62 males, 91 females) and analyzed by MANCOVA and follow-up univariate hierarchical MRC analyses for ANCOVAs. Based on the covariate-adjusted CSAT scores, the results indicated that students using CAI cooperatively had a significantly higher mean than those using CAI individually. Neither gender nor interaction effects were found. Regarding the covariate-adjusted CAS scores, the results showed that males had a significantly higher mean than females. No treatment or interaction effects were found. Due to the higher computer achievement resulted from cooperative learning with CAI, this study suggested that instructors apply cooperative learning strategy in CAI settings in computer courses

  6. Comparison of technetium-99m pyrophosphate and technetium-99m DTPA aerosols for SPECT ventilation lung imaging

    SciTech Connect

    Isitman, A.T.; Collier, B.D.; Palmer, D.W.; Trembath, L.; Krasnow, A.Z.; Rao, S.A.; Hellman, R.S.; Hoffmann, R.G.; Peck, D.C.; Dellis, C.J.

    1988-11-01

    Although (/sup 99m/Tc) diethylenetriaminepentaacetic acid (DTPA) is currently the most widely used radioaerosol, rapid alveolar clearance limits its usefulness for single photon emission computed tomography (SPECT) ventilation lung imaging. Previous research has shown that (/sup 99m/Tc)phosphate compounds have high alveolar deposition and slow clearance and thus provide suitable aerosols for pulmonary ventilation studies. We have compared the pulmonary retention and blood levels of (/sup 99m/Tc)pyrophosphate (PYP) and (99mTc)DTPA in eight normal nonsmoking male volunteers. These two radioaerosols have comparable pulmonary deposition. Technetium-99m PYP, however, has a much slower pulmonary clearance which allows sufficient time (20 or more minutes) for SPECT data acquisition using a single-headed rotating gamma camera. While the radiation absorbed dose to the lungs for (/sup 99m/Tc)PYP (0.31 rad/mCi) is greater than for (/sup 99m/Tc)DTPA (0.11 rad/mCi), it is at a clinically acceptable and safe level.

  7. Processing of refractory meteorite inclusions (CAIs) in parent-body atmospheres

    NASA Technical Reports Server (NTRS)

    Podolak, Morris; Bunch, T. E.; Cassen, Pat; Reynolds, Ray T.; Chang, S.

    1990-01-01

    Ca-Al-rich inclusions (CAIs) in refractory meteorites are shown to have been subject to partial melting during a suitably high gas density/small scale height regime arising during gasdynamic deceleration in a temporary atmosphere around an accreting parent body. The presence of dust in such an atmosphere would have increased the pressure gradient with height, lowering the boiloff rate, and permitting dust particles to become trapped in the partially melted material. CAIs may therefore be studied as probes of a primitive atmosphere.

  8. Estimation of aerosol optical depth and additional atmospheric parameters for the calculation of apparent reflectance from radiance measured by the Airborne Visible/Infrared Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Conel, James E.; Roberts, Dar A.

    1993-01-01

    The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) measures spatial images of the total upwelling spectral radiance from 400 to 2500 nm through 10 nm spectral channels. Quantitative research and application objectives for surface investigations require inversion of the measured radiance of surface reflectance or surface leaving radiance. To calculate apparent surface reflectance, estimates of atmospheric water vapor abundance, cirrus cloud effects, surface pressure elevation, and aerosol optical depth are required. Algorithms for the estimation of these atmospheric parameters from the AVIRIS data themselves are described. From these atmospheric parameters we show an example of the calculation of apparent surface reflectance from the AVIRIS-measured radiance using a radiative transfer code.

  9. Stable Magnesium Isotope Variation in Melilite Mantle of Allende Type B1 CAI EK 459-5-1

    NASA Technical Reports Server (NTRS)

    Kerekgyarto, A. G.; Jeffcoat, C. R.; Lapen, T. J.; Andreasen, R.; Righter, M.; Ross, D. K.

    2014-01-01

    Ca-Al-rich inclusions (CAIs) are the earliest formed crystalline material in our solar system and they record early Solar System processes. Here we present petrographic and delta Mg-25 data of melilite mantles in a Type B1 CAI that records early solar nebular processes.

  10. The Interplay between Different Forms of CAI and Students' Preferences of Learning Environment in the Secondary Science Class

    ERIC Educational Resources Information Center

    Chang, Chun-Yen; Tsai, Chin-Chung

    2005-01-01

    This evaluation study investigated the effects of a teacher-centered versus student-centered computer-assisted instruction (CAI) on 10th graders' earth science student learning outcomes. This study also explored whether the effects of different forms of computer-assisted instruction (CAI) on student learning outcomes were influenced by student…

  11. Gender Role, Gender Identity and Sexual Orientation in CAIS ("XY-Women") Compared With Subfertile and Infertile 46,XX Women.

    PubMed

    Brunner, Franziska; Fliegner, Maike; Krupp, Kerstin; Rall, Katharina; Brucker, Sara; Richter-Appelt, Hertha

    2016-01-01

    The perception of gender development of individuals with complete androgen insensitivity syndrome (CAIS) as unambiguously female has recently been challenged in both qualitative data and case reports of male gender identity. The aim of the mixed-method study presented was to examine the self-perception of CAIS individuals regarding different aspects of gender and to identify commonalities and differences in comparison with subfertile and infertile XX-chromosomal women with diagnoses of Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) and polycystic ovary syndrome (PCOS). The study sample comprised 11 participants with CAIS, 49 with MRKHS, and 55 with PCOS. Gender identity was assessed by means of a multidimensional instrument, which showed significant differences between the CAIS group and the XX-chromosomal women. Other-than-female gender roles and neither-female-nor-male sexes/genders were reported only by individuals with CAIS. The percentage with a not exclusively androphile sexual orientation was unexceptionally high in the CAIS group compared to the prevalence in "normative" women and the clinical groups. The findings support the assumption made by Meyer-Bahlburg ( 2010 ) that gender outcome in people with CAIS is more variable than generally stated. Parents and professionals should thus be open to courses of gender development other than typically female in individuals with CAIS. PMID:26133743

  12. Learner Control of Instructional Sequencing Within an Adaptive Tutorial CAI Environment

    ERIC Educational Resources Information Center

    Seidel, Robert J.; And Others

    1978-01-01

    This study was designed to test effects of a specified degree of learner control over the sequencing of instructional materials in a self contained tutorial CAI course in COBOL programming. Findings describe contributions and interactions of learner controlled variables with respect to instructional effectiveness and efficiency. (RAO)

  13. Role of Computer Assisted Instruction (CAI) in an Introductory Computer Concepts Course.

    ERIC Educational Resources Information Center

    Skudrna, Vincent J.

    1997-01-01

    Discusses the role of computer assisted instruction (CAI) in undergraduate education via a survey of related literature and specific applications. Describes an undergraduate computer concepts course and includes appendices of instructions, flowcharts, programs, sample student work in accounting, COBOL instructional model, decision logic in a…

  14. C.A.I. as a Means for Educational Justice in Primary Schools: A Greek Experience.

    ERIC Educational Resources Information Center

    Raptis, Nicos

    This study examines the effects of computer assisted instruction (CAI) on the inequalities in education among children of less privileged backgrounds. A natural science lesson was taught to 116 children at the fifth level of the Greek primary school. Subjects went to two different public schools, one of which was in a privileged area, and the…

  15. A Pseudo-Language for Creating CAI Programs on APL Systems

    ERIC Educational Resources Information Center

    Gucker, Edward J.

    1973-01-01

    Encourages the use of APL as a language for computer assisted instruction (CAI) instead of such languages as BASIC or COURSEWRITER. Describes a set of APL functions that can simulate to some extent the features of COURSEWRITER, while permitting a more experienced course author to use the full mathematical power of APL. (Author/JF)

  16. Performance assessment of the cellulose absorption index (CAI) method for estimating crop residue cover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate and quick field estimation of crop residues are important for carbon sequestration and biofuel production programs. Landscape-scale assessment of this vital information has promoted the use of remote sensing technology. The cellulose absorption index (CAI) technique has outperformed other ...

  17. Assessing the Impact of Computer-Assisted Instruction (CAI) in Undergraduate Latin American Studies.

    ERIC Educational Resources Information Center

    Child, Jack

    This paper assesses the impact of using computer-assisted instruction (CAI) in three American University undergraduate classes, a General Education survey course on Latin America (taught in English), and two Spanish language courses. The courses utilized both commercial software programs and software programs authored by faculty using Macintosh…

  18. CAI for the Visually Handicapped: Promising Collaboration Between Two and Four-Year Schools.

    ERIC Educational Resources Information Center

    Wilkinson, William K.; And Others

    This report describes the efforts of the Office of Research and Extension of the North Carolina State University (NCSU) School of Education to develop vocal computer-assisted instruction (CAI) tutorials for blind junior college students, the rationale behind those efforts, the costs and means of funding for the project, and suggested ways in which…

  19. 35 Secondary V Students Comment on Their Experience With C.A.I. (Preliminary Report).

    ERIC Educational Resources Information Center

    Gateau, Bernard

    An instrument has been designed and used to quantify the degree of student dissatisfaction with computer-assisted instruction (CAI) experiences. The instrument, entitled PERPI-LPI, was derived from the service test Perceptions Etudiantes de la Relation Professeur-Etudiants (Student Observations on the Teacher-Student Relationship). It measures the…

  20. On the Design and Development of Pedagogy-First CAI Tools for CS Education.

    ERIC Educational Resources Information Center

    Vadaparty, K.; And Others

    This paper presents the implications of an ongoing project on the design and development of multimedia instructional material for teaching and learning computer science topics at both graduate and undergraduate levels. Important pedagogical requirements that CAI software should satisfy include: (1) animation of the changes in tree topologies; (2)…

  1. Evaluation of Title I CAI Programs at Minnesota State Correctional Institutions.

    ERIC Educational Resources Information Center

    Sandman, Richard S.; Welch, Wayne W.

    Three Minnesota correctional institutions used computer-assisted instruction (CAI) on PLATO terminals to improve reading and mathematics skills: (1) the State Reformatory for Men, St. Cloud (males, ages 17-21); (2) the Minnesota Home School, Sauk Centre (males and females, ages 12-18); and (3) the State Training School, Red Wing (males, ages…

  2. Web Pages: An Effective Method of Providing CAI Resource Material in Histology.

    ERIC Educational Resources Information Center

    McLean, Michelle

    2001-01-01

    Presents research that introduces computer-aided instruction (CAI) resource material as an integral part of the second-year histology course at the University of Natal Medical School. Describes the ease with which this software can be developed, using limited resources and available skills, while providing students with valuable learning…

  3. Computer-Assisted Instruction in Engineering Dynamics. CAI-Systems Memo Number 18.

    ERIC Educational Resources Information Center

    Sheldon, John W.

    A 90-minute computer-assisted instruction (CAI) unit course supplemented by a 1-hour lecture on the dynamic nature of three-dimensional rotations and Euler angles was given to 29 undergraduate engineering students. The area of Euler angles was selected because it is essential to problem-working in three-dimensional rotations of a rigid body, yet…

  4. The Anatomy and Bulk Composition of CAI Rims in the Vigarano (CV3) Chondrite

    NASA Astrophysics Data System (ADS)

    Ruzicka, A.; Boynton, W. V.

    1993-07-01

    A striking feature of Ca,Al-rich inclusions (CAIs) in chondrites is the presence of mineralogical layers that typically form rim sequences up to 50 micrometers thick [1]. Many ideas regarding the origin of CAI rims have been proposed, but none are entirely satisfactory. The detailed mineralogy and bulk compositions of relatively unaltered CAI rims in the Vigarano (CV3) chondrite described here provide constraints on hypotheses of rim formation. Rim Mineralogy: CAIs in Vigarano consist of melilite (mel)- and spinel (sp)- rich varieties, both of which are rimmed [2]. Around mel-rich objects, the layer sequence is CAI interior --> sp-rich layer (sometimes absent) --> mel/anorthite (anor) layer --> Ti-Al-rich clinopyroxene (Tpx) layer --> Al- diopside (Al-diop) layer --> olivine (ol) +/- Al-diop layer --> host matrix. The sequence around sp-rich objects differs from this in that the mel/anor layer is absent. Both the sp-rich layer around mel-cored CAIs and the cores of sp-rich CAIs in Vigarano are largely comprised of a fine-grained (<=1 micrometer) intergrowth of sp, Tpx, and minor mel and perovskite. These intergrowths are typically so fine grained that little internal texture is discernible. Mixing calculations suggest the presence of ~10 vol% Tpx in the sp-rich layer of two mel-cored CAIs, and the presence of ~35 vol% Tpx within one sp-cored CAI. The mel/anor layer is sometimes monomineralic, consisting of mel alone, or bimineralic, consisting of both mel and anor. Where bimineralic, anor typically occurs in the outer part of the layer. In places, anor (An(sub)99-100) has partially altered to nepheline and voids. Rim mel is systematically less gehlenitic than mel in the CAI interiors, especially compared to mel in the interior adjacent to the rims. The Tpx layer (>2 and up to 15 wt% TiO2) and Al-diop layer (<2 wt% TiO2) are monomineralic and show chemical zoning trends radial to the CAIs. Moving outward, TiO2 and Al2O3 generally decrease, while SiO2 and Mg

  5. A Cross-National CAI Tool To Support Learning Operations Decision-Making and Market Analysis.

    ERIC Educational Resources Information Center

    Mockler, Robert J.; Afanasiev, Mikhail Y.; Dologite, Dorothy G.

    1999-01-01

    Describes bicultural (United States and Russia) development of a computer-aided instruction (CAI) tool to learn management decision-making using information systems technologies. The program has been used with undergraduate and graduate students in both countries; it integrates free and controlled market concepts and combines traditional computer…

  6. Implementing CAI at San Juan College: Toward the Campus of the Future.

    ERIC Educational Resources Information Center

    Griffiths, John B.

    In 1991, a study was conducted at San Juan College (SJC) to examine existing research, issues, and faculty attitudes and needs regarding computer-assisted instruction (CAI). A faculty needs assessment survey was prepared and conducted, a review of the research literature was undertaken, and initial guidelines were drafted for the utilization of…

  7. Evaluation of aerosol sizing characteristic of an impactor using imaging plate technique.

    PubMed

    Rahman, Naureen Mahbub; Iida, Takao; Saito, Fumihiro; Koarashi, Jun; Yamasaki, Keizou; Yamazawa, Hiromi; Moriizumi, Jun

    2007-01-01

    The activity-size distribution of radon decay products are normally determined using two approaches: direct and indirect. The present study utilises the direct approach to evaluate sizing information of a low pressure cascade impactor using imaging plate (IP) technique for radon decay products. The experiment verified the use of the collection media as suggested by the manufacturer of impactor and proposed a few improvements toward sizing characteristics of impactor. The obtained relative activity-size distribution of radon decay products presents a sharp unimodal log-normal distribution of the particle characterised by activity median aerodynamic diameter (AMAD) of 268 nm and geometric standard deviation (sigma(g)) of 1.66. The obtained data with all the suggested improvements were evaluated by the data obtained from a scanning mobility particle sizer (SMPS, Model 3934, TSI Inc), as reference data. The verification lead to a derivative area ratio of 0.803 between the reference and experimental data. PMID:16936289

  8. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  9. Exploring the effects of landscape structure on aerosol optical depth (AOD) patterns using GIS and HJ-1B images.

    PubMed

    Ye, Luping; Fang, Linchuan; Tan, Wenfeng; Wang, Yunqiang; Huang, Yu

    2016-02-01

    A GIS approach and HJ-1B images were employed to determine the effect of landscape structure on aerosol optical depth (AOD) patterns. Landscape metrics, fractal analysis and contribution analysis were proposed to quantitatively illustrate the impact of land use on AOD patterns. The high correlation between the mean AOD and landscape metrics indicates that both the landscape composition and spatial structure affect the AOD pattern. Additionally, the fractal analysis demonstrated that the densities of built-up areas and bare land decreased from the high AOD centers to the outer boundary, but those of water and forest increased. These results reveal that the built-up area is the main positive contributor to air pollution, followed by bare land. Although bare land had a high AOD, it made a limited contribution to regional air pollution due to its small spatial extent. The contribution analysis further elucidated that built-up areas and bare land can increase air pollution more strongly in spring than in autumn, whereas forest and water have a completely opposite effect. Based on fractal and contribution analyses, the different effects of cropland are ascribed to the greater vegetation coverage from farming activity in spring than in autumn. The opposite effect of cropland on air pollution reveals that green coverage and human activity also influence AOD patterns. Given that serious concerns have been raised regarding the effects of built-up areas, bare land and agricultural air pollutant emissions, this study will add fundamental knowledge of the understanding of the key factors influencing urban air quality. PMID:26766513

  10. Measurements of mesospheric water vapour, aerosols and temperatures with the Spectral Absorption Line Imager (SALI-AT)

    NASA Astrophysics Data System (ADS)

    Shepherd, M. G.; Mullins, M.; Brown, S.; Sargoytchev, S. I.

    2001-08-01

    Water vapour concentration is one of the most important, yet one of the least known quantities of the mesosphere. Knowledge of water vapour concentration is the key to understanding many mesospheric processes, including the one that is primary focus of our investigation, mesospheric clouds (MC). The processes of formation and occurrence parameters of MC constitute an interesting problem in their own right, but recently evidence has been provided which suggests that they are a critical indicator of atmospheric change. The aim of the SALI-AT experiment is to make simultaneous (although not strictly collocated) measurements of water vapour, aerosols and temperature in the mesosphere and the mesopause region under twilight condition in the presence of mesospheric clouds. The water vapour will be measured in the regime of solar occultation utilizing a water vapour absorption band at 936 nm wavelength employing the SALI (Spectral Absorption Line Imager) instrument concept. A three-channel zenith photometer, AT-3, with wavelengths of 385 nm, 525 nm, and 1040 nm will measure Mie and Rayleigh scattering giving both mesospheric temperature profiles and the particle size distribution. Both instruments are small, low cost and low mass. It is envisioned that the SALI-AT experiment be flown on a small rocket - the Improved Orion/Hotel payload configuration, from the Andoya Rocket range, Norway. Alternatively the instrument can be flown as a "passenger" on larger rocket carrying other experiments. In either case flight costs are relatively low. Some performance simulations are presented showing that the instrument we have designed will be sufficiently sensitive to measure water vapor in concentrations that are expected at the summer mesopause, about 85 km height.

  11. An ion microprobe study of CAIs from CO3 meteorites. [Abstract only

    NASA Technical Reports Server (NTRS)

    Russell, S. S.; Greenwood, R. C.; Fahey, A. J.; Huss, G. R.; Wasserburg, G. J.

    1994-01-01

    When attempting to interpret the history of Ca, Al-rich inclusions (CAIs) it is often difficult to distinguish between primary features inherited from the nebula and those produced during secondary processing on the parent body. We have undertaken a systematic study of CAIs from 10 CO chondrites, believed to represent a metamorphic sequence with the goal of distinguishing primary and secondary features. ALHA 77307 (3.0), Colony (3.0), Kainsaz (3.1), Felix (3.2), ALH 82101 (3.3), Ornans (3.3), Lance (3.4), ALHA 77003 (3.5), Warrenton (3.6), and Isna (3.7) were examined by Scanning Electron Microscopy (SEM) and optical microscopy. We have identified 141 CAIs within these samples, and studied in detail the petrology of 34 inclusions. The primary phases in the lower petrologic types are spinel, melilite, and hibonite. Perovskite, FeS, ilmenite, anorthite, kirschsteinite, and metallic Fe are present as minor phases. Melilite becomes less abundant in higher petrologic types and was not detected in chondrites of type 3.5 and above, confirming previous reports that this mineral easily breaks down during heating. Iron, an element that would not be expected to condense at high temperatures, has a lower abundance in spinel from low-petrologic-type meteorites than those of higher grade, and CaTiO3 is replaced by FeTiO3 in meteorites of higher petrologic type. The abundance of CAIs is similar in each meteorite. Eight inclusions have been analyzed by ion probe. The results are summarized. The results obtained to date show that CAIs in CO meteorites, like those from other meteorite classes, contain Mg* and that Mg in some inclusions has been redistributed.

  12. Chronology of chrondrule and CAI formation: Mg-Al isotopic evidence

    NASA Technical Reports Server (NTRS)

    Macpherson, G. J.; Davis, A. M.

    1994-01-01

    Details of the chondrule and Ca-Al-rich inclusion (CAI) formation during the earliest history of the solar system are imperfectly known. Because CAI's are more 'refractory' than ferromagnesian chondrules and have the lowest recorded initial Sr-87/Sr-86 ratios of any solar system materials, the expectation is that CAI's formed earlier than chondrules. But it is not known, for example, if CAI formation had stopped by the time chondrule formation began. Conventional (absolute) age-dating techniques cannot adequately resolve small age differences (less than 10(exp 6) years) between objects of such antiquity. One approach has been to look at systematic differences in the daughter products of short-lived radionuclides such as Al-26 and I-129. Unfortunately, neither system appears to be 'well-behaved.' One possible reason for this circumstance is that later secondary events have partially reset the isotopic systems, but a viable alternative continues to be large-scale (nebular) heterogeneity in initial isotopic abundances, which would of course render the systems nearly useless as chronometers. In the past two years the nature of this problem has been redefined somewhat. Examination of the Al-Mg isotopic database for all CAI's suggests that the vast majority of inclusions originally had the same initial Al-26/Al-27 abundance ratio, and that the ill-behaved isotopic systematics now observed are the results of later partial reequilibration due to thermal processing. Isotopic heterogeneities did exist in the nebula, as demonstrated by the existence of so-called FUN inclusions in CV3 chondrites and isotopically anomalous hibonite grains in CM2 chondrites, which had little or no live Al-26 at the time of their formation. But, among the population of CV3 inclusions at least, FUN inclusions appear to have been a relatively minor nebular component.

  13. Synchronizing the Absolute and Relative Clocks: Pb-Pb and Al-Mg Systematics in CAIs from the Allende and NWA 2364 CV3 Chondrites

    NASA Astrophysics Data System (ADS)

    Bouvier, A.; Wadhwa, M.

    2009-03-01

    A Pb-Pb internal isochron of a type-B CAI from the NWA 2364 CV3 chondrite gives an absolute age of 4568.6 ± 0.2 Ma which contrasts with previous internal Pb-Pb ages of CAIs from Allende and Efremovka. Al-Mg systematics are also reported for CV3 CAIs.

  14. On relationship between aerosols and PM2.5

    NASA Astrophysics Data System (ADS)

    Sano, Itaru; Mukai, Sonoyo; Nakata, Makiko

    2015-04-01

    Since aerosol optical thickness (AOT) is a key parameter of aerosols and description of the Earth's radiation budget, it is widely measured from ground sun photometer network NASA/AERONET [Holben et al., 1998] and from satellite. Fine and surface level aerosol particle called PM2.5, whose diameter is 2.5 μ m or less, is a well-known parameter for understanding polluted level of air. Smirnov et al. reported a good agreement between ground based AERONET AOT (870 nm) and dust concentrations at Barbados [Smirnov et al., 2000]. Wang and Christopher founded a good correlation between satellite based MODIS AOT product and PM2.5 in Alabama area [Wang and 2003]. Long range transported dusts, particularly Asian dust events, are easy to change the vertical profile of aerosol extinction. The vertical profile is important to estimate PM information because both AOT information measured from ground or satellite are integrated value of aerosol extinction from ground to space, i.e. columnar AOT. Thus, we have also proposed correlations between ground level PM2.5 and AERONET AOT (670 nm) in two cases of ordinary air condition and dusty days [Sano et al., 2010]. In this work, we investigate the relationship between PM2.5 and AERONET AOT considering LIDAR measurements. Note that all of instruments are set up at the roof of the University building (50 m) and collocated in 10 m area. Surface-level AOT is derived from AERONET AOT multiplied by an averaged vertical aerosol extinction given by LIDAR. Note that the definition of surface-level AOT in this work is assumed as AOT up to 500 m height. Introduction of surface-level AOT enables to avoid the contamination of dusty aerosol signal existing at high altitude from columnar AOT. The cloud aerosol imager (CAI) on GOSAT satellite has four observing wavelengths, 380, 670, 870 nm, and 1.6 μ m. In this work three channels are selected to estimate aerosol information. Look-up table (LUT) method is applied to estimate the optical properties

  15. Compound ultrarefractory CAI-bearing inclusions from CV3 carbonaceous chondrites

    NASA Astrophysics Data System (ADS)

    Ivanova, Marina A.; Krot, Alexander N.; Nagashima, Kazuhide; MacPherson, Glenn J.

