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Sample records for advanced land observation

  1. Spectroradiometric considerations for advanced land observing systems

    NASA Technical Reports Server (NTRS)

    Slater, P. N.

    1986-01-01

    Research aimed at improving the inflight absolute radiometric calibration of advanced land observing systems was initiated. Emphasis was on the satellite sensor calibration program at White Sands. Topics addressed include: absolute radiometric calibration of advanced remote sensing; atmospheric effects on reflected radiation; inflight radiometric calibration; field radiometric methods for reflectance and atmospheric measurement; and calibration of field relectance radiometers.

  2. Recent advances in land data assimilation for remote sensing observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For a number of decades, remote sensing observations have been used to define static model parameters and/or forcing inputs for a range of land surface models. However, recent advances in remote sensing theory have also enabled the remote retrieval of dynamic land model states (e.g. leaf area inde...

  3. Earth Observing-1 Advanced Land Imager: Radiometric Response Calibration

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.; Lencioni, D. E.; Evans, J. B.

    2000-01-01

    The Advanced Land Imager (ALI) is one of three instruments to be flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). ALI contains a number of innovative features, including a wide field of view optical design, compact multispectral focal plane arrays, non-cryogenic HgCdTe detectors for the short wave infrared bands, and silicon carbide optics. This document outlines the techniques adopted during ground calibration of the radiometric response of the Advanced Land Imager. Results from system level measurements of the instrument response, signal-to-noise ratio, saturation radiance, and dynamic range for all detectors of every spectral band are also presented.

  4. Earth Observing-1 Advanced Land Imager: Dark Current and Noise Characterization and Anomalous Detectors

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.

    2001-01-01

    The dark current and noise characteristics of the Earth Observing-1 Advanced Land Imager measured during ground calibration at MIT Lincoln Laboratory are presented. Data were collected for the nominal focal plane operating temperature of 220 K as well as supplemental operating temperatures (215 and 225 K). Dark current baseline values are provided, and noise characterization includes the evaluation of white, coherent, low frequency, and high frequency components. Finally, anomalous detectors, characterized by unusual dark current, noise, gain, or cross-talk properties are investigated.

  5. Classification of leafy spurge with earth observing-1 advanced land imager

    USGS Publications Warehouse

    Stitt, S.; Root, R.; Brown, K.; Hager, S.; Mladinich, C.; Anderson, G.L.; Dudek, K.; Bustos, M.R.; Kokaly, R.

    2006-01-01

    Leafy spurge (Euphorbia esula L.) is an invasive exotic plant that can completely displace native plant communities. Automated techniques for monitoring the location and extent of leafy spurge, especially if available on a seasonal basis, could add greatly to the effectiveness of control measures. As part of a larger study including multiple sensors, this study examines the utility of mapping the location and extent of leafy spurge in Theodore Roosevelt National Park using Earth Observing-1 satellite Advanced Land Imager (ALI) scanner data. An unsupervised classification methodology was used producing accuracies in the range of 59% to 66%. Existing field studies, with their associated limitations, were used for identifying class membership and accuracy assessment. This sensor could be useful for broad landscape scale mapping of leafy spurge, from which control measures could be based.

  6. Earth Observing-1 Advanced Land Imager: Imaging Performance On-Orbit

    NASA Technical Reports Server (NTRS)

    Hearn, D. R.

    2002-01-01

    This report analyzes the on-orbit imaging performance of the Advanced Land Imager (ALI) on the Earth Observing-1 satellite. The pre-flight calibrations are first summarized. The methods used to reconstruct and geometrically correct the image data from this push-broom sensor are described. The method used here does not refer to the position and attitude telemetry from the spacecraft. Rather, it is assumed that the image of the scene moves across the focal plane with a constant velocity, which can be ascertained from the image data itself. Next, an assortment of the images so reconstructed is presented. Color images sharpened with the 10-m panchromatic band data are shown, and the algorithm for producing them from the 30-m multispectral data is described. The approach taken for assessing spatial resolution is to compare the sharpness of features in the on-orbit image data with profiles predicted on the basis of the pre-flight calibrations. A large assortment of bridge profiles is analyzed, and very good fits to the predicted shapes are obtained. Lunar calibration scans are analyzed to examine the sharpness of the edge-spread function at the limb of the moon. The darkness of the space beyond the limb is better for this purpose than anything that could be simulated on the ground. From these scans, we find clear evidence of scattering in the optical system, as well as some weak ghost images. Scans of planets and stars are also analyzed. Stars are useful point sources of light at all wavelengths, and delineate the point-spread functions of the system. From a quarter-speed scan over the Pleiades, we find that the ALI can detect 6th magnitude stars. The quality of the reconstructed images verifies the capability of the ALI to produce Landsat-type multi spectral data. The signal-to-noise and panchromatic spatial resolution are considerably superior to those of the existing Landsat sensors. The spatial resolution is confirmed to be as good as it was designed to be.