    2012-12-01

    Abstract-Two compound calcium-aluminum-rich inclusions (<span class="hlt">CAIs</span>), 3N from the oxidized CV chondrite Northwest Africa (NWA) 3118 and 33E from the reduced CV chondrite Efremovka, contain ultrarefractory (UR) inclusions. 3N is a forsterite-bearing type B (FoB) <span class="hlt">CAI</span> that encloses UR inclusion 3N-24 composed of Zr,Sc,Y-rich oxides, Y-rich perovskite, and Zr,Sc-rich Al,Ti-diopside. 33E contains a fluffy type A (FTA) <span class="hlt">CAI</span> and UR <span class="hlt">CAI</span> 33E-1, surrounded by Wark-Lovering rim layers of spinel, Al-diopside, and forsterite, and a common forsterite-rich accretionary rim. 33E-1 is composed of Zr,Sc,Y-rich oxides, Y-rich perovskite, Zr,Sc,Y-rich pyroxenes (Al,Ti-diopside, Sc-rich pyroxene), and gehlenite. 3N-24's UR oxides and Zr,Sc-rich Al,Ti-diopsides are 16O-poor (Δ17O approximately -2‰ to -5‰). Spinel in 3N-24 and spinel and Al-diopside in the FoB <span class="hlt">CAI</span> are 16O-rich (Δ17O approximately -23 ± 2‰). 33E-1's UR oxides and Zr,Sc-rich Al,Ti-diopsides are 16O-depleted (Δ17O approximately -2‰ to -5‰) vs. Al,Ti-diopside of the FTA <span class="hlt">CAI</span> and spinel (Δ17O approximately -23 ± 2‰), and Wark-Lovering rim Al,Ti-diopside (Δ17O approximately -7‰ to -19‰). We infer that the inclusions experienced multistage formation in nebular regions with different oxygen-isotope compositions. 3N-24 and 33E-1's precursors formed by evaporation/condensation above 1600 °C. 3N and 33E's precursors formed by condensation and melting (3N only) at significantly lower temperatures. 3N-24 and 3N's precursors aggregated into a compound object and experienced partial melting and thermal annealing. 33E-1 and 33E avoided melting prior to and after aggregation. They acquired Wark-Lovering and common forsterite-rich accretionary rims, probably by condensation, followed by thermal annealing. We suggest 3N-24 and 33E-1 originated in a 16O-rich gaseous reservoir and subsequently experienced isotope exchange in a 16O-poor gaseous reservoir. Mechanism and timing of oxygen-isotope exchange remain</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT........38T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT........38T"><span id="translatedtitle">I. The effect of volcanic <span class="hlt">aerosols</span> on ultraviolet radiation in Antarctica. II. A novel method for enhancing subsurface radar <span class="hlt">imaging</span> using radar interferometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsitas, Steven Ronald</p> <p></p> <p>The theory of radiative transfer is used to explain how a stratospheric <span class="hlt">aerosol</span> layer may, for large solar zenith angles, increase the flux of UV-B light at the ground. As previous explanations are heuristic and incomplete, I first provide a rigorous and complete explanation of how this occurs. I show that an <span class="hlt">aerosol</span> layer lying above Antarctica during spring will decrease the integrated daily dose of biologically weighted irradiance, weighted by the erythema action spectrum, by only up to 5%. Thus after a volcanic eruption, life in Antarctica during spring will suffer the combined effects of the spring ozone hole and ozone destruction induced by volcanic <span class="hlt">aerosols</span>, with the latter effect only slightly offset by <span class="hlt">aerosol</span> scattering. I extend subsurface radar <span class="hlt">imaging</span> by considering the additional information that may be derived from radar interferometry. I show that, under the conditions that temporal and spatial decorrelation between observations is small so that the effects of these decorrelations do not swamp the signature expected from a subsurface layer, the depth of burial of the lower surface may be derived. Also, the echoes from the lower and upper surfaces may be separated. The method is tested with <span class="hlt">images</span> acquired by SIR-C of the area on the Egypt/Sudan border where buried river channels were first observed by SIR-A. Temporal decorrelation between the <span class="hlt">images</span>, due to some combination of physical changes in the scene, changes in the spacecraft attitude and errors in the processing by NASA of the raw radar echoes into the synthetic aperture radar <span class="hlt">images</span>, swamps the expected signature for a layer up to 40 meters thick. I propose a test to determine whether or not simultaneous observations are required, and then detail the radar system requirements for successful application of the method for both possible outcomes of the test. I also describe in detail the possible applications of the method. These include measuring the depth of burial of ice in the polar</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A23B3216M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A23B3216M"><span id="translatedtitle"><span class="hlt">Aerosol</span> retrieval in hazy atmosphere by using polarization and radiance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mukai, S.; Sano, I.; Nakata, M.</p> <p>2014-12-01</p> <p><span class="hlt">Aerosol</span> retrieval is achieved by radiative transfer simulation in the Earth atmosphere model. This work intends to propose an algorithm for multiple light scattering simulations in the hazy polarized radiation field. We have already solved the scalar radiative transfer problem in the case of haze episodes with dense concentrations of atmospheric <span class="hlt">aerosols</span> by the method of successive order of scattering, which is named scalar-MSOS. The term "scalar" indicates radiance alone in the treatment of radiative transfer problem against "vector" involving polarized radiation field. The satellite polarimetric sensor POLDER-1, 2, 3 has shown that the spectro-photopolarimetry of terrestrial atmosphere is very useful for observation of the Earth, especially for <span class="hlt">aerosols</span>. JAXA has been developing the new Earth observing system, GCOM satellite. GCOM-C will board the polarimetric sensor SGLI in 2017. It is highly likely that large-scale <span class="hlt">aerosol</span> episodes will continue to occur, because the air pollution becomes to be severe due to both the increasing emissions of the anthropogenic <span class="hlt">aerosols</span> and the complicated behavior of natural <span class="hlt">aerosols</span>. Then many potential applications for the kind of radiation simulation by MSOS considering the polarization information denoted by Stokes parameters (I, Q, U, V), named vector-MSOS, are desired. It is shown here that dense <span class="hlt">aerosol</span> episodes can be well simulated by a semi-infinite radiation model composed of the proposed <span class="hlt">aerosol</span> models. In addition our vector-MSOS is examined in practice by combination use of PARASOL/POLDER, GOSAT/<span class="hlt">CAI</span> and Aqua/MODIS data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750022313','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750022313"><span id="translatedtitle">Alternative communication network designs for an operational Plato 4 <span class="hlt">CAI</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mobley, R. E., Jr.; Eastwood, L. F., Jr.</p> <p>1975-01-01</p> <p>The cost of alternative communications networks for the dissemination of PLATO IV computer-aided instruction (<span class="hlt">CAI</span>) was studied. Four communication techniques are compared: leased telephone lines, satellite communication, UHF TV, and low-power microwave radio. For each network design, costs per student contact hour are computed. These costs are derived as functions of student population density, a parameter which can be calculated from census data for one potential market for <span class="hlt">CAI</span>, the public primary and secondary schools. Calculating costs in this way allows one to determine which of the four communications alternatives can serve this market least expensively for any given area in the U.S. The analysis indicates that radio distribution techniques are cost optimum over a wide range of conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15858367','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15858367"><span id="translatedtitle">Germination of white radish, buckwheat and qing-geng-<span class="hlt">cai</span> under low pressure in closed environment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hinokuchi, Tsutomu; Oshima, Satoshi; Hashimoto, Hirofumi</p> <p>2004-11-01</p> <p>In order to cultivate plants under low pressure in closed environment, the germination rate of seeds of white radish was investigated under low pressure, low oxygen partial pressure and condition of pure oxygen. The result of these experiments showed that the germination rate was affected by the oxygen partial pressure. From this fact, it is possible to lower the total pressure by using only the pure oxygen in germination. Furthermore, the germination rates of seeds of buckwheat and qing-geng-<span class="hlt">cai</span> were also investigated in pure oxygen for the comparison. Consequently, though tendency in germination rate of white radish was similar to qing-geng-<span class="hlt">cai</span>, it was different from buckwheat. PMID:15858367</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991Geokh.....1307F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991Geokh.....1307F"><span id="translatedtitle">Metal phase in a B1-type <span class="hlt">CAI</span> fragment of the CV Efremovka chondrite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fisenko, A. V.; Ignatenko, K. I.; Lavrukhina, A. K.</p> <p>1991-09-01</p> <p>Results are presented from petrographical, mineralogical, and chemical analyses of metal particles in two B1-type <span class="hlt">CAI</span> fragments obtained from the Efremovka CV chondrite. The fragments were found to have a broken outer border consisting mainly of grains of Ca phosphates and a Fe/Ni phase. Both fragments are associated with V2O3-rich pyroxene. All individual particles and veins of the fragments are made up from high-Ni tenite, sometimes enriched in V. It is suggested that all features of the metal phase of this chondrite are a consequence of oxidation, or of partial evaporation of the metal followed by its oxidation, and that the characteristics of the metal phase of the <span class="hlt">CAI</span> phase of the Efremovka chondrite may correspond to those of the protomatter of some fremdlings, such as the Allende chondrite.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940011928','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940011928"><span id="translatedtitle">Limited subsolidus diffusion in type B1 <span class="hlt">CAI</span>: Evidence from Ti distribution in spinel</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meeker, G. P.; Quick, J. E.; Paque, Julie M.</p> <p>1993-01-01</p> <p>Most models of calcium aluminum-rich inclusions (<span class="hlt">CAI</span>) have focused on early stages of formation by equilibrium crystallization of a homogeneous liquid. Less is known about the subsolidus cooling history of <span class="hlt">CAI</span>. Chemical and isotopic heterogeneties on a scale of tens to hundreds of micrometers (e.g. MacPherson et al. (1989) and Podosek, et al. (1991)) suggest fairly rapid cooling with a minimum of subsolidus diffusion. However, transmission electron microscopy indicates that solid state diffusion may have been an important process at a smaller scale (Barber et al. 1984). If so, chemical evidence for diffusion could provide constraints on cooling times and temperatures. With this in mind, we have begun an investigation of the Ti distribution in spinels from two type B1 <span class="hlt">CAI</span> from Allende to determine if post-crystallization diffusion was a significant process. The type B1 <span class="hlt">CAIs</span>, 3529Z and 5241 have been described by Podosek et al. (1991) and by El Goresy et al. (1985) and MacPherson et al. (1989). We have analyzed spinels in these inclusions using the electron microprobe. These spinels are generally euhedral, range in size from less than 10 to 15 micron and are poikilitically enclosed by millimeter-sized pyroxene, melilite, and anorthite. Analyses were obtained from both the mantles and cores of the inclusions. Compositions of pyroxene in the vicinity of individual spinel grains were obtained by analyzing at least two points on opposite sides of the spinel and averaging the compositions. The pyroxene analyses were obtained within 15 microns of the spinel-pyroxene interface. No compositional gradients were observed within single spinel crystals. Ti concentrations in spinels included within pyroxene, melilite, and anorthite are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007LPI....38.1781S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007LPI....38.1781S"><span id="translatedtitle">Al-26 and Be-10 in Efremovka and Acfer <span class="hlt">CAIs</span>: Constraints on the Origin of Short-lived Radionuclides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srinivasan, G.; Chaussidon, M.; Bischoff, A.</p> <p>2007-03-01</p> <p>In this abstract we present aluminum-26 and beryllium-10 abundances in Efremovka and Acfer <span class="hlt">CAIs</span>. These measurements help us to constrain the origin of short-lived radionuclides aluminum-26, beryllium-10.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511969K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511969K"><span id="translatedtitle">Formation of halogen-induced secondary organic <span class="hlt">aerosol</span> (XOA)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kamilli, Katharina; Ofner, Johannes; Zetzsch, Cornelius; Held, Andreas</p> <p>2013-04-01</p> <p>Reactive halogen species (RHS) are very important due to their potential of stratospheric ozone depletion and surface ozone destruction. RHS seem to interact with precursors of secondary organic <span class="hlt">aerosol</span> (SOA) similarly to common atmospheric oxidants like OH radicals and ozone. The potential interaction of RHS with preformed SOA has recently been studied (Ofner et al., 2012). Although <span class="hlt">aerosol</span> formation from reaction of RHS with typical SOA precursors was previously studied (e.g. <span class="hlt">Cai</span> et al., 2006), no data are available on bromine-induced <span class="hlt">aerosol</span> formation from organic precursors yet. An <span class="hlt">aerosol</span> smog-chamber was used to examine the halogen-induced secondary organic <span class="hlt">aerosol</span> (XOA) formation under atmospheric conditions using simulated sunlight. With a concentration of 10 ppb for the organic precursor, 2 ppb for molecular chlorine, and 10 ppb for molecular bromine, the experimental setup is close to ambient conditions. By combined measurements of the <span class="hlt">aerosol</span> size distribution, ozone and NOx mixing ratios, as well as the decay of the organic precursor, <span class="hlt">aerosol</span> yields and <span class="hlt">aerosol</span> growth rates were determined. The decay of the organic precursor was analyzed by capillary gas chromatography coupled with flame-ionization detection (GC-FID) and the <span class="hlt">aerosol</span> size distribution was measured using a Scanning Mobility Particle Sizer (SMPS). Additionally, with the decay rate of the precursor and the calculated photolysis rates of molecular halogen species, based on the well-known spectrum of the solar simulator, mechanistic details on the XOA formation pathways can be determined. We observed XOA formation even at very low precursor and RHS concentrations with a diameter mode at 10-20 nm and a number concentration up to 1000000 particles cm-3. While the XOA formation from chlorine is very rapid, the interaction of bromine with the organic precursors is about five times slower. The <span class="hlt">aerosol</span> yield reached maximum values of 0.01 for the reaction of chlorine with α-pinene and 0.0004 for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016M%26PS...51..818I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016M%26PS...51..818I"><span id="translatedtitle">Rare earth element measurements and mapping of minerals in the Allende <span class="hlt">CAI</span>, 7R19-1, by NanoSIMS ion microprobe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ito, Motoo; Messenger, Scott</p> <p>2016-04-01</p> <p>We have established analytical procedures for quantitative rare earth element (REE) measurements by NanoSIMS 50L ion microprobe with 2-10 μm spatial resolution. Measurements are performed by multidetection using energy filtering under several static magnetic field settings. Relative sensitivity factors and REE oxide/REE element secondary ion ratios that we determined for the NanoSIMS match values previously determined for other ion microprobes. REE measurements of 100 ppm REE glass standards yielded reproducibility and accuracy of 0.5-2.5% and 5-15%, respectively. REE measurements of minerals of an Allende type-A <span class="hlt">CAI</span>, 7R19-1, were performed using three different methods: spot analysis, line profile, and <span class="hlt">imaging</span>. These data are in excellent agreement with previous REE measurements of this inclusion by IMS-3f ion microprobe. The higher spatial resolution NanoSIMS measurements provide additional insight into the formation process of this <span class="hlt">CAI</span> and offer a promising new tool for analysis of fine-grained and complexly zoned materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25186361','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25186361"><span id="translatedtitle">Crystal structures of hydrates of simple inorganic salts. II. Water-rich calcium bromide and iodide hydrates: CaBr2 · 9H2O, <span class="hlt">CaI</span>2 · 8H2O, <span class="hlt">CaI</span>2 · 7H2O and <span class="hlt">CaI</span>2 · 6.5H2O.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hennings, Erik; Schmidt, Horst; Voigt, Wolfgang</p> <p>2014-09-01</p> <p>Single crystals of calcium bromide enneahydrate, CaBr(2) · 9H2O, calcium iodide octahydrate, <span class="hlt">CaI</span>(2) · 8H2O, calcium iodide heptahydrate, <span class="hlt">CaI</span>(2) · 7H2O, and calcium iodide 6.5-hydrate, <span class="hlt">CaI</span>(2) · 6.5H2O, were grown from their aqueous solutions at and below room temperature according to the solid-liquid phase diagram. The crystal structure of <span class="hlt">CaI</span>(2) · 6.5H2O was redetermined. All four structures are built up from distorted Ca(H2O)8 antiprisms. The antiprisms of the iodide hydrate structures are connected either via trigonal-plane-sharing or edge-sharing, forming dimeric units. The antiprisms in calcium bromide enneahydrate are monomeric. PMID:25186361</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011oss..prop....6K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011oss..prop....6K"><span id="translatedtitle">Mineralogy and isotope chemistry of FUN (fractionation and nuclear isotope effects) and F (fractionation) <span class="hlt">CAIs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krot, Alexander</p> <p></p> <p>To understand the origin and formation conditions of FUN (Fractionation and Unidentified Nuclear isotope effects) and F (fractionation) Ca,Al-rich inclusions (<span class="hlt">CAIs</span>), and their significance for constraining the origin of 26Al and O-isotopic compositions of the primordial dust and gas in the early Solar System, we propose to study mineralogy, petrology, oxidation state of Ti, trace element abundances, and O-, Mg-, Si-, Ca-, and Ti- isotope compositions of FUN and F <span class="hlt">CAIs</span> previously identified in CV and CR chondrites. Twelve out of ~20 FUN and F <span class="hlt">CAIs</span> known will be available for mineralogical study and isotope measurements; these include 1623-5, C1, EK1-4-1, CG-14, BG82DH8, B7F6, B7H10, BG82HB1, KT-1, AXCAI-2771, TE, and Gao-Guenie (b) #3. We will also search for additional FUN and F inclusions among Allende and Efremovka <span class="hlt">CAIs</span> with large mass-dependent fractionation effects in Mg. This interdisciplinary research will be done in collaboration with I. Hutcheon (NanoSIMS), G. Huss (SIMS), S. Sutton (XANES), R. Mendybaev and A. Davis (evaporation experiments), F. Ciesla (modeling of evolution of O-isotope reservoirs in the solar nebula), and B. Meyer (modeling of Galactic chemical evolution of O-isotope compositions of dust and gas in the protosolar molecular cloud, and of stellar origin of short-lived radionuclides). The research proposed here is highly relevant to the Science Goals and Objectives of NASA and the Origins of Solar Systems Program, specifically ascertain the content, origin, and history of the solar system, and the potential for life elsewhere and increase the understanding of the chemical origin of the Solar System and the processes by which its planets and small bodies have evolved to their present states¿. Our interdisciplinary research (mineralogical and isotopic studies of the earliest solar-system solids, and astrophysical modeling) is designed to understand the origin of 26Al-poor <span class="hlt">CAIs</span> with large mass-dependent isotope fractionation effects, and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011oss..prop.1106K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011oss..prop.1106K"><span id="translatedtitle">Mineralogy and isotope chemistry of FUN (fractionation and nuclear isotope effects) and F (fractionation) <span class="hlt">CAIs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krot, Alexander</p> <p></p> <p>To understand the origin and formation conditions of FUN (Fractionation and Unidentified Nuclear isotope effects) and F (fractionation) Ca,Al-rich inclusions (<span class="hlt">CAIs</span>), and their significance for constraining the origin of 26Al and O-isotopic compositions of the primordial dust and gas in the early Solar System, we propose to study mineralogy, petrology, oxidation state of Ti, trace element abundances, and O-, Mg-, Si-, Ca-, and Ti- isotope compositions of FUN and F <span class="hlt">CAIs</span> previously identified in CV and CR chondrites. Twelve out of ~20 FUN and F <span class="hlt">CAIs</span> known will be available for mineralogical study and isotope measurements; these include 1623-5, C1, EK1-4-1, CG-14, BG82DH8, B7F6, B7H10, BG82HB1, KT-1, AXCAI-2771, TE, and Gao-Guenie (b) #3. We will also search for additional FUN and F inclusions among Allende and Efremovka <span class="hlt">CAIs</span> with large mass-dependent fractionation effects in Mg. This interdisciplinary research will be done in collaboration with I. Hutcheon (NanoSIMS), G. Huss (SIMS), S. Sutton (XANES), R. Mendybaev and A. Davis (evaporation experiments), F. Ciesla (modeling of evolution of O-isotope reservoirs in the solar nebula), and B. Meyer (modeling of Galactic chemical evolution of O-isotope compositions of dust and gas in the protosolar molecular cloud, and of stellar origin of short-lived radionuclides). The research proposed here is highly relevant to the Science Goals and Objectives of NASA and the Origins of Solar Systems Program, specifically ascertain the content, origin, and history of the solar system, and the potential for life elsewhere and increase the understanding of the chemical origin of the Solar System and the processes by which its planets and small bodies have evolved to their present states. Our interdisciplinary research (mineralogical and isotopic studies of the earliest solar-system solids, and astrophysical modeling) is designed to understand the origin of 26Al-poor <span class="hlt">CAIs</span> with large mass-dependent isotope fractionation effects, and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090020501','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090020501"><span id="translatedtitle">Rare Earth Element Measurements of Melilite and Fassaite in Allende <span class="hlt">Cai</span> by Nanosims</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ito, M.; Messenger, Scott</p> <p>2009-01-01</p> <p>The rare earth elements (REEs) are concentrated in <span class="hlt">CAIs</span> by approx. 20 times the chondritic average [e.g., 1]. The REEs in <span class="hlt">CAIs</span> are important to understand processes of <span class="hlt">CAI</span> formation including the role of volatilization, condensation, and fractional crystallization [1,2]. REE measurements are a well established application of ion microprobes [e.g., 3]. However the spatial resolution of REE measurements by ion microprobe (approx.20 m) is not adequate to resolve heterogeneous distributions of REEs among/within minerals. We have developed methods for measuring REE with the NanoSIMS 50L at smaller spatial scales. Here we present our initial measurements of REEs in melilite and fassaite in an Allende Type-A <span class="hlt">CAI</span> with the JSC NanoSIMS 50L. We found that the key parameters for accurate REE abundance measurements differ between the NanoSIMS and conventional SIMS, in particular the oxide-to-element ratios, the relative sensitivity factors, the energy distributions, and requisite energy offset. Our REE abundance measurements of the 100 ppm REE diopside glass standards yielded good reproducibility and accuracy, 0.5-2.5 % and 5-25 %, respectively. We determined abundances and spatial distributions of REEs in core and rim within single crystals of fassaite, and adjacent melilite with 5-10 m spatial resolution. The REE abundances in fassaite core and rim are 20-100 times CI abundance but show a large negative Eu anomaly, exhibiting a well-defined Group III pattern. This is consistent with previous work [4]. On the other hand, adjacent melilite shows modified Group II pattern with no strong depletions of Eu and Yb, and no Tm positive anomaly. REE abundances (2-10 x CI) were lower than that of fassaite. These patterns suggest that fassaite crystallized first followed by a crystallization of melilite from the residual melt. In future work, we will carry out a correlated study of O and Mg isotopes and REEs of the <span class="hlt">CAI</span> in order to better understand the nature and timescales of its</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26PSL.440...62A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26PSL.440...62A"><span id="translatedtitle">Oxygen isotopes in the early protoplanetary disk inferred from pyroxene in a classical type B <span class="hlt">CAI</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aléon, Jérôme</p> <p>2016-04-01</p> <p>A major unanswered question in solar system formation is the origin of the oxygen isotopic dichotomy between the Sun and the planets. Individual Calcium-Aluminum-rich inclusions (<span class="hlt">CAIs</span>) from CV chondrites exhibit almost the full isotopic range, but how their composition evolved is still unclear, which prevents robust astrochemical conclusions. A key issue is notably the yet unsolved origin of the 16O-rich isotopic composition of pyroxene in type B <span class="hlt">CAIs</span>. Here, I report an in-situ oxygen isotope study of the archetypal type B <span class="hlt">CAI</span> USNM-3529-Z from Allende with emphasis on the isotopic composition of pyroxene and its isotopic and petrographic relationships with other major minerals. The O isotopic composition of pyroxene is correlated with indicators of magmatic growth, indicating that the pyroxene evolved from a 16O-poor composition and became progressively enriched in 16O during its crystallization, contrary to the long held assumption that pyroxene was initially 16O-rich. This variation is well explained by isotopic exchange between a 16O-poor partial melt having the isotopic composition of melilite and a 16O-rich gas having the isotopic composition of spinel, during pyroxene crystallization. The isotopic evolution of 3529-Z is consistent with formation in an initially 16O-rich environment where spinel and gehlenitic melilite crystallized, followed by a 16O-depletion associated with melilite partial melting and recrystallization and finally a return to the initial 16O-rich environment before pyroxene crystallization. This strongly suggests that the environment of <span class="hlt">CAI</span> formation was globally 16O-rich, with local 16O-depletions systematically associated with high temperature events. The Al/Mg isotopic systematics of 3529-Z further indicates that this suite of isotopic changes occurred in the first 150 000 yr of the solar system, during the main <span class="hlt">CAI</span> formation period. A new astrophysical setting is proposed, where the 16O-depletion occurs in an optically thin surface</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38..355M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38..355M"><span id="translatedtitle">Radiation Transfer Model for <span class="hlt">Aerosol</span> Events in the Earth Atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mukai, Sonoyo; Yokomae, Takuma; Nakata, Makiko; Sano, Itaru</p> <p></p> <p>Recently large scale-forest fire, which damages the Earth environment as biomass burning and emission of carbonaceous particles, frequently occurs due to the unstable climate and/or global warming tendency. It is also known that the heavy soil dust is transported from the China continent to Japan on westerly winds, especially in spring. Furthermore the increasing emis-sions of anthropogenic particles associated with continuing economic growth scatter serious air pollutants. Thus atmospheric <span class="hlt">aerosols</span>, especially in Asia, are very complex and heavy loading, which is called <span class="hlt">aerosol</span> event. In the case of <span class="hlt">aerosol</span> events, it is rather difficult to do the sun/sky photometry from the ground, however satellite observation is an effective for <span class="hlt">aerosol</span> monitoring. Here the detection algorithms from space for such <span class="hlt">aerosol</span> events as dust storm or biomass burn-ing are dealt with multispectral satellite data as ADEOS-2/GLI, Terra/Aqua/MODIS and/or GOSAT/<span class="hlt">CAI</span> first. And then <span class="hlt">aerosol</span> retrieval algorithms are examined based on new radiation transfer code for semi-infinite atmosphere model. The derived space-based results are validated with ground-based measurements and/or model simulations. Namely the space-or surface-based measurements, multiple scattering calculations and model simulations are synthesized together for <span class="hlt">aerosol</span> retrieval in this work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AMTD....7.2187G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AMTD....7.2187G"><span id="translatedtitle">The Heidelberg Airborne <span class="hlt">Imaging</span> DOAS Instrument (HAIDI) - a novel <span class="hlt">Imaging</span> DOAS device for 2-D and 3-D <span class="hlt">imaging</span> of trace gases and <span class="hlt">aerosols</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>General, S.; Pöhler, D.; Sihler, H.; Bobrowski, N.; Frieß, U.; Zielcke, J.; Horbanski, M.; Shepson, P. B.; Stirm, B. H.; Simpson, W. R.; Weber, K.; Fischer, C.; Platt, U.</p> <p>2014-03-01</p> <p>Many relevant processes in tropospheric chemistry take place on rather small scales (e.g. tens to hundreds of meters) but often influence areas of several square kilometer. Thus, measurements of the involved trace gases with high spatial resolution are of great scientific interest. In order to identify individual sources and sinks and ultimately to improve chemical transport models, we developed a new airborne instrument, which is based on the well established DOAS method. The Heidelberg Airborne <span class="hlt">Imaging</span> Differential Optical Absorption Spectrometer Instrument (HAIDI) is a passive <span class="hlt">imaging</span> DOAS spectrometer, which is capable of recording horizontal and vertical trace gas distributions with a resolution of better than 100 m. Observable species include NO2, HCHO, C2H2O2, H2O, O3, O4, SO2, IO, OClO and BrO. Here we report a technical description of the instrument including its custom build spectrographs and CCD detectors. Also first results from measurements with the new instrument are presented. These comprise spatial resolved SO2 and BrO in volcanic plumes, mapped at Mt. Etna (Sicily, Italy), NO2 emissions in the metropolitan area of Indianapolis (Indiana, USA) as well as BrO and NO2 distributions measured during arctic springtime in context of the BROMEX campaign, which was performed 2012 in Barrow (Alaska, USA).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AMT.....7.3459G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AMT.....7.3459G"><span id="translatedtitle">The Heidelberg Airborne <span class="hlt">Imaging</span> DOAS Instrument (HAIDI) - a novel <span class="hlt">imaging</span> DOAS device for 2-D and 3-D <span class="hlt">imaging</span> of trace gases and <span class="hlt">aerosols</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>General, S.; Pöhler, D.; Sihler, H.; Bobrowski, N.; Frieß, U.; Zielcke, J.; Horbanski, M.; Shepson, P. B.; Stirm, B. H.; Simpson, W. R.; Weber, K.; Fischer, C.; Platt, U.</p> <p>2014-10-01</p> <p>Many relevant processes in tropospheric chemistry take place on rather small scales (e.g., tens to hundreds of meters) but often influence areas of several square kilometer. Thus, measurements of the involved trace gases with high spatial resolution are of great scientific interest. In order to identify individual sources and sinks and ultimately to improve chemical transport models, we developed a new airborne instrument, which is based on the well established Differential Optical Absorption Spectroscopy (DOAS) method. The Heidelberg Airborne <span class="hlt">Imaging</span> DOAS Instrument (HAIDI) is a passive <span class="hlt">imaging</span> DOAS spectrometer, which is capable of recording horizontal and vertical trace gas distributions with a resolution of better than 100 m. Observable species include NO2, HCHO, C2H2O2, H2O, O3, O4, SO2, IO, OClO and BrO. Here we give a technical description of the instrument including its custom-built spectrographs and CCD detectors. Also first results from measurements with the new instrument are presented. These comprise spatial resolved SO2 and BrO in volcanic plumes, mapped at Mt. Etna (Sicily, Italy), NO2 emissions in the metropolitan area of Indianapolis (Indiana, USA) as well as BrO and NO2 distributions measured during arctic springtime in context of the BRomine, Ozone, and Mercury EXperiment (BROMEX) campaign, which was performed 2012 in Barrow (Alaska, USA).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeCoA.145..206K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeCoA.145..206K"><span id="translatedtitle">Calcium-aluminum-rich inclusions with fractionation and unknown nuclear effects (FUN <span class="hlt">CAIs</span>): I. Mineralogy, petrology, and oxygen isotopic compositions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krot, Alexander N.; Nagashima, Kazuhide; Wasserburg, Gerald J.; Huss, Gary R.; Papanastassiou, Dimitri; Davis, Andrew M.; Hutcheon, Ian D.; Bizzarro, Martin</p> <p>2014-11-01</p> <p>We present a detailed characterization of the mineralogy, petrology, and oxygen isotopic compositions of twelve FUN <span class="hlt">CAIs</span>, including C1 and EK1-4-1 from Allende (CV), that were previously shown to have large isotopic fractionation patterns for magnesium and oxygen, and large isotopic anomalies of several elements. The other samples show more modest patterns of isotopic fractionation and have smaller but significant isotopic anomalies. All FUN <span class="hlt">CAIs</span> studied are coarse-grained igneous inclusions: Type B, forsterite-bearing Type B, compact Type A, and hibonite-rich. Some inclusions consist of two mineralogically distinct lithologies, forsterite-rich and forsterite-free/poor. All the CV FUN <span class="hlt">CAIs</span> experienced postcrystallization open-system iron-alkali-halogen metasomatic alteration resulting in the formation of secondary minerals commonly observed in non-FUN <span class="hlt">CAIs</span> from CV chondrites. The CR FUN <span class="hlt">CAI</span> GG#3 shows no evidence for alteration. In all samples, clear evidence of oxygen isotopic fractionation was found. Most samples were initially 16O-rich. On a three-oxygen isotope diagram, various minerals in each FUN <span class="hlt">CAI</span> (spinel, forsterite, hibonite, dmisteinbergite, most fassaite grains, and melilite (only in GG#3)), define mass-dependent fractionation lines with a similar slope of ∼0.5. The different inclusions have different Δ17O values ranging from ∼-25‰ to ∼-16‰. Melilite and plagioclase in the CV FUN <span class="hlt">CAIs</span> have 16O-poor compositions (Δ17O ∼-3‰) and plot near the intercept of the Allende <span class="hlt">CAI</span> line and the terrestrial fractionation line. We infer that mass-dependent fractionation effects of oxygen isotopes in FUN <span class="hlt">CAI</span> minerals are due to evaporation during melt crystallization. Differences in Δ17O values of mass-dependent fractionation lines defined by minerals in individual FUN <span class="hlt">CAIs</span> are inferred to reflect differences in Δ17O values of their precursors. Differences in δ18O values of minerals defining the mass-dependent fractionation lines in several FUN <span class="hlt">CAIs</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/944372','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/944372"><span id="translatedtitle">OXYGEN ISOTOPIC COMPOSITIONS OF THE ALLENDE TYPE C <span class="hlt">CAIs</span>: EVIDENCE FOR ISOTOPIC EXCHANGE DURING NEBULAR MELTING AND ASTEROIDAL THERMAL METAMORPHISM</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Krot, A N; Chaussidon, M; Yurimoto, H; Sakamoto, N; Nagashima, K; Hutcheon, I D; MacPherson, G J</p> <p>2008-02-21</p> <p>Based on the mineralogy and petrography, coarse-grained, igneous, anorthite-rich (Type C) calcium-aluminum-rich inclusions (<span class="hlt">CAIs</span>) in the CV3 carbonaceous chondrite Allende have been recently divided into three groups: (i) <span class="hlt">CAIs</span> with melilite and Al,Ti-diopside of massive and lacy textures (coarse grains with numerous rounded inclusions of anorthite) in a fine-grained anorthite groundmass (6-1-72, 100, 160), (ii) <span class="hlt">CAI</span> CG5 with massive melilite, Al,Ti-diopside and anorthite, and (iii) <span class="hlt">CAIs</span> associated with chondrule material: either containing chondrule fragments in their peripheries (ABC, TS26) or surrounded by chondrule-like, igneous rims (93) (Krot et al., 2007a,b). Here, we report in situ oxygen isotopic measurements of primary (melilite, spinel, Al,Ti-diopside, anorthite) and secondary (grossular, monticellite, forsterite) minerals in these <span class="hlt">CAIs</span>. Spinel ({Delta}{sup 17}O = -25{per_thousand} to -20{per_thousand}), massive and lacy Al,Ti-diopside ({Delta}{sup 17}O = -20{per_thousand} to -5{per_thousand}) and fine-grained anorthite ({Delta}{sup 17}O = -15{per_thousand} to -2{per_thousand}) in 100, 160 and 6-1-72 are {sup 16}O-enriched relative spinel and coarse-grained Al,Ti-diopside and anorthite in ABC, 93 and TS26 ({Delta}{sup 17}O ranges from -20{per_thousand} to -15{per_thousand}, from -15{per_thousand} to -5{per_thousand}, and from -5{per_thousand} to 0{per_thousand}, respectively). In 6-1-72, massive and lacy Al,Ti-diopside grains are {sup 16}O-depleted ({Delta}{sup 17}O {approx} -13{per_thousand}) relative to spinel ({Delta}{sup 17}O = -23{per_thousand}). Melilite is the most {sup 16}O-depleted mineral in all Allende Type C <span class="hlt">CAIs</span>. In <span class="hlt">CAI</span> 100, melilite and secondary grossular, monticellite and forsterite (minerals replacing melilite) are similarly {sup 16}O-depleted, whereas grossular in <span class="hlt">CAI</span> 160 is {sup 16}O-enriched ({Delta}{sup 17}O = -10{per_thousand} to -6{per_thousand}) relative to melilite ({Delta}{sup 17}O = -5{per_thousand} to -3{per_thousand}). We infer</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.V43J..02O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.V43J..02O"><span id="translatedtitle">The isotopic homogeneity in the early solar system: Revisiting the <span class="hlt">CAI</span> oxygen isotopic anomaly</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozima, M.; Yamada, A.</p> <p>2009-12-01</p> <p>Since the first discovery of the mass-independently fractionated oxygen isotopes in anhydrous, high temperature Ca-Al rich inclusion minerals in carbonaceous meteorites (<span class="hlt">CAIs</span>) by Clayton et al. (1), their common occurrence in primitive meteorites has generally been regarded to reflect some fundamental process prevalent in the early solar nebula. The <span class="hlt">CAI</span> oxygen isotopic composition is uniquely characterized by (i) large mass independent isotopic fractionation and (ii) their isotopic data in an oxygen three isotope plot (δ17O - δ18O (δ17O ≡ {(17O/16O)/(17O/16O)SMOW - 1} × 1000) yield nearly a straight line with a slope 1.0. In establishing these characteristics, ion microprobe analyses has played a central role, especially an isotopic mapping technique (isotopography) was crucial (e.g., 2). The extraordinary oxygen isotopic ratio in <span class="hlt">CAIs</span> is widely attributed to the self-shielding absorption of UV radiation in CO, one of the dominant chemical compounds in the early solar nebula (3). However, the self-shielding scenario necessarily leads to the unusual prediction that a mean solar oxygen isotopic composition differs from most of planetary bodies including Earth, Moon, and Mars. If the self-shielding process were indeed responsible to the <span class="hlt">CAI</span> oxygen isotopic anomaly, this would require a fundamental revision of the current theory of the origin of the solar system, which generally assumes the initial total vaporization of nebula material to give rise to isotopic homogenization. The GENESIS mission launched in 2001(4), which collected oxygen in the solar wind was hoped to resolve the isotopic composition of the Sun. However, because of difficulties in correcting for instrumental and more importantly for intrinsic isotopic fractionation between the SW and the Sun, a final answer is yet to be seen (5). Here, we show on the basis of the oxygen isotopic fractionation systematics that the self shielding hypothesis cannot explain the key characteristics of the <span class="hlt">CAI</span> oxygen</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000074637&hterms=learn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dlearn','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000074637&hterms=learn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dlearn"><span id="translatedtitle">What we Hope to Learn about Global Mineral Dust <span class="hlt">Aerosols</span> from EOS Multi-Angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahn, Ralph</p> <p>2000-01-01</p> <p>On global scales, just a few broad atmospheric <span class="hlt">aerosol</span> compositional groups are commonly observed. Of these, "mineral dust" is the only group which both contains non-spherical particles, and typically has size distributions with enough large particles for particle shape to affect its visible-light-scattering properties. The MISR instrument is scheduled for launch into a 10:30 AM sun-synchronous, polar orbit aboard the EOS Terra satellite in 1999. MISR will measure the upwelling visible radiance from Earth in 4 spectral bands centered at 446, 558, 672, and 866 nm, at each of 9 emission angles spread out in the forward and aft directions along the flight path at +/-70.5 deg, +/-60.0 deg, +/-45.6 deg, +/-26.1deg, and nadir. Over a period of 7 minutes, as the spacecraft flies along, a 360 km wide swath of Earth will successively be viewed by each of the cameras, allowing MISR to sample a very large range of scattering angles; in mid latitudes, the instrument will observe scattering angles between about 60 deg and 160 deg. Global coverage will be acquired about once in 9 days at the equator; the nominal mission lifetime is 6 years. The distinction in single scattering phase function between natural distributions of spherical and randomly oriented, non-spherical particles, with a broad range of aspect ratios, shows up strongly for scattering angles ranging from about 90 deg to near 180 deg. For non-spherical particle distributions, single scattering phase functions tend to be much flatter in this region than for spherical particles. Since MISR samples the relevant range of scattering angles very well, we expect to be able to make critical distinctions between natural distributions of spherical and randomly oriented, non-spherical particles with MISR data. We anticipate that the new multiangle, multispectral data from MISR will also contain other information about particle properties, a major step beyond current spacecraft remote sensing retrievals, which obtain <span class="hlt">aerosol</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009gdca.conf..321C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009gdca.conf..321C&link_type=ABSTRACT"><span id="translatedtitle">Problem Solving Process Research of Everyone Involved in Innovation Based on <span class="hlt">CAI</span> Technology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Tao; Shao, Yunfei; Tang, Xiaowo</p> <p></p> <p>It is very important that non-technical department personnel especially bottom line employee serve as innovators under the requirements of everyone involved in innovation. According the view of this paper, it is feasible and necessary to build everyone involved in innovation problem solving process under Total Innovation Management (TIM) based on the Theory of Inventive Problem Solving (TRIZ). The tools under the <span class="hlt">CAI</span> technology: How TO mode and science effects database could be very useful for all employee especially non-technical department and bottom line for innovation. The problem solving process put forward in the paper focus on non-technical department personnel especially bottom line employee for innovation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993Metic..28Q.335C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993Metic..28Q.335C"><span id="translatedtitle">Thermal Histories of PGE-rich Metal Particles in a Vigarano <span class="hlt">CAI</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Casanova, I.; Grossman, L.</p> <p>1993-07-01</p> <p>Metal particles in Vigarano 1623-8, a Type B2 <span class="hlt">CAI</span> [1], underwent virtually no sulfidation, as is typical of opaque assemblages from Ca, Al-rich inclusions in the reduced CV3 chondrites [2]. In this study, we have identified two large metal grains (M1 and M2) with chemical and mineralogical features that may indicate cooling under different conditions and are, therefore, difficult to understand in the environment of a single <span class="hlt">CAIs</span> thermal evolution. M1 is an almost spherical, kamacite+taenite-bearing particle included in a fassaite grain of the <span class="hlt">CAI</span> host; a 17.5 micrometer-long (0.5 micrometer steps) microprobe traverse along M1 shows that Ni and Ru contents in the taenite (31.5 and 1.1 wt%, respectively) are uniform, and differ from those in the adjacent kamacite (Ni=4.5, Ru=0.7 wt%). M2 is a 20 micrometer, irregularly-shaped taenite particle, embedded in a fine-grained (spinel-rich) portion of 1623-8. It has a homogeneous composition with 10.5 wt% Ni, 0.4% Co, 0.7% Re, 0.6% Pt and high concentrations of Ru (6.5 wt%), Os (4.3 wt%) and Ir (8.2 wt%), as previously recognized by [1]. The composition of M2 is such that it should have undergone exsolution at 800 = T >= 600 degrees C (according to experimental data by [3]) to form at least two (alpha+gamma-NiFe), or probably three (+epsilon-RuFe) different phases. Lack of exsolution features in this large grain is therefore indicative of equilibration at relatively high temperatures (T>600 degrees C) followed by rapid cooling. Other metal particles of similar bulk compositions in <span class="hlt">CAIs</span> from the Leoville chondrite (also a reduced CV3) show extensive exsolution features that have been interpreted as the result of low- temperature equilibration of the <span class="hlt">CAI</span> and their constituents after incorporation into their parent body [4, 5]. The relatively high equilibration temperature of M2 is, however, inconsistent with the existence of kamacite in M1. From the phase relations in the Fe-Ni binary, a grain like M1, with 25 wt% bulk Ni</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..132W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..132W"><span id="translatedtitle">A novel method to retrieve <span class="hlt">Aerosol</span> Optical Thickness from high-resolution optical satellite <span class="hlt">images</span> using an extended version of the Haze Optimized Transform (HOTBAR)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilson, Robin; Milton, Edward; Nield, Joanna</p> <p>2016-04-01</p> <p><span class="hlt">Aerosol</span> Optical Thickness (AOT) data has many important applications including atmospheric correction of satellite imagery and monitoring of particulate matter air pollution. Current data products are generally available at a kilometre-scale resolution, but many applications require far higher resolutions. For example, particulate matter concentrations vary on a metre-scale, and thus data products at a similar scale are required to provide accurate assessments of particle densities and allow effective monitoring of air quality and analysis of local air quality effects on health. A novel method has been developed which retrieves per-pixel AOT values from high-resolution (~30m) satellite data. This method is designed to work over a wide range of land covers - including both bright and dark surfaces - and requires only standard visible and near-infrared data, making it applicable to a range of data from sensors such as Landsat, SPOT and Sentinel-2. The method is based upon an extension of the Haze Optimized Transform (HOT). The HOT was originally designed for assessing areas of thick haze in satellite imagery by calculating a 'haziness' value for each pixel in an <span class="hlt">image</span> as the distance from a 'Clear Line' in feature space, defined by the high correlation between visible bands. Here, we adapt the HOT method and use it to provide AOT data instead. Significant extensions include Monte Carlo estimation of the 'Clear Line', object-based correction for land cover, and estimation of AOT from the haziness values through radiative transfer modelling. This novel method will enable many new applications of AOT data that were impossible with previously available low-resolution data, and has the potential to contribute significantly to our understanding of the air quality on health, the accuracy of satellite <span class="hlt">image</span> atmospheric correction and the role of <span class="hlt">aerosols</span> in the climate system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/907835','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/907835"><span id="translatedtitle">Constraints on the Origin of Chondrules and <span class="hlt">CAIs</span> from Short-Lived and Long-Lived Radionuclides</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kita, N T; Huss, G R; Tachibana, S; Amelin, Y; Nyquist, L E; Hutcheon, I D</p> <p>2005-10-24</p> <p>The high time resolution Pb-Pb ages and short-lived nuclide based relative ages for <span class="hlt">CAIs</span> and chondrules are reviewed. The solar system started at 4567.2 {+-} 0.6Ma inferred from the high precision Pb-Pb ages of <span class="hlt">CAIs</span>. Time scales of <span class="hlt">CAIs</span> ({le}0.1Myr), chondrules (1-3Myr), and early asteroidal differentiation ({ge}3Myr) inferred from {sup 26}Al relative ages are comparable to the time scale estimated from astronomical observations of young star; proto star, classical T Tauri star and week-lined T Tauri star, respectively. Pb-Pb ages of chondrules also indicate chondrule formation occur within 1-3 Myr after <span class="hlt">CAIs</span>. Mn-Cr isochron ages of chondrules are similar to or within 2 Myr after <span class="hlt">CAI</span> formation. Chondrules from different classes of chondrites show the same range of {sup 26}Al ages in spite of their different oxygen isotopes, indicating that chondrule formed in the localized environment. The {sup 26}Al ages of chondrules in each chondrite class show a hint of correlation with their chemical compositions, which implies the process of elemental fractionation during chondrule formation events.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2500149','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2500149"><span id="translatedtitle">HIV-1 Capsid Assembly Inhibitor (<span class="hlt">CAI</span>) Peptide: Structural Preferences and Delivery into Human Embryonic Lung Cells and Lymphocytes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Braun, Klaus; Frank, Martin; Pipkorn, Rüdiger; Reed, Jennifer; Spring, Herbert; Debus, Jürgen; Didinger, Bernd; von der Lieth, Claus-Wilhelm; Wiessler, Manfred; Waldeck, Waldemar</p> <p>2008-01-01</p> <p>The Human immunodeficiency virus 1 derived capsid assembly inhibitor peptide (HIV-1 <span class="hlt">CAI</span>-peptide) is a promising lead candidate for anti-HIV drug development. Its drawback, however, is that it cannot permeate cells directly. Here we report the transport of the pharmacologically active <span class="hlt">CAI</span>-peptide into human lymphocytes and Human Embryonic Lung cells (HEL) using the BioShuttle platform. Generally, the transfer of pharmacologically active substances across membranes, demonstrated by confocal laser scanning microscopy (CLSM), could lead to a loss of function by changing the molecule's structure. Molecular dynamics (MD) simulations and circular dichroism (CD) studies suggest that the <span class="hlt">CAI</span>-peptide has an intrinsic capacity to form a helical structure, which seems to be critical for the pharmacological effect as revealed by intensive docking calculations and comparison with control peptides. This coupling of the <span class="hlt">CAI</span>-peptide to a BioShuttle-molecule additionally improved its solubility. Under the conditions described, the HIV-1 <span class="hlt">CAI</span> peptide was transported into living cells and could be localized in the vicinity of the mitochondria. PMID:18695744</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/global_aerosols','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/global_aerosols"><span id="translatedtitle">Global <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2013-04-19</p> <p>... sizes and from multiple sources, including biomass burning, mineral dust, sea salt and regional industrial pollution. A color scale is ... desert source region. Deserts are the main sources of mineral dust, and MISR obtains <span class="hlt">aerosol</span> optical depth at visible wavelengths ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15746387','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15746387"><span id="translatedtitle">Supra-canonical 26Al/27Al and the residence time of <span class="hlt">CAIs</span> in the solar protoplanetary disk.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Young, Edward D; Simon, Justin I; Galy, Albert; Russell, Sara S; Tonui, Eric; Lovera, Oscar</p> <p>2005-04-01</p> <p>The canonical initial 26Al/27Al ratio of 4.5 x 10(-5) has been a fiducial marker for the beginning of the solar system. Laser ablation and whole-rock multiple-collector inductively coupled plasma-source mass spectrometry magnesium isotope analyses of calcium- and aluminum-rich inclusions (<span class="hlt">CAIs</span>) from CV3 meteorites demonstrate that some <span class="hlt">CAIs</span> had initial 26Al/27Al values at least 25% greater than canonical and that the canonical initial 26Al/27Al cannot mark the beginning of solar system formation. Using rates of Mg diffusion in minerals, we find that the canonical initial 26Al/27Al is instead the culmination of thousands of brief high-temperature events incurred by <span class="hlt">CAIs</span> during a 10(5)-year residence time in the solar protoplanetary disk. PMID:15746387</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890006945','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890006945"><span id="translatedtitle">Extending the granularity of representation and control for the MIL-STD <span class="hlt">CAIS</span> 1.0 node model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rogers, Kathy L.</p> <p>1986-01-01</p> <p>The Common APSE (Ada 1 Program Support Environment) Interface Set (<span class="hlt">CAIS</span>) (DoD85) node model provides an excellent baseline for interfaces in a single-host development environment. To encompass the entire spectrum of computing, however, the <span class="hlt">CAIS</span> model should be extended in four areas. It should provide the interface between the engineering workstation and the host system throughout the entire lifecycle of the system. It should provide a basis for communication and integration functions needed by distributed host environments. It should provide common interfaces for communications mechanisms to and among target processors. It should provide facilities for integration, validation, and verification of test beds extending to distributed systems on geographically separate processors with heterogeneous instruction set architectures (ISAS). Additions to the PROCESS NODE model to extend the <span class="hlt">CAIS</span> into these four areas are proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21624269','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21624269"><span id="translatedtitle">[Demotion and promotion of <span class="hlt">CAI</span> Jing and the Medicine School's establishment and abolition three times in the North Song dynasty].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yu-Qing</p> <p>2011-03-01</p> <p><span class="hlt">CAI</span> Jing was appointed the prime minister in the Chongning period of Song Hui-tsung. The Medical School was moved to the Imperial College from Taichang Temple. It used a 3-year education system and divided graduates into three grades. The preferential policies promised top students as 8 or 9-rank official position, which attracted a lot of intellectuals into the field of medicine. <span class="hlt">CAI</span> Jing was demoted three times respectively in the fifth year of the Chongning period, the third year of the Daguan period and the second year of the Zhenghe period, and was promoted again after each demotion. Influenced by changes of <span class="hlt">CAI</span> Jing's position and relative policies, the Medical School was also established and abolished three times. PMID:21624269</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012818','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012818"><span id="translatedtitle">In Situ Trace Element Analysis of an Allende Type B1 <span class="hlt">CAI</span>: EK-459-5-1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jeffcoat, C. R.; Kerekgyarto, A.; Lapen, T. J.; Andreasen, R.; Righter, M.; Ross, D. K.</p> <p>2014-01-01</p> <p>Variations in refractory major and trace element composition of calcium, aluminum-rich inclusions (<span class="hlt">CAIs</span>) provide constraints on physical and chemical conditions and processes in the earliest stages of the Solar System. Previous work indicates that <span class="hlt">CAIs</span> have experienced complex histories involving, in many cases, multiple episodes of condensation, evaporation, and partial melting. We have analyzed major and trace element abundances in two core to rim transects of the melilite mantle as well as interior major phases of a Type B1 <span class="hlt">CAI</span> (EK-459-5-1) from Allende by electron probe micro-analyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to investigate the behavior of key trace elements with a primary focus on the REEs Tm and Yb.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=107209','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=107209"><span id="translatedtitle">Regulation of the Carnitine Pathway in Escherichia coli: Investigation of the <span class="hlt">cai</span>-fix Divergent Promoter Region</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Buchet, Anne; Eichler, Knut; Mandrand-Berthelot, Marie-Andrée</p> <p>1998-01-01</p> <p>The divergent structural operons <span class="hlt">cai</span>TABCDE and fixABCX of Escherichia coli are required for anaerobic carnitine metabolism. Transcriptional monocopy lacZ fusion studies showed that both operons are coexpressed during anaerobic growth in the presence of carnitine, respond to common environmental stimuli (like glucose and nitrate), and are modulated positively by the same general regulators, CRP and FNR, and negatively by H-NS. Overproduction of the <span class="hlt">Cai</span>F specific regulatory protein mediating the carnitine signal restored induction in an fnr mutant, corresponding to its role as the primary target for anaerobiosis. Transcript analysis identified two divergent transcription start points initiating 289 bp apart. DNase I footprinting revealed three sites with various affinities for the binding of the cAMP-CRP complex inside this regulatory region. Site-directed mutagenesis experiments indicated that previously reported perfect CRP motif 1, centered at −41.5 of the <span class="hlt">cai</span> transcriptional start site, plays a direct role in the sole <span class="hlt">cai</span> activation. In contrast, mutation in CRP site 2, positioned at −69.5 of the fix promoter, caused only a threefold reduction in fix expression. Thus, the role of the third CRP site, located at −126.5 of fix, might be to reinforce the action of site 2. A critical 50-bp cis-acting sequence overlapping the fix mRNA start site was found, by deletion analysis, to be necessary for <span class="hlt">cai</span> transcription. This region is thought to be involved in transduction of the signal mediated by the <span class="hlt">Cai</span>F regulator. PMID:9573142</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A33I3308B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A33I3308B"><span id="translatedtitle">Using the OMI <span class="hlt">Aerosol</span> Index and Absorption <span class="hlt">Aerosol</span> Optical Depth to Evaluate the NASA MERRA <span class="hlt">Aerosol</span> Reanalysis.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buchard, V.; da Silva, A. M., Jr.; Colarco, P. R.; Darmenov, A.; Govindaraju, R.</p> <p>2014-12-01</p> <p>A radiative transfer interface has been developed to simulate the UV <span class="hlt">Aerosol</span> Index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) <span class="hlt">aerosol</span> assimilated fields. The purpose of this work is to use the AI derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications <span class="hlt">Aerosol</span> Reanalysis (MERRAero). In this presentation we show comparisons of model produced AI with the corresponding OMI measurements during several months of 2007 characterized by a good sampling of dust and biomass burning events. In parallel, model produced Absorption <span class="hlt">Aerosol</span> Optical Depth (AAOD) were compared to OMI AAOD for the same period, identifying regions where the model representation of absorbing <span class="hlt">aerosols</span> were deficient. Since AI is dependent on <span class="hlt">aerosol</span> concentration, optical properties and altitude of the <span class="hlt">aerosol</span> layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR) and the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) sensors, <span class="hlt">aerosol</span> retrievals from the <span class="hlt">Aerosol</span> Robotic Network (AERONET) and attenuated backscatter coefficients from the Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain misplacement of plume height by the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120001852','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120001852"><span id="translatedtitle">Ca-Fe and Alkali-Halide Alteration of an Allende Type B <span class="hlt">CAI</span>: Aqueous Alteration in Nebular or Asteroidal Settings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ross, D. K.; Simon, J. I.; Simon, S. B.; Grossman, L.</p> <p>2012-01-01</p> <p>Ca-Fe and alkali-halide alteration of <span class="hlt">CAIs</span> is often attributed to aqueous alteration by fluids circulating on asteroidal parent bodies after the various chondritic components have been assembled, although debate continues about the roles of asteroidal vs. nebular modification processes [1-7]. Here we report de-tailed observations of alteration products in a large Type B2 <span class="hlt">CAI</span>, TS4 from Allende, one of the oxidized subgroup of CV3s, and propose a speculative model for aqueous alteration of <span class="hlt">CAIs</span> in a nebular setting. Ca-Fe alteration in this <span class="hlt">CAI</span> consists predominantly of end-member hedenbergite, end-member andradite, and compositionally variable, magnesian high-Ca pyroxene. These phases are strongly concentrated in an unusual "nodule" enclosed within the interior of the <span class="hlt">CAI</span> (Fig. 1). The Ca, Fe-rich nodule superficially resembles a clast that pre-dated and was engulfed by the <span class="hlt">CAI</span>, but closer inspection shows that relic spinel grains are enclosed in the nodule, and corroded <span class="hlt">CAI</span> primary phases interfinger with the Fe-rich phases at the nodule s margins. This <span class="hlt">CAI</span> also contains abundant sodalite and nepheline (alkali-halide) alteration that occurs around the rims of the <span class="hlt">CAI</span>, but also penetrates more deeply into the <span class="hlt">CAI</span>. The two types of alteration (Ca-Fe and alkali-halide) are adjacent, and very fine-grained Fe-rich phases are associated with sodalite-rich regions. Both types of alteration appear to be replacive; if that is true, it would require substantial introduction of Fe, and transport of elements (Ti, Al and Mg) out of the nodule, and introduction of Na and Cl into alkali-halide rich zones. Parts of the <span class="hlt">CAI</span> have been extensively metasomatized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160002651','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160002651"><span id="translatedtitle">Calcium and Titanium Isotope Fractionation in <span class="hlt">CAIS</span>: Tracers of Condensation and Inheritance in the Early Solar Protoplanetary Disk</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simon, J. I.; Jordan, M. K.; Tappa, M. J.; Kohl, I. E.; Young, E. D.</p> <p>2016-01-01</p> <p>The chemical and isotopic compositions of calcium-aluminum-rich inclusions (<span class="hlt">CAIs</span>) can be used to understand the conditions present in the protoplantary disk where they formed. The isotopic compositions of these early-formed nebular materials are largely controlled by chemical volatility. The isotopic effects of evaporation/sublimation, which are well explained by both theory and experimental work, lead to enrichments of the heavy isotopes that are often exhibited by the moderately refractory elements Mg and Si. Less well understood are the isotopic effects of condensation, which limits our ability to determine whether a <span class="hlt">CAI</span> is a primary condensate and/or retains any evidence of its primordial formation history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010679','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010679"><span id="translatedtitle">Microstructures of Hibonite From an ALH A77307 (CO3.0) <span class="hlt">CAI</span>: Evidence for Evaporative Loss of Calcium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Han, Jangmi; Brearley, Adrian J.; Keller, Lindsay P.</p> <p>2014-01-01</p> <p>Hibonite is a comparatively rare, primary phase found in some <span class="hlt">CAIs</span> from different chondrite groups and is also common in Wark-Lovering rims [1]. Hibonite is predicted to be one of the earliest refractory phases to form by equilibrium condensation from a cooling gas of solar composition [2] and, therefore, can be a potential recorder of very early solar system processes. In this study, we describe the microstructures of hibonite from one <span class="hlt">CAI</span> in ALH A77307 (CO3.0) using FIB/TEM techniques in order to reconstruct its formational history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920021861&hterms=co2+profile+measurements&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dco2%2Bprofile%2Bmeasurements','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920021861&hterms=co2+profile+measurements&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dco2%2Bprofile%2Bmeasurements"><span id="translatedtitle"><span class="hlt">Aerosol</span> extinction measurements with CO2-lidar</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hagard, Arne; Persson, Rolf</p> <p>1992-01-01</p> <p>With the aim to develop a model for infrared extinction due to <span class="hlt">aerosols</span> in slant paths in the lower atmosphere we perform measurements with a CO2-lidar. Earlier measurements with a transmissometer along horizontal paths have been used to develop relations between <span class="hlt">aerosol</span> extinction and meteorological parameters. With the lidar measurements we hope to develop corresponding relations for altitude profiles of the <span class="hlt">aerosol</span> extinction in the infrared. An important application is prediction of detection range for infrared <span class="hlt">imaging</span> systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25284435','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25284435"><span id="translatedtitle">Brain responses to sexual <span class="hlt">images</span> in 46,XY women with complete androgen insensitivity syndrome are female-typical.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hamann, Stephan; Stevens, Jennifer; Vick, Janice Hassett; Bryk, Kristina; Quigley, Charmian A; Berenbaum, Sheri A; Wallen, Kim</p> <p>2014-11-01</p> <p>Androgens, estrogens, and sex chromosomes are the major influences guiding sex differences in brain development, yet their relative roles and importance remain unclear. Individuals with complete androgen insensitivity syndrome (<span class="hlt">CAIS</span>) offer a unique opportunity to address these issues. Although women with <span class="hlt">CAIS</span> have a Y chromosome, testes, and produce male-typical levels of androgens, they lack functional androgen receptors preventing responding to their androgens. Thus, they develop a female physical phenotype, are reared as girls, and develop into women. Because sexually differentiated brain development in primates is determined primarily by androgens, but may be affected by sex chromosome complement, it is currently unknown whether brain structure and function in women with <span class="hlt">CAIS</span> is more like that of women or men. In the first functional neuroimaging study of (46,XY) women with <span class="hlt">CAIS</span>, typical (46,XX) women, and typical (46, XY) men, we found that men showed greater amygdala activation to sexual <span class="hlt">images</span> than did either typical women or women with <span class="hlt">CAIS</span>. Typical women and women with <span class="hlt">CAIS</span> had highly similar patterns of brain activation, indicating that a Y chromosome is insufficient for male-typical human brain responses. Because women with <span class="hlt">CAIS</span> produce male-typical or elevated levels of testosterone which is aromatized to estradiol these results rule out aromatization of testosterone to estradiol as a determinate of sex differences in patterns of brain activation to sexual <span class="hlt">images</span>. We cannot, however, rule out an effect of social experience on the brain responses of women with <span class="hlt">CAIS</span> as all were raised as girls. PMID:25284435</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003TrGeo...4...91B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003TrGeo...4...91B"><span id="translatedtitle">Tropospheric <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buseck, P. R.; Schwartz, S. E.</p> <p>2003-12-01</p> <p>It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, <span class="hlt">aerosols</span> - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of <span class="hlt">aerosol</span> particles per cubic meter of air.Atmospheric <span class="hlt">aerosols</span> are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. <span class="hlt">Aerosol</span> particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background <span class="hlt">aerosol</span> has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric <span class="hlt">aerosols</span> in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by <span class="hlt">aerosols</span>. Photographs at Yosemite National Park, California, USA. (a) Low <span class="hlt">aerosol</span> concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10 </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=exercise+AND+weight+AND+loss&pg=5&id=EJ528590','ERIC'); return false;" href="http://eric.ed.gov/?q=exercise+AND+weight+AND+loss&pg=5&id=EJ528590"><span id="translatedtitle">A One Year Post-program Assessment of a Computer-Assisted Instruction (<span class="hlt">CAI</span>) Weight Management Program for Industrial Employees: Lessons Learned.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dennison, Kathryn F.; And Others</p> <p>1996-01-01</p> <p>This study examined whether a computer-assisted instruction (<span class="hlt">CAI</span>) nutrition program would help employees maintain weight loss and dietary intake improvements over time. Subjects received either no nutrition education, education with microcomputer use, or education without microcomputers. Posttesting found greater weight loss for <span class="hlt">CAI</span> participants,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED503459.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED503459.pdf"><span id="translatedtitle">A Comparative Study to Evaluate the Effectiveness of Computer Assisted Instruction (<span class="hlt">CAI</span>) versus Class Room Lecture (RL) for Computer Science at ICS Level</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kausar, Tayyaba; Choudhry, Bushra Naoreen; Gujjar, Aijaz Ahmed</p> <p>2008-01-01</p> <p>This study was aimed to evaluate the effectiveness of <span class="hlt">CAI</span> vs. classroom lecture for computer science at ICS level. The objectives were to compare the learning effects of two groups with class room lecture and computer assisted instruction studying the same curriculum and the effects of <span class="hlt">CAI</span> and CRL in terms of cognitive development. Hypothesis of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1102933.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1102933.pdf"><span id="translatedtitle">A Comparative Study to Evaluate the Effectiveness of Computer Assisted Instruction (<span class="hlt">CAI</span>) versus Class Room Lecture (CRL) for Computer Science at ICS Level</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kausar, Tayyaba; Choudhry, Bushra Naoreen; Gujjar, Aijaz Ahmed</p> <p>2008-01-01</p> <p>This study was aimed to evaluate the effectiveness of <span class="hlt">CAI</span> vs. classroom lecture for computer science at ICS level. The objectives were to compare the learning effects of two groups with class room lecture and computer assisted instruction studying the same curriculum and the effects of <span class="hlt">CAI</span> and CRL in terms of cognitive development. Hypothesis of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060047785','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060047785"><span id="translatedtitle"><span class="hlt">Aerosol</span> Lidar and MODIS Satellite Comparisons for Future <span class="hlt">Aerosol</span> Loading Forecast</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>DeYoung, Russell; Szykman, James; Severance, Kurt; Chu, D. Allen; Rosen, Rebecca; Al-Saadi, Jassim</p> <p>2006-01-01</p> <p>Knowledge of the concentration and distribution of atmospheric <span class="hlt">aerosols</span> using both airborne lidar and satellite instruments is a field of active research. An aircraft based <span class="hlt">aerosol</span> lidar has been used to study the distribution of atmospheric <span class="hlt">aerosols</span> in the California Central Valley and eastern US coast. Concurrently, satellite <span class="hlt">aerosol</span> retrievals, from the MODIS (Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer) instrument aboard the Terra and Aqua satellites, were take over the Central Valley. The MODIS Level 2 <span class="hlt">aerosol</span> data product provides retrieved ambient <span class="hlt">aerosol</span> optical properties (e.g., optical depth (AOD) and size distribution) globally over ocean and land at a spatial resolution of 10 km. The Central Valley topography was overlaid with MODIS AOD (5x5 sq km resolution) and the <span class="hlt">aerosol</span> scattering vertical profiles from a lidar flight. Backward air parcel trajectories for the lidar data show that air from the Pacific and northern part of the Central Valley converge confining the <span class="hlt">aerosols</span> to the lower valley region and below the mixed layer. Below an altitude of 1 km, the lidar <span class="hlt">aerosol</span> and MODIS AOD exhibit good agreement. Both data sets indicate a high presence of <span class="hlt">aerosols</span> near Bakersfield and the Tehachapi Mountains. These and other results to be presented indicate that the majority of the <span class="hlt">aerosols</span> are below the mixed layer such that the MODIS AOD should correspond well with surface measurements. Lidar measurements will help interpret satellite AOD retrievals so that one day they can be used on a routine basis for prediction of boundary layer <span class="hlt">aerosol</span> pollution events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010652','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010652"><span id="translatedtitle">A FIB/TEM/Nanosims Study of a Wark-Lovering Rim on an Allende <span class="hlt">CAI</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keller, L. P.; Needham, A. W.; Messenger, S.</p> <p>2014-01-01</p> <p>Ca- Al-rich inclusions (<span class="hlt">CAIs</span>) are commonly surrounded by Wark-Lovering (WL) rims - thin (approx. 50 micrometers) multilayered sequences - whose mineralogy is dominated by high temperature minerals similar to those that occur in the cores of <span class="hlt">CAIs</span> [1]. The origins of these WL rims involved high temperature events in the early nebula such as condensation, flashheating or reaction with a nebular reservoir, or combinations of these processes. These rims formed after <span class="hlt">CAI</span> formation but prior to accretion into their parent bodies. We have undertaken a coordinated mineralogical and isotopic study of WL rims to determine the formation conditions of the individual layers and to constrain the isotopic reservoirs they interacted with during their history. We focus here on the spinel layer, the first-formed highest- temperature layer in the WL rim sequence. Results and Discussion: We have performed mineralogical, chemical and isotopic analyses of an unusual ultrarefractory inclusion from the Allende CV3 chondrite (SHAL) consisting of an approx. 500 micrometers long single crystal of hibonite and co-existing coarsegrained perovskite. SHAL is partially surrounded by WL rim. We previously reported on the mineralogy, isotopic compositions and trace elements in SHAL [2-4]. The spinel layer in the WL rim is present only on the hibonite and terminates abruptly at the contact with the coarse perovskite. This simple observation shows that the spinel layer is not a condensate in this case (otherwise spinel would have condensed on the perovskite as well). The spinel layer appears to have formed by gas-phase corrosion of the hibonite by Mg-rich vapors such that the spinel layer grew at the expense of the hibonite. We also found that the spinel layer has the same 16Orich composition as the hibonite. The spinel layer is polycrystalline and individual crystals do not show a crystallographic relationship with the hibonite. An Al-diopside layer overlies the spinel layer, and is present on both</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED505173.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED505173.pdf"><span id="translatedtitle">Computer-Assisted Instruction (<span class="hlt">CAI</span>) in Language Arts: Investigating the Influence of Teacher Knowledge and Attitudes on the Learning Environment</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Davis, Jamie M.</p> <p>2009-01-01</p> <p>The integration of Computer-Assisted Instruction (<span class="hlt">CAI</span>) into the language arts classroom can greatly assist teachers meet the needs of diverse literacy learners. However, this new technology does not come without some concerns, including but not limited to ease of implementation, funding for new hardware and software, appropriate teacher support,…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26159472','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26159472"><span id="translatedtitle">Changes in flavour and microbial diversity during natural fermentation of suan-<span class="hlt">cai</span>, a traditional food made in Northeast China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Rina; Yu, Meiling; Liu, Xiaoyu; Meng, Lingshuai; Wang, Qianqian; Xue, Yating; Wu, Junrui; Yue, Xiqing</p> <p>2015-10-15</p> <p>We measured changes in the main physical and chemical properties, flavour compounds and microbial diversity in suan-<span class="hlt">cai</span> during natural fermentation. The results showed that the pH and concentration of soluble protein initially decreased but were then maintained at a stable level; the concentration of nitrite increased in the initial fermentation stage and after reaching a peak it decreased significantly to a low level by the end of fermentation. Suan-<span class="hlt">cai</span> was rich in 17 free amino acids. All of the free amino acids increased in concentration to different degrees, except histidine. Total free amino acids reached their highest levels in the mid-fermentation stage. The 17 volatile flavour components identified at the start of fermentation increased to 57 by the mid-fermentation stage; esters and aldehydes were in the greatest diversity and abundance, contributing most to the aroma of suan-<span class="hlt">cai</span>. Bacteria were more abundant and diverse than fungi in suan-<span class="hlt">cai</span>; 14 bacterial species were identified from the genera Leuconostoc, Bacillus, Pseudomonas and Lactobacillus. The predominant fungal species identified were Debaryomyces hansenii, Candida tropicalis and Penicillium expansum. PMID:26159472</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26832141','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26832141"><span id="translatedtitle">Phenotypic diversity and correlation between white-opaque switching and the <span class="hlt">CAI</span> microsatellite locus in Candida albicans.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Jian; Guan, Guobo; Dai, Yu; Tao, Li; Zhang, Jianzhong; Li, Houmin; Huang, Guanghua</p> <p>2016-08-01</p> <p>Candida albicans is a commensal fungal pathogen that is often found as part of the human microbial flora. The aim of the present study was to establish a relationship between diverse genotypes and phenotypes of clinical isolates of C. albicans. Totally 231 clinical isolates were collected and used for genotyping and phenotypic switching analysis. Based on the microsatellite locus (<span class="hlt">CAI</span>) genotyping assay, 65 different genotypes were identified, and some dominant types were found in certain human niches. For example, the genotypes of 30-44 and 30-45 were enriched in vaginal infection samples. C. albicans has a number of morphological forms including the single-celled yeasts, multicellular filaments, white, and opaque cell types. The relationship between the <span class="hlt">CAI</span> genotype and the ability to undergo phenotypic switching was examined in the clinical isolates. We found that the strains with longer CAA/G repeats in both alleles of the <span class="hlt">CAI</span> locus were more opaque competent. We also discovered that some MTL heterozygous (a/alpha) isolates could undergo white-opaque switching when grown on regular culture medium (containing glucose as the sole carbon source). Our study establishes a link between phenotypic switching and genotypes of the <span class="hlt">CAI</span> microsatellite locus in clinical isolates of C. albicans. PMID:26832141</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=%22knowledge+management%22&pg=6&id=EJ1062828','ERIC'); return false;" href="http://eric.ed.gov/?q=%22knowledge+management%22&pg=6&id=EJ1062828"><span id="translatedtitle">From Corporate Social Responsibility, through Entrepreneurial Orientation, to Knowledge Sharing: A Study in <span class="hlt">Cai</span> Luong (Renovated Theatre) Theatre Companies</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tuan, Luu Trong</p> <p>2015-01-01</p> <p>Purpose: This paper aims to examine the role of antecedents such as corporate social responsibility (CSR) and entrepreneurial orientation in the chain effect to knowledge sharing among members of <span class="hlt">Cai</span> Luong theatre companies in the Vietnamese context. Knowledge sharing contributes to the depth of the knowledge pool of both the individuals and the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED077195.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED077195.pdf"><span id="translatedtitle">A Model Driven Question-Answering System for a <span class="hlt">CAI</span> Environment. Final Report (July 1970 to May 1972).</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, John S.; And Others</p> <p></p> <p>A question answering system which permits a computer-assisted instruction (<span class="hlt">CAI</span>) student greater initiative in the variety of questions he can ask is described. A method is presented to represent the dynamic processes of a subject matter area by augmented finite state automata, which permits efficient inferencing about dynamic processes and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2784433','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2784433"><span id="translatedtitle">Hunting and use of terrestrial fauna used by <span class="hlt">Cai</span>çaras from the Atlantic Forest coast (Brazil)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2009-01-01</p> <p>Background The Brazilian Atlantic Forest is considered one of the hotspots for conservation, comprising remnants of rain forest along the eastern Brazilian coast. Its native inhabitants in the Southeastern coast include the <span class="hlt">Cai</span>çaras (descendants from Amerindians and European colonizers), with a deep knowledge on the natural resources used for their livelihood. Methods We studied the use of the terrestrial fauna in three <span class="hlt">Cai</span>çara communities, through open-ended interviews with 116 native residents. Data were checked through systematic observations and collection of zoological material. Results The dependence on the terrestrial fauna by <span class="hlt">Cai</span>çaras is especially for food and medicine. The main species used are Didelphis spp., Dasyprocta azarae, Dasypus novemcinctus, and small birds (several species of Turdidae). Contrasting with a high dependency on terrestrial fauna resources by native Amazonians, the <span class="hlt">Cai</span>çaras do not show a constant dependency on these resources. Nevertheless, the occasional hunting of native animals represents a complimentary source of animal protein. Conclusion Indigenous or local knowledge on native resources is important in order to promote local development in a sustainable way, and can help to conserve biodiversity, particularly if the resource is sporadically used and not commercially exploited. PMID:19930595</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SciEd..89..707C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SciEd..89..707C"><span id="translatedtitle">The interplay between different forms of <span class="hlt">CAI</span> and students' preferences of learning environment in the secondary science class</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Chun-Yen; Tsai, Chin-Chung</p> <p>2005-09-01</p> <p>This evaluation study investigated the effects of a teacher-centered versus student-centered computer-assisted instruction (<span class="hlt">CAI</span>) on 10th graders' earth science student learning outcomes. This study also explored whether the effects of different forms of computer-assisted instruction (<span class="hlt">CAI</span>) on student learning outcomes were influenced by student preferences of learning environment (PLE). A total of 347 10th-grade senior high school students participated in this nonequivalent control group quasiexperiment. During a one-week period, one group of students (n = 216) were taught by a teacher-centered <span class="hlt">CAI</span> (TCCAI) model whereas the other group of students (n = 131) were subject to a student-centered <span class="hlt">CAI</span> (SCCAI) method. Results showed that (a) no statistically significant difference on students' earth science achievement was found for either group; (b) TCCAI group had significantly better attitudes toward earth science than did the SCCAI group; furthermore (c) a significant PLE-treatment interaction was found on student attitudes toward the subject matter, where the teacher-centered instructional approach seemed to enhance more positive attitudes of less constructivist-oriented learning preferences students, whereas the student-centered method was more beneficial to more constructivist-oriented learning preferences students on their attitudes toward earth science in a computer-assisted learning environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED532902.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED532902.pdf"><span id="translatedtitle">Investigating Learning Achievements of Thai High School Students in a Sequences and Series Lesson Delivered on <span class="hlt">CAI</span>-Based Materials</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chundang, Ungsana; Singhaprink, Wipawaan; Pongpullponsak, Adisak; Tantipisalkul, Tasanee; Praekhaow, Puchong</p> <p>2012-01-01</p> <p>The current experimental research aims to investigate students' learning outcomes in classes in which the interactive <span class="hlt">CAI</span> (computer-assisted instruction)-based materials were implemented. It also aims to compare the learning outcomes of the students based on regions in which their school is located. The participants were 326 Matthayom-4 students…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030102194','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030102194"><span id="translatedtitle">The MODIS <span class="hlt">Aerosol</span> Algorithm, Products and Validation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, L. A.; Kaufman, Y. J.; Tanre, D.; Mattoo, S.; Chu, D. A.; Martins, J. V.; Li, R.-R.; Ichoku, C.; Levy, R. C.; Kleidman, R. G.</p> <p>2003-01-01</p> <p>The MODerate resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) aboard both NASA's Terra and Aqua satellites is making near global daily observations of the earth in a wide spectral range. These measurements are used to derive spectral <span class="hlt">aerosol</span> optical thickness and <span class="hlt">aerosol</span> size parameters over both land and ocean. The <span class="hlt">aerosol</span> products available over land include <span class="hlt">aerosol</span> optical thickness at three visible wavelengths, a measure of the fraction of <span class="hlt">aerosol</span> optical thickness attributed to the fine mode and several derived parameters including reflected spectral solar flux at top of atmosphere. Over ocean, the <span class="hlt">aerosol</span> optical thickness is provided in seven wavelengths from 0.47 microns to 2.13 microns. In addition, quantitative <span class="hlt">aerosol</span> size information includes effective radius of the <span class="hlt">aerosol</span> and quantitative fraction of optical thickness attributed to the fine mode. Spectral <span class="hlt">aerosol</span> flux, mass concentration and number of cloud condensation nuclei round out the list of available <span class="hlt">aerosol</span> products over the ocean. The spectral optical thickness and effective radius of the <span class="hlt">aerosol</span> over the ocean are validated by comparison with two years of AERONET data gleaned from 133 AERONET stations. 8000 MODIS <span class="hlt">aerosol</span> retrievals colocated with AERONET measurements confirm that one-standard deviation of MODIS optical thickness retrievals fall within the predicted uncertainty of delta tauapproximately equal to plus or minus 0.03 plus or minus 0.05 tau over ocean and delta tay equal to plus or minus 0.05 plus or minus 0.15 tau over land. 271 MODIS <span class="hlt">aerosol</span> retrievals co-located with AERONET inversions at island and coastal sites suggest that one-standard deviation of MODIS effective radius retrievals falls within delta r_eff approximately equal to 0.11 microns. The accuracy of the MODIS retrievals suggests that the product can be used to help narrow the uncertainties associated with <span class="hlt">aerosol</span> radiative forcing of global climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.A33B0979H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.A33B0979H"><span id="translatedtitle">Seasonality of Forcing by Carbonaceous <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habib, G.; Bond, T.; Rasch, P. J.; Coleman, D.</p> <p>2006-12-01</p> <p><span class="hlt">Aerosols</span> can influence the energy balance of Earth-Atmosphere system with profound effect on regional climate. Atmospheric processes, such as convection, scavenging, wet and dry deposition, govern the lifetime and location of <span class="hlt">aerosol</span>; emissions affect its quantity and location. Both affect climate forcing. Here we investigate the effect of seasonality in emissions and atmospheric processes on radiative forcing by carbonaceous <span class="hlt">aerosols</span>, focusing on <span class="hlt">aerosol</span> from fossil fuel and biofuel. Because <span class="hlt">aerosol</span> lifetime is seasonal, ignoring the seasonality of sources such as residential biofuel may introduce a bias in <span class="hlt">aerosol</span> burden and therefore in predicted climate forcing. We present a global emission inventory of carbonaceous <span class="hlt">aerosols</span> with seasonality, and simulate atmospheric concentrations using the Community Atmosphere Model (CAM). We discuss where and when the seasonality of emissions and atmospheric processes has strong effects on atmospheric burden, lifetime, climate forcing and <span class="hlt">aerosol</span> optical depth (AOD). Previous work has shown that <span class="hlt">aerosol</span> forcing is higher in summer than in winter, and has identified the importance of <span class="hlt">aerosol</span> above cloud in determining black carbon forcing. We show that predicted cloud height is a very important factor in determining normalized radiative forcing (forcing per mass), especially in summer. This can affect the average summer radiative forcing by nearly 50%. Removal by cloud droplets is the dominant atmospheric cleansing mechanism for carbonaceous <span class="hlt">aerosols</span>. We demonstrate the modeled seasonality of removal processes and compare the importance of scavenging by warm and cold clouds. Both types of clouds contribute significantly to <span class="hlt">aerosol</span> removal. We estimate uncertainty in direct radiative forcing due to scavenging by tagging the <span class="hlt">aerosol</span> which has experienced cloud interactions. Finally, seasonal variations offer an opportunity to assess modeled processes when a single process dominates variability. We identify regions where <span class="hlt">aerosol</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997SPIE.3125..214K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997SPIE.3125..214K"><span id="translatedtitle"><span class="hlt">Aerosol</span> modulation transfer function: an overview</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kopeika, Norman S.</p> <p>1997-09-01</p> <p>The <span class="hlt">aerosol</span> modulation transfer function (MTF) describes blurring deriving from light scatter caused by <span class="hlt">aerosols</span>. Little scintillations or <span class="hlt">image</span> dancing are involved. When overall atmospheric point spread function (PSF) is analyzed for its turbulence component deriving from angle-of-arrival fluctuations or scintillations, a significant portion of the PSF is left over. This is the <span class="hlt">aerosol</span> component. This overview describes the basic physical mechanisms for <span class="hlt">aerosol</span> MTF and its wavelength, weather, and time exposure dependences, as well as a comparison to turbulence MiT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020008210','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020008210"><span id="translatedtitle">Validation of MODIS <span class="hlt">Aerosol</span> Retrieval Over Ocean</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, Lorraine A.; Tanre, Didier; Kaufman, Yoram J.; Ichoku, Charles; Mattoo, Shana; Levy, Robert; Chu, D. Allen; Holben, Brent N.; Dubovik, Oleg; Ahmad, Ziauddin; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>The MODerate resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) algorithm for determining <span class="hlt">aerosol</span> characteristics over ocean is performing with remarkable accuracy. A two-month data set of MODIS retrievals co-located with observations from the <span class="hlt">AErosol</span> RObotic NETwork (AERONET) ground-based sunphotometer network provides the necessary validation. Spectral radiation measured by MODIS (in the range 550 - 2100 nm) is used to retrieve the <span class="hlt">aerosol</span> optical thickness, effective particle radius and ratio between the submicron and micron size particles. MODIS-retrieved <span class="hlt">aerosol</span> optical thickness at 660 nm and 870 nm fall within the expected uncertainty, with the ensemble average at 660 nm differing by only 2% from the AERONET observations and having virtually no offset. MODIS retrievals of <span class="hlt">aerosol</span> effective radius agree with AERONET retrievals to within +/- 0.10 micrometers, while MODIS-derived ratios between large and small mode <span class="hlt">aerosol</span> show definite correlation with ratios derived from AERONET data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ACP....15.5743B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ACP....15.5743B"><span id="translatedtitle">Using the OMI <span class="hlt">aerosol</span> index and absorption <span class="hlt">aerosol</span> optical depth to evaluate the NASA MERRA <span class="hlt">Aerosol</span> Reanalysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.</p> <p>2015-05-01</p> <p>A radiative transfer interface has been developed to simulate the UV <span class="hlt">aerosol</span> index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) <span class="hlt">aerosol</span> assimilated fields. The purpose of this work is to use the AI and <span class="hlt">aerosol</span> absorption optical depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications <span class="hlt">Aerosol</span> Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, <span class="hlt">Aerosol</span>, Radiation, and Transport (GOCART) <span class="hlt">aerosol</span> module and includes assimilation of <span class="hlt">aerosol</span> optical depth (AOD) from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) sensor. Since AI is dependent on <span class="hlt">aerosol</span> concentration, optical properties and altitude of the <span class="hlt">aerosol</span> layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR), <span class="hlt">aerosol</span> retrievals from the <span class="hlt">AErosol</span> RObotic NETwork (AERONET) and attenuated backscatter coefficients from the Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model-produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing <span class="hlt">aerosols</span> was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust <span class="hlt">aerosol</span> optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with <span class="hlt">aerosol</span> absorption measurements from OMI. The analysis conducted over the southern African and South American biomass burning regions indicates that revising the spectrally dependent <span class="hlt">aerosol</span> absorption properties in the near-UV region improves the modeled-observed AI comparisons</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ACP....1510597P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ACP....1510597P"><span id="translatedtitle">A global <span class="hlt">aerosol</span> classification algorithm incorporating multiple satellite data sets of <span class="hlt">aerosol</span> and trace gas abundances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Penning de Vries, M. J. M.; Beirle, S.; Hörmann, C.; Kaiser, J. W.; Stammes, P.; Tilstra, L. G.; Tuinder, O. N. E.; Wagner, T.</p> <p>2015-09-01</p> <p>Detecting the optical properties of <span class="hlt">aerosols</span> using passive satellite-borne measurements alone is a difficult task due to the broadband effect of <span class="hlt">aerosols</span> on the measured spectra and the influences of surface and cloud reflection. We present another approach to determine <span class="hlt">aerosol</span> type, namely by studying the relationship of <span class="hlt">aerosol</span> optical depth (AOD) with trace gas abundance, <span class="hlt">aerosol</span> absorption, and mean <span class="hlt">aerosol</span> size. Our new Global <span class="hlt">Aerosol</span> Classification Algorithm, GACA, examines relationships between <span class="hlt">aerosol</span> properties (AOD and extinction Ångström exponent from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS), UV <span class="hlt">Aerosol</span> Index from the second Global Ozone Monitoring Experiment, GOME-2) and trace gas column densities (NO2, HCHO, SO2 from GOME-2, and CO from MOPITT, the Measurements of Pollution in the Troposphere instrument) on a monthly mean basis. First, <span class="hlt">aerosol</span> types are separated based on size (Ångström exponent) and absorption (UV <span class="hlt">Aerosol</span> Index), then the dominating sources are identified based on mean trace gas columns and their correlation with AOD. In this way, global maps of dominant <span class="hlt">aerosol</span> type and main source type are constructed for each season and compared with maps of <span class="hlt">aerosol</span> composition from the global MACC (Monitoring Atmospheric Composition and Climate) model. Although GACA cannot correctly characterize transported or mixed <span class="hlt">aerosols</span>, GACA and MACC show good agreement regarding the global seasonal cycle, particularly for urban/industrial <span class="hlt">aerosols</span>. The seasonal cycles of both <span class="hlt">aerosol</span> type and source are also studied in more detail for selected 5° × 5° regions. Again, good agreement between GACA and MACC is found for all regions, but some systematic differences become apparent: the variability of <span class="hlt">aerosol</span> composition (yearly and/or seasonal) is often not well captured by MACC, the amount of mineral dust outside of the dust belt appears to be overestimated, and the abundance of secondary organic <span class="hlt">aerosols</span> is underestimated in comparison</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120003705','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120003705"><span id="translatedtitle">Informing <span class="hlt">Aerosol</span> Transport Models With Satellite Multi-Angle <span class="hlt">Aerosol</span> Measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Limbacher, J.; Patadia, F.; Petrenko, M.; Martin, M. Val; Chin, M.; Gaitley, B.; Garay, M.; Kalashnikova, O.; Nelson, D.; Scollo, S.</p> <p>2011-01-01</p> <p>As the <span class="hlt">aerosol</span> products from the NASA Earth Observing System's Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR) mature, we are placing greater focus on ways of using the <span class="hlt">aerosol</span> amount and type data products, and <span class="hlt">aerosol</span> plume heights, to constrain <span class="hlt">aerosol</span> transport models. We have demonstrated the ability to map <span class="hlt">aerosol</span> air-mass-types regionally, and have identified product upgrades required to apply them globally, including the need for a quality flag indicating the <span class="hlt">aerosol</span> type information content, that varies depending upon retrieval conditions. We have shown that MISR <span class="hlt">aerosol</span> type can distinguish smoke from dust, volcanic ash from sulfate and water particles, and can identify qualitative differences in mixtures of smoke, dust, and pollution <span class="hlt">aerosol</span> components in urban settings. We demonstrated the use of stereo <span class="hlt">imaging</span> to map smoke, dust, and volcanic effluent plume injection height, and the combination of MISR and MODIS <span class="hlt">aerosol</span> optical depth maps to constrain wildfire smoke source strength. This talk will briefly highlight where we stand on these application, with emphasis on the steps we are taking toward applying the capabilities toward constraining <span class="hlt">aerosol</span> transport models, planet-wide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26ES...18a2098W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26ES...18a2098W"><span id="translatedtitle"><span class="hlt">Aerosol</span> retrieval algorithm for the characterization of local <span class="hlt">aerosol</span> using MODIS L1B data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wahab, A. M.; Sarker, M. L. R.</p> <p>2014-02-01</p> <p>Atmospheric <span class="hlt">aerosol</span> plays an important role in radiation budget, climate change, hydrology and visibility. However, it has immense effect on the air quality, especially in densely populated areas where high concentration of <span class="hlt">aerosol</span> is associated with premature death and the decrease of life expectancy. Therefore, an accurate estimation of <span class="hlt">aerosol</span> with spatial distribution is essential, and satellite data has increasingly been used to estimate <span class="hlt">aerosol</span> optical depth (AOD). <span class="hlt">Aerosol</span> product (AOD) from Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) data is available at global scale but problems arise due to low spatial resolution, time-lag availability of AOD product as well as the use of generalized <span class="hlt">aerosol</span> models in retrieval algorithm instead of local <span class="hlt">aerosol</span> models. This study focuses on the <span class="hlt">aerosol</span> retrieval algorithm for the characterization of local <span class="hlt">aerosol</span> in Hong Kong for a long period of time (2006-2011) using high spatial resolution MODIS level 1B data (500 m resolution) and taking into account the local <span class="hlt">aerosol</span> models. Two methods (dark dense vegetation and MODIS land surface reflectance product) were used for the estimation of the surface reflectance over land and Santa Barbara DISORT Radiative Transfer (SBDART) code was used to construct LUTs for calculating the <span class="hlt">aerosol</span> reflectance as a function of AOD. Results indicate that AOD can be estimated at the local scale from high resolution MODIS data, and the obtained accuracy (ca. 87%) is very much comparable with the accuracy obtained from other studies (80%-95%) for AOD estimation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=GL-2002-002141&hterms=ocean+images&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Docean%2Bimages','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=GL-2002-002141&hterms=ocean+images&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Docean%2Bimages"><span id="translatedtitle">Effects of <span class="hlt">Aerosols</span> over the Indian Ocean</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p><span class="hlt">Aerosols</span> that contain black carbon both absorb and reflect incoming sunlight. Even as these atmospheric particles reduce the amount of sunlight reaching the surface, they increase the amount of solar energy absorbed in the atmosphere, thus making it possible to both cool the surface and warm the atmosphere. The <span class="hlt">images</span> above show satellite measurements of the region studied during the Indian Ocean Experiment (INDOEX)a vast region spanning the Arabian Sea and Bay of Bengal (west to east), and from the foot of the Himalayan Mountains, across the Indian subcontinent to the southern Indian Ocean (north to south). The <span class="hlt">Aerosol</span> <span class="hlt">images</span> show <span class="hlt">aerosol</span> pollution (brownish pixels) in the lower atmosphere over the INDOEX study area, as measured by the Moderate-resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) aboard Terra. These were composited from March 14-21, 2001. The Albedo <span class="hlt">images</span> show the total solar energy reflected back to space, as measured by Clouds and Earth's Radiant Energy System (CERES) aboard Terra. White pixels show high values, greens are intermediate values, and blues are low. Note how the <span class="hlt">aerosols</span>, particularly over the ocean, increase the amount of energy reflected back to space. The Atmospheric Warming <span class="hlt">images</span> show the absorption of the black carbon <span class="hlt">aerosols</span> in the atmosphere. Where the <span class="hlt">aerosols</span> are most dense, the absorption is highest. Red pixels indicate the highest levels of absorption, blues are low. The Surface Cooling <span class="hlt">images</span> show that the <span class="hlt">aerosol</span> particles reduce the amount of sunlight reaching the surface. Dark pixels show where the <span class="hlt">aerosols</span> exert their cooling influence on the surface (or a high magnitude of negative radiative forcing). The bright pixels show where there is much less <span class="hlt">aerosol</span> pollution and the incoming sunlight is relatively unaffected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016SPIE.9882E..08P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016SPIE.9882E..08P&link_type=ABSTRACT"><span id="translatedtitle">Genesis of elevated <span class="hlt">aerosol</span> loading over the Indian region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prijith, S. S.; Rao, P. V. N.; Mohan, Mannil</p> <p>2016-05-01</p> <p>Elevated <span class="hlt">aerosols</span> assume importance as the diabatic heating due to <span class="hlt">aerosol</span> absorption is more intense at higher altitudes where the atmosphere becomes thinner. Indian region, especially its central and northern latitudes, experiences significant loading of elevated <span class="hlt">aerosols</span> during pre-monsoon and summer months. Genesis of elevated <span class="hlt">aerosol</span> loading over Indian region is investigated in the present study, using multi-year satellite observations from Cloud <span class="hlt">Aerosol</span> Lidar with Orthogonal Polarization (CALIOP) and Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) along with reanalysis winds from MERRA. Central India is observed to have prominent <span class="hlt">aerosols</span> loading at higher altitudes during pre-monsoon season, whereas it is during summer months over north-west India. Further analysis reveals that the elevated <span class="hlt">aerosols</span> over Indian region in pre-monsoon and summer months are significantly contributed by transported mineral dust from the arid continental regions at west. In addition to the mineral dust advection, <span class="hlt">aerosols</span> at higher altitudes over Indian region are enriched by strong convection and associated vertical transport of surface level <span class="hlt">aerosols</span>. Vertical transport of <span class="hlt">aerosols</span> observed over Indian region during pre-monsoon and summer months is aided by intense convergence at the surface level and divergence at the upper level. Moreover, <span class="hlt">aerosol</span> source/sink strength estimated using <span class="hlt">aerosol</span> flux continuity equation show significant <span class="hlt">aerosol</span> production over central India during pre-monsoon. Strong vertical transport prevails during pre-monsoon uplifts the locally produced <span class="hlt">aerosols</span>, with considerable anthropogenic fraction, to higher altitudes where their impacts would be more intense.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015M%26PS...50.1512I&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015M%26PS...50.1512I&link_type=ABSTRACT"><span id="translatedtitle">A compound Ca-, Al-rich inclusion from CV3 chondrite Northwest Africa 3118: Implications for understanding processes during <span class="hlt">CAI</span> formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ivanova, Marina A.; Lorenz, Cyril A.; Krot, Alexander N.; MacPherson, Glenn J.</p> <p>2015-09-01</p> <p>A calcium-aluminum-rich inclusion 3N from the Northwest Africa (NWA) 3118 CV3 carbonaceous chondrite is a unique cm-sized compound object, primarily a forsterite-bearing type B (FoB) <span class="hlt">CAI</span>, that encloses at least 26 smaller <span class="hlt">CAIs</span> of different types, including compact type A (CTA), B, C, and an ultra-refractory inclusion. Relative to typical type A and B <span class="hlt">CAIs</span> found elsewhere, the bulk compositions of the types A and B <span class="hlt">CAIs</span> within 3N more closely match the bulk compositions predicted by equilibrium condensation of a gas of solar composition. Being trapped within the FoB melt may have protected them from melt evaporation that affected most "stand-alone" <span class="hlt">CAIs</span>. 3N originated either as an aggregate of many smaller (mostly types A, B, C) <span class="hlt">CAIs</span> plus accreted Fo-bearing material (like an amoeboid olivine aggregate) which experienced partial melting of the whole, or else as a FoB melt droplet that collided with and trapped many smaller solid <span class="hlt">CAIs</span>. In the former case, 3N recorded the earliest accretion of pebble-sized bodies known. In the latter case, the presence of a large number of individual refractory inclusions within 3N suggests a very high local density of refractory solids in the immediate region of the host <span class="hlt">CAI</span> during the brief time while it was melted. Collisions would have occurred on time scales of hours at most, assuming a melt solidification interval for the host <span class="hlt">CAI</span> of 300-400 °C (maximum) and a cooling rate of ~10 °C/h.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010057626','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010057626"><span id="translatedtitle">Atmospheric <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pueschel, R. F.; Lawless, James G. (Technical Monitor)</p> <p>1994-01-01</p> <p><span class="hlt">Aerosols</span>, defined as particles and droplets suspended in air, are always present in the atmosphere. They are part of the earth-atmosphere climate system, because they interact with both incoming solar and outgoing terrestrial radiation. They do this directly through scattering and absorption, and indirectly through effects on clouds. Submicrometer <span class="hlt">aerosols</span> usually predominate in terms of number of particles per unit volume of air. They have dimensions close to the wavelengths of visible light, and thus scatter radiation from the sun very effectively. They are produced in the atmosphere by chemical reactions of sulfur-, nitrogen- and carbon-containing gases of both natural and anthropogenic origins. Light absorption is dominated by particles containing elemental carbon (soot), produced by incomplete combustion of fossil fuels and by biomass burning. Light-scattering dominates globally, although absorption can be significant at high latitudes, particularly over highly reflective snow- or ice-covered surfaces. Other <span class="hlt">aerosol</span> substances that may be locally important are those from volcanic eruptions, wildfires and windblown dust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930046612&hterms=scanner&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dscanner','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930046612&hterms=scanner&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dscanner"><span id="translatedtitle">Comment on '<span class="hlt">Aerosol</span> and Rayleigh radiance contributions to Coastal Zone Colour Scanner <span class="hlt">images</span>' by Eckstein and Simpson</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gordon, H. R.; Evans, R. H.</p> <p>1993-01-01</p> <p>In a recent paper Eckstein and Simpson describe what they believe to be serious difficulties and/or errors with the CZCS (Coastal Zone Color Scanner) processing algorithms based on their analysis of seven <span class="hlt">images</span>. Here we point out that portions of their analysis, particularly those dealing with multiple scattered Rayleigh radiance, are incorrect. We also argue that other problems they discuss have already been addressed in the literature. Finally, we suggest that many apparent artifacts in CZCS-derived pigment fields are likely to be due to inadequacies in the sensor band set or to poor radiometric stability, both of which will be remedied with the next generation of ocean color sensors.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120017003','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120017003"><span id="translatedtitle">Estimating Marine <span class="hlt">Aerosol</span> Particle Volume and Number from Maritime <span class="hlt">Aerosol</span> Network Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sayer, A. M.; Smirnov, A.; Hsu, N. C.; Munchak, L. A.; Holben, B. N.</p> <p>2012-01-01</p> <p>As well as spectral <span class="hlt">aerosol</span> optical depth (AOD), <span class="hlt">aerosol</span> composition and concentration (number, volume, or mass) are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to <span class="hlt">aerosol</span> composition. This study uses spectral AOD measured on Maritime <span class="hlt">Aerosol</span> Network (MAN) cruises, with the additional constraint of a microphysical model for unpolluted maritime <span class="hlt">aerosol</span> based on analysis of <span class="hlt">Aerosol</span> Robotic Network (AERONET) inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime <span class="hlt">aerosol</span>, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and <span class="hlt">aerosol</span> number for unpolluted maritime cases are also compared with Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different <span class="hlt">aerosol</span> microphysical models. The average solution MODIS dataset agrees more closely with MAN than the best solution dataset. Terra tends to retrieve lower <span class="hlt">aerosol</span> number than MAN, and Aqua higher, linked with differences in the <span class="hlt">aerosol</span> models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and <span class="hlt">aerosol</span> microphysical properties are reasonably well-constrained, estimates of <span class="hlt">aerosol</span> number and volume using MAN or similar data would provide for a greater variety of potential comparisons with <span class="hlt">aerosol</span> properties derived from satellite or chemistry transport model data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3120871','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3120871"><span id="translatedtitle">Qualitative Real-Time Schlieren and Shadowgraph <span class="hlt">Imaging</span> of Human Exhaled Airflows: An Aid to <span class="hlt">Aerosol</span> Infection Control</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tang, Julian W.; Nicolle, Andre D. G.; Pantelic, Jovan; Jiang, Mingxiu; Sekhr, Chandra; Cheong, David K. W.; Tham, Kwok Wai</p> <p>2011-01-01</p> <p>Using a newly constructed airflow <span class="hlt">imaging</span> system, airflow patterns were visualized that were associated with common, everyday respiratory activities (e.g. breathing, talking, laughing, whistling). The effectiveness of various interventions (e.g. putting hands and tissues across the mouth and nose) to reduce the potential transmission of airborne infection, whilst coughing and sneezing, were also investigated. From the digital video footage recorded, it was seen that both coughing and sneezing are relatively poorly contained by commonly used configurations of single-handed shielding maneuvers. Only some but not all of the forward momentum of the cough and sneeze puffs are curtailed with various hand techniques, and the remaining momentum is disseminated in a large puff in the immediate vicinity of the cougher, which may still act as a nearby source of infection. The use of a tissue (in this case, 4-ply, opened and ready in the hand) proved to be surprisingly effective, though the effectiveness of this depends on the tissue remaining intact and not ripping apart. Interestingly, the use of a novel ‘coughcatcher’ device appears to be relatively effective in containing coughs and sneezes. One aspect that became evident during the experimental procedures was that the effectiveness of all of these barrier interventions is very much dependent on the speed with which the user can put them into position to cover the mouth and nose effectively. From these qualitative schlieren and shadowgraph <span class="hlt">imaging</span> experiments, it is clear that making some effort to contain one's cough or sneeze puffs is worthwhile. Obviously, there will be a large amount of variation between individuals in the exact hand or tissue (the most common methods) configuration used for this and other practical factors may hinder such maneuvers in daily life, for example, when carrying shopping bags or managing young children. PMID:21731730</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009GeCoA..73.5100P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009GeCoA..73.5100P&link_type=ABSTRACT"><span id="translatedtitle">Petrologic study of SJ101, a new forsterite-bearing <span class="hlt">CAI</span> from the Allende CV3 chondrite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petaev, Michail I.; Jacobsen, Stein B.</p> <p>2009-09-01</p> <p>The forsterite-bearing Type B (FoB) <span class="hlt">CAI</span> SJ101 consists of three major structural units: (1) light patches of sector-zoned, poikilitic Al-rich clinopyroxene (Cpx) with numerous inclusions of small spinel grains and aggregates and subordinate amounts of Mg-rich melilite (Mel) and anorthite (An) (Sp-Cpx lithology), (2) dark sinuous bands of Al-rich clinopyroxene with large (up to ˜300 × 60 μm) poikilitically enclosed euhedral forsterite (Fo) crystals (Fo-Cpx lithology), and (3) the external Cpx-Sp-An rim overlying the entire inclusion. The two major lithologies are always separated by a transition zone of clinopyroxene poikilitically enclosing both forsterite and spinel. The patches of the Sp-Cpx lithology exhibit significant textural and mineralogical variability that is size-dependent. Small patches typically consist of Cpx and spinel with minor remnants of melilite and/or its alteration products. Large patches contain Mel-An-rich cores with either equigranular-ophitic-subophitic or 'lacy' textures reminiscent of those in Types B or C <span class="hlt">CAIs</span>, respectively. All silicates poikilitically enclose numerous spinel grains of identical habit. Both melilite and anorthite gradually disappear toward the boundary with the Fo-Cpx lithology. Neither the evaporation mantle of Al-rich melilite typical of other FoBs nor the Wark-Lovering rim is present. Secondary minerals include grossular, monticellite, magnetite, and a few grains of wollastonite, andradite, and nepheline. Being a rather typical FoB mineralogically and chemically, texturally SJ101 differs from other FoBs in displaying the nearly complete segregation of forsterite from spinel which occur only in the Fo-Cpx and Sp-Cpx lithologies, respectively. The complex, convoluted internal structure of SJ101 suggests that the coarse-grained Sp-An-Mel-Cpx cores and Fo-Cpx lithology represent the precursor materials of FoBs, proto-<span class="hlt">CAIs</span> and Fo-rich accretionary rims. While the inferred chemistry and mineralogy of the Fo-rich rims</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950012911&hterms=Fractionation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DFractionation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950012911&hterms=Fractionation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DFractionation"><span id="translatedtitle">Heating during solar nebula formation and Mg isotopic fractionation in precursor grains of <span class="hlt">CAIs</span> and chondrules</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sasaki, S.; Nagahara, H.; Kitagami, K.; Nakagawa, Y.</p> <p>1994-01-01</p> <p>In some Ca-Al-rich inclusion (<span class="hlt">CAI</span>) grains, mass-dependent isotopic fractionations of Mg, Si, and O are observed and large Mg isotopic fractionation is interpreted to have been produced by cosmochemical processes such as evaporation and condensation. Mass-dependent Mg isotopic fractionation was found in olivine chondrules of Allende meteorites. Presented is an approximate formula for the temperature of the solar nebula that depends on heliocentric distance and the initial gas distribution. Shock heating during solar nebula formation can cause evaporative fractionation within interstellar grains involved in a gas at the inner zone (a less than 3 AU) of the disk. Alternatively collision of late-accreting gas blobs might cause similar heating if Sigma(sub s) and Sigma are large enough. Since the grain size is small, the solid/gas mass ratio is low and solar (low P(sub O2)), and the ambient gas pressure is low, this heating event could not produce chondrules themselves. Chondrule formation should proceed around the disk midplane after dust grains would grow and sediment to increase the solid/gas ratio there. The heating source there is uncertain, but transient rapid accretion through the disk could release a large amount of heat, which would be observed as FU Orionis events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16929642','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16929642"><span id="translatedtitle">Organic pollution and salt intrusion in <span class="hlt">Cai</span> Nuoc District, Ca Mau Province, Vietnam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tho, Nguyen; Vromant, Nico; Hung, Nguyen Thanh; Hens, Luc</p> <p>2006-07-01</p> <p>In Ca Mau, Vietnam, farmers converted from rice to shrimp farming, while ignoring the degradation of the aquatic environment. We assessed the seasonal variations in organic pollution of the surface water and salt intrusion in one district and assessed the difference in chemical characteristics of the surface water of shrimp ponds and canals. Several variables reflecting salinity and organic pollution were measured in the wet and dry season. The results show that in the dry season salinity increased to 37.36-42.73 g l(-1) and COD and suspended solids increased to a maximum of 268.7 mg l(-1) and 1312.0 mg l(-1), respectively. In the wet season salinity values of 8.16 to 10.60 g l(-1) were recorded, indicating that salinity could no longer be washed out completely in this season. It is concluded that salinity and suspended solids in the aquatic environment in the <span class="hlt">Cai</span> Nuoc district are increased by shrimp monoculture, whereas organic pollution is contributed by human population pressure. PMID:16929642</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994Metic..29..461E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994Metic..29..461E"><span id="translatedtitle">Efremovka E49: A compact type-A <span class="hlt">CAI</span> containing a partially molten spinel-melilite-diopside xenolith</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El Goresy, A.; Zinner, E. K.</p> <p>1994-07-01</p> <p>Eframovka E49 is a triangular 2-mm segment from a Compact Type A (CTA) inclusion with large portions of intact core and rim sequence. It is probably a fragment from an originally round approximately equal to 4-mm Ca-Al rich Inclusion (<span class="hlt">CAI</span>). The core consists of two lithologically different assemblages: (1) The major portion of the <span class="hlt">CAI</span> contains melilite sprinkled with rare spinel, perovskite, and the new Ca-Ti silicate. It is covered by a six-layer rim consisting of (from the interior outward): two layers of Zr- and Y-rich perovskite, spinel, Al-diopside, diopside, and forsteritic olivine. (2) A 650-micron wide complex xenolith contains coarse spinel, melilite, perovskite, and metal in its interior, surrounded by a broad shell of Al-diopside, diopside, and minor fassaite and anorthite, and in the rim fassaite yields Al-diopside yields diopside. Coarse spinels abundantly display resorbtion outlines and some of the grains have been broken down to several amoeboid fragments floating in the eutectic assemblage. All these textures are evidence of local melting of the xenolith followed by fast cooling. No such features are observed in the host <span class="hlt">CAI</span>. Since melting is confined to the xenolith, the melt event must have predated its capture into the core of E49. Ion microprobe trace-element studies reveal distinct differences between Rare Earth Element (REE) abundances in perovskites in the xenolith and the host <span class="hlt">CAI</span>. Perovskites in the xenolith display REE patterns with prominent Yb and small Ce excesses and large Eu depletions. Perovskites in the xenolith show higher abundances of Nb, Zr, and V. Magnesium in xenolith and the host is almost unfractionated. Excesses of Mg-26 are found both in the xenolith and the host with data points plotting along a line with a slope of 4 x 105. This is in accord with the petrographic interpretation and indicates that the melting of the xenolith and its capture in E49 took place early.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040004300','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040004300"><span id="translatedtitle"><span class="hlt">Aerosol</span> Models for the CALIPSO Lidar Inversion Algorithms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Omar, Ali H.; Winker, David M.; Won, Jae-Gwang</p> <p>2003-01-01</p> <p>We use measurements and models to develop <span class="hlt">aerosol</span> models for use in the inversion algorithms for the Cloud <span class="hlt">Aerosol</span> Lidar and <span class="hlt">Imager</span> Pathfinder Spaceborne Observations (CALIPSO). Radiance measurements and inversions of the <span class="hlt">AErosol</span> RObotic NETwork (AERONET1, 2) are used to group global atmospheric <span class="hlt">aerosols</span> using optical and microphysical parameters. This study uses more than 105 records of radiance measurements, <span class="hlt">aerosol</span> size distributions, and complex refractive indices to generate the optical properties of the <span class="hlt">aerosol</span> at more 200 sites worldwide. These properties together with the radiance measurements are then classified using classical clustering methods to group the sites according to the type of <span class="hlt">aerosol</span> with the greatest frequency of occurrence at each site. Six significant clusters are identified: desert dust, biomass burning, urban industrial pollution, rural background, marine, and dirty pollution. Three of these are used in the CALIPSO <span class="hlt">aerosol</span> models to characterize desert dust, biomass burning, and polluted continental <span class="hlt">aerosols</span>. The CALIPSO <span class="hlt">aerosol</span> model also uses the coarse mode of desert dust and the fine mode of biomass burning to build a polluted dust model. For marine <span class="hlt">aerosol</span>, the CALIPSO <span class="hlt">aerosol</span> model uses measurements from the SEAS experiment 3. In addition to categorizing the <span class="hlt">aerosol</span> types, the cluster analysis provides all the column optical and microphysical properties for each cluster.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006IJCEM...7...41C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006IJCEM...7...41C"><span id="translatedtitle">Numerical Investigation Into Effect of Fuel Injection Timing on <span class="hlt">CAI</span>/HCCI Combustion in a Four-Stroke GDI Engine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Li; Zhao, Hua; Jiang, Xi; Kalian, Navin</p> <p>2006-02-01</p> <p>The Controlled Auto-Ignition (<span class="hlt">CAI</span>) combustion, also known as Homogeneous Charge Compression Ignition (HCCI), was achieved by trapping residuals with early exhaust valve closure in conjunction with direct injection. Multi-cycle 3D engine simulations have been carried out for parametric study on four different injection timings in order to better understand the effects of injection timings on in-cylinder mixing and <span class="hlt">CAI</span> combustion. The full engine cycle simulation including complete gas exchange and combustion processes was carried out over several cycles in order to obtain the stable cycle for analysis. The combustion models used in the present study are the Shell auto-ignition model and the characteristic-time combustion model, which were modified to take the high level of EGR into consideration. A liquid sheet breakup spray model was used for the droplet breakup processes. The analyses show that the injection timing plays an important role in affecting the in-cylinder air/fuel mixing and mixture temperature, which in turn affects the <span class="hlt">CAI</span> combustion and engine performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850054072&hterms=Plus+prizes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D10%26Ntt%3DPlus%2Bprizes','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850054072&hterms=Plus+prizes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D10%26Ntt%3DPlus%2Bprizes"><span id="translatedtitle">Willy: A prize noble Ur-Fremdling - Its history and implications for the formation of Fremdlinge and <span class="hlt">CAI</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Armstrong, J. T.; El Goresy, A.; Wasserburg, G. J.