  7. Earth Observing-1 Advanced Land Imager Flight Performance Assessment: Noise and Dark Current Stability During the First Year on Orbit

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.; Gibbs, M. D.

    2002-01-01

    The noise and dark current stability of the Advanced Land Imager during the first year on orbit (November 21, 2000 - November 21, 2001) are presented. Data have been separated into short-term and long-term periods. The analysis of short-term data indicate some SWIR detectors may drift up to ten digital numbers between the pre and post dark observations of a given data collection event. Analysis of long-term data suggest the SWIR dark current has deviated by less than ten digital numbers and some SCA SWIR dark Current have increased by up to 200 digital numbers during the first year on orbit.

  8. Earth Observing-1 Advanced Land Imager Flight Performance Assessment: Absolute Radiometry and Stability During the First Year

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.; Lencioni, D. E.

    2002-01-01

    The absolute radiometry of the Advanced Land Imager during the first year on orbit (November 21,2000 - November 21, 2001) is presented. Results derived from solar, lunar, ground truth, and internal reference lamp measurements are presented. An 18% drop in the radiometric response of the Band 1p data since preflight calibration at Lincoln Laboratory is observed using all techniques. This decrease cannot be accounted for by preflight calibration errors, stray light, or contamination of the focal plane. A slight drooping of the VNIR response toward the blue and a 5-12% increase in the Band 5 response is also apparent in all the data. Radiometric response correction factors have been calculated and preflight calibration coefficients have been updated in order to provide +/- 5% agreement between the measured solar, lunar, and ground truth data and the expected values. The radiometric stability of the ALI during the first year of operation is also presented for each spectral band. Internal reference lamp data indicate the focal plane has been stable to within 1% for bands 1p, 1, 2, 5p, 5, 7, pan and 3% for Bands 3,4, 4p since launch. Solar, lunar, and ground truth measurements indicate the optical train and solar diffuser of the instrument has been stable to within 1% since initial measurements on orbit in late December 2000.

  9. Comparison of Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Earth Observing One (EO-1) Advanced Land Imager

    NASA Technical Reports Server (NTRS)

    Pedelty, Jeffrey A.; Morisette, Jeffrey T.; Smith, James A.

    2004-01-01

    We compare images from the Enhanced Thematic Mapper Plus (ETM+) sensor on Landsat-7 and the Advanced Land Imager (ALI) instrument on Earth Observing One (EO-1) over a test site in Rochester, New York. The site contains a variety of features, ranging from water of varying depths, deciduous/coniferous forest, and grass fields, to urban areas. Nearly coincident cloud-free images were collected one minute apart on 25 August 2001. We also compare images of a forest site near Howland, Maine, that were collected on 7 September, 2001. We atmospherically corrected each pair of images with the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) atmosphere model, using aerosol optical thickness and water vapor column density measured by in situ Cimel sun photometers within the Aerosol Robotic Network (AERONET), along with ozone density derived from the Total Ozone Mapping Spectrometer (TOMS) on the Earth Probe satellite. We present true-color composites from each instrument that show excellent qualitative agreement between the multispectral sensors, along with grey-scale images that demonstrate a significantly improved ALI panchromatic band. We quantitatively compare ALI and ETM+ reflectance spectra of a grassy field in Rochester and find < or equal to 6% differences in the visible/near infrared and approx. 2% differences in the short wave infrared. Spectral comparisons of forest sites in Rochester and Howland yield similar percentage agreement except for band 1, which has very low reflectance. Principal component analyses and comparison of normalized difference vegetation index histograms for each sensor indicate that the ALI is able to reproduce the information content in the ETM+ but with superior signal-to-noise performance due to its increased 12-bit quantization.