</p> <p>1985-01-01</p> <p>The structure and composition of Willy, a 150-micron-diameter Fremdling in <span class="hlt">CAI</span> 5241 from the Allende meteorite, are investigated using optical, secondary-electron, and electron-backscatter microscopy and electron-microprobe analysis. The results are presented in diagrams, maps, tables, graphs, and micrographs and compared with those for other Allende Fremdlinge. Willy is found to have a concentric-zone structure comprising a complex porous core of magnetite, metal, sulfide, scheelite, and other minor phases; a compact magnetite-apatite mantle; a thin (20 microns or less) reaction-assemblage zone; and a dense outer rim of fassaite with minor spinel. A multistage formation sequence involving changes in T and fO2 and preceding the introduction of Willy into the <span class="hlt">CAI</span> (which itself preceded <span class="hlt">CAI</span> spinel and silicate formation) is postulated, and it is inferred from the apparent lack of post-capture recrystallization that Willy has not been subjected to temperatures in excess of 600 C and may represent the precursor material for many other Fremdlinge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040035547&hterms=aerosols+desert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Daerosols%2Bdesert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040035547&hterms=aerosols+desert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Daerosols%2Bdesert"><span id="translatedtitle">MODIS Retrieval of Dust <span class="hlt">Aerosol</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, Lorraine A.; Kaufman, Yoram J.; Tanre, Didier</p> <p>2003-01-01</p> <p>The MODerate resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) currently aboard both the Terra and Aqua satellites produces a suite of products designed to characterize global <span class="hlt">aerosol</span> distribution, optical thickness and particle size. Never before has a space-borne instrument been able to provide such detailed information, operationally, on a nearly global basis every day. The three years of Terra-MODIS data have been validated by comparing with co-located AERONET observations of <span class="hlt">aerosol</span> optical thickness and derivations of <span class="hlt">aerosol</span> size parameters. Some 8000 comparison points located at 133 AERONET sites around the globe show that the MODIS <span class="hlt">aerosol</span> optical thickness retrievals are accurate to within the pre-launch expectations. However, the validation in regions dominated by desert dust is less accurate than in regions dominated by fine mode <span class="hlt">aerosol</span> or background marine sea salt. The discrepancy is most apparent in retrievals of <span class="hlt">aerosol</span> size parameters over ocean. In dust situations, the MODIS algorithm tends to under predict particle size because the reflectances at top of atmosphere measured by MODIS exhibit the stronger spectral signature expected by smaller particles. This pattern is consistent with the angular and spectral signature of non-spherical particles. All possible <span class="hlt">aerosol</span> models in the MODIS Look-Up Tables were constructed from Mie theory, assuming a spherical shape. Using a combination of MODIS and AERONET observations, in regimes dominated by desert dust, we construct phase functions, empirically, with no assumption of particle shape. These new phase functions are introduced into the MODIS algorithm, in lieu of the original options for large dust-like particles. The results will be analyzed and examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120011689','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120011689"><span id="translatedtitle">Global Atmospheric <span class="hlt">Aerosol</span> Modeling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hendricks, Johannes; Aquila, Valentina; Righi, Mattia</p> <p>2012-01-01</p> <p>Global <span class="hlt">aerosol</span> models are used to study the distribution and properties of atmospheric <span class="hlt">aerosol</span> particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric <span class="hlt">aerosol</span> modeling and shows some examples from a global <span class="hlt">aerosol</span> simulation. Particular emphasis is placed on the simulation of <span class="hlt">aerosol</span> particles and their effects within global climate models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459365','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459365"><span id="translatedtitle">Crystal structures of coordination polymers from <span class="hlt">CaI</span>2 and proline</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lamberts, Kevin; Englert, Ulli</p> <p>2015-01-01</p> <p>Completing our reports concerning the reaction products from calcium halides and the amino acid proline, two different solids were found for the reaction of l- and dl-proline with <span class="hlt">CaI</span>2. The enanti­opure amino acid yields the one-dimensional coordination polymer catena-poly[[aqua-μ3-l-proline-tetra-μ2-l-proline-dicalcium] tetra­iodide 1.7-hydrate], {[Ca2(C5H9NO2)5(H2O)]I4·1.7H2O}n, (1), with two independent Ca2+ cations in characteristic seven- and eightfold coordination. Five symmetry-independent zwitterionic l-proline mol­ecules bridge the metal sites into a cationic polymer. Racemic proline forms with Ca2+ cations heterochiral chains of the one-dimensional polymer catena-poly[[di­aquadi-μ2-dl-proline-calcium] diiodide], {[Ca(C5H9NO2)2(H2O)2]I2}n, (2). The centrosymmetric structure is built by one Ca2+ cation that is bridged towards its symmetry equivalents by two zwitterionic proline mol­ecules. In both structures, the iodide ions remain non-coordinating and hydrogen bonds are formed between these counter-anions, the amino groups, coordinating and co-crystallized water mol­ecules. While the overall composition of (1) and (2) is in line with other structures from calcium halides and amino acids, the diversity of the carboxyl­ate coordination geometry is quite surprising. PMID:26090148</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20160009531&hterms=project&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dproject','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20160009531&hterms=project&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dproject"><span id="translatedtitle">New Satellite Project <span class="hlt">Aerosol</span>-UA: Remote Sensing of <span class="hlt">Aerosols</span> in the Terrestrial Atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Milinevsky, G.; Yatskiv, Ya.; Degtyaryov, O.; Syniavskyi, I.; Mishchenko, Michael I.; Rosenbush, V.; Ivanov, Yu.; Makarov, A.; Bovchaliuk, A.; Danylevsky, V.; Sosonkin, M.; Moskalov, S.; Bovchaliuk, V; Lukenyuk, A.; Shymkiv, A.</p> <p>2016-01-01</p> <p>We discuss the development of the Ukrainian space project <span class="hlt">Aerosol</span>-UA which has the following three main objectives: (1) to monitor the spatial distribution of key characteristics of terrestrial tropospheric and stratospheric <span class="hlt">aerosols</span>; (2) to provide a comprehensive observational database enabling accurate quantitative estimates of the <span class="hlt">aerosol</span> contribution to the energy budget of the climate system; and (3) quantify the contribution of anthropogenic <span class="hlt">aerosols</span> to climate and ecological processes. The remote sensing concept of the project is based on precise orbital measurements of the intensity and polarization of sunlight scattered by the atmosphere and the surface with a scanning polarimeter accompanied by a wide-angle multispectral <span class="hlt">imager</span>-polarimeter. Preparations have already been made for the development of the instrument suite for the <span class="hlt">Aerosol</span>-UA project, in particular, of the multi-channel scanning polarimeter (ScanPol) designed for remote sensing studies of the global distribution of <span class="hlt">aerosol</span> and cloud properties (such as particle size, morphology, and composition) in the terrestrial atmosphere by polarimetric and spectrophotometric measurements of the scattered sunlight in a wide range of wavelengths and viewing directions from which a scene location is observed. ScanPol is accompanied by multispectral wide-angle <span class="hlt">imager</span>-polarimeter (MSIP) that serves to collect information on cloud conditions and Earths surface <span class="hlt">image</span>. Various components of the polarimeter ScanPol have been prototyped, including the opto-mechanical and electronic assemblies and the scanning mirror controller. Preliminary synthetic data simulations for the retrieval of <span class="hlt">aerosol</span> parameters over land surfaces have been performed using the Generalized Retrieval of <span class="hlt">Aerosol</span> and Surface Properties (GRASP) algorithm. Methods for the validation of satellite data using ground-based observations of <span class="hlt">aerosol</span> properties are also discussed. We assume that designing, building, and launching into orbit a multi</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcAau.123..292M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcAau.123..292M"><span id="translatedtitle">New satellite project <span class="hlt">Aerosol</span>-UA: Remote sensing of <span class="hlt">aerosols</span> in the terrestrial atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milinevsky, G.; Yatskiv, Ya.; Degtyaryov, O.; Syniavskyi, I.; Mishchenko, M.; Rosenbush, V.; Ivanov, Yu.; Makarov, A.; Bovchaliuk, A.; Danylevsky, V.; Sosonkin, M.; Moskalov, S.; Bovchaliuk, V.; Lukenyuk, A.; Shymkiv, A.; Udodov, E.</p> <p>2016-06-01</p> <p>We discuss the development of the Ukrainian space project <span class="hlt">Aerosol</span>-UA which has the following three main objectives: (1) to monitor the spatial distribution of key characteristics of terrestrial tropospheric and stratospheric <span class="hlt">aerosols</span>; (2) to provide a comprehensive observational database enabling accurate quantitative estimates of the <span class="hlt">aerosol</span> contribution to the energy budget of the climate system; and (3) quantify the contribution of anthropogenic <span class="hlt">aerosols</span> to climate and ecological processes. The remote sensing concept of the project is based on precise orbital measurements of the intensity and polarization of sunlight scattered by the atmosphere and the surface with a scanning polarimeter accompanied by a wide-angle multispectral <span class="hlt">imager</span>-polarimeter. Preparations have already been made for the development of the instrument suite for the <span class="hlt">Aerosol</span>-UA project, in particular, of the multi-channel scanning polarimeter (ScanPol) designed for remote sensing studies of the global distribution of <span class="hlt">aerosol</span> and cloud properties (such as particle size, morphology, and composition) in the terrestrial atmosphere by polarimetric and spectrophotometric measurements of the scattered sunlight in a wide range of wavelengths and viewing directions from which a scene location is observed. ScanPol is accompanied by multispectral wide-angle <span class="hlt">imager</span>-polarimeter (MSIP) that serves to collect information on cloud conditions and Earth's surface <span class="hlt">image</span>. Various components of the polarimeter ScanPol have been prototyped, including the opto-mechanical and electronic assemblies and the scanning mirror controller. Preliminary synthetic data simulations for the retrieval of <span class="hlt">aerosol</span> parameters over land surfaces have been performed using the Generalized Retrieval of <span class="hlt">Aerosol</span> and Surface Properties (GRASP) algorithm. Methods for the validation of satellite data using ground-based observations of <span class="hlt">aerosol</span> properties are also discussed. We assume that designing, building, and launching into orbit a multi</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=163264&keyword=climate+AND+extinction&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65211013&CFTOKEN=52266151','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=163264&keyword=climate+AND+extinction&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65211013&CFTOKEN=52266151"><span id="translatedtitle">A COMPARISON OF CMAQ-BASED <span class="hlt">AEROSOL</span> PROPERTIES WITH IMPROVE, MODIS, AND AERONET DATA</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>We compare select <span class="hlt">aerosol</span> Properties derived from the Community Multiscale Air Quality (CMAQ) model-simulated <span class="hlt">aerosol</span> mass concentrations with routine data from the National Aeronautics and Space Administration (NASA) satellite-borne Moderate Resolution <span class="hlt">Imaging</span> Spectro-radiometer...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100027520','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100027520"><span id="translatedtitle"><span class="hlt">Aerosol</span> gels</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sorensen, Christopher M. (Inventor); Chakrabarti, Amitabha (Inventor); Dhaubhadel, Rajan (Inventor); Gerving, Corey (Inventor)</p> <p>2010-01-01</p> <p>An improved process for the production of ultralow density, high specific surface area gel products is provided which comprises providing, in an enclosed chamber, a mixture made up of small particles of material suspended in gas; the particles are then caused to aggregate in the chamber to form ramified fractal aggregate gels. The particles should have a radius (a) of up to about 50 nm and the <span class="hlt">aerosol</span> should have a volume fraction (f.sub.v) of at least 10.sup.-4. In preferred practice, the mixture is created by a spark-induced explosion of a precursor material (e.g., a hydrocarbon) and oxygen within the chamber. New compositions of matter are disclosed having densities below 3.0 mg/cc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4146S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4146S"><span id="translatedtitle">Retrieval of <span class="hlt">Aerosol</span> Height with TROPOMI</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanders, A. F. J.; de Haan, J. F.; Veefkind, J. P.</p> <p>2012-04-01</p> <p>The Tropospheric Monitoring Instrument (TROPOMI), to be launched in 2015, will feature a new <span class="hlt">aerosol</span> product providing the height of <span class="hlt">aerosol</span> layers. <span class="hlt">Aerosol</span> Layer Height will be one of two <span class="hlt">aerosol</span> products, the other one being the Absorbing <span class="hlt">Aerosol</span> Index. TROPOMI is a UV-VIS-NIR <span class="hlt">imaging</span> spectrometer with daily global coverage. It will be part of ESA's Sentinel-5 Precursor mission. Algorithm development for the <span class="hlt">aerosol</span> height product is currently underway at KNMI. In this presentation we will introduce the algorithm, highlight some of the development issues and discuss possible applications and example <span class="hlt">aerosol</span> cases. <span class="hlt">Aerosol</span> height observations from the near-infrared wavelength range will improve retrieval of other <span class="hlt">aerosol</span> properties, particularly retrieval of absorption optical thickness. An increase in absorption in the ultraviolet wavelength range can be due to a higher imaginary part of the refractive index or to the <span class="hlt">aerosol</span> layer being at a higher altitude. Independent height observations will therefore further constrain retrieval of the single scattering albedo. Furthermore, <span class="hlt">aerosol</span> profile information is an important parameter when estimating radiative forcings and climate impacts of <span class="hlt">aerosol</span>, it is a significant source of uncertainty in trace gas retrieval and it helps in understanding atmospheric transport mechanisms. Finally, timely available, global observations of <span class="hlt">aerosol</span> height will be of interest to aviation safety agencies. The retrieval algorithm for <span class="hlt">aerosol</span> height will be based on absorption by oxygen in the A-band (759-770 nm). <span class="hlt">Aerosols</span> are assumed to be contained in a single layer. A spectral fit of reflectance (resolution 0.5 nm) across the absorption band provides layer height. The retrieval method will be optimal estimation to ensure a proper error analysis. Sensitivity studies have indicated that accuracy and precision of retrieved height for cloud-free scenes will be well below the TROPOMI science requirements (1 km). They have also shown that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......109N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......109N"><span id="translatedtitle">Understanding the impact of saharan dust <span class="hlt">aerosols</span> on tropical cyclones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Naeger, Aaron</p> <p></p> <p>Genesis of Tropical Cyclones (TCs) in the main development region for Atlantic hurricanes is tied to convection initiated by African easterly waves (AEWs) during Northern hemisphere summer and fall seasons. The main development region is also impacted by dust <span class="hlt">aerosols</span> transported from the Sahara. It has been hypothesized that dust <span class="hlt">aerosols</span> can modulate the development of TCs through <span class="hlt">aerosol</span>-radiation and <span class="hlt">aerosol</span>-cloud interaction processes. In this study, we investigate the impact of dust <span class="hlt">aerosols</span> on TC development using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). We first develop a technique to constrain the WRF-Chem model with a realistic three-dimensional spatial distribution of dust <span class="hlt">aerosols</span>. The horizontal distribution of dust is specified using the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) derived <span class="hlt">aerosol</span> products and output from the Goddard Chemistry <span class="hlt">Aerosol</span> Radiation and Transport (GOCART) model. The vertical distribution of dust is constrained using the Cloud <span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). We validate our technique through in situ aircraft measurements where both showed <span class="hlt">aerosol</span> number concentrations from 20-30 cm-3 in the atmosphere for Saharan dust moving over the eastern Atlantic Ocean. Then, we use the satellite data constraint technique to nudge the WRF-Chem <span class="hlt">aerosol</span> fields throughout the simulation of TC Florence developing over the eastern Atlantic Ocean during September 2006. Three different experiments are conducted where the <span class="hlt">aerosol</span>-radiation and <span class="hlt">aerosol</span>-cloud interaction processes are either activated or deactivated in the model while all other model options are identical between the experiments. By comparing the model experiment results, the impact of the <span class="hlt">aerosol</span> interaction processes on TC development can be understood. The results indicate that dust <span class="hlt">aerosols</span> can delay or prevent the development of a TC as the minimum sea level pressure of TC Florence was 13 h</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1815332M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1815332M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Aerosol</span> typing - key information from <span class="hlt">aerosol</span> studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina</p> <p>2016-04-01</p> <p><span class="hlt">Aerosol</span> typing is a key source of <span class="hlt">aerosol</span> information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, <span class="hlt">aerosol</span> typing can be used as input for retrievals or represents an output for other applications. Typically <span class="hlt">aerosol</span> retrievals require some a priori or external <span class="hlt">aerosol</span> type information. The accuracy of the derived <span class="hlt">aerosol</span> products strongly depends on the reliability of these assumptions. Different sensors can make use of different <span class="hlt">aerosol</span> type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of <span class="hlt">aerosol</span> types, showing for example the main source regions and typical transport paths. Climatological studies of <span class="hlt">aerosol</span> load at global and regional scales often rely on inferred <span class="hlt">aerosol</span> type. There is still a high degree of inhomogeneity among satellite <span class="hlt">aerosol</span> typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d <span class="hlt">aerosol</span> type distribution at these scales is essential for understanding the impact of different <span class="hlt">aerosol</span> sources on climate, precipitation and air quality. All this information is needed for planning upcoming <span class="hlt">aerosol</span> emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing <span class="hlt">aerosol</span> type distribution uncertainties. <span class="hlt">Aerosol</span> typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite <span class="hlt">Aerosol</span> Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of <span class="hlt">aerosol</span> typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A13J0310S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A13J0310S"><span id="translatedtitle">Critical evaluation of cloud contamination in MISR <span class="hlt">aerosol</span> product using collocated MODIS <span class="hlt">aerosol</span> and cloud products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Y.; Zhang, J.; Reid, J. S.; Liu, B.; Deshmukh, R.</p> <p>2012-12-01</p> <p>Unique in its ability of observing the atmospheric state in nine angles nearly simultaneously, the Multi-angle <span class="hlt">Imaging</span> Spectroradiometer (MISR) instrument has been successfully used for various applications including remote sensing of <span class="hlt">aerosol</span> properties. However, MISR has limited spectral channels compared with other multi-spectral sensors such as the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS), which poses a challenge to cloud screening for applications using MISR. This is particularly important for <span class="hlt">aerosol</span> property retrievals as cloud contamination and cloud artifacts are one of the larger error sources in satellite <span class="hlt">aerosol</span> products. Using collocated MODIS and MISR data sets, the potential effects of cloud contamination on the MISR <span class="hlt">aerosol</span> product are studied. Over global oceans, for non-glint regions, the cloud mask from the level 2 MODIS <span class="hlt">aerosol</span> products (MOD04) is used. Over ocean glint regions as well as land, the level 2 MODIS cloud mask products (MOD35) are used. The relations between cloud coverage and the bias of MISR AOD are examined using collocated the MODIS cloud information and MISR AOD data. In particular, the suspicious high AOD loading band reported by the MISR <span class="hlt">aerosol</span> product over high latitude southern oceans is investigated. Finally, a level 3 MISR <span class="hlt">aerosol</span> product with a new cloud screening method is developed and the potential usage of such a product in satellite <span class="hlt">aerosol</span> data assimilation is explored.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......222B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......222B"><span id="translatedtitle">An investigative study into the effectiveness of using computer-aided instruction (<span class="hlt">CAI</span>) as a laboratory component of college-level biology: A case study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barrett, Joan Beverly</p> <p></p> <p>Community colleges serve the most diverse student populations in higher education. They consist of non-traditional, part-time, older, intermittent, and mobile students of different races, ethnic backgrounds, language preferences, physical and mental abilities, and learning style preferences. Students who are academically challenged may have diverse learning characteristics that are not compatible with the more traditional approaches to the delivery of instruction. With this need come new ways of solving the dilemma, such as Computer-aided Instruction (<span class="hlt">CAI</span>). This case study investigated the use of <span class="hlt">CAI</span> as a laboratory component of college-level biology in a small, rural community college setting. The intent was to begin to fill a void that seems to exist in the literature regarding the role of the faculty in the development and use of <span class="hlt">CAI</span>. In particular, the investigator was seeking to understand the practice and its effectiveness, especially in helping the under prepared student. The case study approach was chosen to examine a specific phenomenon within a single institution. Ethnographic techniques, such as interviewing, documentary analysis, life's experiences, and participant observations were used to collect data about the phenomena being studied. Results showed that the faculty was primarily self-motivated and self-taught in their use of <span class="hlt">CAI</span> as a teaching and learning tool. The importance of faculty leadership and collegiality was evident. Findings showed the faculty confident that expectations of helping students who have difficulties with mathematical concepts have been met and that <span class="hlt">CAI</span> is becoming the most valuable of learning tools. In a traditional college classroom, or practice, time is the constant (semesters) and competence is the variable. In the <span class="hlt">CAI</span> laboratory time became the variable and competence the constant. The use of <span class="hlt">CAI</span> also eliminated hazardous chemicals that were routinely used in the more traditional lab. Outcomes showed that annual savings</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A23B3218B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A23B3218B"><span id="translatedtitle"><span class="hlt">Aerosol</span>/Radiation, VNIR/NIR/TIR <span class="hlt">Imaging</span>, Net Solar and Longwave Radiation, Meteorological Fluxes, Atmospheric Dropsonde, and Ocean Temperature/Salinity Microbuoy Payloads for Earth Observations Using a Manta Unmanned Aerial System (UAS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bates, T. S.; Gao, R. S.; Murphy, D. M.; Telg, H.; Brown, S.; Dhakai, T.; Zappa, C. J.; Stalin, S.</p> <p>2014-12-01</p> <p>Several new payloads have been developed for use in the Manta UAS. The NOAA/PMEL <span class="hlt">aerosol</span> payload (Atmos. Meas. Tech., 6, 2115-2120, 2013) has been expanded to include a printed optical particle spectrometer to obtain <span class="hlt">aerosol</span> size distributions and an upward looking radiometer to measure radiant flux densities through <span class="hlt">aerosol</span> layers. Lamont-Doherty Earth Observatory (LDEO) has improved its visible and infrared <span class="hlt">imaging</span> payload to provide precise measurements of ice/snow/ocean surface temperatures accurate to 0.1°C. LDEO has also developed a number of new payloads that include: i) hyperspectral aberration-corrected <span class="hlt">imaging</span> spectrometers to measure VNIR (400-1000 nm) and NIR (900-1700 nm) spectral radiance of the upper-ocean and sea ice to determine ocean color, ice-age distributions and ice-surface type; ii) up- and downward-looking hemispheric pyrgeometers and pyranometers to measure the net longwave and net shortwave radiation for ice-ocean albedo studies with an onboard visible camera to determine the sea ice fraction and whitecapping; iii) meteorological measurements of turbulent momentum, sensible, and latent fluxes as well as wave height, ice freeboard, and surface roughness with a LIDAR; iv) four dropsonde-microbuoys (DMB) that can be deployed from the Manta. The four DMB measure temperature, pressure, and relative humidity as they descend through the atmosphere. Once they land on the ocean's surface, they deploy a string of sensors that measures temperature and salinity of the upper three meters of the ocean. The ocean sensors telemeter data back to the UAS on subsequent flights. The DMB can also be dropped on an ice flow to measure the rate of the ice movement. Details of these payloads and example data will be reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFDG16007M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFDG16007M"><span id="translatedtitle">An <span class="hlt">image</span>-based automatic mesh generation and numerical simulation for a population-based analysis of <span class="hlt">aerosol</span> delivery in the human lungs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Lin, Ching-Long</p> <p>2013-11-01</p> <p>The authors propose a method to automatically generate three-dimensional subject-specific airway geometries and meshes for computational fluid dynamics (CFD) studies of <span class="hlt">aerosol</span> delivery in the human lungs. The proposed method automatically expands computed tomography (CT)-based airway skeleton to generate the centerline (CL)-based model, and then fits it to the CT-segmented geometry to generate the hybrid CL-CT-based model. To produce a turbulent laryngeal jet known to affect <span class="hlt">aerosol</span> transport, we developed a physiologically-consistent laryngeal model that can be attached to the trachea of the above models. We used Gmsh to automatically generate the mesh for the above models. To assess the quality of the models, we compared the regional <span class="hlt">aerosol</span> distributions in a human lung predicted by the hybrid model and the manually generated CT-based model. The <span class="hlt">aerosol</span> distribution predicted by the hybrid model was consistent with the prediction by the CT-based model. We applied the hybrid model to 8 healthy and 16 severe asthmatic subjects, and average geometric error was 3.8% of the branch radius. The proposed method can be potentially applied to the branch-by-branch analyses of a large population of healthy and diseased lungs. NIH Grants R01-HL-094315 and S10-RR-022421, CT data provided by SARP, and computer time provided by XSEDE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/919902','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/919902"><span id="translatedtitle"><span class="hlt">Aerosol</span> mobility size spectrometer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wang, Jian; Kulkarni, Pramod</p> <p>2007-11-20</p> <p>A device for measuring <span class="hlt">aerosol</span> size distribution within a sample containing <span class="hlt">aerosol</span> particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording <span class="hlt">aerosol</span> size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an <span class="hlt">aerosol</span> injection port adjacent the inlet for introducing a charged <span class="hlt">aerosol</span> sample into the chamber, a separation section for applying an electric field to the <span class="hlt">aerosol</span> sample across the flow direction and an outlet opposite the inlet. In the separation section, the <span class="hlt">aerosol</span> sample becomes entrained in the flow medium and the <span class="hlt">aerosol</span> particles within the <span class="hlt">aerosol</span> sample are separated by size into a plurality of <span class="hlt">aerosol</span> flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one <span class="hlt">aerosol</span> flow stream exiting the outlet and for optically detecting the number of <span class="hlt">aerosol</span> particles within the at least one <span class="hlt">aerosol</span> flow stream.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeCoA.153..183F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeCoA.153..183F"><span id="translatedtitle">Evidence for an early nitrogen isotopic evolution in the solar nebula from volatile analyses of a <span class="hlt">CAI</span> from the CV3 chondrite NWA 8616</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Füri, Evelyn; Chaussidon, Marc; Marty, Bernard</p> <p>2015-03-01</p> <p>Nitrogen and noble gas (Ne-Ar) abundances and isotope ratios, determined by CO2 laser extraction static mass spectrometry analysis, as well as Al-Mg and O isotope data from secondary ion mass spectrometry (SIMS) analyses, are reported for a type B calcium-aluminum-rich inclusion (<span class="hlt">CAI</span>) from the CV3 chondrite NWA 8616. The high (26Al/27Al)i ratio of (5.06 ± 0.50) × 10-5 dates the last melting event of the <span class="hlt">CAI</span> at 39-99+109ka after "time zero", limiting the period during which high-temperature exchanges between the <span class="hlt">CAI</span> and the nebular gas could have occurred to a very short time interval. Partial isotopic exchange with a 16O-poor reservoir resulted in Δ17O > -5‰ for melilite and anorthite, whereas spinel and Al-Ti-pyroxene retain the inferred original 16O-rich signature of the solar nebula (Δ17O ⩽ -20‰). The low 20Ne/22Ne (⩽0.83) and 36Ar/38Ar (⩽0.75) ratios of the <span class="hlt">CAI</span> rule out the presence of any trapped planetary or solar noble gases. Cosmogenic 21Ne and 38Ar abundances are consistent with a cosmic ray exposure (CRE) age of ∼14 to 20 Ma, assuming CR fluxes similar to modern ones, without any evidence for pre-irradiation of the <span class="hlt">CAI</span> before incorporation into the meteorite parent body. Strikingly, the <span class="hlt">CAI</span> contains 1.4-3.4 ppm N with a δ15N value of +8‰ to +30‰. Even after correcting the measured δ15N values for cosmogenic 15N produced in situ, the <span class="hlt">CAI</span> is highly enriched in 15N compared to the protosolar nebula (δ15NPSN = -383 ± 8‰; Marty et al., 2011), implying that the <span class="hlt">CAI</span>-forming region was contaminated by 15N-rich material within the first 0.15 Ma of Solar System history, or, alternatively, that the <span class="hlt">CAI</span> was ejected into the outer Solar System where it interacted with a 15N-rich reservoir.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013E%26PSL.374...11S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013E%26PSL.374...11S"><span id="translatedtitle">Constraints on 10Be and 41Ca distribution in the early solar system from 26Al and 10Be studies of Efremovka <span class="hlt">CAIs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srinivasan, Gopalan; Chaussidon, Marc</p> <p>2013-07-01</p> <p>Three refractory coarse grained <span class="hlt">CAIs</span> from the Efremovka CV3 chondrite, one (E65) previously shown to have formed with live 41Ca, were studied by ion microprobe for their 26Al-26Mg and 10Be-10B systematic in order to better understand the origin of 10Be. The high precision Al-Mg data and the inferred 26Al/27Al values attest that the precursors of the three <span class="hlt">CAIs</span> evolved in the solar nebula over a period of few hundred thousand years before last melting-crystallization events. The initial 10Be/9Be ratios and δ10B values defined by the 10Be isochrons for the three Efremovka <span class="hlt">CAIs</span> are similar within errors. The <span class="hlt">CAI</span> 10Be abundance in published data underscores the large range for initial 10Be/9Be ratios. This is contrary to the relatively small range of 26Al/27Al variations in <span class="hlt">CAIs</span> around the canonical ratio. Two models that could explain the origin of this large 10Be/9Be range are assessed from the collateral variations predicted for the initial δ10B values: (i) closed system decay of 10Be from a "canonical" 10Be/9Be ratio and (ii) formation of <span class="hlt">CAIs</span> from a mixture of solid precursors and nebula gas irradiated during up to a few hundred thousand years. The second scenario is shown to be the most consistent with the data. This shows that the major fraction of 10Be in <span class="hlt">CAIs</span> was produced by irradiation of refractory grains, while contributions of galactic cosmic rays trapping and early solar wind irradiation are less dominant. The case for 10Be production by solar cosmic rays irradiation of solid refractory precursors poses a conundrum for 41Ca because the latter is easily produced by irradiation and should be more abundant than what is observed in <span class="hlt">CAIs</span>. 10Be production by irradiation from solar energetic particles requires high 41Ca abundance in early solar system, however, this is not observed in <span class="hlt">CAIs</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15473646','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15473646"><span id="translatedtitle">Genotypic differences in effects of cadmium exposure on plant growth and contents of cadmium and elements in 14 cultivars of bai <span class="hlt">cai</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Zhu-Jun; Sun, Guang-Wen; Fang, Xue-Zhi; Qian, Qiong-Qiu; Yang, Xiao-E</p> <p>2004-05-01</p> <p>Fourteen cultivars of bai <span class="hlt">cai</span> (Brassica campestris L. ssp. chinensis var. communis) were grown in the nutrient solutions containing 0-0.5 microg mL(-1) of cadmium (Cd) to investigate genotypic differences in the effects of Cd exposure on the plant growth and uptake and distribution of Cd in bai <span class="hlt">cai</span> plants. The Cd exposure significantly reduced the dry and fresh weights of roots and shoots, the dry weight ratio of shoot/root (S/R), total biomass, and chlorophyll content (SPAD value). Cd concentrations in bai <span class="hlt">cai</span> ranged from 13.3 to 74.9 microg g(-1) DW in shoots and from 163.1 to 574.7 microg g(-1) DW in roots under Cd exposure, respectively. The considerable genotypic differences of Cd concentrations and accumulations in both shoots and roots were observed among 14 bai <span class="hlt">cai</span> cultivars. Moreover, Cd mainly accumulated in the roots. Cd also caused the changes of uptake and distribution of nutrients in bai <span class="hlt">cai</span> and under the influence of cadmium, the concentration of potassium (K) decreased in shoot and increased in root. However, the concentrations of magnesium (Mg), phosphorus (P), manganese (Mn), boron (B), and iron (Fe) increased in shoots and decreased in roots. In addition, Cd exposure resulted in an increase in calcium (Ca), sulphur (S), and zinc (Zn) concentrations in both shoots and roots but had no significant effects on the whole uptake of the examined mineral nutrients except for S. PMID:15473646</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040016045&hterms=lille&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dlille','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040016045&hterms=lille&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dlille"><span id="translatedtitle">The MODIS <span class="hlt">Aerosol</span> Algorithm, Products, Validation and Applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, L. A.; Kaufman, Y. J.; Tanre, D.</p> <p>2003-01-01</p> <p>The MODerate resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) currently aboard both the Terra and Aqua satellites produces a suite of products designed to characterize global <span class="hlt">aerosol</span> distribution, optical thickness and particle size. Never before has a space-borne instrument been able to provide such detailed information, complementing field and modeling efforts to produce a comprehensive picture of <span class="hlt">aerosol</span> characteristics. The three years of Terra-MODIS data have been validated by comparing with co-located AERONET observations of <span class="hlt">aerosol</span> optical thickness and derivations of <span class="hlt">aerosol</span> size parameters. Some 8000 comparison points located at 133 AERONET sites around the globe show that the MODIS <span class="hlt">aerosol</span> optical thickness retrievals are accurate to within the pre-launch expectations. MODIS-derived size parameters are also compared with AERONET retrievals and found to agree well for fine-mode dominated <span class="hlt">aerosol</span> regimes. <span class="hlt">Aerosol</span> regimes dominated by dust <span class="hlt">aerosol</span> are less accurate, attributed to what is thought to be nonsphericity. Errors due to nonsphericity will be reduced by introducing a new set of empirical phase functions, derived without any assumptions of particle shape. The major innovation that MODIS bring to the field of remote sensing of <span class="hlt">aerosol</span> is the measure of particle size and the separation of finemode and coarsemode dominated <span class="hlt">aerosol</span> regimes. Particle size can separate finemode man-made <span class="hlt">aerosols</span> created during combustion, from larger natural <span class="hlt">aerosols</span> originating from salt spray or wind erosion. This separation allows for the calculation of <span class="hlt">aerosol</span> radiative effect and the estimation of the man-made <span class="hlt">aerosol</span> radiative forcing. MODIS can also be used in regional studies of <span class="hlt">aerosol</span>-cloud interaction that affect the global radiative and hydrological cycles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=62967&keyword=clouds&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77956987&CFTOKEN=79541490','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=62967&keyword=clouds&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77956987&CFTOKEN=79541490"><span id="translatedtitle"><span class="hlt">AEROSOL</span> AND GAS MEASUREMENT</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Measurements provide fundamental information for evaluating and managing the impact of <span class="hlt">aerosols</span> on air quality. Specific measurements of <span class="hlt">aerosol</span> concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010NW.....97..117C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010NW.....97..117C&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Aerosols</span> and environmental pollution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colbeck, Ian; Lazaridis, Mihalis</p> <p>2010-02-01</p> <p>The number of publications on atmospheric <span class="hlt">aerosols</span> has dramatically increased in recent years. This review, predominantly from a European perspective, summarizes the current state of knowledge of the role played by <span class="hlt">aerosols</span> in environmental pollution and, in addition, highlights gaps in our current knowledge. <span class="hlt">Aerosol</span> particles are ubiquitous in the Earth’s atmosphere and are central to many environmental issues; ranging from the Earth’s radiative budget to human health. <span class="hlt">Aerosol</span> size distribution and chemical composition are crucial parameters that determine their dynamics in the atmosphere. Sources of <span class="hlt">aerosols</span> are both anthropogenic and natural ranging from vehicular emissions to dust resuspension. Ambient concentrations of <span class="hlt">aerosols</span> are elevated in urban areas with lower values at rural sites. A comprehensive understanding of <span class="hlt">aerosol</span> ambient characteristics requires a combination of measurements and modeling tools. Legislation for ambient <span class="hlt">aerosols</span> has been introduced at national and international levels aiming to protect human health and the environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014SPIE.9259E..0ZL&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014SPIE.9259E..0ZL&link_type=ABSTRACT"><span id="translatedtitle">Investigation of <span class="hlt">aerosol</span> optical properties for remote sensing through DRAGON (distributed regional <span class="hlt">aerosol</span> gridded observation networks) campaign in Korea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lim, Jae-Hyun; Ahn, Joon Young; Park, Jin-Soo; Hong, You-Deok; Han, Jin-Seok; Kim, Jhoon; Kim, Sang-Woo</p> <p>2014-11-01</p> <p><span class="hlt">Aerosols</span> in the atmosphere, including dust and pollutants, scatters/absorbs solar radiation and change the microphysics of clouds, thus influencing the Earth's energy budget, climate, air quality, visibility, agriculture and water circulation. Pollutants have also been reported to threaten the human health. The present research collaborated with the U.S. NASA and the U.S. <span class="hlt">Aerosol</span> Robotic Network (AERONET) is to study the <span class="hlt">aerosol</span> characteristics in East Asia and improve the long-distance transportation monitoring technology by analyzing the observations of <span class="hlt">aerosol</span> characteristics in East Asia during Distributed Regional <span class="hlt">Aerosol</span> Gridded Observation Networks (DRAGON) Campaign (March 2012-May 2012). The sun photometers that measure the <span class="hlt">aerosol</span> optical characteristics were placed evenly throughout the Korean Peninsula and concentrated in Seoul and the metropolitan area. Observation data are obtained from the DRAGON campaign and the first year (2012) observation data (<span class="hlt">aerosol</span> optical depth and <span class="hlt">aerosol</span> spatial distribution) are analyzed. Sun photometer observations, including <span class="hlt">aerosol</span> optical depth (AOD), are utilized to validate satellite observations from Geostationary Ocean Color <span class="hlt">Imager</span> (GOCI) and Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS). Additional analysis is performed associated with the Northeast Asia, the Korean Peninsula in particular, to determine the spatial distribution of the <span class="hlt">aerosol</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5271142','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5271142"><span id="translatedtitle"><span class="hlt">Aerosol</span> distribution apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hanson, W.D.</p> <p></p> <p>An apparatus for uniformly distributing an <span class="hlt">aerosol</span> to a plurality of filters mounted in a plenum, wherein the <span class="hlt">aerosol</span> and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous <span class="hlt">aerosol</span>-testing of all the filters in the plenum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7273153','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7273153"><span id="translatedtitle">Solid <span class="hlt">aerosol</span> generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prescott, D.S.; Schober, R.K.; Beller, J.</p> <p>1992-03-17</p> <p>An improved solid <span class="hlt">aerosol</span> generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid <span class="hlt">aerosol</span> generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated <span class="hlt">aerosol</span> in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6283819','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6283819"><span id="translatedtitle">Improved solid <span class="hlt">aerosol</span> generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prescott, D.S.; Schober, R.K.; Beller, J.</p> <p>1988-07-19</p> <p>An improved solid <span class="hlt">aerosol</span> generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid <span class="hlt">aerosol</span> generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated <span class="hlt">aerosol</span> in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/868192','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/868192"><span id="translatedtitle">Solid <span class="hlt">aerosol</span> generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prescott, Donald S.; Schober, Robert K.; Beller, John</p> <p>1992-01-01</p> <p>An improved solid <span class="hlt">aerosol</span> generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid <span class="hlt">aerosol</span> generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated <span class="hlt">aerosol</span> in a grounded, conical heating chamber, achieving high recovery and flow rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2005/1078/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2005/1078/"><span id="translatedtitle">Thermal maturity patterns (<span class="hlt">CAI</span> and %Ro) in the Ordovician and Devonian rocks of the Appalachian basin in West Virginia</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Repetski, John E.; Ryder, Robert T.; Avary, Katharine Lee; Trippi, Michael H.</p> <p>2005-01-01</p> <p>The objective of this study is to enhance existing thermal maturity maps in West Virginia by establishing: 1) new subsurface <span class="hlt">CAI</span> data points for the Ordovician and Devonian and 2) new %Ro and Rock Eval subsurface data points for Middle and Upper Devonian black shale units. Thermal maturity values for the Ordovician and Devonian strata are of major interest because they contain the source rocks for most of the oil and natural gas resources in the basin. Thermal maturity patterns of the Middle Ordovician Trenton Limestone are evaluated here because they closely approximate those of the overlying Ordovician Utica Shale that is believed to be the source rock for the regional oil and gas accumulation in Lower Silurian sandstones (Ryder and others, 1998) and for natural gas fields in fractured dolomite reservoirs of the Ordovician Black River-Trenton Limestones. Improved <span class="hlt">CAI</span>-based thermal maturity maps of the Ordovician are important to identify areas of optimum gas generation from the Utica Shale and to provide constraints for interpreting the origin of oil and gas in the Lower Silurian regional accumulation and Ordovician Black River-Trenton fields. Thermal maturity maps of the Devonian will better constrain burial history-petroleum generation models of the Utica Shale, as well as place limitations on the origin of regional oil and gas accumulations in Upper Devonian sandstone and Middle to Upper Devonian black shale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008APS..MARS26001W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008APS..MARS26001W"><span id="translatedtitle">Tropopsheric <span class="hlt">Aerosol</span> Chemistry via <span class="hlt">Aerosol</span> Mass Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Worsnop, Douglas</p> <p>2008-03-01</p> <p>A broad overview of size resolved <span class="hlt">aerosol</span> chemistry in urban, rural and remote regions is evolving from deployment of <span class="hlt">aerosol</span> mass spectrometers (AMS) throughout the northern hemisphere. Using thermal vaporization and electron impact ionization as universal detector of non-refractory inorganic and organic composition, the accumulation of AMS results represent a library of mass spectral signatures of <span class="hlt">aerosol</span> chemistry. For organics in particular, mass spectral factor analysis provides a procedure for classifying (and simplifying) complex mixtures composed of the hundreds or thousands of individual compounds. Correlations with parallel gas and <span class="hlt">aerosol</span> measurements (e.g. GC/MS, HNMR, FTIR) supply additional chemical information needed to interpret mass spectra. The challenge is to separate primary and secondary; anthropogenic, biogenic and biomass burning sources - and subsequent - transformations of <span class="hlt">aerosol</span> chemistry and microphysics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020081319&hterms=usher&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dusher','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020081319&hterms=usher&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dusher"><span id="translatedtitle">Global <span class="hlt">Aerosol</span> Remote Sensing from MODIS</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ichoku, Charles; Kaufman, Yoram J.; Remer, Lorraine A.; Chu, D. Allen; Mattoo, Shana; Tanre, Didier; Levy, Robert; Li, Rong-Rong; Martins, Jose V.; Lau, William K. M. (Technical Monitor)</p> <p>2002-01-01</p> <p>The physical characteristics, composition, abundance, spatial distribution and dynamics of global <span class="hlt">aerosols</span> are still very poorly known, and new data from satellite sensors have long been awaited to improve current understanding and to give a boost to the effort in future climate predictions. The derivation of <span class="hlt">aerosol</span> parameters from the MODerate resolution <span class="hlt">Imaging</span> Spectro-radiometer (MODIS) sensors aboard the Earth Observing System (EOS) Terra and Aqua polar-orbiting satellites ushers in a new era in <span class="hlt">aerosol</span> remote sensing from space. Terra and Aqua were launched on December 18, 1999 and May 4, 2002 respectively, with daytime equator crossing times of approximately 10:30 am and 1:30 pm respectively. Several <span class="hlt">aerosol</span> parameters are retrieved at 10-km spatial resolution (level 2) from MODIS daytime data. The MODIS <span class="hlt">aerosol</span> algorithm employs different approaches to retrieve parameters over land and ocean surfaces, because of the inherent differences in the solar spectral radiance interaction with these surfaces. The parameters retrieved include: <span class="hlt">aerosol</span> optical thickness (AOT) at 0.47, 0.55 and 0.66 micron wavelengths over land, and at 0.47, 0.55, 0.66, 0.87, 1.2, 1.6, and 2.1 micron over ocean; Angstrom exponent over land and ocean; and effective radii, and the proportion of AOT contributed by the small mode <span class="hlt">aerosols</span> over ocean. To ensure the quality of these parameters, a substantial part of the Terra-MODIS <span class="hlt">aerosol</span> products were validated globally and regionally, based on cross correlation with corresponding parameters derived from ground-based measurements from AERONET (<span class="hlt">AErosol</span> RObotic NETwork) sun photometers. Similar validation efforts are planned for the Aqua-MODIS <span class="hlt">aerosol</span> products. The MODIS level 2 <span class="hlt">aerosol</span> products are operationally aggregated to generate global daily, eight-day (weekly), and monthly products at one-degree spatial resolution (level 3). MODIS <span class="hlt">aerosol</span> data are used for the detailed study of local, regional, and global <span class="hlt">aerosol</span> concentration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..120.4248K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..120.4248K"><span id="translatedtitle">An analysis of global <span class="hlt">aerosol</span> type as retrieved by MISR</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kahn, Ralph A.; Gaitley, Barbara J.</p> <p>2015-05-01</p> <p>In addition to <span class="hlt">aerosol</span> optical depth (AOD), <span class="hlt">aerosol</span> type is required globally for climate forcing calculations, constraining <span class="hlt">aerosol</span> transport models and other applications. However, validating satellite <span class="hlt">aerosol</span>-type retrievals is more challenging than testing AOD results, because <span class="hlt">aerosol</span> type is a more complex quantity, and ground truth data are far less numerous and generally not as robust. We evaluate the Multiangle <span class="hlt">Imaging</span> Spectroradiometer (MISR) Version 22 <span class="hlt">aerosol</span>-type retrievals by assessing product self-consistency on a regional basis and by making comparisons with general expectation and with the <span class="hlt">Aerosol</span> Robotic Network <span class="hlt">aerosol</span>-type climatology, as available. The results confirm and add detail to the observation that <span class="hlt">aerosol</span>-type discrimination improves dramatically where midvisible AOD exceeds about 0.15 or 0.2. When the <span class="hlt">aerosol</span>-type information content of the observations is relatively low, increased scattering-angle range improves particle-type sensitivity. The MISR standard, operational product discriminates among small, medium, and large particles and exhibits qualitative sensitivity to single-scattering albedo (SSA) under good <span class="hlt">aerosol</span>-type retrieval conditions, providing a categorical <span class="hlt">aerosol</span>-type classification. MISR Ångström exponent deviates systematically from ground truth where particle types missing from the algorithm climatology are present, or where cloud contamination is likely to occur, and SSA tends to be overestimated where absorbing particles are found. We determined that the number of mixtures passing the algorithm acceptance criteria (#SuccMix) represents <span class="hlt">aerosol</span>-type retrieval quality effectively, providing a useful <span class="hlt">aerosol</span>-type quality flag.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110007304','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110007304"><span id="translatedtitle">Global CALIPSO Observations of <span class="hlt">Aerosol</span> Changes Near Clouds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Varnai, Tamas; Marshak, Alexander</p> <p>2011-01-01</p> <p>Several recent studies have found that clouds are surrounded by a transition zone of rapidly changing <span class="hlt">aerosol</span> optical properties and particle size. Characterizing this transition zone is important for better understanding <span class="hlt">aerosol</span>-cloud interactions and <span class="hlt">aerosol</span> radiative effects, and also for improving satellite retrievals of <span class="hlt">aerosol</span> properties. This letter presents a statistical analysis of a monthlong global data set of Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar observations over oceans. The results show that the transition zone is ubiquitous over all oceans and extends up to 15 km away from clouds. They also show that near-cloud enhancements in backscatter and particle size are strongest at low altitudes, slightly below the top of the nearest clouds. Also, the enhancements are similar near illuminated and shadowy cloud sides, which confirms that the asymmetry of Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer reflectances found in an earlier study comes from 3-D radiative processes and not from differences in <span class="hlt">aerosol</span> properties. Finally, the effects of CALIPSO <span class="hlt">aerosol</span> detection and cloud identification uncertainties are discussed. The findings underline the importance of accounting for the transition zone to avoid potential biases in studies of satellite <span class="hlt">aerosol</span> products, <span class="hlt">aerosol</span>-cloud interactions, and <span class="hlt">aerosol</span> direct radiative effects.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4460978','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4460978"><span id="translatedtitle">Monitoring the Impacts of Wildfires on Forest Ecosystems and Public Health in the Exo-Urban Environment Using High-Resolution Satellite <span class="hlt">Aerosol</span> Products from the Visible Infrared <span class="hlt">Imaging</span> Radiometer Suite (VIIRS)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Huff, Amy K; Kondragunta, Shobha; Zhang, Hai; Hoff, Raymond M</p> <p>2015-01-01</p> <p>Increasing development of exo-urban environments and the spread of urbanization into forested areas is making humans and forest ecosystems more susceptible to the risks associated with wildfires. Larger and more damaging wildfires are having a negative impact on forest ecosystem services, and smoke from wildfires adversely affects the public health of people living in exo-urban environments. Satellite <span class="hlt">aerosol</span> measurements are valuable tools that can track the evolution of wildfires and monitor the transport of smoke plumes. Operational users, such as air quality forecasters and fire management officials, can use satellite observations to complement ground-based and aircraft measurements of wildfire activity. To date, wildfire applications of satellite <span class="hlt">aerosol</span> products, such as <span class="hlt">aerosol</span> optical depth (AOD), have been limited by the relatively coarse resolution of available AOD data. However, the new Visible Infrared <span class="hlt">Imaging</span> Radiometer Suite (VIIRS) instrument on the Suomi National Polar-orbiting Partnership (S-NPP) satellite has high-resolution AOD that is ideally suited to monitoring wildfire impacts on the exo-urban scale. Two AOD products are available from VIIRS: the 750-m × 750-m nadir resolution Intermediate Product (IP) and the 6-km × 6-km resolution Environmental Data Record product, which is aggregated from IP measurements. True color (red, green, and blue [RGB]) imagery and a smoke mask at 750-m × 750-m resolution are also available from VIIRS as decision aids for wildfire applications; they serve as counterparts to AOD measurements by providing visible information about areas of smoke in the atmosphere. To meet the needs of operational users, who do not have time to process raw data files and need access to VIIRS products in near-real time (NRT), VIIRS AOD and RGB NRT imagery are available from the Infusing satellite Data into Environmental Applications (IDEA) web site. A key feature of IDEA is an interactive visualization tool that allows users to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26078588','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26078588"><span id="translatedtitle">Monitoring the Impacts of Wildfires on Forest Ecosystems and Public Health in the Exo-Urban Environment Using High-Resolution Satellite <span class="hlt">Aerosol</span> Products from the Visible Infrared <span class="hlt">Imaging</span> Radiometer Suite (VIIRS).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huff, Amy K; Kondragunta, Shobha; Zhang, Hai; Hoff, Raymond M</p> <p>2015-01-01</p> <p>Increasing development of exo-urban environments and the spread of urbanization into forested areas is making humans and forest ecosystems more susceptible to the risks associated with wildfires. Larger and more damaging wildfires are having a negative impact on forest ecosystem services, and smoke from wildfires adversely affects the public health of people living in exo-urban environments. Satellite <span class="hlt">aerosol</span> measurements are valuable tools that can track the evolution of wildfires and monitor the transport of smoke plumes. Operational users, such as air quality forecasters and fire management officials, can use satellite observations to complement ground-based and aircraft measurements of wildfire activity. To date, wildfire applications of satellite <span class="hlt">aerosol</span> products, such as <span class="hlt">aerosol</span> optical depth (AOD), have been limited by the relatively coarse resolution of available AOD data. However, the new Visible Infrared <span class="hlt">Imaging</span> Radiometer Suite (VIIRS) instrument on the Suomi National Polar-orbiting Partnership (S-NPP) satellite has high-resolution AOD that is ideally suited to monitoring wildfire impacts on the exo-urban scale. Two AOD products are available from VIIRS: the 750-m × 750-m nadir resolution Intermediate Product (IP) and the 6-km × 6-km resolution Environmental Data Record product, which is aggregated from IP measurements. True color (red, green, and blue [RGB]) imagery and a smoke mask at 750-m × 750-m resolution are also available from VIIRS as decision aids for wildfire applications; they serve as counterparts to AOD measurements by providing visible information about areas of smoke in the atmosphere. To meet the needs of operational users, who do not have time to process raw data files and need access to VIIRS products in near-real time (NRT), VIIRS AOD and RGB NRT imagery are available from the Infusing satellite Data into Environmental Applications (IDEA) web site. A key feature of IDEA is an interactive visualization tool that allows users to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ocgy...55..339L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ocgy...55..339L"><span id="translatedtitle">Dissolved, particulate, and sedimentary organic matter in the <span class="hlt">Cai</span> River basin (Nha Trang Bay of the South China Sea)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lobus, N. V.; Peresypkin, V. I.; Shulga, N. A.; Drozdova, A. N.; Gusev, E. S.</p> <p>2015-05-01</p> <p>The data were obtained on the content of organic carbon in the water, particulate matter, and bottom sediments of the <span class="hlt">Cai</span> River and its tributaries (the basin of Nha Trang Bay). The surface waters of the considered basin contained OM mainly in a dissolved form (DOC/POC = 3). The fraction of Corg in particulate matter amounted to 4.9% on average. Based on the analysis of n-alkanes in bottom sediments, three OM types—autochthonous, mixed, and mainly terrigenous genesis—were distinguished. These types are alternated in series in the lengthwise profile of the river. All the OM types are in close relation to the peculiarities of sedimentation and hydrodynamics of the waters in the treated aquatic area. The geochemical indices (Pr/Ph, OEP17-19, and CPI values) represent the influence of oxidative conditions on OM formation and the intense microbiological transformation of its autochthonous component.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016SPIE.9882E..18T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016SPIE.9882E..18T&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Aerosol</span>-cloud interactions: effect on precipitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takle, Jasmine; Maheskumar, R.</p> <p>2016-05-01</p> <p><span class="hlt">Aerosols</span> are tiny suspended particle in the atmosphere with high variability in time and space, play a major role in modulating the cloud properties and thereby precipitation. To understand the <span class="hlt">aerosol</span> induced Invigoration effect predictors like <span class="hlt">aerosol</span> optical depth, cloud optical depth, cloud top temperature, cloud effective radii, ice water path, retrieved from the Moderate resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) level-3 aqua satellite data were analysed for pre monsoon April-May and post monsoon October-November months over the Indian subcontinent 8 ° N to 33° N, 65 °E to 100 °E during the period 2003-2013. Apart from the above data, mesoscale dynamical parameters such as vertical wind shear of horizontal wind, relative humidity, were also considered to understand their role in invigoration. Case studies have been carried out for the regions having heavy rainfall events & minimal rainfall events during high <span class="hlt">Aerosol</span> optical depths occasions respectively. Analysis revealed that the heavy rainfall which occurred in this region with higher optical depths might be due to invigoration effect of <span class="hlt">aerosols</span> wherein the dynamical as well as thermodynamical parameters were also found favourable. Minimal rainfall events were also observed most probably due to the suppression of rain formation/delay in precipitation due to high amount of <span class="hlt">aerosol</span> concentration in these regions. Prominent 36 such cases were studied all over India during Pre & Post monsoon months.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED267762.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED267762.pdf"><span id="translatedtitle">The Effects of Video-Only, <span class="hlt">CAI</span> Only, and Interactive Video Instructional Systems on Learner Performance and Attitude: An Exploratory Study.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dalton, David W.; Hannafin, Michael J.</p> <p></p> <p>This study compared the effects of interactive video instruction on learner performance and attitude with the effects of conventional computer assisted instruction (<span class="hlt">CAI</span>) and stand-alone video. Based on pretest scores, 134 junior high industrial arts students designated as relatively high or low in prior achievement were randomly assigned to one of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26522496','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26522496"><span id="translatedtitle">The contribution of the androgen receptor (AR) in human spatial learning and memory: A study in women with complete androgen insensitivity syndrome (<span class="hlt">CAIS</span>).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mueller, S C; Verwilst, T; Van Branteghem, A; T'Sjoen, G; Cools, M</p> <p>2016-02-01</p> <p>Few studies have examined the impact of androgen insensitivity on human spatial learning and memory. In the present study, we tested 11 women with complete androgen insensitivity syndrome (<span class="hlt">CAIS</span>), a rare genetic disorder characterized by complete absence of AR activity, and compared their performance against 20 comparison males and 19 comparison females on a virtual analog of the Morris Water Maze task. The results replicated a main sex effect showing that men relative to women were faster in finding the hidden platform and had reduced heading error. Furthermore, findings indicated that mean performance of women with <span class="hlt">CAIS</span> was between control women and control men, though the differences were not statistically significant. Effect size estimates (and corresponding confidence intervals) of spatial learning trials showed little difference between women with <span class="hlt">CAIS</span> and control women but <span class="hlt">CAIS</span> women differed from men, but not women, on two variables, latency to find the platform and first-move latency. No differences between groups were present during visible platform trials or the probe trial, a measure of spatial memory. Moreover, groups also did not differ on estimates of IQ and variability of performance. The findings are discussed in relation to androgen insensitivity in human spatial learning and memory. PMID:26522496</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LPI....40.2495W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LPI....40.2495W"><span id="translatedtitle">Evidence of Disturbance in the 26Al-26Mg Systematics of the Efremovka E60 <span class="hlt">CAI</span>: Implications for the High-Resolution Chronology of the Early Solar System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wadhwa, M.; Janney, P. E.; Krot, A. N.</p> <p>2009-03-01</p> <p>We report results of a laser ablation MC-ICPMS study of the Efremovka E60 <span class="hlt">CAI</span>. Our data indicate that the 26Al-26Mg systematics in E60 are disturbed and we present the chronological implications of this finding.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008LPI....39.2486D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008LPI....39.2486D"><span id="translatedtitle">In-Situ UV-Laser Fluorination Oxygen Isotopic Analyses of an Efremovka <span class="hlt">CAI</span> and Matrix: Implications for Oxygen Isotopic Exchange in the Solar Nebula</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dyl, K. A.; Young, E. D.; Krot, A. N.</p> <p>2008-03-01</p> <p>Using a UV-laser ablation fluorination system, we obtained high-precision in situ data for E44 and surrounding matrix. The 16O-rich anorthite and solid-state diffusion calculations indicate that this process may be important to the evolution of oxygen in this <span class="hlt">CAI</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.6195O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.6195O"><span id="translatedtitle">Halogen-induced organic <span class="hlt">aerosol</span> (XOA) formation and decarboxylation of carboxylic acids by reactive halogen species - a time-resolved <span class="hlt">aerosol</span> flow-reactor study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ofner, Johannes; Zetzsch, Cornelius</p> <p>2013-04-01</p> <p>Reactive halogen species (RHS) are released to the atmosphere from various sources like photo-activated sea-salt <span class="hlt">aerosol</span> and salt lakes. Recent studies (<span class="hlt">Cai</span> et al., 2006 and 2008, Ofner et al., 2012) indicate that RHS are able to interact with SOA precursors similarly to common atmospheric oxidizing gases like OH radicals and ozone. The reaction of RHS with SOA precursors like terpenes forms so-called halogen-induced organic <span class="hlt">aerosol</span> (XOA). On the other hand, RHS are also able to change the composition of functional groups, e.g. to initiate the decarboxylation of carboxylic acids (Ofner et al., 2012). The present study uses a 50 cm <span class="hlt">aerosol</span> flow-reactor, equipped with a solar simulator to investigate the time-resolved evolution and transformation of vibrational features in the mid-infrared region. The <span class="hlt">aerosol</span> flow-reactor is coupled to a home-made multi-reflection cell (Ofner et al., 2010), integrated into a Bruker IFS 113v FTIR spectrometer. The reactor is operated with an inlet feed (organic compound) and a surrounding feed (reactive halogen species). The moveable inlet of the flow reactor allows us to vary reaction times between a few seconds and up to about 3 minutes. Saturated vapours of different SOA precursors and carboxylic acids were fed into the flow reactor using the moveable inlet. The surrounding feed inside the flow reactor was a mixture of zero air with molecular chlorine as the precursor for the formation of reactive halogen species. Using this setup, the formation of halogen-induced organic <span class="hlt">aerosol</span> could be monitored with a high time resolution using FTIR spectroscopy. XOA formation is characterized by hydrogen-atom abstraction, carbon-chlorine bond formation and later, even formation of carboxylic acids. Several changes of the entire structure of the organic precursor, caused by the reaction of RHS, are visible. While XOA formation is a very fast process, the decarboxylation of carboxylic acids, induced by RHS is rather slow. However, XOA formation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.6238W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.6238W&link_type=ABSTRACT"><span id="translatedtitle">Development the EarthCARE <span class="hlt">aerosol</span> classification scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wandinger, Ulla; Baars, Holger; Hünerbein, Anja; Donovan, Dave; van Zadelhoff, Gerd-Jan; Fischer, Jürgen; von Bismarck, Jonas; Eisinger, Michael; Lajas, Dulce; Wehr, Tobias</p> <p>2015-04-01</p> <p>The Earth Clouds, <span class="hlt">Aerosols</span> and Radiation Explorer (EarthCARE) mission is a joint ESA/JAXA mission planned to be launched in 2018. The multi-sensor platform carries a cloud-profiling radar (CPR), a high-spectral-resolution cloud/<span class="hlt">aerosol</span> lidar (ATLID), a cloud/<span class="hlt">aerosol</span> multi-spectral <span class="hlt">imager</span> (MSI), and a three-view broad-band radiometer (BBR). Three out of the four instruments (ATLID, MSI, and BBR) will be able to sense the global <span class="hlt">aerosol</span> distribution and contribute to the overarching EarthCARE goals of sensor synergy and radiation closure with respect to <span class="hlt">aerosols</span>. The high-spectral-resolution lidar ATLID obtains profiles of particle extinction and backscatter coefficients, lidar ratio, and linear depolarization ratio as well as the <span class="hlt">aerosol</span> optical thickness (AOT) at 355 nm. MSI provides AOT at 670 nm (over land and ocean) and 865 nm (over ocean). Next to these primary observables the <span class="hlt">aerosol</span> type is one of the required products to be derived from both lidar stand-alone and ATLID-MSI synergistic retrievals. ATLID measurements of the <span class="hlt">aerosol</span> intensive properties (lidar ratio, depolarization ratio) and ATLID-MSI observations of the spectral AOT will provide the basic input for <span class="hlt">aerosol</span>-type determination. <span class="hlt">Aerosol</span> typing is needed for the quantification of anthropogenic versus natural <span class="hlt">aerosol</span> loadings of the atmosphere, the investigation of <span class="hlt">aerosol</span>-cloud interaction, assimilation purposes, and the validation of atmospheric transport models which carry components like dust, sea salt, smoke and pollution. Furthermore, <span class="hlt">aerosol</span> classification is a prerequisite for the estimation of direct <span class="hlt">aerosol</span> radiative forcing and radiative closure studies. With an appropriate underlying microphysical particle description, the categorization of <span class="hlt">aerosol</span> observations into predefined <span class="hlt">aerosol</span> types allows us to infer information needed for the calculation of shortwave radiative effects, such as mean particle size, single-scattering albedo, and spectral conversion factors. In order to ensure</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1610290S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1610290S"><span id="translatedtitle"><span class="hlt">Aerosol</span> optical properties in the ABL over arctic sea ice from airborne <span class="hlt">aerosol</span> lidar measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmidt, Lukas; Neuber, Roland; Ritter, Christoph; Maturilli, Marion; Dethloff, Klaus; Herber, Andreas</p> <p>2014-05-01</p> <p>Between 2009 and 2013 <span class="hlt">aerosols</span>, sea ice properties and meteorological variables were measured during several airborne campaigns covering a wide range of the western Arctic Ocean. The campaigns were carried out with the aircraft Polar 5 of the German Alfred-Wegener-Institute (AWI) during spring and summer periods. Optical properties of accumulation mode <span class="hlt">aerosol</span> and clouds were measured with the nadir looking AMALi <span class="hlt">aerosol</span> lidar covering the atmospheric boundary layer and the free troposphere up to 3000m, while dropsondes provided coincident vertical profiles of meteorological quantities. Based on these data we discuss the vertical distribution of <span class="hlt">aerosol</span> backscatter in and above the atmospheric boundary layer and its dependence on relative humidity, dynamics and underlying sea ice properties. We analyze vertical profiles of lidar and coincident dropsonde measurements from various locations in the European and Canadian Arctic from spring and summer campaigns. Sea ice cover is derived from modis satellite and aircraft onboard camera <span class="hlt">images</span>. The <span class="hlt">aerosol</span> load in the arctic atmospheric boundary layer shows a high variability. Various meteorological parameters and in particular boundary layer properties are discussed with their respective influence on <span class="hlt">aerosol</span> features. To investigate the effect of the frequency and size of open water patches on <span class="hlt">aerosol</span> properties, we relate the profiles to the sea ice properties influencing the atmosphere in the upwind region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....9292C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....9292C"><span id="translatedtitle">B and Mg isotopic variations in Leoville mrs-06 type B1 <span class="hlt">cai</span>:origin of 10Be and 26Al</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaussidon, M.; Robert, F.; Russel, S. S.; Gounelle, M.; Ash, R. D.</p> <p>2003-04-01</p> <p>The finding [1-3] in Ca-Al-rich refractory inclusions (<span class="hlt">CAI</span>) of primitive chondrites of traces of the in situ decay of radioactive 10Be (half-life 1.5Myr) indicates that irradiation of the protosolar nebula by the young Sun in its T-Tauri phase has produced significant amounts of the Li-Be-B elements. This irradiation may have produced also some or all of the short-lived 26Al (half-life 0.7Myr) and 41Ca (half-life 0.1Myr) previously detected in <span class="hlt">CAIs</span>. To constrain the origin of 10Be and 10Al it is important to look for coupled variations in the 10Be/9Be and 26Al/27Al ratios in <span class="hlt">CAIs</span> and to understand the processes responsible for these variations (e.g. variations in the fluences of irradiation, secondary perturbations of the <span class="hlt">CAIs</span>, ...) We have thus studied the Li and B isotopic compositions and the Be/Li and Be/B concentration ratios in one <span class="hlt">CAI</span> (MRS-06) from the Leoville CV3 chondrite in which large variations of the Mg isotopic compositions showing both the in situ decay of 26Al and the secondary redistribution of Mg isotopes have been observed [4]. The results show large variations for the Li and B isotopic compositions (^7Li/^6Li ranging from 11.02±0.21 to 11.82±0.07, and 10B/11B ratios ranging from 0.2457±0.0053 to 0.2980±0.0085). The ^7Li/^6Li ratio tend to decrease towards the rim of the inclusion. The 10B/11B ratios are positively correlated with the ^9Be/11B ratios indicating the in situ decay of 10Be. However perturbations of the 10Be/B system are observed. They would correspond to an event which occurred approximately 2Myr after the formation of the <span class="hlt">CAI</span> and the irradiation of the <span class="hlt">CAI</span> precursors which is responsible for the 10Be observed in the core of the <span class="hlt">CAI</span>. These perturbations seem compatible with those observed for the 26Al/Mg system but they might be due to an irradiation of the already-formed, isolated <span class="hlt">CAI</span> which would have resulted in increased 10Be/^9Be ratios and low ^7Li/^6Li ratios in the margin of the <span class="hlt">CAI</span>. [1] McKeegan K. D. et al. (2000</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780007267','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780007267"><span id="translatedtitle">Thermoluminescent <span class="hlt">aerosol</span> analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rogowski, R. S.; Long, E. R., Jr. (Inventor)</p> <p>1977-01-01</p> <p>A method for detecting and measuring trace amounts of <span class="hlt">aerosols</span> when reacted with ozone in a gaseous environment was examined. A sample <span class="hlt">aerosol</span> was exposed to a fixed ozone concentration for a fixed period of time, and a fluorescer was added to the exposed sample. The sample was heated in a 30 C/minute linear temperature profile to 200 C. The trace peak was measured and recorded as a function of the test <span class="hlt">aerosol</span> and the recorded thermoluminescence trace peak of the fluorescer is specific to the <span class="hlt">aerosol</span> being tested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980201315','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980201315"><span id="translatedtitle">Radiative Effects of <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Valero, Francisco P. J.</p> <p>1997-01-01</p> <p>During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in <span class="hlt">aerosol</span> optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size resolved <span class="hlt">aerosol</span> microphysics and chemistry. Both profiles included pollution haze layer from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) <span class="hlt">aerosol</span> were determined and thermal analysis of the pollution haze indicated that the fine <span class="hlt">aerosol</span> was composed primarily of a sulfate/water mixture with a refractory soot-like core.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070009991','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070009991"><span id="translatedtitle">Isotopic Measurements in <span class="hlt">CAIs</span> with the Nanosims: Implications to the understanding of the Formation process of Ca, Al-Rich Inclusions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ito, M.; Messenger, S.; Walker, Robert M.</p> <p>2007-01-01</p> <p>Ca, Al-rich Inclusions (<span class="hlt">CAIs</span>) preserve evidence of thermal events that they experienced during their formation in the early solar system. Most <span class="hlt">CAIs</span> from CV and CO chondrites are characterized by large variations in O-isotopic compositions of primary minerals, with spinel, hibonite, and pyroxene being more O-16-rich than melilite and anorthite, with delta 17, O-18 = approx. -40%o (DELTA O-17 = delta O-17 - 0.52 x delta O-18 = approx. - 20%o ). These anomalous compositions cannot be accounted for by standard mass dependent fractionation and diffusive process of those minerals. It requires the presence of an anomalous oxygen reservoir of nucleosynthetic origin or mass independent fractionations before the formation of <span class="hlt">CAIs</span> in the early solar system. The CAMECA NanoSIMS is a new generation ion microprobe that offers high sensitivity isotopic measurements with sub 100 nm spatial resolution. The NanoSIMS has significantly improved abilities in the study of presolar grains in various kind of meteorites and the decay products of extinct nuclides in ancient solar system matter. This instrument promises significant improvements over other conventional ion probes in the precision isotopic characterization of sub-micron scales. We report the results of our first O isotopic measurements of various <span class="hlt">CAI</span> minerals from EK1-6-3 and 7R19-1(a) utilizing the JSC NanoSIMS 50L ion microprobe. We evaluate the measurement conditions, the instrumental mass fractionation factor (IMF) for O isotopic measurement and the accuracy of the isotopic ratio through the analysis of a San Carlos olivine standard and <span class="hlt">CAI</span> sample of 7R19-1(a).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1614434T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614434T"><span id="translatedtitle">Towards a true <span class="hlt">aerosol</span>-and-cloud retrieval scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, Gareth; Poulsen, Caroline; Povey, Adam; McGarragh, Greg; Jerg, Matthias; Siddans, Richard; Grainger, Don</p> <p>2014-05-01</p> <p>The Optimal Retrieval of <span class="hlt">Aerosol</span> and Cloud (ORAC) - formally the Oxford-RAL <span class="hlt">Aerosol</span> and Cloud retrieval - offers a framework that can provide consistent and well characterised properties of both <span class="hlt">aerosols</span> and clouds from a range of <span class="hlt">imaging</span> satellite instruments. Several practical issues stand in the way of achieving the potential of this combined scheme however; in particular the sometimes conflicting priorities and requirements of <span class="hlt">aerosol</span> and cloud retrieval problems, and the question of the unambiguous identification of <span class="hlt">aerosol</span> and cloud pixels. This presentation will present recent developments made to the ORAC scheme for both <span class="hlt">aerosol</span> and cloud, and detail how these are being integrated into a single retrieval framework. The implementation of a probabilistic method for pixel identification will also be presented, for both cloud detection and <span class="hlt">aerosol</span>/cloud type selection. The method is based on Bayesian methods applied the optimal estimation retrieval output of ORAC and is particularly aimed at providing additional information in the so-called "twilight zone", where pixels can't be unambiguously identified as either <span class="hlt">aerosol</span> or cloud and traditional cloud or <span class="hlt">aerosol</span> products do not provide results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A31D0080M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A31D0080M"><span id="translatedtitle">The Retrieval of <span class="hlt">Aerosol</span> Optical Thickness Using the MERIS Instrument</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mei, L.; Rozanov, V. V.; Vountas, M.; Burrows, J. P.; Levy, R. C.; Lotz, W.</p> <p>2015-12-01</p> <p>Retrieval of <span class="hlt">aerosol</span> properties for satellite instruments without shortwave-IR spectral information, multi-viewing, polarization and/or high-temporal observation ability is a challenging problem for spaceborne <span class="hlt">aerosol</span> remote sensing. However, space based instruments like the MEdium Resolution <span class="hlt">Imaging</span> Spectrometer (MERIS) and the successor, Ocean and Land Colour Instrument (OLCI) with high calibration accuracy and high spatial resolution provide unique abilities for obtaining valuable <span class="hlt">aerosol</span> information for a better understanding of the impact of <span class="hlt">aerosols</span> on climate, which is still one of the largest uncertainties of global climate change evaluation. In this study, a new <span class="hlt">Aerosol</span> Optical Thickness (AOT) retrieval algorithm (XBAER: eXtensible Bremen <span class="hlt">AErosol</span> Retrieval) is presented. XBAER utilizes the global surface spectral library database for the determination of surface properties while the MODIS collection 6 <span class="hlt">aerosol</span> type treatment is adapted for the <span class="hlt">aerosol</span> type selection. In order to take the surface Bidirectional Reflectance Distribution Function (BRDF) effect into account for the MERIS reduce resolution (1km) retrieval, a modified Ross-Li mode is used. The AOT is determined in the algorithm using lookup tables including polarization created using Radiative Transfer Model SCIATRAN3.4, by minimizing the difference between atmospheric corrected surface reflectance with given AOT and the surface reflectance calculated from the spectral library. The global comparison with operational MODIS C6 product, Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR) product, Advanced Along-Track Scanning Radiometer (AATSR) <span class="hlt">aerosol</span> product and the validation using <span class="hlt">AErosol</span> RObotic NETwork (AERONET) show promising results. The current XBAER algorithm is only valid for <span class="hlt">aerosol</span> remote sensing over land and a similar method will be extended to ocean later.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20120003889&hterms=aerosols+desert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Daerosols%2Bdesert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20120003889&hterms=aerosols+desert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Daerosols%2Bdesert"><span id="translatedtitle">Multiangle Implementation of Atmospheric Correction (MAIAC): 2. <span class="hlt">Aerosol</span> Algorithm</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyapustin, A.; Wang, Y.; Laszlo, I.; Kahn, R.; Korkin, S.; Remer, L.; Levy, R.; Reid, J. S.</p> <p>2011-01-01</p> <p>An <span class="hlt">aerosol</span> component of a new multiangle implementation of atmospheric correction (MAIAC) algorithm is presented. MAIAC is a generic algorithm developed for the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS), which performs <span class="hlt">aerosol</span> retrievals and atmospheric correction over both dark vegetated surfaces and bright deserts based on a time series analysis and <span class="hlt">image</span>-based processing. The MAIAC look-up tables explicitly include surface bidirectional reflectance. The <span class="hlt">aerosol</span> algorithm derives the spectral regression coefficient (SRC) relating surface bidirectional reflectance in the blue (0.47 micron) and shortwave infrared (2.1 micron) bands; this quantity is prescribed in the MODIS operational Dark Target algorithm based on a parameterized formula. The MAIAC <span class="hlt">aerosol</span> products include <span class="hlt">aerosol</span> optical thickness and a fine-mode fraction at resolution of 1 km. This high resolution, required in many applications such as air quality, brings new information about <span class="hlt">aerosol</span> sources and, potentially, their strength. AERONET validation shows that the MAIAC and MOD04 algorithms have similar accuracy over dark and vegetated surfaces and that MAIAC generally improves accuracy over brighter surfaces due to the SRC retrieval and explicit bidirectional reflectance factor characterization, as demonstrated for several U.S. West Coast AERONET sites. Due to its generic nature and developed angular correction, MAIAC performs <span class="hlt">aerosol</span> retrievals over bright deserts, as demonstrated for the Solar Village <span class="hlt">Aerosol</span> Robotic Network (AERONET) site in Saudi Arabia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A13K0337B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A13K0337B"><span id="translatedtitle">Comparison of <span class="hlt">Aerosol</span> Classification from Airborne High Spectral Resolution Lidar and the CALIPSO Vertical Feature Mask</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burton, S. P.; Ferrare, R. A.; Omar, A. H.; Hostetler, C. A.; Hair, J. W.; Rogers, R.; Obland, M. D.; Butler, C. F.; Cook, A. L.; Harper, D. B.</p> <p>2012-12-01</p> <p> applications. The HSRL products are used to apportion AOT by type and vertical location in the column, and to characterize the frequency of cases where multiple types are present in the column. Resolving scenes with multiple types in the column is not possible with passive <span class="hlt">imaging</span> radiometer and polarimeter measurements. The HSRL <span class="hlt">aerosol</span> type also has higher resolution than the CALIPSO layer-wise product and provides insight into the performance of CALIPSO layer separation. Information about the vertical distribution of <span class="hlt">aerosol</span> types is useful for estimating radiative forcing, understanding <span class="hlt">aerosol</span> lifetime and transport, and assessing the predictions of transport models. CALIPSO has been a pathfinder, providing the first long-term global data set of <span class="hlt">aerosol</span> vertical distribution. Based on our results, a future satellite lidar similar to CALIPSO, but with the addition of polarization sensitivity at 1064 nm and the HSRL technique at 532 nm, could provide a significant advance in characterizing the vertical distribution of <span class="hlt">aerosol</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AtmEn.141..532B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AtmEn.141..532B&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Aerosol</span> types and radiative forcing estimates over East Asia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhawar, Rohini L.; Lee, Woo-Seop; Rahul, P. R. C.</p> <p>2016-09-01</p> <p>Using the CALIPSO (Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observations) and MODIS (Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer) satellite data sets along with the CSIRO-MK 3.6.0 model simulations, we analyzed the <span class="hlt">aerosol</span> optical depth (AOD) variability during March-May (MAM), June-August (JJA) along with their annual mean variability over East Asia for the period 2006-2012. The CALIPSO measurements correlated well with the MODIS measurements and the CSIRO-MK 3.6.0 model simulations over the spatial distribution patterns of the <span class="hlt">aerosols</span>, but CALIPSO underestimated the magnitudes of the AOD. Maximum smoke <span class="hlt">aerosol</span> loading is observed to occur during JJA, as a result of wind transport from Southern China while dust loading dominated during MAM via the transport from desert region. The vertical distribution profiles revealed that there is uniform distribution of smoke <span class="hlt">aerosols</span> during both MAM and JJA, only differing at the altitude at which they peak; while the dust <span class="hlt">aerosols</span> during MAM showed a significant distribution from the surface to 10 km altitude and JJA was marked with lower dust loading at the same altitudes. Both dust and smoke <span class="hlt">aerosols</span> warm the atmosphere in MAM but due to the absorbing nature of smoke <span class="hlt">aerosols</span>, they cause considerable cooling at the surface which is double when compared to the dust <span class="hlt">aerosols</span>. The top of the atmosphere <span class="hlt">aerosol</span> radiative forcing (ARF) due to smoke and dust <span class="hlt">aerosols</span> is positive in MAM which indicates warming over East Asia. During MAM a consistent declining trend of the surface ARF due to smoke <span class="hlt">aerosols</span> persisted over the last three decades as conspicuously evidenced from model analysis; the decline is ∼10 W/m2 from 1980 to 2012.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFM.A53C1340T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFM.A53C1340T&link_type=ABSTRACT"><span id="translatedtitle">Does the Madden-Julian Oscillation Influence <span class="hlt">Aerosol</span> Variability?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, B.; Waliser, D. E.; Kahn, R. A.; Li, Q.; Yung, Y. L.; Tyranowski, T.; Geogdzhayev, I. V.; Mishchenko, M. I.; Torres, O.; Smirnov, A.</p> <p>2007-12-01</p> <p>We investigate the modulation of <span class="hlt">aerosols</span> by the Madden-Julian Oscillation (MJO) using satellite-based global <span class="hlt">aerosol</span> products, including <span class="hlt">aerosol</span> index (AI) from the Total Ozone Mapping Spectrometer (TOMS) on Nimbus-7, and <span class="hlt">aerosol</span> optical thickness (AOT) from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) on Terra and Aqua and the Advanced Very High Resolution Radiometer (AVHRR) on NOAA satellites. A composite analysis is performed for boreal winter, and the global pentad rainfall data from the NOAA Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) are used to identify MJO events. The MJO composites exhibit large variations in the TOMS AI and MODIS/AVHRR AOT over the equatorial Indian and western Pacific Oceans where MJO convection is active, as well as the tropical Africa and Atlantic Ocean where MJO convection is relatively weak but the background <span class="hlt">aerosol</span> level is relatively high. A strong inverse linear relationship between the TOMS AI and rainfall anomalies, but a weaker, less coherent positive correlation between the MODIS/AVHRR AOT and rainfall anomalies, were found. The <span class="hlt">Aerosol</span> Robotic Network AOT pattern at Kaashidoo (73.5°E, 4.9°N) and Nauru (167°E, 0.5°S) is more consistent with MODIS and AVHRR. These results indicate a connection between the MJO, its associated rainfall and circulation variability, and the observed <span class="hlt">aerosol</span> variations. Several physical and non-physical factors that may contribute to the observed <span class="hlt">aerosol</span>-rainfall relationship, such as <span class="hlt">aerosol</span> humidification effect, wet deposition, surface wind speed, phytoplankton, different sensor sensitivities (absorbing versus non-absorbing <span class="hlt">aerosols</span> and upper versus lower tropospheric <span class="hlt">aerosols</span>), sampling issue, and cloud contamination, are discussed. However, a clear causal explanation for the observed patterns remains elusive. Further investigation is needed to unravel this complex <span class="hlt">aerosol</span>-rainfall relationship.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=38399&keyword=balloon&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=59538464&CFTOKEN=55929761','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=38399&keyword=balloon&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=59538464&CFTOKEN=55929761"><span id="translatedtitle">HOUSTON <span class="hlt">AEROSOL</span> CHARACTERIZATION STUDY</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>An intensive field study of ambient <span class="hlt">aerosols</span> was conducted in Houston between September 14 and October 14, 1978. Measurements at 12 sites were made using (1) two relocatable monitoring systems instrumented for <span class="hlt">aerosol</span> and gaseous pollutants, (2) a network of high volume samplers ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/global_aerosol_observations','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/global_aerosol_observations"><span id="translatedtitle">Global <span class="hlt">Aerosol</span> Observations</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2013-04-19</p> <p>... atmosphere, directly influencing global climate and human health. Ground-based networks that accurately measure column <span class="hlt">aerosol</span> amount and ... being used to improve Air Quality Models and for regional health studies. To assess the human-health impact of chronic <span class="hlt">aerosol</span> exposure, ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1169526','SCIGOV-DOEDE'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1169526"><span id="translatedtitle">Direct <span class="hlt">Aerosol</span> Forcing Uncertainty</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p>Mccomiskey, Allison</p> <p>2008-01-15</p> <p>Understanding sources of uncertainty in <span class="hlt">aerosol</span> direct radiative forcing (DRF), the difference in a given radiative flux component with and without <span class="hlt">aerosol</span>, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: <span class="hlt">aerosol</span> optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual <span class="hlt">aerosol</span> or surface properties, are calculated at three locations representing distinct <span class="hlt">aerosol</span> types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective <span class="hlt">aerosol</span> or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, <span class="hlt">aerosol</span> type, and <span class="hlt">aerosol</span> optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/880369','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/880369"><span id="translatedtitle">Portable <span class="hlt">Aerosol</span> Contaminant Extractor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Carlson, Duane C.; DeGange, John J.; Cable-Dunlap, Paula</p> <p>2005-11-15</p> <p>A compact, portable, <span class="hlt">aerosol</span> contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that <span class="hlt">aerosol</span> particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002GeCoA..66.1459E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002GeCoA..66.1459E"><span id="translatedtitle">Efremovka 101.1: a <span class="hlt">CAI</span> with ultrarefractory REE patterns and enormous enrichments of Sc, Zr, and Y in Fassaite and Perovskite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El Goresy, A.; Zinner, E.; Matsunami, S.; Palme, H.; Spettel, B.; Lin, Y.; Nazarov, M.</p> <p>2002-04-01</p> <p>Inclusion 101.1 from the CV3 carbonaceous chondrite Efremovka is a compact Type A Ca-Al-rich inclusion (<span class="hlt">CAI</span>) highly enriched in ultrarefractory (UR) oxides. It is the first complete <span class="hlt">CAI</span> with a UR rare earth element (REE) pattern found in a CV3 chondrite. The inclusion is petrographically complex and was formed in a multistage process. It consists of several lithologically unrelated units. The core contains abundant Y- and Zr-perovskite, Sc- and Zr-rich fassaite, and metallic FeNi enclosed in melilite. All mineral species (except spinel) in all lithological units exhibit the same basic UR REE pattern. Four different populations of perovskites are distinguished by different Y/Zr ratios. A few of the perovskites have Y/Zr ratios similar to those obtained from crystal/liquid fractionation experiments. Perovskites from the other three populations have either chondritic, lower than chondritic Y/Zr ratios or extremely low Zr contents. Ca isotopic ratios differ among three perovskites from different populations, demonstrating a variety of sources and formational processes. Most fassaites crystallized in situ through reaction between the <span class="hlt">CAI</span> liquid and preexisting perovskites. This process induced redistribution of Zr, Y, Sc, and V between perovskite and fassaite, thus overprinting the original abundances in perovskite. Fassaite reaction rims around FeNi metals are also encountered. They are enriched in V, which was gained from the metal through oxidation of V in metal during fassaite crystallization. The relative abundances of Zr, Y, and Sc in perovskites are complementary to the abundances of these elements in Sc- and Zr-fassaite, indicating subsolidus partitioning of these elements between the two phases. Perovskites are enriched in Y and depleted in Sc and Zr in comparison to fassaites. The core contains two complete captured <span class="hlt">CAIs</span>, several sinuous fragments, and fine-grained polygonal refractory fragments. An assemblage of andradite-wollastonite-hedenbergite and pure</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970001690','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970001690"><span id="translatedtitle">Radiative Effects of <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Valero, Francisco P. J.</p> <p>1996-01-01</p> <p>During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in <span class="hlt">aerosol</span> optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size-resolved <span class="hlt">aerosol</span> microphysics and chemistry. Both profiles included a pollution haze from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) <span class="hlt">aerosol</span> were determined and thermal analysis of the pollution haze indicated that the fine <span class="hlt">aerosol</span> was composed primarily of a sulfate/water mixture with a refractory soot-like core. The soot core increased the calculated extinction by about 10% in the most polluted drier layer relative to a pure sulfate <span class="hlt">aerosol</span> but had significantly less effect at higher humidities. A 3 km descent through a boundary layer air mass dominated by pollutant <span class="hlt">aerosol</span> with relative humidities (RH) 10-77% yielded a close agreement between the measured and calculated <span class="hlt">aerosol</span> optical depths (550 nm) of 0.160 (+/- 0.07) and 0. 157 (+/- 0.034) respectively. During descent the <span class="hlt">aerosol</span> mass scattering coefficient per unit sulfate mass varied from about 5 to 16 m(exp 2)/g and primarily dependent upon ambient RH. However, the total scattering coefficient per total fine mass was far less variable at about 4+/- 0.7 m(exp 2)/g. A subsequent descent through a Saharan dust layer located above the pollution <span class="hlt">aerosol</span> layer revealed that both layers contributed similarly to <span class="hlt">aerosol</span> optical depth. The scattering per unit mass of the coarse aged dust was estimated at 1.1 +/- 0.2 m(exp 2)/g. The large difference (50%) in measured and calculated optical depth for the dust layer exceeded measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/114763','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/114763"><span id="translatedtitle">A spectroscopic tour through the liquid <span class="hlt">aerosol</span> interface: Implications for atmospheric chemistry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhang, J.X.; Aiello, D.; Aker, P.M.</p> <p>1994-12-20</p> <p>A novel nonlinear Raman spectroscopic technique has been used to <span class="hlt">image</span> the extent of hydrogen bonding at water <span class="hlt">aerosol</span> interfaces. The <span class="hlt">aerosols</span> probed were generated in the laboratory using the vibrating orifice technique. The spectroscopic results show that the <span class="hlt">aerosols</span> suffer severe hydrogen bond disruption and that the structural impairment is more pronounced at the surface. Laboratory <span class="hlt">aerosols</span> generated this way do not mimic those found naturally. Thus mass accommodation coefficients measured using such <span class="hlt">aerosols</span> should not be used in global climate-modeling calculations. 13 refs., 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459184','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459184"><span id="translatedtitle">Impact of assimilated and interactive <span class="hlt">aerosol</span> on tropical cyclogenesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Reale, O; Lau, K M; da Silva, A; Matsui, T</p> <p>2014-01-01</p> <p>This article investigates the impact of Saharan dust on the development of tropical cyclones in the Atlantic. A global data assimilation and forecast system, the NASA GEOS-5, is used to assimilate all satellite and conventional data sets used operationally for numerical weather prediction. In addition, this new GEOS-5 version includes assimilation of <span class="hlt">aerosol</span> optical depth from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer. The analysis so obtained comprises atmospheric quantities and a realistic 3-D <span class="hlt">aerosol</span> and cloud distribution, consistent with the meteorology and validated against Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observation and CloudSat data. These improved analyses are used to initialize GEOS-5 forecasts, explicitly accounting for <span class="hlt">aerosol</span> direct radiative effects and their impact on the atmospheric dynamics. Parallel simulations with/without <span class="hlt">aerosol</span> radiative effects show that effects of dust on static stability increase with time, becoming highly significant after day 5 and producing an environment less favorable to tropical cyclogenesis. PMID:26074648</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012070','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012070"><span id="translatedtitle">Impact of Assimilated and Interactive <span class="hlt">Aerosol</span> on Tropical Cyclogenesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reale, O.; Lau, K. M.; daSilva, A.; Matsui, T.</p> <p>2014-01-01</p> <p>This article investigates the impact 3 of Saharan dust on the development of tropical cyclones in the Atlantic. A global data assimilation and forecast system, the NASA GEOS-5, is used to assimilate all satellite and conventional data sets used operationally for numerical weather prediction. In addition, this new GEOS-5 version includes assimilation of <span class="hlt">aerosol</span> optical depth from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS). The analysis so obtained comprises atmospheric quantities and a realistic 3-d <span class="hlt">aerosol</span> and cloud distribution, consistent with the meteorology and validated against Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat data. These improved analyses are used to initialize GEOS-5 forecasts, explicitly accounting for <span class="hlt">aerosol</span> direct radiative effects and their impact on the atmospheric dynamics. Parallel simulations with/without <span class="hlt">aerosol</span> radiative effects show that effects of dust on static stability increase with time, becoming highly significant after day 5 and producing an environment less favorable to tropical cyclogenesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17034300','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17034300"><span id="translatedtitle">Generating monodisperse pharmacological <span class="hlt">aerosols</span> using the spinning-top <span class="hlt">aerosol</span> generator.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Biddiscombe, Martyn F; Barnes, Peter J; Usmani, Omar S</p> <p>2006-01-01</p> <p>Pharmacological <span class="hlt">aerosols</span> of precisely controlled particle size and narrow dispersity can be generated using the spinning-top <span class="hlt">aerosol</span> generator (STAG). The ability of the STAG to generate monodisperse <span class="hlt">aerosols</span> from solutions of raw drug compounds makes it a valuable research instrument. In this paper, the versatility of this instrument has been further demonstrated by <span class="hlt">aerosolizing</span> a range of commercially available nebulized pulmonary therapy preparations. Nebules of Flixotide (fluticasone propionate), Pulmicort (budesonide), Combivent (salbutamol sulphate and ipratropium bromide), Bricanyl (terbutaline sulphate), Atrovent(ipratropium bromide), and Salamol (salbutamol sulphate) were each mixed with ethanol and delivered to the STAG. Monodisperse drug <span class="hlt">aerosol</span> distributions were generated with MMADs of 0.95-6.7 microm. To achieve larger particle sizes from the nebulizer drug suspensions, the STAG formed compound particle agglomerates derived from the smaller insoluble drug particles. These compound agglomerates behaved aerodynamically as a single particle, and this was verified using an aerodynamic particle sizer and an Andersen Cascade Impactor. Scanning electron microscope <span class="hlt">images</span> demonstrated their physical structure. On the other hand using the nebulizer drug solutions, spherical particles proportional to the original droplet diameter were generated. The <span class="hlt">aerosols</span> generated by the STAG can allow investigators to study the scientific principles of inhaled drug deposition and lung physiology for a range of therapeutic agents. PMID:17034300</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.118..135B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.118..135B"><span id="translatedtitle">Sugars in Antarctic <span class="hlt">aerosol</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barbaro, Elena; Kirchgeorg, Torben; Zangrando, Roberta; Vecchiato, Marco; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea</p> <p>2015-10-01</p> <p>The processes and transformations occurring in the Antarctic <span class="hlt">aerosol</span> during atmospheric transport were described using selected sugars as source tracers. Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were measured in the Antarctic <span class="hlt">aerosol</span> collected during four different sampling campaigns. For quantification, a sensitive high-pressure anion exchange chromatography was coupled with a single quadrupole mass spectrometer. The method was validated, showing good accuracy and low method quantification limits. This study describes the first determination of sugars in the Antarctic <span class="hlt">aerosol</span>. The total mean concentration of sugars in the <span class="hlt">aerosol</span> collected at the "Mario Zucchelli" coastal station was 140 pg m-3; as for the <span class="hlt">aerosol</span> collected over the Antarctic plateau during two consecutive sampling campaigns, the concentration amounted to 440 and 438 pg m-3. The study of particle-size distribution allowed us to identify the natural emission from spores or from sea-spray as the main sources of sugars in the coastal area. The enrichment of sugars in the fine fraction of the <span class="hlt">aerosol</span> collected on the Antarctic plateau is due to the degradation of particles during long-range atmospheric transport. The composition of sugars in the coarse fraction was also investigated in the <span class="hlt">aerosol</span> collected during the oceanographic cruise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.A11D..01K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.A11D..01K"><span id="translatedtitle">Space-borne Observations of <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaufman, Y. J.; Tanre, D.; Coakley, J. A.; Fraser, R. S.</p> <p>2005-12-01</p> <p>As early as 1963, photographs of the twilight horizon from the Vostok-6 spaceship were used by G. V. Rozenberg and V. V. Nikolaeva-Tereshkova to derive profiles of stratospheric <span class="hlt">aerosols</span>. The launch of the ATS III satellite in 1967 sparked interest in using satellites to observe <span class="hlt">aerosol</span> emission, transport, and their effects on climate, precipitation and health. The first use of autonomous satellites in <span class="hlt">aerosol</span> research appears to be by Toby Carlson and Joe Prospero who tracked dust from the Sahara to the Americas in the early `70s using ATS III <span class="hlt">images</span>. The launch of the calibrated Landsat instrument in 1972 allowed Bob Fraser to perform quantitative analyses of dust column concentrations for individual scenes. GOES launched in 1975 provided hourly data that allowed Walter Lyons and J.C. Dooley in the late 70's to report on the transport of sulfate air pollution which was later followed by estimates of the export of sulfate <span class="hlt">aerosol</span> from the US to the Atlantic Ocean. With the launch of SAGE in 1979, Pat McCormick and co-workers began long term observations of statospheric <span class="hlt">aerosols</span>. The launch of TIROS(N) and the AVHRR in 1979 marked the start of concerted efforts by Larry Stowe and his colleagues to produce operationally an <span class="hlt">aerosol</span> product over oceans from the NOAA polar orbiting satellite. With the launch of the Earth Radiation Budget Experiment scanners in the late 1980's, Sundar Christopher and his colleagues began linking AVHRR-derived <span class="hlt">aerosol</span> burdens to their effects on the Earth's radiation budget. A remarkable aspect of this early work is that instruments like the AVHRR, Landsat, and GOES <span class="hlt">imager</span> were not originally designed to perform quantitative estimates of <span class="hlt">aerosol</span> properties. In fact, corrections for the effects of <span class="hlt">aerosols</span> in determining ocean reflectances implemented primarily through the work of Howard Gordon, facilitated much improved pictures of chlorophyll in the upper oceans than had been hoped for from CZCS data collected in the late 70's. This</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2233515','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2233515"><span id="translatedtitle">The development and evaluation of an adaptable computer aided instruction(<span class="hlt">CAI</span>) program for acquiring problem solving skills in biochemistry on the WWW: The "BioChem Thinker".</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hershkovitz, B.</p> <p>1997-01-01</p> <p>BioChem Thinker is a <span class="hlt">CAI</span> program that was developed to enhance problem solving skills and ability to integrate knowledge in biochemistry for medical and dental students. The program runs on a WWW browser. BioChem Thinker is adaptable, it enables the teacher to create a new problem solving assignment, or edit existing assignments without in-depth knowledge of computer programming. This provides teachers with greater independence and flexibility so as to be able to adapt the program to their own course requirements. The program was implemented and evaluated in the 3rd year biochemistry course of The Hebrew University-Hadassah Medical School. The tool used to develop Biochem Thinker can be utilized to develop similar <span class="hlt">CAI</span> in other biomedical areas. PMID:9357717</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160002232','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160002232"><span id="translatedtitle">New Petrology, Mineral Chemistry and Stable MG Isotope Compositions of an Allende <span class="hlt">CAI</span>: EK-459-7-2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jeffcoat, C. R.; Kerekgyarto, A. G.; Lapen, T. J.; Righter, M.; Simon, J. I.; Ross, D. K.</p> <p>2016-01-01</p> <p>Calcium-aluminum-rich inclusions (<span class="hlt">CAIs</span>) are the key to understanding physical and chemical conditions in the nascent solar nebula. These inclusions have the oldest radiometric ages of solar system materials and are composed of phases that are predicted to condense early from a gas of solar composition. Thus, their chemistry and textures record conditions and processes in the earliest stages of development of the solar nebula. Type B inclusions are typically larger and more coarse grained than other types with substantial evidence that many of them were at least partially molten. Type B inclusions are further subdivided into Type B1 (possess thick melilite mantle) and Type B2 (lack melilite mantle). Despite being extensively studied, the origin of the melilite mantles of Type B1 inclusions remains uncertain. We present petrologic and chemical data for a Type B inclusion, EK-459-7-2, that bears features found in both Type B1 and B2 inclusions and likely represents an intermediate between the two types. Detailed studies of more of these intermediate objects may help to constrain models for Type B1 rim formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A53K..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A53K..03L"><span id="translatedtitle">A 10-year global gridded <span class="hlt">Aerosol</span> Optical Thickness Reanalysis for climate and applied applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lynch, P.; Reid, J. S.; Zhang, J.; Westphal, D. L.; Campbell, J. R.; Curtis, C. A.; Hegg, D.; Hyer, E. J.; Sessions, W.; Shi, Y.; Turk, J.</p> <p>2013-12-01</p> <p>While standalone satellite and model <span class="hlt">aerosol</span> products see wide utilization, there is a significant need of a best-available fused product on a regular grid for numerous climate and applied applications. Remote sensing and modeling technologies have now advanced to a point where <span class="hlt">aerosol</span> data assimilation is an operational reality at numerous centers. It is inevitable that, like meteorological reanalyses, <span class="hlt">aerosol</span> reanalyses will see heavy use in the near future. A first long term, 2003-2012 global 1x1 degree and 6-hourly <span class="hlt">aerosol</span> optical thickness (AOT) reanalysis product has been generated. The goal of this effort is not only for climate applications, but to generate a dataset that can be used by the US Navy to understand operationally hindering <span class="hlt">aerosol</span> events, <span class="hlt">aerosol</span> impacts on numerical weather prediction, and application of electro-optical technologies. The reanalysis utilizes Navy <span class="hlt">Aerosol</span> Analysis and Prediction System (NAAPS) at its core and assimilates quality controlled collection 5 Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) AOD with minor corrections from Multi-angle <span class="hlt">Imaging</span> SpectroRaditometer (MISR). A subset of this product includes Cloud-<span class="hlt">Aerosol</span> Lidar with Orthogonal Polarization (CALIOP) lidar assimilation since its launch in mid-2006. Surface <span class="hlt">aerosol</span> sources, including dust and smoke, in the <span class="hlt">aerosol</span> model have been regionally tuned so that fine and coarse mode AOTs best match those resolve by ground-based <span class="hlt">Aerosol</span> Robotic Network (AERONET). The AOT difference between the model and satellite AOT is then used to adjust other <span class="hlt">aerosol</span> processes, eg., sources, dry deposition, etc. <span class="hlt">Aerosol</span> wet deposition is constrained with satellite-retrieved precipitation. The final AOT reanalysis is shown to exhibit good agreement with AERONET. Here we review the development of the reanalysis and consider issues particular to <span class="hlt">aerosol</span> reanalyses that make them distinct from standard meteorological reanalyses. Considerations are also made for extending such work</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9520M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9520M"><span id="translatedtitle"><span class="hlt">Aerosol</span> optical depth retrieval using the MERIS observation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mei, Linlu; Rozanov, Vladimir; Vountas, Marco; Burrows, John P.</p> <p>2015-04-01</p> <p>Surface reflectance determination and <span class="hlt">aerosol</span> type selection are the two main challenges for space-borne <span class="hlt">aerosol</span> remote sensing, especially for those instruments lacking of near-infrared channels, high-temporal observations, multi-angles abilities and/or polarization information. However, space based instruments like the MEdium Resolution <span class="hlt">Imaging</span> Spectrometer (MERIS) and the successor, Ocean and Land Colour Instrument (OLCI) with high calibration accuracy and high spatial resolution provide unique abilities for obtaining valuable <span class="hlt">aerosol</span> information for a better understanding of the impact of <span class="hlt">aerosols</span> on climate, which is still one of the largest uncertainties of global climate change evaluation. In this study, a new <span class="hlt">Aerosol</span> Optical Depth (AOD) retrieval algorithm is presented. Global <span class="hlt">aerosol</span> type and surface spectral dataset were used for the <span class="hlt">aerosol</span> type selection and surface reflectance determination. A modified Ross-Li mode is used to describe the surface Bidirectional Reflectance Distribution Function (BRDF) effect. The comparison with operational MODIS C6 product and the validation using <span class="hlt">AErosol</span> RObotic NETwork (AERONET) show promising results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/231060','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/231060"><span id="translatedtitle">Characterization of Mojave Desert <span class="hlt">aerosols</span>: Their effect on radiometer performance</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mathews, L.A.; Salgado, D.P.; Walker, P.L.</p> <p>1994-12-31</p> <p>The Antelope Valley is part of the southwestern Mojave Desert lying fifty miles north of Los Angeles International Airport. The Antelope Valley is separated from the Los Angeles and San Fernando Valley air basins by the San Gabriel Mountains. The Tehachapi Mountains, to the west, separate the Antelope Valley from the San Joaquin Valley. Combustion <span class="hlt">aerosols</span> are transported from the San Joaquin Valley through the Tehachapi Pass and through the Soledad and Cajun passes from the Los Angeles air basin. Thus the valley`s atmosphere contains a spatially and temporally complex mixture of <span class="hlt">aerosols</span> of urban, industrial and desert origin. The Visibility Impact Summer Study held from July to September 1990 was an intense, comprehensive study intended to measure <span class="hlt">aerosol</span> size and chemical composition and to ascertain their optical effects. Size distributions for particle diameters from 0.01 to 10 {micro} were measured at hourly intervals and particle samplers were used to obtain chemical compositions at daily intervals at Tehachapi Pass and Edwards AFB, California. The extracted <span class="hlt">aerosol</span> characteristics are discussed and compared to the desert <span class="hlt">aerosol</span> model in LOWTRAN and the size and estimated composition of <span class="hlt">aerosols</span> at China Lake reported upon earlier. The authors obtain relationships between <span class="hlt">aerosol</span> mass and wind speed, diurnal size changes, and meteorological effects. Secondarily, extinction was calculated and used with LOWTRAN and radiosonde data for examination of <span class="hlt">aerosol</span> effects on narrow band 3--5 and 8--12 {micro} <span class="hlt">imaging</span> radiometer performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6406E..0EF','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6406E..0EF"><span id="translatedtitle">MAUVE/SWIPE: an <span class="hlt">imaging</span> instrument concept with multi-angular, -spectral, and -polarized capability for remote sensing of <span class="hlt">aerosols</span>, ocean color, clouds, and vegetation from space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frouin, Robert; Deschamps, Pierre-Yves; Rothschild, Richard; Stephan, Edward; Leblanc, Philippe; Duttweiler, Fred; Ghaemi, Tony; Riedi, Jérôme</p> <p>2006-12-01</p> <p>The Monitoring <span class="hlt">Aerosols</span> in the Ultraviolet Experiment (MAUVE) and the Short-Wave Infrared Polarimeter Experiment (SWIPE) instruments have been designed to collect, from a typical sun-synchronous polar orbit at 800 km altitude, global observations of the spectral, polarized, and directional radiance reflected by the earth-atmosphere system for a wide range of applications. Based on the heritage of the POLDER radiometer, the MAUVE/SWIPE instrument concept combines the merits of TOMS for observing in the ultra-violet, MISR for wide field-of-view range, MODIS, for multi-spectral aspects in the visible and near infrared, and the POLDER instrument for polarization. The instruments are camera systems with 2-dimensional detector arrays, allowing a 120-degree field-of-view with adequate ground resolution (i.e., 0.4 or 0.8 km at nadir) from satellite altitude. Multi-angle viewing is achieved by the along-track migration at spacecraft velocity of the 2-dimensional field-of-view. Between the cameras' optical assembly and detector array are two filter wheels, one carrying spectral filters, the other polarizing filters, allowing measurements of the first three Stokes parameters, I. Q, and V, of the incident radiation in 16 spectral bands optimally placed in the interval 350-2200 nm. The spectral range is 350-1050 nm for the MAUVE instrument and 1050-2200 nm for the SWIPE instrument. The radiometric requirements are defined to fully exploit the multi-angular, multi-spectral, and multi-polarized capability of the instruments. These include a wide dynamic range, a signal-to-noise ratio above 500 in all channels at maximum radiance level, i.e., when viewing a surface target of albedo equal to 1, and a noise-equivalent-differential reflectance better than 0.0005 at low signal level for a sun at zenith. To achieve daily global coverage, a pair of MAUVE and SWIPE instruments would be carried by each of two mini-satellites placed on interlaced orbits. The equator crossing time of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20160000375&hterms=PROPERTIES&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DPROPERTIES','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20160000375&hterms=PROPERTIES&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DPROPERTIES"><span id="translatedtitle">Volcanic <span class="hlt">Aerosol</span> Radiative Properties</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lacis, Andrew</p> <p>2015-01-01</p> <p>Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid <span class="hlt">aerosol</span> droplets that exert a radiative cooling effect on the global climate system lasting for several years.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatGe...8..174P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatGe...8..174P"><span id="translatedtitle">Palaeoclimate: <span class="hlt">Aerosols</span> and rainfall</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Partin, Jud</p> <p>2015-03-01</p> <p>Instrumental records have hinted that <span class="hlt">aerosol</span> emissions may be shifting rainfall over Central America southwards. A 450-year-long precipitation reconstruction indicates that this shift began shortly after the Industrial Revolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21886230','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21886230"><span id="translatedtitle"><span class="hlt">Aerosol</span> lenses propagation model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tremblay, Grégoire; Roy, Gilles</p> <p>2011-09-01</p> <p>We propose a model based on the properties of cascading lenses modulation transfer function (MTF) to reproduce the irradiance of a screen illuminated through a dense <span class="hlt">aerosol</span> cloud. In this model, the <span class="hlt">aerosol</span> cloud is broken into multiple thin layers considered as individual lenses. The screen irradiance generated by these individual layers is equivalent to the point-spread function (PSF) of each <span class="hlt">aerosol</span> lens. Taking the Fourier transform of the PSF as a MTF, we cascade the lenses MTF to find the cloud MTF. The screen irradiance is found with the Fourier transform of this MTF. We show the derivation of the model and we compare the results with the Undique Monte Carlo simulator for four <span class="hlt">aerosols</span> at three optical depths. The model is in agreement with the Monte Carlo for all the cases tested. PMID:21886230</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/788898','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/788898"><span id="translatedtitle">Emergency Protection from <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cristy, G.A.</p> <p>2001-11-13</p> <p>Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) <span class="hlt">aerosols</span>. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the <span class="hlt">aerosol</span> cloud. Protection factors of 800 and above were achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150000796','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150000796"><span id="translatedtitle">MISR <span class="hlt">Aerosol</span> Typing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahn, Ralph A.</p> <p>2014-01-01</p> <p>AeroCom is an open international initiative of scientists interested in the advancement of the understanding of global <span class="hlt">aerosol</span> properties and <span class="hlt">aerosol</span> impacts on climate. A central goal is to more strongly tie and constrain modeling efforts to observational data. A major element for exchanges between data and modeling groups are annual meetings. The meeting was held September 20 through October 2, 1014 and the organizers would like to post the presentations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/867343','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867343"><span id="translatedtitle">Monodisperse <span class="hlt">aerosol</span> generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ortiz, Lawrence W.; Soderholm, Sidney C.