  10. Advanced Land Imager Assessment System

    NASA Technical Reports Server (NTRS)

    Chander, Gyanesh; Choate, Mike; Christopherson, Jon; Hollaren, Doug; Morfitt, Ron; Nelson, Jim; Nelson, Shar; Storey, James; Helder, Dennis; Ruggles, Tim; Kaita, Ed; Levy, Raviv; Ong, Lawrence; Markham, Brian; Schweiss, Robert

    2008-01-01

    The Advanced Land Imager Assessment System (ALIAS) supports radiometric and geometric image processing for the Advanced Land Imager (ALI) instrument onboard NASA s Earth Observing-1 (EO-1) satellite. ALIAS consists of two processing subsystems for radiometric and geometric processing of the ALI s multispectral imagery. The radiometric processing subsystem characterizes and corrects, where possible, radiometric qualities including: coherent, impulse; and random noise; signal-to-noise ratios (SNRs); detector operability; gain; bias; saturation levels; striping and banding; and the stability of detector performance. The geometric processing subsystem and analysis capabilities support sensor alignment calibrations, sensor chip assembly (SCA)-to-SCA alignments and band-to-band alignment; and perform geodetic accuracy assessments, modulation transfer function (MTF) characterizations, and image-to-image characterizations. ALIAS also characterizes and corrects band-toband registration, and performs systematic precision and terrain correction of ALI images. This system can geometrically correct, and automatically mosaic, the SCA image strips into a seamless, map-projected image. This system provides a large database, which enables bulk trending for all ALI image data and significant instrument telemetry. Bulk trending consists of two functions: Housekeeping Processing and Bulk Radiometric Processing. The Housekeeping function pulls telemetry and temperature information from the instrument housekeeping files and writes this information to a database for trending. The Bulk Radiometric Processing function writes statistical information from the dark data acquired before and after the Earth imagery and the lamp data to the database for trending. This allows for multi-scene statistical analyses.

  11. Advances in Land Data Assimilation Systems

    NASA Technical Reports Server (NTRS)

    Houser, Paul R.

    2001-01-01

    Assimilation of remotely sensed land surface observations into regional to global scale numerical models have the potential to significantly advance our ability, to assess, understand, and predict surface water, energy, and carbon cycles. This session seeks to assess the state-of-the-art in data assimilation methods for integrating land surface remote sensing and modeling, with a focus on practical applications and techniques. Assimilated land surface variables of interest include (but are not limited to, soil moisture, surface temperature, snowpack, streamflow, vegetation dynamics, and carbon storage. Contributions describing the development of practical land surface data assimilation methods, multivariate land surface data assimilation strategies, evaluation of the required accuracy and resolution of remote sensing observations, the effects of scale, process complexity, and uncertainty on data assimilation, and the optimal treatment of model and observation errors are encouraged.

  12. Advanced Land Observing Satellite (ALOS) Phased Array Type L-Band Synthetic Aperture Radar (PALSAR) mosaic for the Kahiltna terrane, Alaska, 2007-2010

    USGS Publications Warehouse

    Cole, Christopher J.; Johnson, Michaela R.; Graham, Garth E.

    2015-01-01

    The USGS has compiled a continuous, cloud-free 12.5-meter resolution radar mosaic of SAR data of approximately 212,000 square kilometers to examine the suitability of this technology for geologic mapping. This mosaic was created from Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data collected from 2007 to 2010 spanning the Kahiltna terrane and the surrounding area. Interpretation of these data may help geologists understand past geologic processes and identify areas with potential for near-surface mineral resources for further ground-based geological and geochemical investigations.

  13. Urban change detection with polarimetric Advanced Land Observing Satellite phased array type L-band synthetic aperture radar data: a case study of Tai'an, China

    NASA Astrophysics Data System (ADS)

    Xu, Jinyan; Zhang, Lu; Wang, Yong; Wang, He; Liao, Mingsheng

    2013-01-01

    Change detection in Tai'an city of eastern China using a pair of qual-polarimetric Advanced Land Observing Satellite phased array type L-band synthetic aperture radar (ALOS PALSAR) data was studied. The procedures consisted of polarimetric features extraction, optimal polarimetric feature group selection, supervised classification, and result accuracy assessment. Feature extraction from PALSAR data was performed first, and then the polarimetric features were categorized into several groups. Polarimetric optimum index factor (POIF) and distance factor (DF) were selected to measure and evaluate the suitability of each feature group for urban change detection. The best group of features was identified including linear polarization correlation coefficient (ρ), right-left (R-L) circular polarization correlation coefficient (ρ), total power (TP), and cross-polarization isolation (XPI). Afterward, four difference images of the identified features extracted from the two PALSAR data were derived, respectively. Then, the random forest (RF) classifier was employed to perform a supervised classification of the four difference images. Three classes were quantified, including no-change, change from undeveloped area to developed area, and vice versa. The overall accuracy of change detection was about 84% and Cohen's Kappa coefficient was 0.71. Consequently, satisfactory outcomes were obtained in the application of the polarimetric ALOS PALSAR data of moderate resolution in detecting urban land use and land cover type changes.

  14. Advancements in medium and high resolution Earth observation for land-surface imaging: Evolutions, future trends and contributions to sustainable development

    NASA Astrophysics Data System (ADS)

    Ouma, Yashon O.

    2016-01-01

    Technologies for imaging the surface of the Earth, through satellite based Earth observations (EO) have enormously evolved over the past 50 years. The trends are likely to evolve further as the user community increases and their awareness and demands for EO data also increases. In this review paper, a development trend on EO imaging systems is presented with the objective of deriving the evolving patterns for the EO user community. From the review and analysis of medium-to-high resolution EO-based land-surface sensor missions, it is observed that there is a predictive pattern in the EO evolution trends such that every 10-15 years, more sophisticated EO imaging systems with application specific capabilities are seen to emerge. Such new systems, as determined in this review, are likely to comprise of agile and small payload-mass EO land surface imaging satellites with the ability for high velocity data transmission and huge volumes of spatial, spectral, temporal and radiometric resolution data. This availability of data will magnify the phenomenon of "Big Data" in Earth observation. Because of the "Big Data" issue, new computing and processing platforms such as telegeoprocessing and grid-computing are expected to be incorporated in EO data processing and distribution networks. In general, it is observed that the demand for EO is growing exponentially as the application and cost-benefits are being recognized in support of resource management.

  15. Land reclamation: Advances in research technology

    SciTech Connect

    Younos, T.; Diplas, P.; Mostaghimi, S.

    1992-01-01

    Land reclamation encompasses remediation of industrial wasteland, improvement of infertile land for agricultural production, preservation of wetlands, and restoration of disturbed areas. Land reclamation is an integral part of sustainable development which aims to reconcile economic productivity with environmental preservation. During the 1980s, significant progress was achieved in the application of advanced technologies to sustainable development projects. The goal of this international symposium was to serve as a forum to review current research and state-of-the-art technology dealing with various aspects of land reclamation, and provide an opportunity for professional interaction and exchange of information in a multi-disciplinary setting. The scope of the symposium was as broad as the topic itself. The keynote address by Professor John Cairns focused on a systems approach in land restoration projects and challenges facing scientists in global biotic impoverishment. Other topics discussed in ten mechanical sessions included development and applications of computer models, geographic information systems, remote sensing technology, salinity problems, surface and ground water monitoring, reclamation of mine areas, soil amendment methods and impacts, wetland restoration techniques, and land use planning for resource protection.

  16. Radar observations of land breeze fronts.

    NASA Technical Reports Server (NTRS)

    Meyer, J. H.

    1971-01-01

    Description of a radar-observed apparent land breeze front 12 to 14 n mi off the coast of Wallops Island, Va. Accompanying meteorological data show the land breeze at the shore to be a layer of cold air less than 300 ft deep moving seaward at approximately 2 knots. The radar observations show the land breeze vertical frontal surface sloping landward at about 20 deg, with convection over the warm water increasing the layer thickness to 2000 ft near the frontal zone. The radar-observed horizontal frontal surface is a sharp scalloped line echo in the lower 1000 ft, but becomes diffuse above. As the local circulation during daylight hours changes to a sea breeze, the land breeze front recedes toward land and dissipates.