</p> <p>1990-01-01</p> <p>An <span class="hlt">aerosol</span> generator is described which is capable of producing a monodisperse <span class="hlt">aerosol</span> within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6737E..0DS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6737E..0DS"><span id="translatedtitle">Coded aperture systems as non-conventional lensless <span class="hlt">imagers</span> for the visible and infrared</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Slinger, Chris; Gordon, Neil; Lewis, Keith; McDonald, Gregor; McNie, Mark; Payne, Doug; Ridley, Kevin; Strens, Malcolm; De Villiers, Geoff; Wilson, Rebecca</p> <p>2007-10-01</p> <p>Coded aperture <span class="hlt">imaging</span> (<span class="hlt">CAI</span>) has been used extensively at gamma- and X-ray wavelengths, where conventional refractive and reflective techniques are impractical. <span class="hlt">CAI</span> works by coding optical wavefronts from a scene using a patterned aperture, detecting the resulting intensity distribution, then using inverse digital signal processing to reconstruct an <span class="hlt">image</span>. This paper will consider application of <span class="hlt">CAI</span> to the visible and IR bands. Doing so has a number of potential advantages over existing <span class="hlt">imaging</span> approaches at these longer wavelengths, including low mass, low volume, zero aberrations and distortions and graceful failure modes. Adaptive coded aperture (ACAI), facilitated by the use of a reconfigurable mask in a <span class="hlt">CAI</span> configuration, adds further merits, an example being the ability to implement agile <span class="hlt">imaging</span> modes with no macroscopic moving parts. However, diffraction effects must be considered and photon flux reductions can have adverse consequences on the <span class="hlt">image</span> quality achievable. An analysis of these benefits and limitations is described, along with a description of a novel micro optical electro mechanical (MOEMS) microshutter technology for use in thermal band infrared ACAI systems. Preliminary experimental results are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1028128','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1028128"><span id="translatedtitle">RACORO <span class="hlt">aerosol</span> data processing</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Elisabeth Andrews</p> <p>2011-10-31</p> <p>The RACORO <span class="hlt">aerosol</span> data (cloud condensation nuclei (CCN), condensation nuclei (CN) and <span class="hlt">aerosol</span> size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter <span class="hlt">aerosol</span> data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured <span class="hlt">aerosol</span> size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several <span class="hlt">aerosol</span> data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-<span class="hlt">aerosol</span> interactions and improved cloud simulations in climate models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993Metic..28Q.344E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993Metic..28Q.344E"><span id="translatedtitle">Efremovka 101.1: A Primitive <span class="hlt">CAI</span> with Superrefractory REE Patterns and Enormous Enrichments of Sc, Zr, and Y in Fassaite and Perovskite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El Goresy, A.; Zinner, E. K.; Matsunami, S.; Palme, H.; Spettel, B.; Lin, Y.; Nazarov, M.</p> <p>1993-07-01</p> <p>A fragment (30 mg) consisting of two inclusions (101.1 and 101.2) was separated from the Efremovka (CV3) meteorite. 101.1 is an unusual Type A <span class="hlt">CAI</span>, whereas 101.2 consists of Cr-spinel and fassaite. INAA of the whole fragment revealed 16% MgO reflecting significant contributions from 101.2. Refractory lithophile elements in the bulk fragment have CI-enrichment factors of ~14 with two times enrichment factors for Ca, Eu, and Yb. <span class="hlt">CAI</span> 101.1 (1.6 mm) contains more than 90% gehlenitic melilite (Ak(sub)1- Ak(sub)32) in its core. It is surrounded by a 5 layer rim sequence (~40 micrometers thick) consisting of spinel -->Al- diopside + fassaite (<= 0.7% Sc2O3) -->forsterite (Fo(sub)97- Fo(sub)100) --> diopside --> forsterite. Two small complete <span class="hlt">CAIs</span> with a two layer sequence (diopside + anorthite) are contained within the core. Numerous layered sinuous inclusions presumably rim sequence fragments also consisting of diopside + anorthite, are locally crowded in the core. The melilite core is sprinkled with fassaite, perovskite, FeNi, and OsRu-rich metal blebs. Fassaite grains (<= 30 micrometers) contain enormous concentrations in Sc (up to 12.9% Sc2O3) and Zr (up to 5.4% ZrO2). Fassaite rims around FeNi blebs are rich in V (up to 5.4% V2O3) and are zoned with decreasing Sc-, Zr-, and V-concents from the metal cores to the outer fassaite rims. Sc2O3 and ZrO2 concentrations in fassaite display a positive correlation with a correlation coeffient of 0.88. This coherent behavior is a result of a complex cation substitution involving Mg, Ti, Sc, Zr, and V. A coupled substitution is demonstrated by the excellent linear correlation between Mg^2++Ti^4+(y) and Sc^3++Zr^4++Ti^3++V^3+(x) satisfying the equation y = 0.70-0.66x and having a linear regression coefficient of 0.84. Ti^3+/Ti^tot varies between 0.27 and 1. In contrast to fassaites, perovskites are generally depleted in Sc and Zr and enriched in Y (<=1.4% Y2O3). The assemblage andradite+wollastonite+ Fe^degree/or FeNi metal was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1614354L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614354L"><span id="translatedtitle"><span class="hlt">Aerosol</span> Measurements from Current and Future EUMETSAT Satellites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lang, Ruediger; Munro, Rosemary; Kokhanovsky, Alexander; Grzegorski, Michael; Poli, Gabriele; Holdak, Andriy; Retscher, Christian; Marbach, Thierry</p> <p>2014-05-01</p> <p>EUMETSAT supports the operational monitoring and forecasting of atmospheric composition including various <span class="hlt">aerosol</span> optical properties through specific products from its geostationary and polar-orbiting satellites. Meteosat imagery is used to characterise <span class="hlt">aerosols</span> in the atmosphere, including volcanic ash and dust storms at high temporal resolution, while the GOME-2, AVHRR and IASI and instruments on Metop observe <span class="hlt">aerosol</span> optical properties from the UV/vis to the infra-red spectral region from a polar morning orbit. The role of EUMETSAT in observing <span class="hlt">aerosol</span> optical properties will expand further towards the 2020 timeframe when EUMETSAT also becomes the operator of the Copernicus Sentinel-3, 4 and 5 missions. This expanding role will be realised through additional atmospheric composition sounding instruments such as the UVN/Sentinel-4 on the Meteosat Third Generation (MTG) geostationary platforms and the 3MI, METimage, and Sentinel-5 instruments on the EPS Second Generation (EPS-SG) satellites. The synergistic use of <span class="hlt">imager</span>, spectrometer and interferometer data will, with the availability of this new generation of instrumentation and with the need for measuring <span class="hlt">aerosol</span> optical properties at short-time scales, high spatial resolution and over a broad spectra region, play and increasingly important role in the field of <span class="hlt">aerosol</span> remote sensing. With its new Polar Multi-mission <span class="hlt">Aerosol</span> optical properties (PMAp) product, providing <span class="hlt">aerosol</span> and cloud optical depth information, as well as fine mode, dust and volcanic ash characterisation over ocean and in the future also over land, EUMETSAT has recently been implementing the first framework for such synergistic retrievals for the remote sensing of <span class="hlt">aerosol</span> optical properties from GOME-2, AVHRR and IASI instruments on Metop. We will present an overview of the ongoing and the future developments at EUMETSAT concerning <span class="hlt">aerosol</span> remote sensing from Metop as well as from the current MSG geostationary platforms and from the future</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=50042&keyword=CAD+AND+cam&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74608372&CFTOKEN=62078087','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=50042&keyword=CAD+AND+cam&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74608372&CFTOKEN=62078087"><span id="translatedtitle"><span class="hlt">AEROSOL</span> CHARACTERIZATION WITH CENTRIFUCAL <span class="hlt">AEROSOL</span> SPECTROMETERS: THEORY AND EXPERIMENT</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A general mathematical model describing the motion of particles in <span class="hlt">aerosol</span> centrifuges has been developed. t has been validated by comparisons of theoretically predicted calibration sites with experimental data from tests sizing <span class="hlt">aerosols</span> in instruments of three different spiral d...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED111337.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED111337.pdf"><span id="translatedtitle">CHARGE <span class="hlt">Image</span> Generator: Theory of Operation and Author Language Support. Technical Report 75-3.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gunwaldsen, Roger L.</p> <p></p> <p>The <span class="hlt">image</span> generator function and author language software support for the CHARGE (Color Halftone Area Graphics Environment) Interactive Graphics System are described. Designed initially for use in computer-assisted instruction (<span class="hlt">CAI</span>) systems, the CHARGE Interactive Graphics System can provide graphic displays for various applications including…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/841588','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/841588"><span id="translatedtitle">Representing Cloud Processing of <span class="hlt">Aerosol</span> in Numerical Models</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mechem, D.B.; Kogan, Y.L.</p> <p>2005-03-18</p> <p>The satellite imagery in Figure 1 provides dramatic examples of how <span class="hlt">aerosol</span> influences the cloud field. <span class="hlt">Aerosol</span> from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top <span class="hlt">image</span>), or can enhance the reflectance/albedo in already cloudy regions. This <span class="hlt">image</span> is a demonstration of the first indirect effect, in which changes in <span class="hlt">aerosol</span> modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), <span class="hlt">aerosol</span> can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom <span class="hlt">image</span>) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low <span class="hlt">aerosol</span> concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-<span class="hlt">aerosol</span> system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-<span class="hlt">aerosol</span> problem. 1. Drizzling and nondrizzling simulations demonstrate the effect of drizzle on a mesoscale forecast off the California coast. 2. LES experiments with explicit (bin) microphysics gauge the relative importance of the shape of the <span class="hlt">aerosol</span> spectrum on the 3D dynamics and cloud structure. 3. Idealized mesoscale model simulations evaluate the relative roles of various processes, sources, and sinks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20120003884&hterms=disentangling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddisentangling','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20120003884&hterms=disentangling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddisentangling"><span id="translatedtitle">Observational Evidence of <span class="hlt">Aerosol</span> Enhancement of Lightning Activity and Convective Invigoration</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yuan, Tianle; Remer, Lorraine A.; Pickering, Kenneth E.; Yu, Hongbin</p> <p>2011-01-01</p> <p>Lightning activity over the West Pacific Ocean east of the Philippines is usually much less frequent than over the nearby maritime continents. However, in 2005 the Lightning <span class="hlt">Imaging</span> Sensor (LIS) aboard the TRMM satellite observed anomalously high lightning activity in that area. In the same year the Moderate resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) measured anomalously high <span class="hlt">aerosol</span> loading. The high <span class="hlt">aerosol</span> loading was traced to volcanic activity, and not to any factor linked to meteorology, disentangling the usual convolution between <span class="hlt">aerosols</span> and meteorology. We show that in general lightning activity is tightly correlated with <span class="hlt">aerosol</span> loadings at both inter-annual and biweekly time scales. We estimate that a approximately 60% increase in <span class="hlt">aerosol</span> loading leads to more than 150% increase in lightning flashes. <span class="hlt">Aerosols</span> increase lightning activity through modification of cloud microphysics. Cloud ice particle sizes are reduced and cloud glaciation is delayed to colder temperature when <span class="hlt">aerosol</span> loading is increased. TRMM precipitation radar measurements indicate that anomalously high <span class="hlt">aerosol</span> loading is associated with enhanced cloud mixed phase activity and invigorated convection over the maritime ocean. These observed associations between <span class="hlt">aerosols</span>, cloud microphysics, morphology and lightning activity are not related to meteorological variables or ENSO events. The results have important implications for understanding the variability of lightning and resulting <span class="hlt">aerosol</span>-chemistry interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930010913','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930010913"><span id="translatedtitle"><span class="hlt">Aerosol</span> chemistry in GLOBE</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clarke, Antony D.; Rothermel, Jeffry; Jarzembski, Maurice A.</p> <p>1993-01-01</p> <p>This task addresses the measurement and understanding of the physical and chemical properties of <span class="hlt">aerosol</span> in remote regions that are responsible for <span class="hlt">aerosol</span> backscatter at infrared wavelengths. Because it is representative of other clean areas, the remote Pacific is of extreme interest. Emphasis is on the determination size dependent <span class="hlt">aerosol</span> properties that are required for modeling backscatter at various wavelengths and upon those features that may be used to help understand the nature, origin, cycling and climatology of these <span class="hlt">aerosols</span> in the remote troposphere. Empirical relationships will be established between lidar measurements and backscatter derived from the <span class="hlt">aerosol</span> microphysics as required by the NASA Doppler Lidar Program. This will include the analysis of results from the NASA GLOBE Survey Mission Flight Program. Additional instrument development and deployment will be carried out in order to extend and refine this data base. Identified activities include participation in groundbased and airborne experiments. Progress to date includes participation in, analysis of, and publication of results from Mauna Loa Backscatter Intercomparison Experiment (MABIE) and Global Backscatter Experiment (GLOBE).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011SPIE.8018E..02B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011SPIE.8018E..02B&link_type=ABSTRACT"><span id="translatedtitle">Biological <span class="hlt">aerosol</span> background characterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blatny, Janet; Fountain, Augustus W., III</p> <p>2011-05-01</p> <p>To provide useful information during military operations, or as part of other security situations, a biological <span class="hlt">aerosol</span> detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if <span class="hlt">aerosol</span> particles have viability characteristics. Still, such commercially available biological <span class="hlt">aerosol</span> detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological <span class="hlt">aerosol</span> characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological <span class="hlt">aerosol</span> characteristics to reduce false alarm rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=43127&keyword=Erwinia+AND+herbicola&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74609510&CFTOKEN=98528667','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=43127&keyword=Erwinia+AND+herbicola&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74609510&CFTOKEN=98528667"><span id="translatedtitle">SURVIVAL OF BACTERIA DURING <span class="hlt">AEROSOLIZATION</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>One form of commercial application of microorganisms, including genetically engineered microorganisms is as an <span class="hlt">aerosol</span>. To study the effect of <span class="hlt">aerosol</span>-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, Enterobacter clo...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16798603','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16798603"><span id="translatedtitle">Other medications for <span class="hlt">aerosol</span> delivery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rubin, Bruce K</p> <p>2006-01-01</p> <p>Although <span class="hlt">aerosol</span> therapy is most commonly used to treat asthma and COPD, there are a large number of <span class="hlt">aerosol</span> medications now used or in development for other diseases. Mucoactive agents have long been available by <span class="hlt">aerosol</span>, but now we have truly effective drugs to improve effective airway clearance including dornase alfa, hyperosmolar saline, and <span class="hlt">aerosol</span> surfactant. Inhaled antibiotics are available for the treatment of cystic fibrosis, bronchiectasis and other chronic airway infections. With the development of devices that can target <span class="hlt">aerosol</span> to the deep lung, the opportunity to deliver medications systemically by the <span class="hlt">aerosol</span> route has become a reality. Insulin, recently approved in the US as <span class="hlt">aerosol</span> therapy, and other peptides are systemically absorbed from the distal airway and alveolus. <span class="hlt">Aerosol</span> gene transfer therapy to correct abnormalities associated with cystic fibrosis, primary ciliary dyskinesia and other airway diseases also holds great potential. PMID:16798603</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016NatGe...9....7Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016NatGe...9....7Z&link_type=ABSTRACT"><span id="translatedtitle">Atmospheric Chemistry: Nature's plasticized <span class="hlt">aerosols</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ziemann, Paul J.</p> <p>2016-01-01</p> <p>The structure of atmospheric <span class="hlt">aerosol</span> particles affects their reactivity and growth rates. Measurements of <span class="hlt">aerosol</span> properties over the Amazon rainforest indicate that organic particles above tropical rainforests are simple liquid drops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26ES...18a2085L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26ES...18a2085L"><span id="translatedtitle">Preliminary results of the <span class="hlt">aerosol</span> optical depth retrieval in Johor, Malaysia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lim, H. Q.; Kanniah, K. D.; Lau, A. M. S.</p> <p>2014-02-01</p> <p>Monitoring of atmospheric <span class="hlt">aerosols</span> over the urban area is important as tremendous amounts of pollutants are released by industrial activities and heavy traffic flow. Air quality monitoring by satellite observation provides better spatial coverage, however, detailed <span class="hlt">aerosol</span> properties retrieval remains a challenge. This is due to the limitation of <span class="hlt">aerosol</span> retrieval algorithm on high reflectance (bright surface) areas. The aim of this study is to retrieve <span class="hlt">aerosol</span> optical depth over urban areas of Iskandar Malaysia; the main southern development zone in Johor state, using Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) 500 m resolution data. One of the important steps is the <span class="hlt">aerosol</span> optical depth retrieval is to characterise different types of <span class="hlt">aerosols</span> in the study area. This information will be used to construct a Look Up Table containing the simulated <span class="hlt">aerosol</span> reflectance and corresponding <span class="hlt">aerosol</span> optical depth. Thus, in this study we have characterised different <span class="hlt">aerosol</span> types in the study area using <span class="hlt">Aerosol</span> Robotic Network (AERONET) data. These data were processed using cluster analysis and the preliminary results show that the area is consisting of coastal urban (65%), polluted urban (27.5%), dust particles (6%) and heavy pollution (1.5%) <span class="hlt">aerosols</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPA....1b2121S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPA....1b2121S"><span id="translatedtitle">Stereoscopic full aperture <span class="hlt">imaging</span> in nuclear medicine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Strocovsky, Sergio G.; Otero, Dino</p> <p>2011-06-01</p> <p><span class="hlt">Images</span> of planar scintigraphy and single photon emission computerized tomography (SPECT) used in nuclear medicine are often low quality. They usually appear to be blurred and noisy. This problem is due to the low spatial resolution and poor sensitivity of the acquisition technique with the gamma camera (GC). Other techniques, such as coded aperture <span class="hlt">imaging</span> (<span class="hlt">CAI</span>) reach higher spatial resolutions than GC. However, <span class="hlt">CAI</span> is not frequently used for <span class="hlt">imaging</span> in nuclear medicine, due to the decoding complexity of some <span class="hlt">images</span> and the difficulty in controlling the noise magnitude. Summing up, the <span class="hlt">images</span> obtained through GC are low quality and it is still difficult to implement <span class="hlt">CAI</span> technique. A novel technique, full aperture <span class="hlt">Imaging</span> (FAI), also uses gamma ray-encoding to obtain <span class="hlt">images</span>, but the coding system and the method of <span class="hlt">images</span> reconstruction are simpler than those used in <span class="hlt">CAI</span>. In addition, FAI also reaches higher spatial resolution than GC. In this work, the principles of FAI technique and the method of <span class="hlt">images</span> reconstruction are explained in detail. The FAI technique is tested by means of Monte Carlo simulations with filiform and spherical sources. Spatial resolution tests of GC versus FAI were performed using two different source-detector distances. First, simulations were made without interposing any material between the sources and the detector. Then, other more realistic simulations were made. In these, the sources were placed in the centre of a rectangular prismatic region, filled with water. A rigorous comparison was made between GC and FAI <span class="hlt">images</span> of the linear filiform sources, by means of two methods: mean fluence profile graphs and correlation tests. Finally, three-dimensional capacity of FAI was tested with two spherical sources. The results show that FAI technique has greater sensitivity (>100 times) and greater spatial resolution (>2.6 times) than that of GC with LEHR collimator, in both cases, with and without attenuating material and long and short</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=238721','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=238721"><span id="translatedtitle">Method for detecting viruses in <span class="hlt">aerosols</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wallis, C; Melnick, J L; Rao, V C; Sox, T E</p> <p>1985-01-01</p> <p>A simple method with poliovirus as the model was developed for recovering human enteric viruses from <span class="hlt">aerosols</span>. Filterite filters (pore size, 0.45 micron; Filterite Corp., Timonium, Md.) moistened with glycine buffer (pH 3.5) were used for adsorbing the <span class="hlt">aerosolized</span> virus. No virus passed the filter, even with air flow rates of 100 liters/min. Virus recovery from the filter was achieved by rapid elution with 800 ml of glycine buffer, pH 10. The virus in the primary eluate was reconcentrated by adjusting the pH to 3.5, adding AlCl3 to 0.0005 M, collecting the virus on a 0.25-micron-pore Filerite disk (diameter, 25 mm) and and eluting with 6 ml of buffer, pH 10. With this method, virus could be detected regularly in <span class="hlt">aerosols</span> produced by flushing when 3 X 10(8) PFU of poliovirus were present in the toilet bowl. Poliovirus-containing fecal material from two of four infants who had recently received oral polio vaccine also yielded virus in the <span class="hlt">aerosols</span> when feces containing 2.4 X 10(7) to 4.5 X 10(7) PFU of virus had been added to the toilet bowl. Persons infected with a variety of natural enteric viruses are known to excrete this amount of virus in their daily stools. <span class="hlt">Images</span> PMID:3004329</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014SPIE.9232E..0NS&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014SPIE.9232E..0NS&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Aerosol</span> characterization with lidar methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sugimoto, Nobuo; Nishizawa, Tomoaki; Shimizu, Atsushi; Matsui, Ichiro</p> <p>2014-08-01</p> <p><span class="hlt">Aerosol</span> component analysis methods for characterizing <span class="hlt">aerosols</span> were developed for various types of lidars including polarization-sensitive Mie scattering lidars, multi-wavelength Raman scattering lidars, and multi-wavelength highspectral- resolution lidars. From the multi-parameter lidar data, the extinction coefficients for four <span class="hlt">aerosol</span> components can be derived. The microphysical parameters such as single scattering albedo and effective radius can be also estimated from the derived <span class="hlt">aerosol</span> component distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8458E..29P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8458E..29P"><span id="translatedtitle">Probing the bulk viscosity of particles using <span class="hlt">aerosol</span> optical tweezers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Power, Rory; Bones, David L.; Reid, Jonathan P.</p> <p>2012-10-01</p> <p>Holographic <span class="hlt">aerosol</span> optical tweezers can be used to trap arrays of <span class="hlt">aerosol</span> particles allowing detailed studies of particle properties and processes at the single particle level. Recent observations have suggested that secondary organic <span class="hlt">aerosol</span> may exist as ultra-viscous liquids or glassy states at low relative humidity, potentially a significant factor in influencing their role in the atmosphere and their activation to form cloud droplets. A decrease in relative humidity surrounding a particle leads to an increased concentration of solute in the droplet as the droplet returns to equilibrium and, thus, an increase in the bulk viscosity. We demonstrate that the timescales for condensation and evaporation processes correlate with particle viscosity, showing significant inhibition in mass transfer kinetics using ternary sucrose/sodium chloride/water droplets as a proxy to atmospheric multi-component <span class="hlt">aerosol</span>. We go on to study the fundamental process of <span class="hlt">aerosol</span> coagulation in <span class="hlt">aerosol</span> particle arrays, observing the relaxation of non-spherical composite particles formed on coalescence. We demonstrate the use of bright-field <span class="hlt">imaging</span> and elastic light scattering to make measurements of the timescale for the process of binary coalescence contrasting the rheological properties of aqueous sucrose and sodium chloride <span class="hlt">aerosol</span> over a range of relative humidities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812228M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812228M&link_type=ABSTRACT"><span id="translatedtitle">Optical properties of <span class="hlt">aerosol</span> contaminated cloud derived from MODIS instrument</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mei, Linlu; Rozanov, Vladimir; Lelli, Luca; Vountas, Marco; Burrows, John P.</p> <p>2016-04-01</p> <p>The presence of absorbing <span class="hlt">aerosols</span> above/within cloud can reduce the amount of up-welling radiation in visible (VIS) and short-wave infrared and darken the spectral reflectance when compared with a spectrum of a clean cloud observed by satellite instruments (Jethva et al., 2013). Cloud properties retrieval for <span class="hlt">aerosol</span> contaminated cases is a great challenge. Even small additional injection of <span class="hlt">aerosol</span> particles into clouds in the cleanest regions of Earth's atmosphere will cause significant effect on those clouds and on climate forcing (Koren et al., 2014; Rosenfeld et al., 2014) because the micro-physical cloud process are non-linear with respect to the <span class="hlt">aerosol</span> loading. The current cloud products like Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) ignoring the <span class="hlt">aerosol</span> effect for the retrieval, which may cause significant error in the satellite-derived cloud properties. In this paper, a new cloud properties retrieval method, considering <span class="hlt">aerosol</span> effect, based on the weighting-function (WF) method, is presented. The retrieval results shows that the WF retrieved cloud properties (e.g COT) agrees quite well with MODIS COT product for relative clear atmosphere (AOT ≤ 0.4) while there is a large difference for large <span class="hlt">aerosol</span> loading. The MODIS COT product is underestimated for at least 2 - 3 times for AOT>0.4, and this underestimation increases with the increase of AOT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.7416R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.7416R&link_type=ABSTRACT"><span id="translatedtitle">Merging the SAGE II and OSIRIS Stratospheric <span class="hlt">Aerosol</span> Records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rieger, Landon; Bourassa, Adam; Degenstein, Doug</p> <p>2016-04-01</p> <p>The Optical Spectrograph and InfraRed <span class="hlt">Imaging</span> System (OSIRIS) instrument on the Odin satellite, launched in 2001 and currently operational, measures limb-scattered sunlight from which profiles of stratospheric <span class="hlt">aerosol</span> extinction at 750nm are retrieved. The Stratospheric <span class="hlt">Aerosol</span> and Gas (SAGE) II instrument was operational from 1985 to 2005, and provided <span class="hlt">aerosol</span> extinction at several visible and near infrared wavelengths. This work compares the SAGE II and OSIRIS <span class="hlt">aerosol</span> extinction measurements during the four years of instrument overlap by interpolating the SAGE II data to 750nm using the 525 and 1020nm channels. Agreement is generally favourable in the tropics and mid-latitudes with differences less than 10% for the majority of the <span class="hlt">aerosol</span> layer. However, near the UTLS and outside of the tropics agreement is poorer and reasons for this are investigated. Comparisons between the OSIRIS and SAGE II <span class="hlt">aerosol</span> extinction measurements at 750nm are used to develop a merged <span class="hlt">aerosol</span> climatology as a function of time, latitude and altitude at the native SAGE II wavelength of 525nm. Error due to assumptions in the OSIRIS retrieval and wavelength conversion are explored through simulation studies over a range of particle size distributions and is found to be approximately 20% for the majority of low-to-moderate volcanic loading conditions and OSIRIS geometries. Other sources of error such as cloud contamination in the UTLS are also explored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A21E3085R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A21E3085R"><span id="translatedtitle">Merging the SAGE II and OSIRIS Stratospheric <span class="hlt">Aerosol</span> Records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rieger, L. A.; Bourassa, A. E.; Degenstein, D. A.</p> <p>2014-12-01</p> <p>Since the end of the SAGE II mission several instruments with differing measurement techniques, wavelength ranges, and geographic coverage have taken up the mantle of retrieving stratospheric <span class="hlt">aerosols</span>. Each of these instruments provides unique information on the state of <span class="hlt">aerosols</span>; however, due to the difference in techniques there is no consistent, long-term record of global, stratospheric <span class="hlt">aerosols</span> spanning the previous three decades. One of the instruments currently taking measurements is the Optical Spectrograph and Infrared <span class="hlt">Imaging</span> System which was launched in 2001 and measures limb scatter radiance profiles in the UV to NIR range. OSIRIS produces hundreds of measurements a day covering the majority of the sunlit portion of the globe, providing near global coverage of stratospheric <span class="hlt">aerosols</span>. This work merges the SAGE II and OSIRIS <span class="hlt">aerosol</span> data products to produce a 30 year, near global, 525nm stratospheric <span class="hlt">aerosol</span> record with approximately 2 km vertical resolution. Agreement between the two datasets is typically within 10% in the bulk of the stratosphere, however saturation of the OSIRIS instrument at lower altitudes, especially in the tropical UTLS, likely leads to low biases in the <span class="hlt">aerosol</span> optical depth in this region. To correct these issues it would beneficial to incorporate this merging with other instruments such as CALIOP and GOMOS, which do not suffer from this issue, but would benefit from inclusion of the OSIRIS data in other regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=GL-2002-002182&hterms=Water+pollution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2528Water%2Bpollution%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=GL-2002-002182&hterms=Water+pollution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2528Water%2Bpollution%2529"><span id="translatedtitle"><span class="hlt">Aerosol</span> pollution over Northern India and Bangladesh</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p>The skies over Northern India are filled with a thick soup of <span class="hlt">aerosol</span> particles all along the southern edge of the Himalayan Mountains, and streaming southward over Bangladesh and the Bay of Bengal. Notice that the air over the Tibetan Plateau to the north of the Himalayas is very clear, whereas the view of the land surface south of the mountains is obstructed by the brownish haze. Most of this air pollution comes from human activities. The <span class="hlt">aerosol</span> over this region is notoriously rich in sulfates, nitrates, organic and black carbon, and fly ash. These particles not only represent a health hazard to those people living in the region, but scientists have also recently found that they can have a significant impact on the region's hydrological cycle and climate (click to read the relevant NASA press release). This true-color <span class="hlt">image</span> was acquired on December 4, 2001, by the Moderate-resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. It is interesting to compare the <span class="hlt">image</span> above with this earlier MODIS <span class="hlt">image</span> over the region, acquired on October 23, 2001. Notice the difference in the clarity of the air over the region in the earlier <span class="hlt">image</span>. Under the thick plume of <span class="hlt">aerosol</span>, the Brahmaputra (upper right) and Ganges Rivers are still visible. The many mouths of the Ganges have turned the northern waters of the Bay of Bengal a murky brown as they empty their sediment-laden waters into the bay. Toward the upper lefthand corner of the <span class="hlt">image</span>, there appears to be a fresh swath of snow on the ground just south of the Himalayas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.A33A0810L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.A33A0810L"><span id="translatedtitle">Mexico City <span class="hlt">Aerosol</span> Transect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lewandowski, P. A.; Eichinger, W. E.; Prueger, J.; Holder, H. L.</p> <p>2007-12-01</p> <p>A radiative impact study was conducted in Mexico City during MILAGRO/MIRAGE campaign in March of 2006. On a day when the predominant wind was from the north to the south, authors measured radiative properties of the atmosphere in six locations across the city ranging from the city center, through the city south limits and the pass leading out of the city (causing pollutants to funnel through the area). A large change in <span class="hlt">aerosol</span> optical properties has been noticed. The <span class="hlt">aerosol</span> optical depth has generally increased outside of the city and angstrom coefficient has changed significantly towards smaller values. <span class="hlt">Aerosol</span> size distribution was calculated using SkyRadPack. The total optical depths allowed coincidental lidar data to calculate total extinction profiles for all the locations for 1064nm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A53C0366L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A53C0366L"><span id="translatedtitle"><span class="hlt">Aerosol</span> Quality Monitor (AQUAM)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, X.; Ignatov, A.</p> <p>2011-12-01</p> <p>The Advanced Clear-Sky Processor for Oceans (ACSPO) developed at NESDIS generates three products from AVHRR, operationally: clear sky radiances in all bands, and sea surface temperature (SST) derived from clear-sky brightness temperatures (BT) in Ch3B (centered at 3.7 μm), Ch4 (11 μm) and Ch5 (12 μm), and <span class="hlt">aerosol</span> optical depths (AOD) derived from clear-sky reflectances in Ch1 (0.63), Ch2 (0.83) and Ch3A (1.61 μm). An integral part of ACSPO is the fast Community Radiative Transfer Model (CRTM), which calculates first-guess clear-sky BTs using global NCEP forecast atmospheric and Reynolds SST fields. Simulated BTs are employed in ACSPO for improved cloud screening, physical (RTM-based) SST inversions, and to monitor and validate satellite BTs. The model minus observation biases are monitored online in near-real time using the Monitoring IR Clear-sky radiances over Oceans for SST (MICROS; http://www.star.nesdis.noaa.gov/sod/sst/micros/). A persistent positive M-O bias is observed in MICROS, partly attributed to missing <span class="hlt">aerosol</span> in CRTM input, causing "M" to be warmer than "O". It is thus necessary to include <span class="hlt">aerosols</span> in CRTM and quantify their effects on AVHRR BTs and SSTs. However, sensitivity of thermal bands to <span class="hlt">aerosol</span> is only minimal, and use of solar reflectance bands is preferable to evaluate the accuracy of CRTM modeling, with global <span class="hlt">aerosol</span> fields as input (from e.g. Goddard Chemistry <span class="hlt">Aerosol</span> Radiation and Transport, GOCART, or Navy <span class="hlt">Aerosol</span> Analysis and Prediction System, NAAPS). Once available, the corresponding M-O biases in solar reflectance bands will be added to MICROS. Also, adding CRTM simulated reflectances in ACSPO would greatly improve cloud detection, help validate CRTM in the solar reflectance bands, and assist <span class="hlt">aerosol</span> retrievals. Running CRTM with global <span class="hlt">aerosol</span> as input is very challenging, computationally. While CRTM is being optimized to handle such global scattering computations, a near-real time web-based <span class="hlt">Aerosol</span> Quality Monitor (AQUAM</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1230771','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1230771"><span id="translatedtitle">Cantera <span class="hlt">Aerosol</span> Dynamics Simulator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moffat, Harry</p> <p>2004-09-01</p> <p>The Cantera <span class="hlt">Aerosol</span> Dynamics Simulator (CADS) package is a general library for <span class="hlt">aerosol</span> modeling to address <span class="hlt">aerosol</span> general dynamics, including formation from gas phase reactions, surface chemistry (growth and oxidation), bulk particle chemistry, transport by Brownian diffusion, thermophoresis, and diffusiophoresis with linkage to DSMC studies, and thermal radiative transport. The library is based upon Cantera, a C++ Cal Tech code that handles gas phase species transport, reaction, and thermodynamics. The method uses a discontinuous galerkin formulation for the condensation and coagulation operator that conserves particles, elements, and enthalpy up to round-off error. Both O-D and 1-D time dependent applications have been developed with the library. Multiple species in the solid phase are handled as well. The O-D application, called Tdcads (Time Dependent CADS) is distributed with the library. Tdcads can address both constant volume and constant pressure adiabatic homogeneous problems. An extensive set of sample problems for Tdcads is also provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12492171','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12492171"><span id="translatedtitle">Indian <span class="hlt">aerosols</span>: present status.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mitra, A P; Sharma, C</p> <p>2002-12-01</p> <p>This article presents the status of <span class="hlt">aerosols</span> in India based on the research activities undertaken during last few decades in this region. Programs, like International Geophysical Year (IGY), Monsoon Experiment (MONEX), Indian Middle Atmospheric Program (IMAP) and recently conducted Indian Ocean Experiment (INDOEX), have thrown new lights on the role of <span class="hlt">aerosols</span> in global change. INDOEX has proved that the effects of <span class="hlt">aerosols</span> are no longer confined to the local levels but extend at regional as well as global scales due to occurrence of long range transportation of <span class="hlt">aerosols</span> from source regions along with wind trajectories. The loading of <span class="hlt">aerosols</span> in the atmosphere is on rising due to energy intensive activities for developmental processes and other anthropogenic activities. One of the significant observation of INDOEX is the presence of high concentrations of carbonaceous <span class="hlt">aerosols</span> in the near persistent winter time haze layer over tropical Indian Ocean which have probably been emitted from the burning of fossil-fuels and biofuels in the source region. These have significant bearing on the radiative forcing in the region and, therefore, have potential to alter monsoon and hydrological cycles. In general, the SPM concentrations have been found to be on higher sides in ambient atmosphere in many Indian cities but the NOx concentrations have been found to be on lower side. Even in the haze layer over Indian Ocean and surrounding areas, the NOx concentrations have been reported to be low which is not conducive of O3 formation in the haze/smog layer. The acid rain problem does not seem to exist at the moment in India because of the presence of neutralizing soil dust in the atmosphere. But the high particulate concentrations in most of the cities' atmosphere in India are of concern as it can cause deteriorated health conditions. PMID:12492171</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002JAtS...59..249M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002JAtS...59..249M"><span id="translatedtitle">Global <span class="hlt">Aerosol</span> Climatology Project.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mishchenko, Michael; Penner, Joyce; Anderson, Donald</p> <p>2002-02-01</p> <p>This paper is concerned with uncertainties in the Advanced Very High Resolution Radiometer (AVHRR)-based retrieval of optical depth for heavy smoke <span class="hlt">aerosol</span> plumes generated from forest fires that occurred in Canada due to a lack of knowledge on their optical properties (single-scattering albedo and asymmetry parameter). Typical values of the optical properties for smoke <span class="hlt">aerosols</span> derived from such field experiments as Smoke, Clouds, and Radiation-Brazil (SCAR-B); Transport and Atmospheric Chemistry near the Equator-Atlantic (TRACE-A); Biomass Burning Airborne and Spaceborne Experiment in the Amazonas (BASE-A); and Boreal Ecosystem-Atmosphere Study (BOREAS) were first assumed for retrieving smoke optical depths. It is found that the maximum top-of-atmosphere (TOA) reflectance values calculated by models with these <span class="hlt">aerosol</span> parameters are less than observations whose values are considerably higher. A successful retrieval would require an <span class="hlt">aerosol</span> model that either has a substantially smaller asymmetry parameter (g < 0.4 versus g > 0.5), or higher single-scattering albedo ( 0.9 versus < 0.9), or both (e.g., g = 0.39 and = 0.91 versus g = 0.57 and = 0.87) than the existing models. Several potential causes were examined including small smoke particle size, low black carbon content, humidity effect, calibration errors, inaccurate surface albedo, mixture of cloud and <span class="hlt">aerosol</span> layers, etc. A more sound smoke <span class="hlt">aerosol</span> model is proposed that has a lower content of black carbon (mass ratio = 0.015) and smaller size (mean radius = 0.02 m for dry smoke particles), together with consideration of the effect of relative humidity. Ground-based observations of smoke suggest that for < 2.5 there is an increasing trend in and a decreasing trend in g with increases in , which is consistent with the results of satellite retrievals. Using these relationships as constraints, more plausible values of can be obtained for heavy smoke <span class="hlt">aerosol</span>. The possibility of smoke-cloud mixtures is also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7003621','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7003621"><span id="translatedtitle">Highly stable <span class="hlt">aerosol</span> generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>DeFord, H.S.; Clark, M.L.</p> <p>1981-11-03</p> <p>An improved compressed air nebulizer has been developed such that a uniform <span class="hlt">aerosol</span> particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of <span class="hlt">aerosol</span> generators and only one central makeup assembly. 2 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864035','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864035"><span id="translatedtitle">Highly stable <span class="hlt">aerosol</span> generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>DeFord, Henry S.; Clark, Mark L.</p> <p>1981-01-01</p> <p>An improved compressed air nebulizer has been developed such that a uniform <span class="hlt">aerosol</span> particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of <span class="hlt">aerosol</span> generators and only one central makeup assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030066709&hterms=Smith+Michael&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2528Smith%2BMichael%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030066709&hterms=Smith+Michael&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2528Smith%2BMichael%2529"><span id="translatedtitle">THEMIS Observations of Atmospheric <span class="hlt">Aerosol</span> Optical Depth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Michael D.; Bandfield, Joshua L.; Christensen, Philip R.; Richardson, Mark I.</p> <p>2003-01-01</p> <p>The Mars Odyssey spacecraft entered into Martian orbit in October 2001 and after successful aerobraking began mapping in February 2002 (approximately Ls=330 deg.). <span class="hlt">Images</span> taken by the Thermal Emission <span class="hlt">Imaging</span> System (THEMIS) on-board the Odyssey spacecraft allow the quantitative retrieval of atmospheric dust and water-ice <span class="hlt">aerosol</span> optical depth. Atmospheric quantities retrieved from THEMIS build upon existing datasets returned by Mariner 9, Viking, and Mars Global Surveyor (MGS). Data from THEMIS complements the concurrent MGS Thermal Emission Spectrometer (TES) data by offering a later local time (approx. 2:00 for TES vs. approx. 4:00 - 5:30 for THEMIS) and much higher spatial resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ability+AND+burn&pg=3&id=ED229789','ERIC'); return false;" href="http://eric.ed.gov/?q=ability+AND+burn&pg=3&id=ED229789"><span id="translatedtitle"><span class="hlt">CAI</span> Invention Strategies.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rodrigues, Raymond J.; Rodrigues, Dawn</p> <p></p> <p>Prewriting programs using computers fall into two broad categories: interactive and noninteractive. An early example of a noninteractive program is that of Ellen Nold, called "Cinnamon." Its purpose was to present the student with a series of content questions. In answering such questions, the student would be accumulating a set of data that could…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED087423.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED087423.pdf"><span id="translatedtitle"><span class="hlt">CAI</span> In Chicago.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Litman, George H.</p> <p></p> <p>A computer-assisted instructional system has been implemented in 21 elementary schools in Chicago. The system runs on a UNIVAC 418-III computer which processes concurrently the reading, language arts, and mathematics drill and practice strand programs of the Computer Curriculum Corporation. All students participating qualified under the Elementary…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030112095&hterms=Measuring+instruments&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DMeasuring%2Binstruments','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030112095&hterms=Measuring+instruments&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DMeasuring%2Binstruments"><span id="translatedtitle">Measuring <span class="hlt">Aerosol</span> Optical Properties with the Ozone Monitoring Instrument (OMI)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Veefkind, J. P.; Torres, O.; Syniuk, A.; Decae, R.; deLeeuw, G.</p> <p>2003-01-01</p> <p>The Ozone Monitoring Instrument (OMI) is the Dutch-Finnish contribution to the NASA EOS-Aura mission scheduled for launch in January 2004. OM1 is an <span class="hlt">imaging</span> spectrometer that will measure the back-scattered Solar radiance between 270 an 500 nm. With its relatively high spatial resolution (13x24 sq km at nadir) and daily global coverage. OM1 will make a major contribution to our understanding of atmospheric chemistry and to climate research. OM1 will provide data continuity with the TOMS instruments. One of the pleasant surprises of the TOMS data record was its information on <span class="hlt">aerosol</span> properties. First, only the absorbing <span class="hlt">aerosol</span> index, which is sensitive to elevated lay- ers of <span class="hlt">aerosols</span> such as desert dust and smoke <span class="hlt">aerosols</span>, was derived. Recently these methods were further improved to yield <span class="hlt">aerosol</span> optical thickness and single scattering albedo over land and ocean for 19 years of TOMS data (1979-1992,1997-2002), making it one of the longest and most valuable time series for <span class="hlt">aerosols</span> presently available. Such long time series are essential to quantify the effect of <span class="hlt">aerosols</span> on the Earth& climate. The OM1 instrument is better suited to measure <span class="hlt">aerosols</span> than the TOMS instruments because of the smaller footprint, and better spectral coverage. The better capabilities of OMI will enable us to provide an improved <span class="hlt">aerosol</span> product, but the knowledge will also be used for further analysis of the <span class="hlt">aerosol</span> record from TOMS. The OM1 <span class="hlt">aerosol</span> product that is currently being developed for OM1 combines the TOMS experience and the multi-spectral techniques that are used in the visible and near infrared. The challenge for this new product is to provide <span class="hlt">aerosol</span> optical thickness and single scattering albedo from the near ultraviolet to the visible (330-500 nm) over land and ocean. In this presentation the methods for deriving the OM1 <span class="hlt">aerosol</span> product will be presented. Part of these methods developed for OM1 can already be applied to TOMS data and results of such analysis will be shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010119957','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010119957"><span id="translatedtitle">Validation of MODIS <span class="hlt">Aerosol</span> Optical Depth Retrieval Over Land</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chu, D. A.; Kaufman, Y. J.; Ichoku, C.; Remer, L. A.; Tanre, D.; Holben, B. N.; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p><span class="hlt">Aerosol</span> optical depths are derived operationally for the first time over land in the visible wavelengths by MODIS (Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer) onboard the EOSTerra spacecraft. More than 300 Sun photometer data points from more than 30 AERONET (<span class="hlt">Aerosol</span> Robotic Network) sites globally were used in validating the <span class="hlt">aerosol</span> optical depths obtained during July - September 2000. Excellent agreement is found with retrieval errors within (Delta)tau=+/- 0.05 +/- 0.20 tau, as predicted, over (partially) vegetated surfaces, consistent with pre-launch theoretical analysis and aircraft field experiments. In coastal and semi-arid regions larger errors are caused predominantly by the uncertainty in evaluating the surface reflectance. The excellent fit was achieved despite the ongoing improvements in instrument characterization and calibration. This results show that MODIS-derived <span class="hlt">aerosol</span> optical depths can be used quantitatively in many applications with cautions for residual clouds, snow/ice, and water contamination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AMTD....710131H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AMTD....710131H"><span id="translatedtitle">Development of synthetic GOES-R ABI <span class="hlt">aerosol</span> products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoff, R. M.; Kondragunta, S.; Ciren, P.; Xu, C.; Zhang, H.; Huff, A.</p> <p>2014-09-01</p> <p>An Observing Systems Simulation Experiment (OSSE) for GOES-R Advanced Baseline <span class="hlt">Imager</span> (ABI) <span class="hlt">aerosol</span> products has been carried out. The generation of simulated data involves prediction of <span class="hlt">aerosol</span> chemical composition fields at one-hour resolution and 12 km × 12 km spacing. These data are then fed to a radiative transfer model to simulate the on-orbit radiances that the GOES-R ABI will see in six channels. This allows the ABI <span class="hlt">aerosol</span> algorithm to be tested to produce products that will be available after launch. In cooperation with a user group of 40+ state and local air quality forecasters, the system has been tested in real-time experiments where the results mimic what the forecasters will see after 2016 when GOES-R launches. Feedback from this group has allowed refinement of the web display system for the ABI <span class="hlt">aerosol</span> products and has creatively called for new products that were not envisaged by the satellite team.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=471441','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=471441"><span id="translatedtitle">Deposition of pressurised <span class="hlt">aerosols</span> in the human respiratory tract.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Newman, S P; Pavia, D; Morén, F; Sheahan, N F; Clarke, S W</p> <p>1981-01-01</p> <p>Although the use of pressurised <span class="hlt">aerosol</span> inhalers is widespread, little is known about the actual deposition of the <span class="hlt">aerosol</span> in the respiratory tract, since this has previously been difficult to measure. We have incorporated Teflon particles (mean diameter 2 micrometer) with aerodynamic properties similar to those of bronchodilator drug crystals into pressurised <span class="hlt">aerosol</span> canisters. Controlled inhalations by eight patients with obstructive airways disease showed that on average 8.8% of the dose was deposited in the lungs (3.0% in the alveoli and 5.8% on the conducting airways) and 80% in the mouth. These figures are in good agreement with previous indirect estimates of deposition based on metabolic studies. The remainder of the dose was either expired (1.0%) or deposited in the <span class="hlt">aerosol</span> actuator (9.8%). This method should have wide application for measurement of deposition patterns under various conditions and for assessment of therapeutic effects. <span class="hlt">Images</span> PMID:7292382</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1089860','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1089860"><span id="translatedtitle">Geometrical Optics of Dense <span class="hlt">Aerosols</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.</p> <p>2013-04-24</p> <p>Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense <span class="hlt">aerosol</span> to assume this geometry. However, whereas the geometrical optics of dilute <span class="hlt">aerosols</span> is a well-developed fi eld, the dense <span class="hlt">aerosol</span> limit is mostly unexplored. Yet controlling the geometrical optics of dense <span class="hlt">aerosols</span> is necessary in preparing such a material slab. Focusing dense <span class="hlt">aerosols</span> is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..120.8890R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..120.8890R"><span id="translatedtitle">Merging the OSIRIS and SAGE II stratospheric <span class="hlt">aerosol</span> records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rieger, L. A.; Bourassa, A. E.; Degenstein, D. A.</p> <p>2015-09-01</p> <p>The Optical Spectrograph and InfraRed <span class="hlt">Imaging</span> System (OSIRIS) instrument on the Odin satellite, launched in 2001 and currently operational, measures limb-scattered sunlight from which profiles of stratospheric <span class="hlt">aerosol</span> extinction are retrieved. The Stratospheric <span class="hlt">Aerosol</span> and Gas Experiment (SAGE) II was launched in 1984 and provided measurements of stratospheric <span class="hlt">aerosol</span> extinction until mid-2005. This provides approximately 4 years of mission overlap which has allowed us to consistently extend the SAGE II version 7.00 record to the present using OSIRIS <span class="hlt">aerosol</span> extinction retrievals. In this work we first compare coincident <span class="hlt">aerosol</span> extinction observations during the overlap period by interpolating the SAGE II 525nm and 1020nm channels to the OSIRIS extinction wavelength of 750nm. In the tropics to midlatitudes mean differences are typically less than 10%, although larger biases are seen at higher latitudes and at altitudes outside the main <span class="hlt">aerosol</span> layer. OSIRIS <span class="hlt">aerosol</span> extinction retrievals at 750nm are used to create a monthly time series zonally averaged in 5°bins and qualitatively compared to SAGE II 525nm observations averaged in the same way. The OSIRIS time series is then translated to 525nm with an Ângström exponent relation and bias corrected. For most locations, this provides agreement during the overlap time period to better than 15%. Uncertainty in the resulting OSIRIS time series is estimated through a series of simulation studies over the range of <span class="hlt">aerosol</span> particle size distributions observed by in situ balloon instruments and is found to be approximately 20% for background and moderately volcanic <span class="hlt">aerosol</span> loading conditions for the majority of OSIRIS measurement conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRD..118.9296H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRD..118.9296H"><span id="translatedtitle">Enhanced Deep Blue <span class="hlt">aerosol</span> retrieval algorithm: The second generation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, N. C.; Jeong, M.-J.; Bettenhausen, C.; Sayer, A. M.; Hansell, R.; Seftor, C. S.; Huang, J.; Tsay, S.-C.</p> <p>2013-08-01</p> <p>The <span class="hlt">aerosol</span> products retrieved using the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) collection 5.1 Deep Blue algorithm have provided useful information about <span class="hlt">aerosol</span> properties over bright-reflecting land surfaces, such as desert, semiarid, and urban regions. However, many components of the C5.1 retrieval algorithm needed to be improved; for example, the use of a static surface database to estimate surface reflectances. This is particularly important over regions of mixed vegetated and nonvegetated surfaces, which may undergo strong seasonal changes in land cover. In order to address this issue, we develop a hybrid approach, which takes advantage of the combination of precalculated surface reflectance database and normalized difference vegetation index in determining the surface reflectance for <span class="hlt">aerosol</span> retrievals. As a result, the spatial coverage of <span class="hlt">aerosol</span> data generated by the enhanced Deep Blue algorithm has been extended from the arid and semiarid regions to the entire land areas. In this paper, the changes made in the enhanced Deep Blue algorithm regarding the surface reflectance estimation, <span class="hlt">aerosol</span> model selection, and cloud screening schemes for producing the MODIS collection 6 <span class="hlt">aerosol</span> products are discussed. A similar approach has also been applied to the algorithm that generates the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Deep Blue products. Based upon our preliminary results of comparing the enhanced Deep Blue <span class="hlt">aerosol</span> products with the <span class="hlt">Aerosol</span> Robotic Network (AERONET) measurements, the expected error of the Deep Blue <span class="hlt">aerosol</span> optical thickness (AOT) is estimated to be better than 0.05 + 20%. Using 10 AERONET sites with long-term time series, 79% of the best quality Deep Blue AOT values are found to fall within this expected error.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100033710&hterms=take+care&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtake%2Bcare','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100033710&hterms=take+care&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtake%2Bcare"><span id="translatedtitle">MISR <span class="hlt">Aerosol</span> Product Attributes and Statistical Comparisons with MODIS</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahn, Ralph A.; Nelson, David L.; Garay, Michael J.; Levy, Robert C.; Bull, Michael A.; Diner, David J.; Martonchik, John V.; Paradise, Susan R.; Hansen, Earl G.; Remer, Lorraine A.</p> <p>2009-01-01</p> <p>In this paper, Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR) <span class="hlt">aerosol</span> product attributes are described, including geometry and algorithm performance flags. Actual retrieval coverage is mapped and explained in detail using representative global monthly data. Statistical comparisons are made with coincident <span class="hlt">aerosol</span> optical depth (AOD) and Angstrom exponent (ANG) retrieval results from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) instrument. The relationship between these results and the ones previously obtained for MISR and MODIS individually, based on comparisons with coincident ground-truth observations, is established. For the data examined, MISR and MODIS each obtain successful <span class="hlt">aerosol</span> retrievals about 15% of the time, and coincident MISR-MODIS <span class="hlt">aerosol</span> retrievals are obtained for about 6%-7% of the total overlap region. Cloud avoidance, glint and oblique-Sun exclusions, and other algorithm physical limitations account for these results. For both MISR and MODIS, successful retrievals are obtained for over 75% of locations where attempts are made. Where coincident AOD retrievals are obtained over ocean, the MISR-MODIS correlation coefficient is about 0.9; over land, the correlation coefficient is about 0.7. Differences are traced to specific known algorithm issues or conditions. Over-ocean ANG comparisons yield a correlation of 0.67, showing consistency in distinguishing <span class="hlt">aerosol</span> air masses dominated by coarse-mode versus fine-mode particles. Sampling considerations imply that care must be taken when assessing monthly global <span class="hlt">aerosol</span> direct radiative forcing and AOD trends with these products, but they can be used directly for many other applications, such as regional AOD gradient and <span class="hlt">aerosol</span> air mass type mapping and <span class="hlt">aerosol</span> transport model validation. Users are urged to take seriously the published product data-quality statements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRD..117.4209N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRD..117.4209N"><span id="translatedtitle">Simulation of South Asian <span class="hlt">aerosols</span> for regional climate studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nair, Vijayakumar S.; Solmon, Fabien; Giorgi, Filippo; Mariotti, Laura; Babu, S. Suresh; Moorthy, K. Krishna</p> <p>2012-02-01</p> <p>Extensive intercomparison of columnar and near-surface <span class="hlt">aerosols</span>, simulated over the South Asian domain using the <span class="hlt">aerosol</span> module included in the regional climate model (RegCM4) of the Abdus Salam International Centre for Theoretical Physics (ICTP) have been carried out using ground-based network of Sun/sky <span class="hlt">Aerosol</span> Robotic Network (AERONET) radiometers, satellite sensors such as Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) and Multiangle <span class="hlt">Imaging</span> Spectroradiometer (MISR), and ground-based black carbon (BC) measurements made at <span class="hlt">Aerosol</span> Radiative Forcing over India (ARFI) network stations. In general, RegCM4 simulations reproduced the spatial and seasonal characteristics of <span class="hlt">aerosol</span> optical depth over South Asia reasonably well, particularly over west Asia, where mineral dust is a major contributor to the total <span class="hlt">aerosol</span> loading. In contrast, RegCM4 simulations drastically underestimated the BC mass concentrations over most of the stations, by a factor of 2 to 5, with a large spatial variability. Seasonally, the discrepancy between the measured and simulated BC tended to be higher during winter and periods when the atmospheric boundary layer is convectively stable (such as nighttime and early mornings), while during summer season and during periods when the boundary layer is convectively unstable (daytime) the discrepancies were much lower, with the noontime values agreeing very closely with the observations. A detailed analysis revealed that the model does not reproduce the nocturnal high in BC, observed at most of the Indian sites especially during winter, because of the excessive vertical transport of <span class="hlt">aerosols</span> under stable boundary layer conditions. As far as the vertical distribution was concerned, the simulated vertical profiles of BC agreed well with airborne measurements during daytime. This comprehensive validation exercise reveals the strengths and weaknesses of the model in simulating the spatial and temporal heterogeneities of the <span class="hlt">aerosol</span> fields over</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26022540','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26022540"><span id="translatedtitle">New breast cancer prognostic factors identified by computer-aided <span class="hlt">image</span> analysis of HE stained histopathology <span class="hlt">images</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Jia-Mei; Qu, Ai-Ping; Wang, Lin-Wei; Yuan, Jing-Ping; Yang, Fang; Xiang, Qing-Ming; Maskey, Ninu; Yang, Gui-Fang; Liu, Juan; Li, Yan</p> <p>2015-01-01</p> <p>Computer-aided <span class="hlt">image</span> analysis (<span class="hlt">CAI</span>) can help objectively quantify morphologic features of hematoxylin-eosin (HE) histopathology <span class="hlt">images</span> and provide potentially useful prognostic information on breast cancer. We performed a <span class="hlt">CAI</span> workflow on 1,150 HE <span class="hlt">images</span> from 230 patients with invasive ductal carcinoma (IDC) of the breast. We used a pixel-wise support vector machine classifier for tumor nests (TNs)-stroma segmentation, and a marker-controlled watershed algorithm for nuclei segmentation. 