  17. Multispectral satellite observations for arid land studies

    NASA Technical Reports Server (NTRS)

    Choudhury, Bhaskar J.

    1992-01-01

    Multispectral satellite data when properly calibrated and standardized can be used synergistically for a quantitative analysis of processes and surface characteristics, and for quantifying land surface change. Relationships among multispectral satellite data (visible reflectance, surface temperature and polarization difference of microwave emission at 37 GHz frequency) have been used to develop hypotheses concerning the relative sensitivity of these data to varied land surface characteristics, which needs to be verified by field observations. Radiative transfer models have also been developed to understand these multispectral data. Interannual variations of visible reflectance and polarization difference for the period 1982-1986 over the Sahel and the Sudan zones of Africa show a lagged response with respect to the rainfall deficit during recovery from drought, which needs to be understood in terms of biophysical parameters.

  18. Advanced microwave forward model for the land surface data assimilation

    NASA Astrophysics Data System (ADS)

    Park, Chang-Hwan; Pause, Marion; Gayler, Sebastian; Wollschlaeger, Ute; Jackson, Thomas J.; LeDrew, Ellsworth; Behrendt, Andreas; Wulfmeyer, Volker

    2015-04-01

    From local to global scales, microwave remote-sensing techniques can provide temporally and spatially highly resolved observations of land surface properties including soil moisture and temperature as well as the state of vegetation. These variables are critical for agricultural productivity and water resource management. Furthermore, having accurate information of these variables allows us to improve the performances of numerical weather forecasts and climate prediction models. However, it is challenging to translate a measured brightness temperature into the multiple land surface properties because of the inherent inversion problem. In this study, we introduce a novel forward model for microwave remote sensing to resolve this inversion problem and to close the gap between land surface modeling and observations. It is composed of the Noah-MP land surface model as well as new models for the dielectric mixing and the radiative transfer. For developing a realistic forward operator, the land surface model must simulate soil and vegetation processes properly. The Noah-MP land surface model provides an excellent starting point because it contains already a sophisticated soil texture and land cover data set. Soil moisture transport is derived using the Richards equation in combination with a set of soil hydraulic parameters. Vegetation properties are considered using several photosynthesis models with different complexity. The energy balance is closed for the top soil and the vegetation layers. The energy flux becomes more realistic due to including not only the volumetric ratio of land surface properties but also their surface fraction as sub-grid scale information (semitile approach). Dielectric constant is the fundamental link to quantify the land surface properties. Our physical based new dielectric-mixing model is superior to previous calibration and semi-empirical approaches. Furthermore, owing to the consideration of the oversaturated surface dielectric behaviour

  19. Industrial use of land observation satellite systems

    NASA Technical Reports Server (NTRS)

    Henderson, F. B., III

    1984-01-01

    The principal industrial users of land observation satellite systems are the geological industries; oil/gas, mining, and engineering/environmental companies. The primary system used is LANDSAT/MSS. Currently, use is also being made of the limited amounts of SKYLAB photography, SEASAT and SIR-A radar, and the new LANDSAT/TM data available. Although considered experimental, LANDSAT data is now used operationally by several hundred exploration and engineering companies worldwide as a vastly improved geological mapping tool to help direct more expensive geophysical and drilling phases, leading to more efficient decision-making and results. Future needs include global LANDSAT/TM; higher spatial resolution; stereo and radar; improved data handling, processing distribution and archiving systems, and integrated geographical information systems (GIS). For a promising future, governments must provide overall continuity (government and/or private sector) of such systems, insure continued government R and D, and commit to operating internationally under the civil Open Skies policy.

  20. Experimental land observing data system feasibility study

    NASA Technical Reports Server (NTRS)

    Buckley, J. L.; Kraiman, H.

    1982-01-01

    An end-to-end data system to support a Shuttle-based Multispectral Linear Array (MLA) mission in the mid-1980's was defined. The experimental Land Observing System (ELOS) is discussed. A ground system that exploits extensive assets from the LANDSAT-D Program to effectively meet the objectives of the ELOS Mission was defined. The goal of 10 meter pixel precision, the variety of data acquisition capabilities, and the use of Shuttle are key to the mission requirements, Ground mission management functions are met through the use of GSFC's Multi-Satellite Operations Control Center (MSOCC). The MLA Image Generation Facility (MIGF) combines major hardware elements from the Applications Development Data System (ADDS) facility and LANDSAT Assessment System (LAS) with a special purpose MLA interface unit. LANDSAT-D image processing techniques, adapted to MLA characteristics, form the basis for the use of existing software and the definition of new software required.

  1. Cities and Urban Land Use in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Ford, Larry R.

    2000-01-01

    Discusses the cities and urban land use section of the Advanced Placement (AP) human geography course, focusing on the: (1) definitions of urbanism; (2) origin and evolution of cities; (3) functional character of contemporary cities; (4) built environment and social space; and (5) responses to urban growth. (CMK)

  2. A Vision For A Land Observing System

    NASA Astrophysics Data System (ADS)

    Lewis, P.; Gomez-Dans, J.; Disney, M.

    2013-12-01

    In this paper, we argue that the exploitation of EO land surface data for modelling and monitoring would be greatly facilitated by the routine generation of inter- operable low-level surface bidirectional reflectance factor (BRF) products. We consider evidence from a range of ESA, NASA and other products and studies as well as underlying research to outline the features such a processing system might have, and to define initial research priorities.

  3. Advancing Lidar Sensors Technologies for Next Generation Landing Missions

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Hines, Glenn D.; Roback, Vincent E.; Petway, Larry B.; Barnes, Bruce W.; Brewster, Paul F.; Pierrottet, Diego F.; Bulyshev, Alexander

    2015-01-01

    Missions to solar systems bodies must meet increasingly ambitious objectives requiring highly reliable "precision landing", and "hazard avoidance" capabilities. Robotic missions to the Moon and Mars demand landing at pre-designated sites of high scientific value near hazardous terrain features, such as escarpments, craters, slopes, and rocks. Missions aimed at paving the path for colonization of the Moon and human landing on Mars need to execute onboard hazard detection and precision maneuvering to ensure safe landing near previously deployed assets. Asteroid missions require precision rendezvous, identification of the landing or sampling site location, and navigation to the highly dynamic object that may be tumbling at a fast rate. To meet these needs, NASA Langley Research Center (LaRC) has developed a set of advanced lidar sensors under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. These lidar sensors can provide precision measurement of vehicle relative proximity, velocity, and orientation, and high resolution elevation maps of the surface during the descent to the targeted body. Recent flights onboard Morpheus free-flyer vehicle have demonstrated the viability of ALHAT lidar sensors for future landing missions to solar system bodies.

  4. Advances in Satellite Microwave Precipitation Retrieval Algorithms Over Land

    NASA Astrophysics Data System (ADS)

    Wang, N. Y.; You, Y.; Ferraro, R. R.

    2015-12-01

    Precipitation plays a key role in the earth's climate system, particularly in the aspect of its water and energy balance. Satellite microwave (MW) observations of precipitation provide a viable mean to achieve global measurement of precipitation with sufficient sampling density and accuracy. However, accurate precipitation information over land from satellite MW is a challenging problem. The Goddard Profiling Algorithm (GPROF) algorithm for the Global Precipitation Measurement (GPM) is built around the Bayesian formulation (Evans et al., 1995; Kummerow et al., 1996). GPROF uses the likelihood function and the prior probability distribution function to calculate the expected value of precipitation rate, given the observed brightness temperatures. It is particularly convenient to draw samples from a prior PDF from a predefined database of observations or models. GPROF algorithm does not search all database entries but only the subset thought to correspond to the actual observation. The GPM GPROF V1 database focuses on stratification by surface emissivity class, land surface temperature and total precipitable water. However, there is much uncertainty as to what is the optimal information needed to subset the database for different conditions. To this end, we conduct a database stratification study of using National Mosaic and Multi-Sensor Quantitative Precipitation Estimation, Special Sensor Microwave Imager/Sounder (SSMIS) and Advanced Technology Microwave Sounder (ATMS) and reanalysis data from Modern-Era Retrospective Analysis for Research and Applications (MERRA). Our database study (You et al., 2015) shows that environmental factors such as surface elevation, relative humidity, and storm vertical structure and height, and ice thickness can help in stratifying a single large database to smaller and more homogeneous subsets, in which the surface condition and precipitation vertical profiles are similar. It is found that the probability of detection (POD) increases