730 morphologic parameters were extracted after segmentation, and 12 parameters identified by Kaplan-Meier analysis were significantly associated with 8-year disease free survival (P < 0.05 for all). Moreover, four <span class="hlt">image</span> features including TNs feature (HR 1.327, 95%CI [1.001-1.759], P = 0.049), TNs cell nuclei feature (HR 0.729, 95%CI [0.537-0.989], P = 0.042), TNs cell density (HR 1.625, 95%CI [1.177-2.244], P = 0.003), and stromal cell structure feature (HR 1.596, 95%CI [1.142-2.229], P = 0.006) were identified by multivariate Cox proportional hazards model to be new independent prognostic factors. The results indicated that <span class="hlt">CAI</span> can assist the pathologist in extracting prognostic information from HE histopathology <span class="hlt">images</span> for IDC. The TNs feature, TNs cell nuclei feature, TNs cell density, and stromal cell structure feature could be new prognostic factors. PMID:26022540</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=51675&keyword=audit+AND+committee&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67492122&CFTOKEN=97384208','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=51675&keyword=audit+AND+committee&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67492122&CFTOKEN=97384208"><span id="translatedtitle">ACID <span class="hlt">AEROSOL</span> MEASUREMENT WORKSHOP</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This report documents the discussion and results of the U.S. EPA Acid <span class="hlt">Aerosol</span> Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=40764&keyword=keeler&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=75877562&CFTOKEN=13669441','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=40764&keyword=keeler&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=75877562&CFTOKEN=13669441"><span id="translatedtitle">EXPOSURES TO ACIDIC <span class="hlt">AEROSOLS</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Ambient monitoring of acid <span class="hlt">aerosol</span> in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=41902&keyword=infrared+AND+spectroscopy+AND+reference&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74078792&CFTOKEN=93319846','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=41902&keyword=infrared+AND+spectroscopy+AND+reference&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74078792&CFTOKEN=93319846"><span id="translatedtitle">FORMATION OF PHOTOCHEMICAL <span class="hlt">AEROSOLS</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The objective was to develop a better understanding of smog <span class="hlt">aerosol</span> formation with particular reference to haze in the Southern California area. This study combined laboratory work with ambient air studies. Counting of particles by light scattering was the principle physical tech...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970024878','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970024878"><span id="translatedtitle">Satellite Estimates of the Direct Radiative Forcing of Biomass Burning <span class="hlt">Aerosols</span> Over South America and Africa</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christopher, Sundar A.; Wang, Min; Kliche, Donna V.; Berendes, Todd; Welch, Ronald M.; Yang, S.K.</p> <p>1997-01-01</p> <p>Atmospheric <span class="hlt">aerosol</span> particles, both natural and anthropogenic are important to the earth's radiative balance. Therefore it is important to provide adequate validation information on the spatial, temporal and radiative properties of <span class="hlt">aerosols</span>. This will enable us to predict realistic global estimates of <span class="hlt">aerosol</span> radiative effects more confidently. The current study utilizes 66 AVHRR LAC (Local Area Coverage) and coincident Earth Radiation Budget Experiment (ERBE) <span class="hlt">images</span> to characterize the fires, smoke and radiative forcings of biomass burning <span class="hlt">aerosols</span> over four major ecosystems of South America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008PhDT........60D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008PhDT........60D&link_type=ABSTRACT"><span id="translatedtitle">An experimental study of dense <span class="hlt">aerosol</span> aggregations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dhaubhadel, Rajan</p> <p></p> <p>We demonstrated that an <span class="hlt">aerosol</span> can gel. This gelation was then used for a one-step method to produce an ultralow density porous carbon or silica material. This material was named an <span class="hlt">aerosol</span> gel because it was made via gelation of particles in the <span class="hlt">aerosol</span> phase. The carbon and silica <span class="hlt">aerosol</span> gels had high specific surface area (200--350 sq m2/g for carbon and 300--500 sq m2/g for silica) and an extremely low density (2.5--6.0 mg/cm3), properties similar to conventional aerogels. Key aspects to form a gel from an <span class="hlt">aerosol</span> are large volume fraction, ca. 10-4 or greater, and small primary particle size, 50 nm or smaller, so that the gel time is fast compared to other characteristic times. Next we report the results of a study of the cluster morphology and kinetics of a dense aggregating <span class="hlt">aerosol</span> system using the small angle light scattering technique. The soot particles started as individual monomers, ca. 38 nm radius, grew to bigger clusters with time and finally stopped evolving after spanning a network across the whole system volume. This spanning is <span class="hlt">aerosol</span> gelation. The gelled system showed a hybrid morphology with a lower fractal dimension at length scales of a micron or smaller and a higher fractal dimension at length scales greater than a micron. The study of the kinetics of the aggregating system showed that when the system gelled, the aggregation kernel homogeneity lambda attained a value 0.4 or higher. The magnitude of the aggregation kernel showed an increase with increasing volume fraction. We also used <span class="hlt">image</span> analysis technique to study the cluster morphology. From the digitized pictures of soot clusters the cluster morphology was determined by two different methods: structure factor and perimeter analysis. We find a hybrid, superaggregate morphology characterized by a fractal dimension of Df ≈ to 1.8 between the monomer size, ca. 50 nm, and 1 mum micron and Df ≈ to 2.6 at larger length scales up to ˜ 10 mum. The superaggregate morphology is a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A21F0124L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A21F0124L"><span id="translatedtitle">Study of atmospheric <span class="hlt">aerosol</span> processing using confocal Raman microspectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laskina, O.; Grassian, V. H.</p> <p>2012-12-01</p> <p><span class="hlt">Aerosols</span> undergo aging and heterogeneous chemistry as they are transported through the atmosphere. This leads to changes in their properties and their effects on climate, biogeochemistry and human health. Chemical <span class="hlt">imaging</span> of individual particles may be used to directly investigate the heterogeneity of composition within atmospheric <span class="hlt">aerosol</span> particles. Single-particle Raman microspectroscopy is a powerful method for chemical <span class="hlt">imaging</span> and non-destructive physico-chemical characterization of <span class="hlt">aerosol</span> particles. In this study we investigate the effect of chemical processing on the distribution of chemical species in single particles of mineral dust <span class="hlt">aerosol</span> using Raman spectral <span class="hlt">imaging</span>. Raman mapping was used to show the distribution of humic substances and organic acids on some major components of mineral dust (quartz, clays and calcium carbonate). It was shown that humic materials form coating on the surface of particles, whereas interactions of calcium carbonate with organic acids (oxalic and acetic acids) lead to reactions that cause a heterogeneous distribution of components within the reacted particle. Additionally, in a newly designed flow system <span class="hlt">aerosol</span> can be equilibrated at different relative humidities to study hygroscopicity and phase transitions within these particles. These types of studies are important as the distribution of species in a single particle determines its reactivity, water uptake, and optical properties and thus defines its impact on climate and environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1250847-image','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1250847-image"><span id="translatedtitle"><span class="hlt">Image</span></span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p>2007-08-31</p> <p>The computer side of the <span class="hlt">IMAGE</span> project consists of a collection of Perl scripts that perform a variety of tasks; scripts are available to insert, update and delete data from the underlying Oracle database, download data from NCBI's Genbank and other sources, and generate data files for download by interested parties. Web scripts make up the tracking interface, and various tools available on the project web-site (<span class="hlt">image</span>.llnl.gov) that provide a search interface to the database.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A21F3093S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A21F3093S"><span id="translatedtitle">Evaluating MODIS Collection 6 Dark Target Over Water <span class="hlt">Aerosol</span> Products for Multi-sensor Data Fusion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Y.; Zhang, J.; Reid, J. S.; Hyer, E. J.; McHardy, T. M.; Lee, L.</p> <p>2014-12-01</p> <p>The Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) <span class="hlt">aerosol</span> products have been widely used in <span class="hlt">aerosol</span> related climate, visibility, and air quality studies for more than a decade. Recently, the MODIS collection 6 (c6) <span class="hlt">aerosol</span> products from MODIS-Aqua have been released. The reported changes between Collection 5 and Collection 6 include updates in the retrieving algorithms and a new cloud filtering process for the over-ocean products. Thus it is necessary to fully evaluate the collection 6 products for applications that require high quality MODIS <span class="hlt">aerosol</span> optical depth data, such as operational <span class="hlt">aerosol</span> data assimilation. The uncertainties in the MODIS c6 DT over ocean products are studied through both inter-comparing with the Multi-angle <span class="hlt">Imaging</span> Spectroradiometer (MISR) <span class="hlt">aerosol</span> products and by evaluation against ground truth. Special attention is given to the low bias in MODIS DT products due to the misclassifications of heavy <span class="hlt">aerosol</span> plumes as clouds. Finally, a quality assured data assimilation grade <span class="hlt">aerosol</span> optical product is constructed for <span class="hlt">aerosol</span> data assimilation related applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.2259M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.2259M"><span id="translatedtitle">Spatial boundaries of <span class="hlt">Aerosol</span> Robotic Network observations over the Mediterranean basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mishra, A. K.; Rudich, Y.; Koren, I.</p> <p>2016-03-01</p> <p>Accurate knowledge of <span class="hlt">aerosol</span> variability on a relatively high spatiotemporal scale is needed for better assessment of <span class="hlt">aerosol</span> radiative effects and <span class="hlt">aerosol</span>-climate interactions. We investigated the spatial boundaries of the <span class="hlt">Aerosol</span> Robotic Network (AERONET) observations over the Mediterranean basin using a statistical approach. We used 13 years (2002-2014) of <span class="hlt">aerosol</span> optical depth (AOD) measurements from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) and 15 AERONET sites around the Mediterranean basin. The gridded correlation maps show moderate to high correlations (R > 0.5) around each AERONET site up to ~200-500 km radius depending on location. Such analyses provide information on the spatial domain in which the AERONET measurements can be reliably used per site. The statistical model provides a better daytime AOD product on finer temporal resolution with higher spatial coverage as compared to using AERONET/MODIS observations separately. The findings from this study can be useful for the assimilation-based model forecasting of <span class="hlt">aerosol</span> properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040171552&hterms=effects+columns&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Deffects%2Bcolumns','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040171552&hterms=effects+columns&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Deffects%2Bcolumns"><span id="translatedtitle">Internally Consistent MODIS Estimate of <span class="hlt">Aerosol</span> Clear-Sky Radiative Effect Over the Global Oceans</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, Lorraine A.; Kaufman, Yoram J.</p> <p>2004-01-01</p> <p>Modern satellite remote sensing, and in particular the MODerate resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS), offers a measurement-based pathway to estimate global <span class="hlt">aerosol</span> radiative effects and <span class="hlt">aerosol</span> radiative forcing. Over the Oceans, MODIS retrieves the total <span class="hlt">aerosol</span> optical thickness, but also reports which combination of the 9 different <span class="hlt">aerosol</span> models was used to obtain the retrieval. Each of the 9 models is characterized by a size distribution and complex refractive index, which through Mie calculations correspond to a unique set of single scattering albedo, assymetry parameter and spectral extinction for each model. The combination of these sets of optical parameters weighted by the optical thickness attributed to each model in the retrieval produces the best fit to the observed radiances at the top of the atmosphere. Thus the MODIS Ocean <span class="hlt">aerosol</span> retrieval provides us with (1) An observed distribution of global <span class="hlt">aerosol</span> loading, and (2) An internally-consistent, observed, distribution of <span class="hlt">aerosol</span> optical models that when used in combination will best represent the radiances at the top of the atmosphere. We use these two observed global distributions to initialize the column climate model by Chou and Suarez to calculate the <span class="hlt">aerosol</span> radiative effect at top of the atmosphere and the radiative efficiency of the <span class="hlt">aerosols</span> over the global oceans. We apply the analysis to 3 years of MODIS retrievals from the Terra satellite and produce global and regional, seasonally varying, estimates of <span class="hlt">aerosol</span> radiative effect over the clear-sky oceans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150019918','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150019918"><span id="translatedtitle">Retrieving the Height of Smoke and Dust <span class="hlt">Aerosols</span> by Synergistic Use of VIIRS, OMPS, and CALIOP Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, Jaehwa; Hsu, N. Christina; Bettenhausen, Corey; Sayer, Andrew M.; Seftor, Colin J.; Jeong, Myeong-Jae</p> <p>2015-01-01</p> <p><span class="hlt">Aerosol</span> Single scattering albedo and Height Estimation (ASHE) algorithm was first introduced in Jeong and Hsu (2008) to provide <span class="hlt">aerosol</span> layer height as well as single scattering albedo (SSA) for biomass burning smoke <span class="hlt">aerosols</span>. One of the advantages of this algorithm was that the <span class="hlt">aerosol</span> layer height can be retrieved over broad areas, which had not been available from lidar observations only. The algorithm utilized <span class="hlt">aerosol</span> properties from three different satellite sensors, i.e., <span class="hlt">aerosol</span> optical depth (AOD) and Ångström exponent (AE) from Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS), UV <span class="hlt">aerosol</span> index (UVAI) from Ozone Monitoring Instrument (OMI), and <span class="hlt">aerosol</span> layer height from Cloud-<span class="hlt">Aerosol</span> Lidar with Orthogonal Polarization (CALIOP). Here, we extend the application of the algorithm to Visible Infrared <span class="hlt">Imaging</span> Radiometer Suite (VIIRS) and Ozone Mapping and Profiler Suite (OMPS) data. We also now include dust layers as well as smoke. Other updates include improvements in retrieving the AOD of nonspherical dust from VIIRS, better determination of the <span class="hlt">aerosol</span> layer height from CALIOP, and more realistic input <span class="hlt">aerosol</span> profiles in the forward model for better accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030112782&hterms=competence&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcompetence','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030112782&hterms=competence&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcompetence"><span id="translatedtitle">Synergism of MODIS <span class="hlt">Aerosol</span> Remote Sensing from Terra and Aqua</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ichoku, Charles; Kaufman, Yoram J.; Remer, Lorraine A.</p> <p>2003-01-01</p> <p>The MODerate-resolution <span class="hlt">Imaging</span> Spectro-radiometer (MODIS) sensors, aboard the Earth Observing System (EOS) Terra and Aqua satellites, are showing excellent competence at measuring the global distribution and properties of <span class="hlt">aerosols</span>. Terra and Aqua were launched on December 18, 1999 and May 4, 2002 respectively, with daytime equator crossing times of approximately 10:30 am and 1:30 pm respectively. Several <span class="hlt">aerosol</span> parameters are retrieved at 10-km spatial resolution from MODIS daytime data over land and ocean surfaces. The parameters retrieved include: <span class="hlt">aerosol</span> optical thickness (AOT) at 0.47, 0.55 and 0.66 micron wavelengths over land, and at 0.47, 0.55, 0.66, 0.87, 1.2, 1.6, and 2.1 microns over ocean; Angstrom exponent over land and ocean; and effective radii, and the proportion of AOT contributed by the small mode <span class="hlt">aerosols</span> over ocean. Since the beginning of its operation, the quality of Terra-MODIS <span class="hlt">aerosol</span> products (especially AOT) have been evaluated periodically by cross-correlation with equivalent data sets acquired by ground-based (and occasionally also airborne) sunphotometers, particularly those coordinated within the framework of the <span class="hlt">AErosol</span> Robotic NETwork (AERONET). Terra-MODIS AOT data have been found to meet or exceed pre-launch accuracy expectations, and have been applied to various studies dealing with local, regional, and global <span class="hlt">aerosol</span> monitoring. The results of these Terra-MODIS <span class="hlt">aerosol</span> data validation efforts and studies have been reported in several scientific papers and conferences. Although Aqua-MODIS is still young, it is already yielding formidable <span class="hlt">aerosol</span> data products, which are also subjected to careful periodic evaluation similar to that implemented for the Terra-MODIS products. This paper presents results of validation of Aqua-MODIS <span class="hlt">aerosol</span> products with AERONET, as well as comparative evaluation against corresponding Terra-MODIS data. In addition, we show interesting independent and synergistic applications of MODIS <span class="hlt">aerosol</span> data from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GeoRL..3615101S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GeoRL..3615101S"><span id="translatedtitle">Cosmic ray decreases affect atmospheric <span class="hlt">aerosols</span> and clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Svensmark, Henrik; Bondo, Torsten; Svensmark, Jacob</p> <p>2009-08-01</p> <p>Close passages of coronal mass ejections from the sun are signaled at the Earth's surface by Forbush decreases in cosmic ray counts. We find that low clouds contain less liquid water following Forbush decreases, and for the most influential events the liquid water in the oceanic atmosphere can diminish by as much as 7%. Cloud water content as gauged by the Special Sensor Microwave/<span class="hlt">Imager</span> (SSM/I) reaches a minimum ≈7 days after the Forbush minimum in cosmic rays, and so does the fraction of low clouds seen by the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) and in the International Satellite Cloud Climate Project (ISCCP). Parallel observations by the <span class="hlt">aerosol</span> robotic network AERONET reveal falls in the relative abundance of fine <span class="hlt">aerosol</span> particles which, in normal circumstances, could have evolved into cloud condensation nuclei. Thus a link between the sun, cosmic rays, <span class="hlt">aerosols</span>, and liquid-water clouds appears to exist on a global scale.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ACP....15.5903P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ACP....15.5903P"><span id="translatedtitle">A multi-model evaluation of <span class="hlt">aerosols</span> over South Asia: common problems and possible causes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pan, X.; Chin, M.; Gautam, R.; Bian, H.; Kim, D.; Colarco, P. R.; Diehl, T. L.; Takemura, T.; Pozzoli, L.; Tsigaridis, K.; Bauer, S.; Bellouin, N.</p> <p>2015-05-01</p> <p>Atmospheric pollution over South Asia attracts special attention due to its effects on regional climate, water cycle and human health. These effects are potentially growing owing to rising trends of anthropogenic <span class="hlt">aerosol</span> emissions. In this study, the spatio-temporal <span class="hlt">aerosol</span> distributions over South Asia from seven global <span class="hlt">aerosol</span> models are evaluated against <span class="hlt">aerosol</span> retrievals from NASA satellite sensors and ground-based measurements for the period of 2000-2007. Overall, substantial underestimations of <span class="hlt">aerosol</span> loading over South Asia are found systematically in most model simulations. Averaged over the entire South Asia, the annual mean <span class="hlt">aerosol</span> optical depth (AOD) is underestimated by a range 15 to 44% across models compared to MISR (Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer), which is the lowest bound among various satellite AOD retrievals (from MISR, SeaWiFS (Sea-Viewing Wide Field-of-View Sensor), MODIS (Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer) Aqua and Terra). In particular during the post-monsoon and wintertime periods (i.e., October-January), when agricultural waste burning and anthropogenic emissions dominate, models fail to capture AOD and <span class="hlt">aerosol</span> absorption optical depth (AAOD) over the Indo-Gangetic Plain (IGP) compared to ground-based <span class="hlt">Aerosol</span> Robotic Network (AERONET) sunphotometer measurements. The underestimations of <span class="hlt">aerosol</span> loading in models generally occur in the lower troposphere (below 2 km) based on the comparisons of <span class="hlt">aerosol</span> extinction profiles calculated by the models with those from Cloud-<span class="hlt">Aerosol</span> Lidar with Orthogonal Polarization (CALIOP) data. Furthermore, surface concentrations of all <span class="hlt">aerosol</span> components (sulfate, nitrate, organic <span class="hlt">aerosol</span> (OA) and black carbon (BC)) from the models are found much lower than in situ measurements in winter. Several possible causes for these common problems of underestimating <span class="hlt">aerosols</span> in models during the post-monsoon and wintertime periods are identified: the <span class="hlt">aerosol</span> hygroscopic growth and formation of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=169768','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=169768"><span id="translatedtitle">Bedding disposal cabinet for containment of <span class="hlt">aerosols</span> generated by animal cage cleaning procedures.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Baldwin, C L; Sabel, F L; Henke, C B</p> <p>1976-01-01</p> <p>Laboratory tests with <span class="hlt">aerosolized</span> spores and animal room tests with uranine dye indicate the effectiveness of a prototype bedding disposal cabinet in reducing airborne contamination generated by cage cleaning procedures. <span class="hlt">Images</span> PMID:826219</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970020060','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970020060"><span id="translatedtitle">First Estimates of the Radiative Forcing of <span class="hlt">Aerosols</span> Generated from Biomass Burning Using Satellite Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christopher, Sundar A.; Kliche, Donna A.; Chou, Joyce; Welch, Ronald M.</p> <p>1996-01-01</p> <p>Collocated measurements from the Advanced Very High Resolution Radiometer (AVHRR) and the Earth Radiation Budget Experiment (ERBE) scanner are used to examine the radiative forcing of atmospheric <span class="hlt">aerosols</span> generated from biomass burning for 13 <span class="hlt">images</span> in South America. Using the AVHRR, Local Area Coverage (LAC) data, a new technique based on a combination of spectral and textural measures is developed for detecting these <span class="hlt">aerosols</span>. Then, the instantaneous shortwave, longwave, and net radiative forcing values are computed from the ERBE instantaneous scanner data. Results for the selected samples from 13 <span class="hlt">images</span> show that the mean instantaneous net radiative forcing for areas with heavy <span class="hlt">aerosol</span> loading is about -36 W/sq m and that for the optically thin <span class="hlt">aerosols</span> are about -16 W/sq m. These results, although preliminary, provide the first estimates of radiative forcing of atmospheric <span class="hlt">aerosols</span> from biomass burning using satellite data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030067938','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030067938"><span id="translatedtitle">Longwave Radiative Forcing of Saharan Dust <span class="hlt">Aerosols</span> Estimated from MODIS, MISR and CERES Observations on Terra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, Jiang-Long; Christopher, Sundar A.</p> <p>2003-01-01</p> <p>Using observations from the Multi-angle <span class="hlt">Imaging</span> Spectroradiometer (MISR), the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS), and the Clouds and the Earth's Radiant Energy System (CERES) instruments onboard the Terra satellite; we present a new technique for studying longwave (LW) radiative forcing of dust <span class="hlt">aerosols</span> over the Saharan desert for cloud-free conditions. The monthly-mean LW forcing for September 2000 is 7 W/sq m and the LW forcing efficiency' (LW(sub eff)) is 15 W/sq m. Using radiative transfer calculations, we also show that the vertical distribution of <span class="hlt">aerosols</span> and water vapor are critical to the understanding of dust <span class="hlt">aerosol</span> forcing. Using well calibrated, spatially and temporally collocated data sets, we have combined the strengths of three sensors from the same satellite to quantify the LW radiative forcing, and show that dust <span class="hlt">aerosols</span> have a "warming" effect over the Saharan desert that will counteract the shortwave "cooling effect" of <span class="hlt">aerosols</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980018611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980018611"><span id="translatedtitle">First Estimates of the Radiative Forcing of <span class="hlt">Aerosols</span> Generated from Biomass Burning using Satellite Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chistopher, Sundar A.; Kliche, Donna V.; Chou, Joyce; Welch, Ronald M.</p> <p>1996-01-01</p> <p>Collocated measurements from the Advanced Very High Resolution Radiometer (AVHRR) and the Earth Radiation Budget Experiment (ERBE) scanner are used to examine the radiative forcing of atmospheric <span class="hlt">aerosols</span> generated from biomass burning for 13 <span class="hlt">images</span> in South America. Using the AVHRR, Local Area Coverage (LAC) data, a new technique based on a combination of spectral and textural measures is developed for detecting these <span class="hlt">aerosols</span>. Then, the instantaneous shortwave, longwave, and net radiative forcing values are computed from the ERBE instantaneous scanner data. Results for the selected samples from 13 <span class="hlt">images</span> show that the mean instantaneous net radiative forcing for areas with heavy <span class="hlt">aerosol</span> loading is about -36 W/sq m and that for the optically thin <span class="hlt">aerosols</span> are about -16 W/sq m. These results, although preliminary, provide the first estimates of radiative forcing of atmospheric <span class="hlt">aerosols</span> from biomass burning using satellite data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010017159','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010017159"><span id="translatedtitle">How Well Will MODIS Measure Top of Atmosphere <span class="hlt">Aerosol</span> Direct Radiative Forcing?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, Lorraine A.; Kaufman, Yoram J.; Levin, Zev; Ghan, Stephen; Einaudi, Franco (Technical Monitor)</p> <p>2000-01-01</p> <p>The new generation of satellite sensors such as the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) will be able to detect and characterize global <span class="hlt">aerosols</span> with an unprecedented accuracy. The question remains whether this accuracy will be sufficient to narrow the uncertainties in our estimates of <span class="hlt">aerosol</span> radiative forcing at the top of the atmosphere. Satellite remote sensing detects <span class="hlt">aerosol</span> optical thickness with the least amount of relative error when <span class="hlt">aerosol</span> loading is high. Satellites are less effective when <span class="hlt">aerosol</span> loading is low. We use the monthly mean results of two global <span class="hlt">aerosol</span> transport models to simulate the spatial distribution of smoke <span class="hlt">aerosol</span> in the Southern Hemisphere during the tropical biomass burning season. This spatial distribution allows us to determine that 87-94% of the smoke <span class="hlt">aerosol</span> forcing at the top of the atmosphere occurs in grid squares with sufficient signal to noise ratio to be detectable from space. The uncertainty of quantifying the smoke <span class="hlt">aerosol</span> forcing in the Southern Hemisphere depends on the uncertainty introduced by errors in estimating the background <span class="hlt">aerosol</span>, errors resulting from uncertainties in surface properties and errors resulting from uncertainties in assumptions of <span class="hlt">aerosol</span> properties. These three errors combine to give overall uncertainties of 1.5 to 2.2 Wm-2 (21-56%) in determining the Southern Hemisphere smoke <span class="hlt">aerosol</span> forcing at the top of the atmosphere. The range of values depend on which estimate of MODIS retrieval uncertainty is used, either the theoretical calculation (upper bound) or the empirical estimate (lower bound). Strategies that use the satellite data to derive flux directly or use the data in conjunction with ground-based remote sensing and <span class="hlt">aerosol</span> transport models can reduce these uncertainties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4126729','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4126729"><span id="translatedtitle">Exhaled <span class="hlt">Aerosol</span> Pattern Discloses Lung Structural Abnormality: A Sensitivity Study Using Computational Modeling and Fractal Analysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xi, Jinxiang; Si, Xiuhua A.; Kim, JongWon; Mckee, Edward; Lin, En-Bing</p> <p>2014-01-01</p> <p>Background Exhaled <span class="hlt">aerosol</span> patterns, also called <span class="hlt">aerosol</span> fingerprints, provide clues to the health of the lung and can be used to detect disease-modified airway structures. The key is how to decode the exhaled <span class="hlt">aerosol</span> fingerprints and retrieve the lung structural information for a non-invasive identification of respiratory diseases. Objective and Methods In this study, a CFD-fractal analysis method was developed to quantify exhaled <span class="hlt">aerosol</span> fingerprints and applied it to one benign and three malign conditions: a tracheal carina tumor, a bronchial tumor, and asthma. Respirations of tracer <span class="hlt">aerosols</span> of 1 µm at a flow rate of 30 L/min were simulated, with exhaled distributions recorded at the mouth. Large eddy simulations and a Lagrangian tracking approach were used to simulate respiratory airflows and <span class="hlt">aerosol</span> dynamics. <span class="hlt">Aerosol</span> morphometric measures such as concentration disparity, spatial distributions, and fractal analysis were applied to distinguish various exhaled <span class="hlt">aerosol</span> patterns. Findings Utilizing physiology-based modeling, we demonstrated substantial differences in exhaled <span class="hlt">aerosol</span> distributions among normal and pathological airways, which were suggestive of the disease location and extent. With fractal analysis, we also demonstrated that exhaled <span class="hlt">aerosol</span> patterns exhibited fractal behavior in both the entire <span class="hlt">image</span> and selected regions of interest. Each exhaled <span class="hlt">aerosol</span> fingerprint exhibited distinct pattern parameters such as spatial probability, fractal dimension, lacunarity, and multifractal spectrum. Furthermore, a correlation of the diseased location and exhaled <span class="hlt">aerosol</span> spatial distribution was established for asthma. Conclusion <span class="hlt">Aerosol</span>-fingerprint-based breath tests disclose clues about the site and severity of lung diseases and appear to be sensitive enough to be a practical tool for diagnosis and prognosis of respiratory diseases with structural abnormalities. PMID:25105680</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000120582&hterms=CHLOROPHYLL+EXTRACTION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCHLOROPHYLL%2BEXTRACTION','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000120582&hterms=CHLOROPHYLL+EXTRACTION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCHLOROPHYLL%2BEXTRACTION"><span id="translatedtitle">Global Distribution of <span class="hlt">Aerosols</span> Over the Open Ocean as Derived from the Coastal Zone Color Scanner</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stegmann, P. M.; Tindale, N. W.</p> <p>1999-01-01</p> <p>Climatological maps of monthly mean <span class="hlt">aerosol</span> radiance levels derived from the coastal zone color scanner (CZCS) were constructed for the world's ocean basins. This is the first study to use the 7.5.-year CZCS data set to examine the distribution and seasonality of <span class="hlt">aerosols</span> over the open ocean on a global scale. Examination of our satellite <span class="hlt">images</span> found the most prominent large-scale patch of elevated <span class="hlt">aerosol</span> radiances in each month off the coast of northwest Africa. The well-known, large-scale plumes of elevated <span class="hlt">aerosol</span> levels in the Arabian Sea, the northwest Pacific, and off the east coast of North America were also successfully captured. Radiance data were extracted from 13 major open-ocean zones, ranging from the subpolar to equatorial regions. Results from these extractions revealed the <span class="hlt">aerosol</span> load in both subpolar and subtropical zones to be higher in the Northern Hemisphere than in the Southern Hemisphere. <span class="hlt">Aerosol</span> radiances in the subtropics of both hemispheres were about 2 times higher in summer than in winter. In subpolar regions, <span class="hlt">aerosol</span> radiances in late spring/early summer were almost 3 times that observed in winter. In general, the <span class="hlt">aerosol</span> signal was higher during the warmer months and lower during the cooler months, irrespective of location. A comparison between our mean monthly <span class="hlt">aerosol</span> radiance maps with mean monthly chlorophyll maps (also from CZCS) showed similar seasonality between <span class="hlt">aerosol</span> and chlorophyll levels in the subpolar zones of both hemispheres, i.e., high levels in summer, low levels in winter. In the subtropics of both hemispheres, however, chlorophyll levels were higher in winter months which coincided with a depressed <span class="hlt">aerosol</span> signal. Our results indicate that the near-IR channel on ocean color sensors can be used to successfully capture well-known, large-scale <span class="hlt">aerosol</span> plumes on a global scale and that future ocean color sensors may provide a platform for long-term synoptic studies of combined <span class="hlt">aerosol</span>-phytoplankton productivity</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AtmEn.135...84C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AtmEn.135...84C"><span id="translatedtitle">Graphical <span class="hlt">aerosol</span> classification method using <span class="hlt">aerosol</span> relative optical depth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Qi-Xiang; Yuan, Yuan; Shuai, Yong; Tan, He-Ping</p> <p>2016-06-01</p> <p>A simple graphical method is presented to classify <span class="hlt">aerosol</span> types based on a combination of <span class="hlt">aerosol</span> optical thickness (AOT) and <span class="hlt">aerosol</span> relative optical thickness (AROT). Six <span class="hlt">aerosol</span> types, including maritime (MA), desert dust (DD), continental (CO), sub-continental (SC), urban industry (UI) and biomass burning (BB), are discriminated in a two dimensional space of AOT440 and AROT1020/440. Numerical calculations are performed using MIE theory based on a multi log-normal particle size distribution, and the AROT ranges for each <span class="hlt">aerosol</span> type are determined. More than 5 years of daily observations from 8 representative <span class="hlt">aerosol</span> sites are applied to the method to confirm spatial applicability. Finally, 3 individual cases are analyzed according to their specific <span class="hlt">aerosol</span> status. The outcomes indicate that the new graphical method coordinates well with regional characteristics and is also able to distinguish <span class="hlt">aerosol</span> variations in individual situations. This technique demonstrates a novel way to estimate different <span class="hlt">aerosol</span> types and provide information on radiative forcing calculations and satellite data corrections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016GeCoA.189...70K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016GeCoA.189...70K&link_type=ABSTRACT"><span id="translatedtitle">A link between oxygen, calcium and titanium isotopes in 26Al-poor hibonite-rich <span class="hlt">CAIs</span> from Murchison and implications for the heterogeneity of dust reservoirs in the solar nebula</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kööp, Levke; Davis, Andrew M.; Nakashima, Daisuke; Park, Changkun; Krot, Alexander N.; Nagashima, Kazuhide; Tenner, Travis J.; Heck, Philipp R.; Kita, Noriko T.</p> <p>2016-09-01</p> <p>PLACs (platy hibonite crystals) and related hibonite-rich calcium-, aluminum-rich inclusions (<span class="hlt">CAIs</span>; hereafter collectively referred to as PLAC-like <span class="hlt">CAIs</span>) have the largest nucleosynthetic isotope anomalies of all materials believed to have formed in the solar system. Most PLAC-like <span class="hlt">CAIs</span> have low inferred initial 26Al/27Al ratios and could have formed prior to injection or widespread distribution of 26Al in the solar nebula. In this study, we report 26Al-26Mg systematics combined with oxygen, calcium, and titanium isotopic compositions for a large number of newly separated PLAC-like <span class="hlt">CAIs</span> from the Murchison CM2 chondrite (32 <span class="hlt">CAIs</span> studied for oxygen, 26 of these also for 26Al-26Mg, calcium and titanium). Our results confirm (1) the large range of nucleosynthetic anomalies in 50Ti and 48Ca (our data range from -70‰ to +170‰ and -60‰ to +80‰, respectively), (2) the substantial range of Δ17O values (-28‰ to -17‰, with Δ17O = δ17O - 0.52 × δ18O), and (3) general 26Al-depletion in PLAC-like <span class="hlt">CAIs</span>. The multielement approach reveals a relationship between Δ17O and the degree of variability in 50Ti and 48Ca: PLAC-like <span class="hlt">CAIs</span> with the highest Δ17O (∼-17‰) show large positive and negative 50Ti and 48Ca anomalies, while those with the lowest Δ17O (∼-28‰) have small to no anomalies in 50Ti and 48Ca. These observations could suggest a physical link between anomalous 48Ca and 50Ti carriers and an 16O-poor reservoir. We suggest that the solar nebula was isotopically heterogeneous shortly after collapse of the protosolar molecular cloud, and that the primordial dust reservoir, in which anomalous carrier phases were heterogeneously distributed, was 16O-poor (Δ17O ⩾ -17‰) relative to the primordial gaseous (CO + H2O) reservoir (Δ17O < -35‰). However, other models such as CO self-shielding in the protoplanetary disk are also considered to explain the link between oxygen and calcium and titanium isotopes in PLAC-like <span class="hlt">CAIs</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Pop+AND+art&pg=4&id=EJ554205','ERIC'); return false;" href="http://eric.ed.gov/?q=Pop+AND+art&pg=4&id=EJ554205"><span id="translatedtitle"><span class="hlt">Images</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Barr, Catherine, Ed.</p> <p>1997-01-01</p> <p>The theme of this month's issue is "<span class="hlt">Images</span>"--from early paintings and statuary to computer-generated design. Resources on the theme include Web sites, CD-ROMs and software, videos, books, and others. A page of reproducible activities is also provided. Features include photojournalism, inspirational Web sites, art history, pop art, and myths. (AEF)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1020729','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1020729"><span id="translatedtitle"><span class="hlt">Aerosol</span> Observing System (AOS) Handbook</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jefferson, A</p> <p>2011-01-17</p> <p>The <span class="hlt">Aerosol</span> Observing System (AOS) is a suite of in situ surface measurements of <span class="hlt">aerosol</span> optical and cloud-forming properties. The instruments measure <span class="hlt">aerosol</span> properties that influence the earth’s radiative balance. The primary optical measurements are those of the <span class="hlt">aerosol</span> scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. <span class="hlt">Aerosol</span> optical measurements are useful for calculating parameters used in radiative forcing calculations such as the <span class="hlt">aerosol</span> single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A51A0002D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A51A0002D"><span id="translatedtitle">Retrieval of Stratospheric <span class="hlt">Aerosol</span> Properties from SCIAMACHY limb observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doerner, S.; Kühl, S.; Pukite, J.; Penning de Vries, M. J.; Hoermann, C.; von Savigny, C.; Deutschmann, T.; Wagner, T.</p> <p>2012-12-01</p> <p>Since the start of the Stratospheric <span class="hlt">Aerosol</span> Measurement program in 1975 satellites have been improving our understanding of the global distribution of trace gases, clouds and <span class="hlt">aerosols</span>. Observations in occultation and limb geometry provide profile information on stratospheric <span class="hlt">aerosol</span>, which have an important influence on the global radiation budget (e.g., after strong volcanic eruptions) and the stratospheric ozone chemistry (e.g., the chlorine activation inside the polar vortex). The Scanning <span class="hlt">Imaging</span> Absorption Spectrometer for Atmospheric CHartographY (SCIAMACHY) on ENVISAT performed measurements in limb geometry for almost ten years between 2002 and 2012. Its vertical resolution of about 3.3 km at the tangent point and the broad spectral range (UV/VIS/NIR) allow to retrieve profile information of stratospheric trace gases (e.g., O3, NO2, BrO or OClO) and stratospheric <span class="hlt">aerosol</span> properties. Pioneering studies (e.g., Savigny et al., 2005) showed that in particular from color indices (including the near IR spectral range) signatures of stratospheric <span class="hlt">aerosols</span> and polar stratospheric clouds (PSCs) can be retrieved. In our study we investigate the sensitivity of SCIAMACHY's broad spectral range to <span class="hlt">aerosol</span> particle properties by comparing measured spectra with simulated results from the 3D full spherical Monte Carlo Atmospheric Radiative Transfer Model McArtim. In particular, we focus on the absorption properties in the UV spectral range, the extinction coefficient and the Angström exponent. The final aim of our study is to use SCIAMACHY limb measurements for the profile retrieval of optical parameters (e.g., absorption and phase function) from which microphysical properties (e.g., mean <span class="hlt">aerosol</span> particle diameter) of the stratospheric <span class="hlt">aerosol</span> particles can be deduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1230771-cantera-aerosol-dynamics-simulator','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1230771-cantera-aerosol-dynamics-simulator"><span id="translatedtitle">Cantera <span class="hlt">Aerosol</span> Dynamics Simulator</span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p>2004-09-01</p> <p>The Cantera <span class="hlt">Aerosol</span> Dynamics Simulator (CADS) package is a general library for <span class="hlt">aerosol</span> modeling to address <span class="hlt">aerosol</span> general dynamics, including formation from gas phase reactions, surface chemistry (growth and oxidation), bulk particle chemistry, transport by Brownian diffusion, thermophoresis, and diffusiophoresis with linkage to DSMC studies, and thermal radiative transport. The library is based upon Cantera, a C++ Cal Tech code that handles gas phase species transport, reaction, and thermodynamics. The method uses a discontinuous galerkinmore » formulation for the condensation and coagulation operator that conserves particles, elements, and enthalpy up to round-off error. Both O-D and 1-D time dependent applications have been developed with the library. Multiple species in the solid phase are handled as well. The O-D application, called Tdcads (Time Dependent CADS) is distributed with the library. Tdcads can address both constant volume and constant pressure adiabatic homogeneous problems. An extensive set of sample problems for Tdcads is also provided.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.1799V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.1799V"><span id="translatedtitle">Assimilation of <span class="hlt">Aerosol</span> Optical Depths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verver, Gé; Henzing, Bas</p> <p></p> <p>Climate predictions are hampered by the large uncertainties involved in the estima- tion of the effects of atmospheric <span class="hlt">aerosol</span> (IPCC,2001). These uncertainties are caused partly because sources and sinks as well as atmospheric processing of the different types of <span class="hlt">aerosol</span> are not accurately known. Moreover, the climate impact (especially the indirect effect) of a certain distribution of <span class="hlt">aerosol</span> is hard to quantify. There have been different approaches to reduce these uncertainties. In recent years intensive ob- servational campaigns such as ACE and INDOEX have been carried out, aiming to in- crease our knowledge of atmospheric processes that determine the fate of atmospheric <span class="hlt">aerosols</span> and to quantify the radiation effects. With the new satellite instruments such as SCIAMACHY and OMI it will be possible in the near future to derive the ge- ographical distribution of the <span class="hlt">aerosol</span> optical depths (AOD) and perhaps additional information on the occurrence of different <span class="hlt">aerosol</span> types. The goal of the ARIA project (started in 2001) is to assimilate global satellite de- rived <span class="hlt">aerosol</span> optical depth (AOD) in an off-line chemistry/transport model TM3. The TM3 model (Jeuken et al. 2001) describes sources, sinks, transformation and transport processes of different types of <span class="hlt">aerosol</span> (mineral dust, carbon, sulfate, nitrate) that are relevant to radiative forcing. All meteorological input is provided by ECMWF. The assimilation procedure constrains the <span class="hlt">aerosol</span> distribution produced by the model on the basis of <span class="hlt">aerosol</span> optical depths observed by satellite. The product, i.e. an optimal estimation of global <span class="hlt">aerosol</span> distribution, is then available for the calculation of radia- tive forcing. Error analyses may provide valuable information on deficiencies of the model. In the ARIA project it is tried to extract additional information on the type of <span class="hlt">aerosol</span> present in the atmosphere by assimilating AOD at multiple wavelengths. First results of the ARIA project will be presented. The values</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770008620','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770008620"><span id="translatedtitle">Atmospheric <span class="hlt">aerosols</span>: Their Optical Properties and Effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1976-01-01</p> <p>Measured properties of atmospheric <span class="hlt">aerosol</span> particles are presented. These include <span class="hlt">aerosol</span> size frequency distribution and complex retractive index. The optical properties of <span class="hlt">aerosols</span> are computed based on the presuppositions of thermodynamic equilibrium and of Mie-theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18391839','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18391839"><span id="translatedtitle"><span class="hlt">Aerosol</span> delivery in ventilated newborn pigs: an MRI evaluation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sood, Beena G; Shen, Yimin; Latif, Zahid; Chen, Xinguang; Sharp, Jody; Neelavalli, Jaladhar; Joshi, Aparna; Slovis, Thomas L; Haacke, E M</p> <p>2008-08-01</p> <p>Pulmonary deposition of inhaled drugs in ventilated neonates has not been studied in vivo. The objective of this study was to evaluate pulmonary delivery of gadopentetate dimeglumine (Gd-DTPA) following nebulization in ventilated piglets using magnetic resonance <span class="hlt">imaging</span>. Seven ventilated piglets (5 +/- 2 d old, weight 1.8 +/- 0.5 kg) were scanned in the Bruker/Siemens 4T magnetic resonance scanner using T1 weighted spin-echo sequence. <span class="hlt">Aerosols</span> of Gd-DTPA were generated continuously using the MiniHeart jet nebulizer. Breath-hold coronal <span class="hlt">images</span> were obtained before and every 10 min during <span class="hlt">aerosolized</span> Gd-DTPA for 90 min. Signal intensity (SI) changes over the lungs, kidneys, liver, skeletal muscle, and heart were evaluated. A significant increase in SI was observed in the lungs, kidney, and liver at 10, 20, and 40 min respectively after start of <span class="hlt">aerosol</span>. At the end of 90 min, the SI increased by 95%, 101%, and 426% over the right lung, left lung, and kidney, respectively. A much smaller increase in SI was observed over the liver. In conclusion, we have demonstrated effective pulmonary <span class="hlt">aerosol</span> delivery within 10 min of contrast nebulization in ventilated piglets. Contrast visualization in the kidneys within 20 min of <span class="hlt">aerosol</span> initiation reflects alveolar absorption, glomerular filtration and renal concentration. PMID:18391839</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820049127&hterms=pollution+Marina&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpollution%2BMarina','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820049127&hterms=pollution+Marina&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpollution%2BMarina"><span id="translatedtitle">Stratospheric <span class="hlt">aerosols</span> - Observation and theory</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Turco, R. P.; Whitten, R. C.; Toon, O. B.</p> <p>1982-01-01</p> <p>Important chemical and physical roles of <span class="hlt">aerosols</span> are discussed, and properties of stratospheric <span class="hlt">aerosols</span> as revealed by experimental data are described. In situ measurements obtained by mechanical collection and scattered-light detection yield the overall size distribution of the <span class="hlt">aerosols</span>, and analyses of preserved <span class="hlt">aerosol</span> precursor gases by wet chemical, cryogenic and spectroscopic techniques indicate the photochemical sources of particle mass. <span class="hlt">Aerosol</span> chemical reactions including those of gaseous precursors, those in aqueous solution, and those on particle surfaces are discussed, in addition to <span class="hlt">aerosol</span> microphysical processes such as nucleation, condensation/evaporation, coagulation and sedimentation. Models of <span class="hlt">aerosols</span> incorporating such chemical and physical processes are presented, and simulations are shown to agree with measurements. Estimates are presented for the potential <span class="hlt">aerosol</span> changes due to emission of particles and gases by aerospace operations and industrial consumption of fossil fuels, and it is demonstrated that although the climatic effects of existing levels of stratospheric <span class="hlt">aerosol</span> pollution are negligible, potential increases in those levels might pose a future threat.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17776243','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17776243"><span id="translatedtitle">Volcanic <span class="hlt">aerosols</span> and lunar eclipses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Keen, R A</p> <p>1983-12-01</p> <p>The moon is visible during total lunar eclipses due to sunlight refracted into the earth's shadow by the atmosphere. Stratospheric <span class="hlt">aerosols</span> can profoundly affect the brightness of the eclipsed moon. Observed brightnesses of 21 lunar eclipses during 1960-1982 are compared with theoretical calculations based on refraction by an <span class="hlt">aerosol</span>-free atmosphere to yield globally averaged <span class="hlt">aerosol</span> optical depths. Results indicate the global <span class="hlt">aerosol</span> loading from the 1982 eruption of El Chichón is similar in magnitude to that from the 1963 Agung eruption. PMID:17776243</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AMTD....7.8945L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AMTD....7.8945L"><span id="translatedtitle">Improving satellite retrieved <span class="hlt">aerosol</span> microphysical properties using GOCART data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, S.; Kahn, R.; Chin, M.; Garay, M. J.; Chen, L.; Liu, Y.</p> <p>2014-09-01</p> <p>The Multi-Angle <span class="hlt">Imaging</span> Spectro-Radiometer (MISR) instrument on NASA's Terra satellite can provide more reliable <span class="hlt">Aerosol</span> Optical Depth (AOD, τ) and more particle information, such as constraints on particle size (Angström exponent or ANG, α), particle shape, and single-scattering albedo (SSA, ω), than many other satellite instruments. However, MISR's ability to retrieve <span class="hlt">aerosol</span> properties is weakened at low AOD levels. When <span class="hlt">aerosol</span>-type information content is low, many candidate <span class="hlt">aerosol</span> mixtures can match the observed radiances. We propose an algorithm to improve MISR <span class="hlt">aerosol</span> retrievals by constraining MISR mixtures' ANG and absorbing AOD (AAOD) with Goddard Chemistry <span class="hlt">Aerosol</span> Radiation and Transport (GOCART) model-simulated <span class="hlt">aerosol</span> properties. To demonstrate this approach, we calculated MISR <span class="hlt">aerosol</span> optical properties over the contiguous US from 2006 to 2009. Sensitivities associated with the thresholds of MISR-GOCART differences were analyzed according to the agreement between our results (AOD, ANG, and AAOD) and <span class="hlt">AErosol</span> RObotic NETwork (AERONET) observations. Overall, our AOD has a good agreement with AERONET because the MISR AOD retrieval is not sensitive to different mixtures under many retrieval conditions. The correlation coefficient (r) between our ANG and AERONET improves to 0.45 from 0.29 for the MISR Version 22 standard product and 0.43 for GOCART when all data points are included. However, when only cases having AOD > 0.2, the MISR product itself has r ~ 0.40, and when only AOD > 0.2 and the best-fitting mixture are considered, r ~ 0.49. So as expected, the ANG improvement occurs primarily when the model constraint is applied in cases where the particle type information content of the MISR radiances is low. Regression analysis for AAOD shows that MISR Version 22 and GOCART misestimate AERONET by a ratio (mean retrieved AAOD to mean AERONET AAOD) of 0.5; our method improves this ratio to 0.74. Large discrepancies are found through an inter</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24216808','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24216808"><span id="translatedtitle">Multi sky-view 3D <span class="hlt">aerosol</span> distribution recovery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aides, Amit; Schechner, Yoav Y; Holodovsky, Vadim; Garay, Michael J; Davis, Anthony B</p> <p>2013-11-01</p> <p><span class="hlt">Aerosols</span> affect climate, health and aviation. Currently, their retrieval assumes a plane-parallel atmosphere and solely vertical radiative transfer. We propose a principle to estimate the <span class="hlt">aerosol</span> distribution as it really is: a three dimensional (3D) volume. The principle is a type of tomography. The process involves wide angle integral <span class="hlt">imaging</span> of the sky on a very large scale. The <span class="hlt">imaging</span> can use an array of cameras in visible light. We formulate an <span class="hlt">image</span> formation model based on 3D radiative transfer. Model inversion is done using optimization methods, exploiting a closed-form gradient which we derive for the model-fit cost function. The tomography model is distinct, as the radiation source is unidirectional and uncontrolled, while off-axis scattering dominates the <span class="hlt">images</span>. PMID:24216808</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20150007827&hterms=3D&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D3D','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20150007827&hterms=3D&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D3D"><span id="translatedtitle">3D Radiative Transfer Effects in Multi-Angle/Multi-Spectral Radio-Polarimetric Signals from a Mixture of Clouds and <span class="hlt">Aerosols</span> Viewed by a Non-<span class="hlt">Imaging</span> Sensor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, Anthony B.; Garay, Michael J.; Xu, Feng; Qu, Zheng; Emde, Claudia</p> <p>2013-01-01</p> <p>When observing a spatially complex mix of <span class="hlt">aerosols</span> and clouds in a single relatively large field-of-view, nature entangles their signals non-linearly through polarized radiation transport processes that unfold in the 3D position and direction spaces. In contrast, any practical forward model in a retrieval algorithm will use only 1D vector radiative transfer (vRT) in a linear mixing technique. We assess the difference between the observed and predicted signals using synthetic data from a high-fidelity 3D vRT model with clouds generated using a Large Eddy Simulation model and an <span class="hlt">aerosol</span> climatology. We find that this difference is signal--not noise--for the <span class="hlt">Aerosol</span> Polarimetry Sensor (APS), an instrument developed by NASA. Moreover, the worst case scenario is also the most interesting case, namely, when the <span class="hlt">aerosol</span> burden is large, hence hase the most impact on the cloud microphysics and dynamics. Based on our findings, we formulate a mitigation strategy for these unresolved cloud adjacency effects assuming that some spatial information is available about the structure of the clouds at higher resolution from "context" cameras, as was planned for NASA's ill-fated Glory mission that was to carry the APS but failed to reach orbit. Application to POLDER (POLarization and Directionality of Earth Reflectances) data from the period when PARASOL (Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar) was in the A-train is briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeCoA.183..176H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeCoA.183..176H"><span id="translatedtitle">Microstructural constraints on complex thermal histories of refractory <span class="hlt">CAI</span>-like objects in an amoeboid olivine aggregate from the ALHA77307 CO3.0 chondrite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Jangmi; Brearley, Adrian J.</p> <p>2016-06-01</p> <p>We have carried out a FIB/TEM study of refractory <span class="hlt">CAI</span>-like objects in one AOA from the ALHA77307 CO3.0 chondrite. The <span class="hlt">CAI</span>-like objects in the AOA consist of a zoned sequence with a spinel-rich core through an intergrowth layer of spinel and Al-Ti-rich diopside to a diopside rim. The spinel-rich core consists of polycrystalline aggregates of spinel and ±minor melilite showing equilibrated grain boundary textures. The intergrowth layer contains fine-grained diopside and spinel with minor anorthite with highly curved and embayed grain boundaries. The diopside rim consists of polycrystalline aggregates of diopside. The compositions of pyroxene change significantly outward from Al-Ti-rich diopside in contact with the spinel-rich core to Al-Ti-poor diopside next to the surrounding olivine of the AOA. Overall microstructural and chemical characteristics suggest that the spinel-rich core formed under equilibrium conditions whereas the intergrowth layer is the result of reactions that occurred under conditions that departed significantly from equilibrium. The remarkable changes in formation conditions of the <span class="hlt">CAI</span>-like objects may have been achieved by transport and injection of refractory objects into a region of a partially-condensed, Ca,Ti-saturated gas which reacted with spinel and melilite to form Al-Ti-rich diopside. Crystallographically-oriented TiO2 nanoparticles decorate the grain boundaries between spinel grains and between spinel and Al-Ti-rich diopside grains. During the disequilibrium back-reaction of spinel with a partially-condensed, Ca,Ti-saturated gas, metastable TiO2 nanoparticles may have condensed by an epitaxial nucleation mechanism and grown on the surface of spinel. These TiO2 nanoparticles are disordered intergrowths of the two TiO2 polymorphs, anatase and rutile. These nanoparticles are inferred to have nucleated as anatase that underwent partial transformation into rutile. The local presence of the TiO2 nanoparticles and intergrowth of anatase and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JQSRT.150...36B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JQSRT.150...36B"><span id="translatedtitle">Holographic interferometry for <span class="hlt">aerosol</span> particle characterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berg, Matthew J.; Subedi, Nava R.</p> <p>2015-01-01</p> <p>Using simulations based on Mie theory, this work shows how double-exposure digital holography can be used to measure the change in size of an expanding, or contracting, spherical particle. Here, a single particle is illuminated by a plane wave twice during its expansion: once when the particle is 27 λ in radius, and again when it is 47 λ. A hologram is formed from each illumination stage from the interference of the scattered and unscattered, i.e., incident, light. The two holograms are then superposed to form a double exposure. By applying the Fresnel-Kirchhoff diffraction theory to the double-exposed hologram, a silhouette-like <span class="hlt">image</span> of the particle is computationally reconstructed that is superposed with interference fringes. These fringes are a direct result of the change in particle size occurring between the two illumination stages. The study finds that expansion on the scale of ~ 6 λ is readily discerned from the reconstructed particle <span class="hlt">image</span>. This work could be important for improved characterization of single and multiple <span class="hlt">aerosol</span> particles in situ. For example, by illuminating an <span class="hlt">aerosol</span> particle with infrared light, it may be possible to measure photothermally induced particle expansion, thus providing insight into a particle's material properties simultaneous with an <span class="hlt">image</span> of the particle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A21C0132W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A21C0132W"><span id="translatedtitle">Evaluation of <span class="hlt">aerosol</span> optical depth and <span class="hlt">aerosol</span> models from MODIS and VIIRS retrieval algorithms over North China Plain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, J.; Zhu, J.; Xia, X.; Chen, H.; Zhang, J.; Xu, X.; Oo, M. M.; Holz, R.; Levy, R. C.</p> <p>2015-12-01</p> <p>After the launch of Suomi National Polar-orbiting Partnership (S-NPP) equipped with the Visible Infrared <span class="hlt">Imaging</span> Radiometer Suit (VIIRS) instrument in late 2011, the <span class="hlt">aerosol</span> products of VIIRS have received much attention. Currently there are two <span class="hlt">aerosol</span> products of VIIRS by using different algorithms: VIIRS Environment Data Record data (VIIRS_EDR) and <span class="hlt">aerosol</span> products by applying MODIS-like algorithm to VIIRS (VIIRS_ML). In this study, the <span class="hlt">aerosol</span> optical depth (AOD) at 550nm and properties of <span class="hlt">aerosol</span> models used in the two VIIRS algorithms (VIIRS_EDR and VIIRS_ML) are compared respectively with their corresponding quantities retrieved from the ground-based Sunphotometer measurements (CE318) during May 2012-March 2014 at three sites over North China Plain (NCP): metropolis-Beijing, suburban-XiangHe and regional background site-Xinglong. The results show that the VIIRS_EDR AOD has a positive mean bias (MB) of 0.04-0.06 and the root mean square error (RMSE) of 0.22-0.24 in NCP region. Among three sites, the largest MB (0.10-0.15) and RMSE (0.27-0.30) are observed in Beijing. The results of evaluation of VIIRS_ML for each site and quality flags analysis are similar to VIIRS_EDR, but in general the VIIRS_ML AOD shows better than VIIRS_EDR except for the MB (0.13-0.14). The model comparisons show that the occurrence percentages of both dust and clean urban <span class="hlt">aerosol</span> in VIIRS_EDR (82% for Beijing, 73% for XiangHe and 50% for Xinglong) are significantly larger than that for CE318, the latter shows the polluted urban <span class="hlt">aerosol</span> is the dominant <span class="hlt">aerosol</span> especially for Beijing (67%) and XiangHe (59%) sites. The values of Single Scattering albedo (SSA) from VIIRS_EDR are higher than from CE318 in all <span class="hlt">aerosol</span> modes, with a positive bias of 0.03-0.06 for fine mode, 0.18-0.22 for coarse model and 0.03-0.08 for total modes and the <span class="hlt">aerosol</span> microphysical properties used in the VIIRS_EDR algorithm for AOD retrieval show a large difference with the counterparts from CE318 inversion results</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20080033606&hterms=geosciences&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dgeosciences','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080033606&hterms=geosciences&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dgeosciences"><span id="translatedtitle"><span class="hlt">Aerosol</span> Absorption and Radiative Forcing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stier, Philip; Seinfeld, J. H.; Kinne, Stefan; Boucher, Olivier</p> <p>2007-01-01</p> <p>We present a comprehensive examination of <span class="hlt">aerosol</span> absorption with a focus on evaluating the sensitivity of the global distribution of <span class="hlt">aerosol</span> absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive <span class="hlt">aerosol</span>-climate model ECHAM5-HAM by effective medium approximations for the calculation of <span class="hlt">aerosol</span> effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of <span class="hlt">aerosol</span> inclusions, as well as by modules for the calculation of long-wave <span class="hlt">aerosol</span> radiative properties and instantaneous <span class="hlt">aerosol</span> forcing. The evaluation of the simulated <span class="hlt">aerosol</span> absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006) significantly improves the previous underestimation of the <span class="hlt">aerosol</span> absorption optical depth. In the global annual-mean, absorption acts to reduce the shortwave anthropogenic <span class="hlt">aerosol</span> top-of-atmosphere (TOA) radiative forcing clear-sky from -0.79 to -0.53 W m(sup -2) (33%) and all-sky from -0.47 to -0.13W m(sup -2 (72%). Our results confirm that basic assumptions about the BC refractive index play a key role for <span class="hlt">aerosol</span> absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic <span class="hlt">aerosol</span> radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19W m(sup -2) (36%) clear-sky and of 0.12W m(sup -2) (92%) all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05W m(sup -2) and a positive TOA forcing perturbation of 0</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......229D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......229D"><span id="translatedtitle">Studies of organic <span class="hlt">aerosol</span> and <span class="hlt">aerosol</span>-cloud interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duong, Hanh To</p> <p></p> <p>Atmospheric <span class="hlt">aerosols</span> can influence society and the environment in many ways including altering the planet's energy budget, the hydrologic cycle, and public health. However, the Fourth Assessment Report of the Intergovernmental Panel on Climate Change indicates that the anthropogenic radiative forcing associated with <span class="hlt">aerosol</span> effects on clouds has the highest uncertainty in the future climate predictions. This thesis focuses on the nature of the organic fraction of ambient particles and how particles interact with clouds using a combination of tools including aircraft and ground measurements, models, and satellite data. Fine <span class="hlt">aerosol</span> particles typically contain between 20 - 90% organic matter by mass and a major component of this fraction includes water soluble organic carbon (WSOC). Consequently, water-soluble organic species can strongly influence <span class="hlt">aerosol</span> water-uptake and optical properties. However, the chemical composition of this fraction is not well-understood. PILS-TOC was used to characterize WSOC in ambient <span class="hlt">aerosol</span> in Los Angeles, California. The spatial distribution of WSOC was found to be influenced by (i) a wide range of <span class="hlt">aerosol</span> sources within this urban metropolitan area, (ii) transport of pollutants by the characteristic daytime sea breeze trajectory, (iii) topography, and (iv) secondary production during transport. Meteorology is linked with the strength of many of these various processes. Many methods and instruments have been used to study <span class="hlt">aerosol</span>-cloud interactions. Each observational platform is characterized by different temporal/spatial resolutions and operational principles, and thus there are disagreements between different studies for the magnitude of mathematical constructs used to represent the strength of <span class="hlt">aerosol</span>-cloud interactions. This work points to the sensitivity of the magnitude of <span class="hlt">aerosol</span>-cloud interactions to cloud lifetime and spatial resolution of measurements and model simulations. Failure to account for above-cloud <span class="hlt">aerosol</span> layers</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AIPC.1531...31L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1531...31L"><span id="translatedtitle">Growing up MODIS: Towards a mature <span class="hlt">aerosol</span> climate data record</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Levy, Robert C.</p> <p>2013-05-01</p> <p><span class="hlt">Aerosols</span> are major players within the Earth's climate system, affecting the radiation budget, clouds and the hydrological cycle. In high concentrations near the surface, <span class="hlt">aerosols</span> (or particulate matter, PM) affect visibility, impact air quality, and can contribute to poor health. Among others, Yoram Kaufman recognized the importance of <span class="hlt">aerosols</span> to climate, and helped to design new instrumentation and algorithms to retrieve and quantify global <span class="hlt">aerosol</span> properties. One instrument, known as the Moderate <span class="hlt">Imaging</span> Resolution Spectro-radiometer (MODIS), was deployed on the AM-1 satellite (later known as Terra), part of NASA's Earth Observing System (EOS). In 1998, armed with an M.S. and job experience in neither <span class="hlt">aerosols</span> nor satellites, I was looking for a new job. I somehow found my way to the MODIS <span class="hlt">Aerosol</span> team. It was only a year before Terra launch, and most major decisions about the MODIS <span class="hlt">aerosol</span> retrieval algorithms had been finalized. Since then, we worked through launch, initial evaluation of the product with AERONET and field deployments, and continued efforts to understand the product and refine retrieval algorithms. I have had opportunities to participate in field experiments, write papers, and earn my PhD. The "second generation" algorithm for <span class="hlt">aerosol</span> retrieval over land has been hugely successful. We have collected nearly a half-million collocations with AERONET and other dataseis, made new discoveries, and have contributed to research and operational projects globally. Due to the dedication of the entire team, the MODIS <span class="hlt">aerosol</span> product now is one of the highlights of NASA's EOS program. It is used for climate research and air quality forecasting, as well for applications not even considered before the MODIS era. More recently, a focus is on stitching the MODIS <span class="hlt">aerosol</span> product into the "climate data record" (CDR) for global <span class="hlt">aerosol</span>, determining whether the product has sufficient length, consistency and continuity to determine climate variability and change</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/210791','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/210791"><span id="translatedtitle"><span class="hlt">Aerosol</span> characteristics in a coastal region (results from MAPTIP) Professional paper</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gathman, S.G.; Jensen, D.R.</p> <p>1995-08-01</p> <p>In coastal areas, the simplifying assumptions of horizontal homogeneity used in open ocean analysis are not always useable. Various human-generated <span class="hlt">aerosol</span> sources such as towns and industrial centers can provide a complex portrait of merging plumes of non-natural <span class="hlt">aerosols</span> which are advected out to the littoral zones. The extensive meteorological and <span class="hlt">aerosol</span> measurements made during the Marine <span class="hlt">Aerosol</span> Properties and Thermal <span class="hlt">Imager</span> Performance (MAPTIP) experiment provided an ideal opportunity to view how these <span class="hlt">aerosol</span> were advected from their sources to the littoral zone of the North Sea. MAPTIP was conducted along the Dutch coast in October/November 1993. The NCCOSC, RDTE DIV (NRaD) instrumented Navajo aircraft flew two star pattern flights a day during the experiment at altitudes below 500 feet. During these flights, <span class="hlt">aerosol</span> size distribution measurements along the flight path were being continuously recorded. These measurements were utilized for making <span class="hlt">aerosol</span> concentration maps of the various sized <span class="hlt">aerosol</span> groups. This paper shows the mesoscale effects of <span class="hlt">aerosol</span> advection making the marine boundary layer in a littoral zone much more complicated than that of an open ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..1714619S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..1714619S&link_type=ABSTRACT"><span id="translatedtitle">Spatial and Temporal Monitoring of <span class="hlt">Aerosol</span> over Selected Urban Areas in Egypt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shokr, Mohammed; El-Tahan, Mohammed; Ibrahim, Alaa</p> <p>2015-04-01</p> <p>We utilize remote sensing data of atmospheric <span class="hlt">aerosols</span> from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) aboard the Terra and Aqua satellites to explore spatio-temporal patterns over selected urban sites in Egypt during 2000-2015. High resolution (10 x 10 km^2) Level 2, collection 5, quality-controlled product was used. The selected sites are characterized by different human and industrial activities as well as landscape and meteorological attributes. These have impacts on the dominant types and intensity of <span class="hlt">aerosols</span>. <span class="hlt">Aerosol</span> robotic network (AERONET) data were used to validate the calculations from MODIS. The suitability of the MODIS product in terms of spatial and temporal coverage as well as accuracy and robustness has been established. Seasonal patterns of <span class="hlt">aerosol</span> concentration are identified and compared between the sites. Spatial gradient of <span class="hlt">aerosol</span> is assessed in the vicinity of major <span class="hlt">aerosol</span>-emission sites (e.g. Cairo) to determine the range of influence of the generated pollution. Peak <span class="hlt">aerosol</span> concentrations are explained in terms of meteorological events and land cover. The limited trends found in the temporal records of the <span class="hlt">aerosol</span> measurements will be confirmed using calibrated long-term ground observations. The study has been conducted under the PEER 2-239 research project titled "The Impact of Biogenic and Anthropogenic Atmospheric <span class="hlt">Aerosols</span> to Climate in Egypt". Project website is CleanAirEgypt.org</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JGRD..121.6459Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JGRD..121.6459Y&link_type=ABSTRACT"><span id="translatedtitle">Distinct impact of different types of <span class="hlt">aerosols</span> on surface solar radiation in China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Xin; Zhao, Chuanfeng; Zhou, Lijing; Wang, Yang; Liu, Xiaohong</p> <p>2016-06-01</p> <p>Observations of surface direct solar radiation (DSR) and visibility, particulate matter with aerodynamic diameters less than 2.5 µm (PM2.5), together with the <span class="hlt">aerosol</span> optical thickness (AOT) taken from Moderate-Resolution <span class="hlt">Imaging</span> Spectroradiometer and Multiangle <span class="hlt">Imaging</span> Spectroradiometer, were investigated to gain insight into the impact of <span class="hlt">aerosol</span> pollution on surface solar radiation in China. The surface DSR decreased during 2004-2014 compared with 1993~2003 over eastern China, but no clear reduction was observed in remote regions with cleaner air. Significant correlations of visibility, PM2.5, and regionally averaged AOT with the surface DSR over eastern China indicate that <span class="hlt">aerosol</span> pollution greatly affects the energy available at the surface. The net loss of surface solar radiation also reduces the surface ground temperature over eastern China. However, the slope of the linear variation of the radiation with respect to atmospheric visibility is distinctly different at different stations, implying that the main <span class="hlt">aerosol</span> type varies regionally. The largest slope value occurs at Zhengzhou and indicates that the <span class="hlt">aerosol</span> absorption in central China is the highest, and lower slope values suggest relatively weakly absorbing types of <span class="hlt">aerosols</span> at other locations. The spatial distribution of the linear slopes agrees well with the geographical distribution of the absorbing <span class="hlt">aerosols</span> derived from the Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observations and Ozone Monitoring Instrument over China. The regional correlation between a larger slope value and higher absorbance properties of <span class="hlt">aerosols</span> indicates that the net effects of <span class="hlt">aerosols</span> on the surface solar energy and corresponding climatic effects are dependent on both <span class="hlt">aerosol</span> amount and optical properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8348P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8348P"><span id="translatedtitle">Evolution of <span class="hlt">aerosol</span> loading in Santiago de Chile between 1997 and 2014</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pistone, Kristina; Gallardo, Laura</p> <p>2015-04-01</p> <p>While <span class="hlt">aerosols</span> produced by major cities are a significant component of anthropogenic climate forcing as well as an important factor in public health, many South American cities have not been a major focus of <span class="hlt">aerosol</span> studies due in part to relatively few long-term observations in the region. Here we present a synthesis of the available data for the emerging megacity of Santiago, Chile. We report new results from a recent NASA AERONET (<span class="hlt">AErosol</span> RObotic NETwork) site in the Santiago basin, combining these with previous AERONET observations in Santiago as well as with a new assessment of the 11-station air quality monitoring network currently administered by the Chilean Environment Ministry (MMA, Ministerio del Medio Ambiente) to assess changes in <span class="hlt">aerosol</span> composition since 1997. While the average surface concentration of pollution components (specifically PM2.5 and PM10) has decreased, no significant change in total <span class="hlt">aerosol</span> optical depth was observed. However, changes in <span class="hlt">aerosol</span> size and composition are suggested by the proxy measurements. Previous studies have revealed limitations in purely satellite-based studies over Santiago due to biases from high surface reflection in the region, particularly in summer months (e.g. Escribano et al 2014). To overcome this difficulty and certain limitations in the air quality data, we next incorporate analysis of <span class="hlt">aerosol</span> products from the Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR) instrument along with those from the Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) instrument, both on NASA's Terra satellite, to better quantify the high bias of MODIS. Thus incorporating these complementary datasets, we characterize the <span class="hlt">aerosol</span> over Santiago over the period 1997 to 2014, including the evolution of <span class="hlt">aerosol</span> properties over time and seasonal dependencies in the observed trends. References: Escribano et al (2014), "Satellite Retrievals of <span class="hlt">Aerosol</span> Optical Depth over a Subtropical Urban Area: The Role of Stratification and Surface</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A21D3070K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A21D3070K"><span id="translatedtitle">Retrieval of <span class="hlt">Aerosol</span> information from UV measurement by using optimal estimation method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>KIM, M.; Kim, J.; Jeong, U.; Kim, W. V.; Kim, S. K.; Lee, S. D.; Moon, K. J.</p> <p>2014-12-01</p> <p>An algorithm to retrieve <span class="hlt">aerosol</span> optical depth (AOD), single scattering albedo (SSA), and <span class="hlt">aerosol</span> loading height is developed for GEMS (Geostationary Environment Monitoring Spectrometer) measurement. The GEMS is planned to be launched in geostationary orbit in 2018, and employs hyper-spectral <span class="hlt">imaging</span> with 0.6 nm resolution to observe solar backscatter radiation in the UV and Visible range. In the UV range, the low surface contribution to the backscattered radiation and strong interaction between <span class="hlt">aerosol</span> absorption and molecular scattering can be advantageous in retrieving <span class="hlt">aerosol</span> information such as AOD and SSA [Torres et al., 2007; Torres et al., 2013; Ahn et al., 2014]. However, the large contribution of atmospheric scattering results in the increase of the sensitivity of the backward radiance to <span class="hlt">aerosol</span> loading height. Thus, the assumption of <span class="hlt">aerosol</span> loading height becomes important issue to obtain accurate result. Accordingly, this study focused on the simultaneous retrieval of <span class="hlt">aerosol</span> loading height with AOD and SSA by utilizing the optimal estimation method. For the RTM simulation, the <span class="hlt">aerosol</span> optical properties were analyzed from AERONET inversion data (level 2.0) at 46 AERONET sites over ASIA. Also, 2-channel inversion method is applied to estimate a priori value of the <span class="hlt">aerosol</span> information to solve the Lavenberg Marquardt equation. The GEMS <span class="hlt">aerosol</span> algorithm is tested with OMI level-1B dataset, a provisional data for GEMS measurement, and the result is compared with OMI standard <span class="hlt">aerosol</span> product and AERONET values. The retrieved AOD and SSA show reasonable distribution compared with OMI products, and are well correlated with the value measured from AERONET. However, retrieval uncertainty in <span class="hlt">aerosol</span> loading height is relatively larger than other results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16076949','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16076949"><span id="translatedtitle">The effect of smoke, dust, and pollution <span class="hlt">aerosol</span> on shallow cloud development over the Atlantic Ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaufman, Yoram J; Koren, Ilan; Remer, Lorraine A; Rosenfeld, Daniel; Rudich, Yinon</p> <p>2005-08-01</p> <p>Clouds developing in a polluted environment tend to have more numerous but smaller droplets. This property may lead to suppression of precipitation and longer cloud lifetime. Absorption of incoming solar radiation by <span class="hlt">aerosols</span>, however, can reduce the cloud cover. The net <span class="hlt">aerosol</span> effect on clouds is currently the largest uncertainty in evaluating climate forcing. Using large statistics of 1-km resolution MODIS (Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer) satellite data, we study the <span class="hlt">aerosol</span> effect on shallow water clouds, separately in four regions of the Atlantic Ocean, for June through August 2002: marine <span class="hlt">aerosol</span> (30 degrees S-20 degrees S), smoke (20 degrees S-5 degrees N), mineral dust (5 degrees N-25 degrees N), and pollution <span class="hlt">aerosols</span> (30 degrees N- 60 degrees N). All four <span class="hlt">aerosol</span> types affect the cloud droplet size. We also find that the coverage of shallow clouds increases in all of the cases by 0.2-0.4 from clean to polluted, smoky, or dusty conditions. Covariability analysis with meteorological parameters associates most of this change to <span class="hlt">aerosol</span>, for each of the four regions and 3 months studied. In our opinion, there is low probability that the net <span class="hlt">aerosol</span> effect can be explained by coincidental, unresolved, changes in meteorological conditions that also accumulate <span class="hlt">aerosol</span>, or errors in the data, although further in situ measurements and model developments are needed to fully understand the processes. The radiative effect at the top of the atmosphere incurred by the <span class="hlt">aerosol</span> effect on the shallow clouds and solar radiation is -11 +/- 3 W/m2 for the 3 months studied; 2/3 of it is due to the <span class="hlt">aerosol</span>-induced cloud changes, and 1/3 is due to <span class="hlt">aerosol</span> direct radiative effect. PMID:16076949</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A24B..02C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A24B..02C"><span id="translatedtitle">The Impact of Caliop <span class="hlt">Aerosol</span> Profiling: How Z Influences the X, Y Satellite Perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Campbell, J. R.; Alfaro-Contreras, R.; Buchard, V.; Toth, T. D.; Vaughan, M.; Zhang, J.</p> <p>2014-12-01</p> <p>The ever-burgeoning satellite remote sensing era has significantly improved our understanding of the role <span class="hlt">aerosol</span> particles play in the earth-atmosphere system. Instruments such as MODIS, MISR, OMI, AVHRR, and now VIIRS, among others, are meeting a growing number of observational demands necessary for characterizing <span class="hlt">aerosol</span> particle influence, on processes such as surface air quality, direct and semi-direct forcing and cloud indirect effects. While these passive sensors have grown to represent the community's fundamental global <span class="hlt">aerosol</span> observing core, their datasets represent, almost exclusively, a column-integrated view of atmospheric <span class="hlt">aerosols</span>. In contrast, however, <span class="hlt">aerosol</span>-climate interaction is inherently sensitive to the vertical distribution of <span class="hlt">aerosol</span> particle presence. Though the CALIOP instrument, with its relatively limited profiling swath, offers a much smaller observational scale compared with passive <span class="hlt">imagers</span>, active-sensor <span class="hlt">aerosol</span> profiling is increasingly adding the necessary vertical perspective required to challenge and fully characterize what has become a predominant two-dimensional global perception of <span class="hlt">aerosols</span>. In this talk, we highlight the impact of CALIOP-based profiling, and describe how the critical third dimension is contributing to this knowledge. We introduce <span class="hlt">aerosol</span> scale-heights and the contribution of near-surface particle presence relative to column-integrated <span class="hlt">aerosol</span> optical depths. We describe the impact of particle profile diffusivity relative to passive-based estimates of surface air quality. The impact of accurate vertical profiling in global modeling systems is conceptualized, through benefits to downwind forecasting from accurate initialization. Sensitivities in semi-direct regional heating rate estimates are shown as a function of model-constrained <span class="hlt">aerosol</span> vertical profiling. Finally, we highlight perhaps the most important CALIOP observation of all, relative to the passive sensors: the presence of optically-thin cirrus clouds</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.A13F0281B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.A13F0281B"><span id="translatedtitle">Quantifying the sensitivity of <span class="hlt">aerosol</span> optical depths retrieved from MSG SEVIRI to a priori data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bulgin, C. E.; Palmer, P. I.; Merchant, C. J.; Siddans, R.; Poulsen, C.; Grainger, R. G.; Thomas, G.; Carboni, E.; McConnell, C.; Highwood, E.</p> <p>2009-12-01</p> <p>Radiative forcing contributions from <span class="hlt">aerosol</span> direct and indirect effects remain one of the most uncertain components of the climate system. Satellite observations of <span class="hlt">aerosol</span> optical properties offer important constraints on atmospheric <span class="hlt">aerosols</span> but their sensitivity to prior assumptions must be better characterized before they are used effectively to reduce uncertainty in <span class="hlt">aerosol</span> radiative forcing. We assess the sensitivity of the Oxford-RAL <span class="hlt">Aerosol</span> and Cloud (ORAC) optimal estimation retrieval of <span class="hlt">aerosol</span> optical depth (AOD) from the Spinning Enhanced Visible and InfraRed <span class="hlt">Imager</span> (SEVIRI) to a priori <span class="hlt">aerosol</span> data. SEVIRI is a geostationary satellite instrument centred over Africa and the neighbouring Atlantic Ocean, routinely sampling desert dust and biomass burning outflow from Africa. We quantify the uncertainty in SEVIRI AOD retrievals in the presence of desert dust by comparing retrievals that use prior information from the Optical Properties of <span class="hlt">Aerosol</span> and Cloud (OPAC) database, with those that use measured <span class="hlt">aerosol</span> properties during the Dust Outflow and Deposition to the Ocean (DODO) aircraft campaign (August, 2006). We also assess the sensitivity of retrieved AODs to changes in solar zenith angle, and the vertical profile of <span class="hlt">aerosol</span> effective radius and extinction coefficient input into the retrieval forward model. Currently the ORAC retrieval scheme retrieves AODs for five <span class="hlt">aerosol</span> types (desert dust, biomass burning, maritime, urban and continental) and chooses the most appropriate AOD based on the cost functions. We generate an improved prior <span class="hlt">aerosol</span> speciation database for SEVIRI based on a statistical analysis of a Saharan Dust Index (SDI) determined using variances of different brightness temperatures, and organic and black carbon tracers from the GEOS-Chem chemistry transport model. This database is described as a function of season and time of day. We quantify the difference in AODs between those chosen based on prior information from the SDI and GEOS</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1182178','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1182178"><span id="translatedtitle">The effect of smoke, dust, and pollution <span class="hlt">aerosol</span> on shallow cloud development over the Atlantic Ocean</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kaufman, Yoram J.; Koren, Ilan; Remer, Lorraine A.; Rosenfeld, Daniel; Rudich, Yinon</p> <p>2005-01-01</p> <p>Clouds developing in a polluted environment tend to have more numerous but smaller droplets. This property may lead to suppression of precipitation and longer cloud lifetime. Absorption of incoming solar radiation by <span class="hlt">aerosols</span>, however, can reduce the cloud cover. The net <span class="hlt">aerosol</span> effect on clouds is currently the largest uncertainty in evaluating climate forcing. Using large statistics of 1-km resolution MODIS (Moderate Resolution <span class="hlt">Imaging</span> Spectroradiometer) satellite data, we study the <span class="hlt">aerosol</span> effect on shallow water clouds, separately in four regions of the Atlantic Ocean, for June through August 2002: marine <span class="hlt">aerosol</span> (30°S–20°S), smoke (20°S–5°N), mineral dust (5°N–25°N), and pollution <span class="hlt">aerosols</span> (30°N– 60°N). All four <span class="hlt">aerosol</span> types affect the cloud droplet size. We also find that the coverage of shallow clouds increases in all of the cases by 0.2–0.4 from clean to polluted, smoky, or dusty conditions. Covariability analysis with meteorological parameters associates most of this change to <span class="hlt">aerosol</span>, for each of the four regions and 3 months studied. In our opinion, there is low probability that the net <span class="hlt">aerosol</span> effect can be explained by coincidental, unresolved, changes in meteorological conditions that also accumulate <span class="hlt">aerosol</span>, or errors in the data, although further in situ measurements and model developments are needed to fully understand the processes. The radiative effect at the top of the atmosphere incurred by the <span class="hlt">aerosol</span> effect on the shallow clouds and solar radiation is –11 ± 3 W/m2 for the 3 months studied; 2/3 of it is due to the <span class="hlt">aerosol</span>-induced cloud changes, and 1/3 is due to <span class="hlt">aerosol</span> direct radiative effect. PMID:16076949</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015IJMPB..2930003C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015IJMPB..2930003C&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Aerosol</span> synthesis and application of folded graphene-based materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yantao; Wang, Zhongying; Qiu, Yang</p> <p>2015-12-01</p> <p>Graphene oxide colloid has been widely used in the synthesis of various graphene-based materials. Graphene oxide sheets, with a low bending rigidity, can be folded when assembled in aqueous phase. A simple but industrial scalable way, <span class="hlt">aerosol</span> processing, can be used to fabricate folded graphene-based materials. These folded materials can carry various cargo materials and be used in different applications such as time-controlled drug release, medical <span class="hlt">imaging</span> enhancement, catalyst support and energy related areas. The <span class="hlt">aerosol</span> synthesis of folded graphene-based materials can also be easily extended to fabricate hybrid nanomaterials without any complicated chemistries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=38459&keyword=particle+AND+physics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67424036&CFTOKEN=65892670','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=38459&keyword=particle+AND+physics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67424036&CFTOKEN=65892670"><span id="translatedtitle"><span class="hlt">AEROSOL</span> EXPOSURE, PHYSICS, AND CHEMISTRY</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A brief review is given of the "Knowledge" and the "Gaps in Knowledge" of <span class="hlt">aerosol</span> exposure, physics and chemistry relevant to health effects of <span class="hlt">aerosols</span>, and presented or discussed in platform or poster presentations at the Symposium on Particulate Air Pollution - Associations wi...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17375556','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17375556"><span id="translatedtitle">Nanotechnology and pharmaceutical inhalation <span class="hlt">aerosols</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Patel, A R; Vavia, P R</p> <p>2007-02-01</p> <p>Pharmaceutical inhalation <span class="hlt">aerosols</span> have been playing a crucial role in the health and well being of millions of people throughout the world for many years. The technology's continual advancement, the ease of use and the more desirable pulmonary-rather-than-needle delivery for systemic drugs has increased the attraction for the pharmaceutical <span class="hlt">aerosol</span> in recent years. But administration of drugs by the pulmonary route is technically challenging because oral deposition can be high, and variations in inhalation technique can affect the quantity of drug delivered to the lungs. Recent advances in nanotechnology, particularly drug delivery field have encouraged formulation scientists to expand their reach in solving tricky problems related to drug delivery. Moreover, application of nanotechnology to <span class="hlt">aerosol</span> science has opened up a new category of pharmaceutical <span class="hlt">aerosols</span> (collectively known as nanoenabled-<span class="hlt">aerosols</span>) with added advantages and effectiveness. In this review, some of the latest approaches of nano-enabled <span class="hlt">aerosol</span> drug delivery system (including nano-suspension, trojan particles, bioadhesive nanoparticles and smart particle <span class="hlt">aerosols</span>) that can be employed successfully to overcome problems of conventional <span class="hlt">aerosol</span> systems have been introduced. PMID:17375556</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820061330&hterms=1092&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231092','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820061330&hterms=1092&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231092"><span id="translatedtitle">Mount Saint Helens <span class="hlt">aerosol</span> evolution</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Oberbeck, V. R.; Farlow, N. H.; Snetsinger, K. G.; Ferry, G. V.; Fong, W.; Hayes, D. M.</p> <p>1982-01-01</p> <p>Stratospheric <span class="hlt">aerosol</span> samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples shows that <span class="hlt">aerosol</span> volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770004138','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770004138"><span id="translatedtitle">Preliminary <span class="hlt">aerosol</span> generator design studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stampfer, J. F., Jr.</p> <p>1976-01-01</p> <p>The design and construction of a prototype vaporization generator for highly dispersed sodium chloride <span class="hlt">aerosols</span> is described. The <span class="hlt">aerosol</span> generating system is to be used in the Science Simulator of the Cloud Physics Laboratory Project and as part of the Cloud Physics Laboratory payload to be flown on the shuttle/spacelab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900002762','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900002762"><span id="translatedtitle"><span class="hlt">Aerosol</span> in the Pacific troposphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clarke, Antony D.</p> <p>1989-01-01</p> <p>The use of near real-time optical techniques is emphasized for the measurement of mid-tropospheric <span class="hlt">aerosol</span> over the Central Pacific. The primary focus is on measurement of the <span class="hlt">aerosol</span> size distribution over the range of particle diameters from 0.15 to 5.0 microns that are essential for modeling CO2 backscatter values in support of the laser atmospheric wind sounder (LAWS) program. The measurement system employs a LAS-X (Laser <span class="hlt">Aerosol</span> Spectrometer-PMS, Boulder, CO) with a custom 256 channel pulse height analyzer and software for detailed measurement and analysis of <span class="hlt">aerosol</span> size distributions. A thermal preheater system (Thermo Optic <span class="hlt">Aerosol</span> Descriminator (TOAD) conditions the <span class="hlt">aerosol</span> in a manner that allows the discrimination of the size distribution of individual <span class="hlt">aerosol</span> components such as sulfuric acid, sulfates and refractory species. This allows assessment of the relative contribution of each component to the BCO2 signal. This is necessary since the different components have different sources, exhibit independent variability and provide different BCO2 signals for a given mass and particle size. Field activities involve experiments designed to examine both temporal and spatial variability of these <span class="hlt">aerosol</span> components from ground based and aircraft platforms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=65916&keyword=references+AND+scientific&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76396475&CFTOKEN=90917732','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=65916&keyword=references+AND+scientific&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76396475&CFTOKEN=90917732"><span id="translatedtitle">INDOOR <span class="hlt">AEROSOLS</span> AND EXPOSURE ASSESSMENT</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This chapter provides an overview of both indoor <span class="hlt">aerosol</span> concentration measurements, and the considerations for assessment of exposure to <span class="hlt">aerosols</span> in non-occupational settings. The fixed-location measurements of concentration at an outdoor location, while commuting inside an a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820023851','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820023851"><span id="translatedtitle">Mount St. Helens <span class="hlt">aerosol</span> evolution</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Oberbeck, V. R.; Farlow, N. H.; Fong, W.; Snetsinger, K. G.; Ferry, G. V.; Hayes, D. M.</p> <p>1982-01-01</p> <p>Stratospheric <span class="hlt">aerosol</span> samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that <span class="hlt">aerosol</span> volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6865571','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6865571"><span id="translatedtitle">Mount St. Helens <span class="hlt">aerosol</span> evolution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Oberbeck, V.R.; Farlow, N.H.; Fong, W.; Snetsinger, K.G.; Ferry, G.V.; Hayes, D.M.</p> <p>1982-09-01</p> <p>Stratospheric <span class="hlt">aerosol</span> samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples show that <span class="hlt">aerosol</span> volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6220982','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6220982"><span id="translatedtitle">Mount St. Helens <span class="hlt">aerosol</span> evolution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Oberbeck, V.R.; Farlow, N.H.</p> <p>1982-08-01</p> <p>Stratospheric <span class="hlt">aerosol</span> samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that <span class="hlt">aerosol</span> volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=dolphin&pg=6&id=ED287161','ERIC'); return false;" href="http://eric.ed.gov/?q=dolphin&pg=6&id=ED287161"><span id="translatedtitle">Cost-Benefit Analysis for ECIA Chapter 1 and State DPPF Programs Comparing Groups Receiving Regular Program Instruction and Groups Receiving Computer Assisted Instruction/Computer Management System (<span class="hlt">CAI</span>/CMS). 1986-87.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chamberlain, Ed</p> <p></p> <p>A cost benefit study was conducted to determine the effectiveness of a computer assisted instruction/computer management system (<span class="hlt">CAI</span>/CMS) as an alternative to conventional methods of teaching reading within Chapter 1 and DPPF funded programs of the Columbus (Ohio) Public Schools. The Chapter 1 funded Compensatory Language Experiences and Reading…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhRvL.106a5502R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhRvL.106a5502R"><span id="translatedtitle">Thermophoretically Dominated <span class="hlt">Aerosol</span> Coagulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosner, Daniel E.; Arias-Zugasti, Manuel</p> <p>2011-01-01</p> <p>A theory of <span class="hlt">aerosol</span> coagulation due to size-dependent thermophoresis is presented. This previously overlooked effect is important when local temperature gradients are large, the sol population is composed of particles of much greater thermal conductivity than the carrier gas, with mean diameters much greater than the prevailing gas mean free path, and an adequate “spread” in sizes (as in metallurgical mists or fumes). We illustrate this via a population-balance analysis of the evolution of an initially log-normal distribution when this mechanism dominates ordinary Brownian diffusion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120011686','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120011686"><span id="translatedtitle"><span class="hlt">Aerosol</span> Remote Sensing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lenoble, Jacqueline (Editor); Remer, Lorraine (Editor); Tanre, Didier (Editor)</p> <p>2012-01-01</p> <p>This book gives a much needed explanation of the basic physical principles of radia5tive transfer and remote sensing, and presents all the instruments and retrieval algorithms in a homogenous manner. For the first time, an easy path from theory to practical algorithms is available in one easily accessible volume, making the connection between theoretical radiative transfer and individual practical solutions to retrieve <span class="hlt">aerosol</span> information from remote sensing. In addition, the specifics and intercomparison of all current and historical methods are explained and clarified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A41F3114A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A41F3114A"><span id="translatedtitle">The <span class="hlt">Aerosol</span> Coarse Mode Initiative</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arnott, W. P.; Adhikari, N.; Air, D.; Kassianov, E.; Barnard, J.</p> <p>2014-12-01</p> <p>Many areas of the world show an <span class="hlt">aerosol</span> volume distribution with a significant coarse mode and sometimes a dominant coarse mode. The large coarse mode is usually due to dust, but sea salt <span class="hlt">aerosol</span> can also play an important role. However, in many field campaigns, the coarse mode tends to be ignored, because it is difficult to measure. This lack of measurements leads directly to a concomitant "lack of analysis" of this mode. Because, coarse mode <span class="hlt">aerosols</span> can have significant effects on radiative forcing, both in the shortwave and longwave spectrum, the coarse mode -- and these forcings -- should be accounted for in atmospheric models. Forcings based only on fine mode <span class="hlt">aerosols</span> have the potential to be misleading. In this paper we describe examples of large coarse modes that occur in areas of large <span class="hlt">aerosol</span> loading (Mexico City, Barnard et al., 2010) as well as small loadings (Sacramento, CA; Kassianov et al., 2012; and Reno, NV). We then demonstrate that: (1) the coarse mode can contribute significantly to radiative forcing, relative to the fine mode, and (2) neglecting the coarse mode may result in poor comparisons between measurements and models. Next we describe -- in general terms -- the limitations of instrumentation to measure the coarse mode. Finally, we suggest a new initiative aimed at examining coarse mode <span class="hlt">aerosol</span> generation mechanisms; transport and deposition; chemical composition; visible and thermal IR refractive indices; morphology; microphysical behavior when deposited on snow and ice; and specific instrumentation needs. Barnard, J. C., J. D. Fast, G. Paredes-Miranda, W. P. Arnott, and A. Laskin, 2010: Technical Note: Evaluation of the WRF-Chem "<span class="hlt">Aerosol</span> Chemical to <span class="hlt">Aerosol</span> Optical Properties" Module using data from the MILAGRO campaign, Atmospheric Chemistry and Physics, 10, 7325-7340. Kassianov, E. I., M. S. Pekour, and J. C. Barnard, 2012: <span class="hlt">Aerosols</span> in Central California: Unexpectedly large contribution of coarse mode to <span class="hlt">aerosol</span> radiative forcing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19980227623&hterms=More+Srl&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMore%2BSrl','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19980227623&hterms=More+Srl&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMore%2BSrl"><span id="translatedtitle">CART and GSFC raman lidar measurements of atmospheric <span class="hlt">aerosol</span> backscattering and extinction profiles for EOS validation and ARM radiation studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ferrare, R. A.; Turner, D. D.; Melfi, S. H.; Whiteman, D. N.; Schwenner, G.; Evans, K. D.; Goldsmith, J. E. M.; Tooman, T.</p> <p>1998-01-01</p> <p>The <span class="hlt">aerosol</span> retrieval algorithms used by the Moderate-Resolution <span class="hlt">Imaging</span> Spectroradiometer (MODIS) and Multi-Angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR) sensors on the Earth Observing Satellite (EOS) AM-1 platform operate by comparing measured radiances with tabulated radiances that have been computed for specific <span class="hlt">aerosol</span> models. These <span class="hlt">aerosol</span> models are based almost entirely on surface and/or column averaged measurements and so may not accurately represent the ambient <span class="hlt">aerosol</span> properties. Therefore, to validate these EOS algorithms and to determine the effects of <span class="hlt">aerosols</span> on the clear-sky radiative flux, we have begun to evaluate the vertical variability of ambient <span class="hlt">aerosol</span> properties using the <span class="hlt">aerosol</span> backscattering and extinction profiles measured by the Cloud and Radiation Testbed (CART) and NASA Goddard Space Flight Center (GSFC) Raman Lidars. Using the procedures developed for the GSFC Scanning Raman Lidar (SRL), we have developed and have begun to implement algorithms for the CART Raman Lidar to routinely provide profiles of <span class="hlt">aerosol</span> extinction and backscattering during both nighttime and ,daytime operations. <span class="hlt">Aerosol</span> backscattering and extinction profiles are computed for both lidar systems using data acquired during the 1996 and 1997 Water Vapor Intensive Operating Periods (IOPs). By integrating these <span class="hlt">aerosol</span> extinction profiles, we derive measurements of <span class="hlt">aerosol</span> optical thickness and compare these with coincident sun photometer measurements. We also use these measurements to measure the <span class="hlt">aerosol</span> extinction/backscatter ratio S(sub a) (i.e. 'lidar ratio'). Furthermore, we use the simultaneous water vapor measurements acquired by these Raman lidars to investigate the effects of water vapor on <span class="hlt">aerosol</span> optical properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.A11E0097G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A11E0097G"><span id="translatedtitle">MISR Global <span class="hlt">Aerosol</span> Product Assessment by Comparison with AERONET</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaitley, B. J.; Kahn, R. A.</p> <p>2010-12-01</p> <p>Barbara J. Gaitley1, Ralph Kahn2, 1Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91109; 818-354-0552; 2NASA Goddard Space Flight Center; e-mail: barbara.gaitley@jpl.nasa.gov As a further step in validating the NASA Earth Observing System Terra satellite’s Multi-angle <span class="hlt">Imaging</span> SpectroRadiometer (MISR) <span class="hlt">aerosol</span> products, an extensive statistical comparison between MISR optical depth and Angstrom exponent and <span class="hlt">Aerosol</span> Robotic Network (AERONET) retrievals has been completed. Angstrom exponent was interpreted in terms of components and mixtures used by the retrieval algorithm. Specific examples illustrating the analysis approach will be shown. Eight years of data from 81 geographically diverse sites having good long-term measurement records were first stratified based on locations where six broad <span class="hlt">aerosol</span> air mass type categories are likely to occur: maritime, biomass burning, desert dust, urban pollution, continental and mixed dust+smoke <span class="hlt">aerosols</span>. The number of actual coincident measurements was constrained by requiring that the AERONET direct sun <span class="hlt">aerosol</span> optical depth (AOD) data was obtained within a two-hour window centered on the MISR overpass time. 5156 coincident observations are included in this AOD data set. AERONET direct sun data were averaged over the measurements obtained within this window, and were then interpolated to the MISR characteristic wavelengths to facilitate comparison. All AERONET measurements are Level 2.0, Version 2 data. A previous, systematic comparison of MISR and AERONET <span class="hlt">aerosol</span> optical depth data [Kahn, Gaitley et al., JGR 110, 2005] identified specific, suggested improvements to the early post-launch MISR Standard <span class="hlt">Aerosol</span> retrieval algorithms. Most of these suggestions were implemented in the uniformly reprocessed MISR Version 22 <span class="hlt">aerosol</span> products used in the current study. We documented the performance of the current MISR products based on the comparison statistics. For example, agreement between AERONET and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26698808','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26698808"><span id="translatedtitle">Atmospheric <span class="hlt">aerosol</span> monitoring by an elastic Scheimpflug lidar system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mei, Liang; Brydegaard, Mikkel</p> <p>2015-11-30</p> <p>This work demonstrates a new approach - Scheimpflug lidar - for atmospheric <span class="hlt">aerosol</span> monitoring. The atmospheric backscattering echo of a high-power continuous-wave laser diode is received by a Newtonian telescope and recorded by a tilted <span class="hlt">imaging</span> sensor satisfying the Scheimpflug condition. The principles as well as the lidar equation are discussed in details. A Scheimpflug lidar system operating at around 808 nm is developed and employed for continuous atmospheric <span class="hlt">aerosol</span> monitoring at daytime. Localized emission, atmospheric variation, as well as the changes of cloud height are observed from the recorded lidar signals. The extinction coefficient is retrieved according to the slope method for a homogeneous atmosphere. This work opens up new possibilities of using a compact and robust Scheimpflug lidar system for atmospheric <span class="hlt">aerosol</span> remote sensing. PMID:26698808</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016tac..workE..14S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016tac..workE..14S"><span id="translatedtitle"><span class="hlt">Aerosols</span> optical propertites in Titan's Detached Haze Layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seignovert, Benoît; Rannou, Pascal; Lavvas, Panayotis; Cours, Thibaud; West, Robert A.</p> <p>2016-06-01</p> <p>Titan's Detached Haze Layer (DHL) first observed in 1983 by Rages and Pollack during the Voyager 2 [1] is a consistent spherical haze feature surrounding Titan's upper atmosphere and detached from the main haze. Since 2005, the <span class="hlt">Imaging</span> Science Subsystem (ISS) instrument on board the Cassini mission performs a continuous survey of the Titan's atmosphere and confirmed its persistence at 500 km up to the equinox (2009) before its drop and disappearance in 2012 [2]. Previous analyses showed, that this layer corresponds to the transition area between small spherical <span class="hlt">aerosols</span> and large fractal aggregates and play a key role in the <span class="hlt">aerosols</span> formation in Titan's atmosphere [3-5]. In this study we perform UV photometric analyses on ISS observations taken from 2005 to 2007 based on radiative transfer inversion to retrieve <span class="hlt">aerosols</span> particles properties in the DHL (bulk and monomer size, fractal dimension and local density).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Icar..226..159Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Icar..226..159Z"><span id="translatedtitle">Stratospheric <span class="hlt">aerosols</span> on Jupiter from Cassini observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, X.; West, R. A.; Banfield, D.; Yung, Y. L.</p> <p>2013-09-01</p> <p>We retrieved global distributions and optical properties of stratospheric <span class="hlt">aerosols</span> on Jupiter from ground-based NIR spectra and multiple-phase-angle <span class="hlt">images</span> from Cassini <span class="hlt">Imaging</span> Science Subsystem (ISS). A high-latitude haze layer is located at ∼10-20 mbar, higher than in the middle and low latitudes (∼50 mbar). Compact sub-micron particles are mainly located in the low latitudes between 40°S and 25°N with the particle radius between 0.2 and 0.5 μm. The rest of the stratosphere is covered by the particles known as fractal aggregates. In the nominal case with the imaginary part of the UV refractive index 0.02, the fractal aggregates are composed of about a thousand 10-nm-size monomers. The column density of the <span class="hlt">aerosols</span> at pressure less than 100 mbar ranges from ∼107 cm-2 at low latitudes to ∼109 cm-2 at high latitudes. The mass loading of <span class="hlt">aerosols</span> in the stratosphere is ∼10-6 g cm-2 at low latitudes to ∼10-4 g cm-2 in the high latitudes. Multiple solutions due to the uncertainty of the imaginary part of the refractive index are discussed. The stratospheric haze optical depths increase from ∼0.03 at low latitudes to about a few at high latitudes in the UV wavelength (∼0.26 μm), and from ∼0.03 at low latitudes to ∼0.1 at high latitudes in the NIR wavelength (∼0.9 μm).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22486582','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22486582"><span id="translatedtitle">SU-C-201-03: Coded Aperture Gamma-Ray <span class="hlt">Imaging</span> Using Pixelated Semiconductor Detectors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Joshi, S; Kaye, W; Jaworski, J; He, Z</p> <p>2015-06-15</p> <p>Purpose: Improved localization of gamma-ray emissions from radiotracers is essential to the progress of nuclear medicine. Polaris is a portable, room-temperature operated gamma-ray <span class="hlt">imaging</span> spectrometer composed of two 3×3 arrays of thick CdZnTe (CZT) detectors, which detect gammas between 30keV and 3MeV with energy resolution of <1% FWHM at 662keV. Compton <span class="hlt">imaging</span> is used to map out source distributions in 4-pi space; however, is only effective above 300keV where Compton scatter is dominant. This work extends <span class="hlt">imaging</span> to photoelectric energies (<300keV) using coded aperture <span class="hlt">imaging</span> (<span class="hlt">CAI</span>), which is essential for localization of Tc-99m (140keV). Methods: <span class="hlt">CAI</span>, similar to the pinhole camera, relies on an attenuating mask, with open/closed elements, placed between the source and position-sensitive detectors. Partial attenuation of the source results in a “shadow” or count distribution that closely matches a portion of the mask pattern. Ideally, each source direction corresponds to a unique count distribution. Using backprojection reconstruction, the source direction is determined within the field of view. The knowledge of 3D position of interaction results in improved <span class="hlt">image</span> quality. Results: Using a single array of detectors, a coded aperture mask, and multiple Co-57 (122keV) point sources, <span class="hlt">image</span> reconstruction is performed in real-time, on an event-by-event basis, resulting in <span class="hlt">images</span> with an angular resolution of ∼6 degrees. Although material nonuniformities contribute to <span class="hlt">image</span> degradation, the superposition of <span class="hlt">images</span> from individual detectors results in improved SNR. <span class="hlt">CAI</span> was integrated with Compton <span class="hlt">imaging</span> for a seamless transition between energy regimes. Conclusion: For the first time, <span class="hlt">CAI</span> has been applied to thick, 3D position sensitive CZT detectors. Real-time, combined <span class="hlt">CAI</span> and Compton <span class="hlt">imaging</span> is performed using two 3×3 detector arrays, resulting in a source distribution in space. This system has been commercialized by H3D, Inc. and is being acquired for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A41D0086C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A41D0086C"><span id="translatedtitle">Evidence for a Glaciation <span class="hlt">Aerosol</span> Indirect Effect from Ship Tracks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Christensen, M.; Suzuki, K.; Stephens, G. L.</p> <p>2013-12-01</p> <p>Ship tracks are a prominent manifestation of the <span class="hlt">aerosol</span> indirect effect that provides a unique opportunity to study <span class="hlt">aerosol</span> interactions in both warm and mixed-phase clouds. While ample evidence supports that an increase in <span class="hlt">aerosol</span> concentration generally suppresses warm phase precipitation leading to longer cloud lifetime and more reflected sunlight (Albrecht, 1989) there is less understood about these effects in mixed-phase clouds. Lohmann, (2002) propose that an increase in IN (Ice Nuclei) may cause a glaciation indirect effect which results in more frequent glaciation of super-cooled droplets via the Bergeron process thereby increasing the amount of precipitation, which could decrease cloud cover, cloud longevity, and reflected sunlight. In this study, over 200 ship tracks are identified in mixed phase clouds using MODIS (MODerate resolution <span class="hlt">Imaging</span> Spectroradiometer) imagery. Retrievals of the ice phase are obtained using CALIPSO (Cloud-<span class="hlt">Aerosol</span> Lidar and Infrared Pathfinder Satellite Observations). These measurements provide evidence that glaciation is more frequent in polluted clouds compared to the unpolluted clouds that lie adjacent to ship tracks. Larger ice fractions may result from the increased IN emitted from the ship or by other processes (e.g., immersion/contact freezing) that lead to faster ice multiplication in polluted clouds with smaller and more numerous supercooled droplets. Observations from the profiling radar on CloudSat show that <span class="hlt">aerosol</span> suppresses warm phase precipitation but enhances the cold phase precipitation. For mixed-phase clouds, these differences roughly cancel resulting in small changes in precipitation between polluted and unpolluted clouds. When cloud tops are warm, <span class="hlt">aerosol</span> decreases precipitation rates and cloud water paths due to the entrainment effect but the differences in cloud water amount are considerably smaller than those found in cold phase clouds. These results provide the first glance of ship tracks in mixed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5571...30V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5571...30V"><span id="translatedtitle">Cloud and <span class="hlt">aerosol</span> studies using combined CPL and MAS data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vaughan, Mark A.; Rodier, Sharon; Hu, Yongxiang; McGill, Matthew J.; Holz, Robert E.</p> <p>2004-11-01</p> <p>Current uncertainties in the role of <span class="hlt">aerosols</span> and clouds in the Earth's climate system limit our abilities to model the climate system and predict climate change. These limitations are due primarily to difficulties of adequately measuring <span class="hlt">aerosols</span> and clouds on a global scale. The A-train satellites (Aqua, CALIPSO, CloudSat, PARASOL, and Aura) will provide an unprecedented opportunity to address these uncertainties. The various active and passive sensors of the A-train will use a variety of measurement techniques to provide comprehensive observations of the multi-dimensional properties of clouds and <span class="hlt">aerosols</span>. However, to fully achieve the potential of this ensemble requires a robust data analysis framework to optimally and efficiently map these individual measurements into a comprehensive set of cloud and <span class="hlt">aerosol</span> physical properties. In this work we introduce the Multi-Instrument Data Analysis and Synthesis (MIDAS) project, whose goal is to develop a suite of physically sound and computationally efficient algorithms that will combine active and passive remote sensing data in order to produce improved assessments of <span class="hlt">aerosol</span> and cloud radiative and microphysical properties. These algorithms include (a) the development of an intelligent feature detection algorithm that combines inputs from both active and passive sensors, and (b) identifying recognizable multi-instrument signatures related to <span class="hlt">aerosol</span> and cloud type derived from clusters of <span class="hlt">image</span> pixels and the associated vertical profile information. Classification of these signatures will lead to the automated identification of <span class="hlt">aerosol</span> and cloud types. Testing of these new algorithms is done using currently existing and readily available active and passive measurements from the Cloud Physics Lidar and the MODIS Airborne Simulator, which simulate, respectively, the CALIPSO and MODIS A-train instruments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.A23Q..07M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.A23Q..07M&link_type=ABSTRACT"><span id="translatedtitle">Novel Measurements of <span class="hlt">Aerosol</span> Particle Interfaces Using Biphasic Microfluidics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Metcalf, A. R.; Dutcher, C. S.</p> <p>2014-12-01</p> <p>Secondary organic <span class="hlt">aerosol</span> (SOA) particles are nearly ubiquitous in the atmosphere and yet there remains large uncertainties in their formation processes and ambient properties. These particles are complex microenvironments, which can contain multiple interfaces due to internal aqueous-organic phase partitioning and to the external liquid-vapor surface. These <span class="hlt">aerosol</span> interfaces can profoundly affect the fate of condensable organic compounds emitted into the atmosphere by altering the way in which organic vapors interact with the ambient <span class="hlt">aerosol</span>. <span class="hlt">Aerosol</span> interfaces affect particle internal structure, species uptake, equilibrium partitioning, activation to cloud condensation or ice nuclei, and optical properties. For example, organic thin films can shield the core of the <span class="hlt">aerosol</span> from the ambient environment, which may disrupt equilibrium partitioning and mass transfer. To improve our ability to accurately predict the fate of SOA in the atmosphere, we must improve our knowledge of <span class="hlt">aerosol</span> interfaces and their interactions with the ambient environment. Few technologies exist to accurately probe <span class="hlt">aerosol</span> interfaces at atmospherically-relevant conditions. In this talk, a novel method using biphasic microscale flows will be introduced for generating, trapping, and perturbing complex interfaces at atmospherically relevant conditions. These microfluidic experiments utilize high-speed <span class="hlt">imaging</span> to monitor interfacial phenomena at the microscale and are performed with phase contrast and fluorescence microscopy on a temperature-controlled inverted microscope stage. From these experiments, interfacial thermodynamic properties such as surface tension, rheological properties such as interfacial moduli, and kinetic properties such as mass transfer coefficients can be measured or inferred. Chemical compositions of the liquid phases studied here span a range of viscosities and include electrolyte and water soluble organic acid species often observed in the atmosphere, such as mixtures</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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