  5. Radiometric calibration of the EO-1 Advanced Land Imager

    NASA Astrophysics Data System (ADS)

    Mendenhall, Jeffrey A.; Lencioni, Donald E.; Parker, Alexander C.

    1999-09-01

    The radiometric calibration of the Earth Observation 1 Advanced Land Imager (EO-1 ALI) was completed in the Spring of 1999 at Lincoln Laboratory. This calibration was conducted with the ALI as a fully assembled instrument in a thermal vacuum chamber at operation temperatures. The ALI was calibrated radiometrically at the system level from 0 to > 100 percent Earth-equivalent albedo using a combination of internal and external halogen and Xenon lamps attached to a large integrating sphere. Absolute radiometric calibration was achieved by measuring the output of the integrating sphere at each radiance level prior to ALI illumination using a NIST-traceable spectroradiometer. Additional radiometric characterization of this instrument was obtained from data collected using a collimator designed for the spectral calibration of the ALI. In this paper we review the techniques employed during radiometric calibration and present the measured gain, linearity, offset, signal-to- noise ratio and polarization sensitivity of each pixel. The testing result of a novel, in-flight solar calibration technique are also discussed. Finally, the results from a Lincoln Laboratory/Goddard Space Flight Center Landsat transfer radiometric study are presented.

  6. Sharpening advanced land imager multispectral data using a sensor model

    USGS Publications Warehouse

    Lemeshewsky, G.P.

    2005-01-01

    The Advanced Land Imager (ALI) instrument on NASA's Earth Observing One (EO-1) satellite provides for nine spectral bands at 30m ground sample distance (GSD) and a 10m GSD panchromatic band. This report describes an image sharpening technique where the higher spatial resolution information of the panchromatic band is used to increase the spatial resolution of ALI multispectral (MS) data. To preserve the spectral characteristics, this technique combines reported deconvolution deblurring methods for the MS data with highpass filter-based fusion methods for the Pan data. The deblurring process uses the point spread function (PSF) model of the ALI sensor. Information includes calculation of the PSF from pre-launch calibration data. Performance was evaluated using simulated ALI MS data generated by degrading the spatial resolution of high resolution IKONOS satellite MS data. A quantitative measure of performance was the error between sharpened MS data and high resolution reference. This report also compares performance with that of a reported method that includes PSF information. Preliminary results indicate improved sharpening with the method reported here.

  7. Multivariate assimilation of satellite-derived land remote sensing datasets: Advances, gaps and challenges

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Peters-Lidard, C. D.; Mocko, D. M.; Jasinski, M. F.; Reichle, R. H.; Zaitchik, B. F.; Getirana, A.; Rodell, M.; Xia, Y.; Ek, M. B.

    2015-12-01

    Remote sensing advancements in recent years have enabled monitoring of the Earth's land surface with unprecedented scale and frequency. In the past decade, remote sensing observations of the land surface have become available from a number of satellite instruments and platforms including soil moisture (AMSR-E, ASCAT, AMSR2, SMOS, SMAP), snow depth (AMSR-E, AMSR2), snow cover (MODIS, VIIRS), terrestrial water storage (GRACE) and land surface temperature (MODIS, VIIRS, GOES). To support the effective exploitation of the information content of the remote sensing observations, computational tools such as data assimilation are necessary. In this presentation, I will describe the efforts towards the concurrent use of all available remote sensing observations in a multivariate data assimilation configuration in the North American Land Data Assimilation System (NLDAS). Though NLDAS has produced over 34 years (Jan 1979 to present) of hourly land-surface meteorology and surface states using the best-available observations and reanalyses for "off-line" land surface model (LSM) simulations, to-date it has not included the assimilation of relevant hydrological remote sensing datasets. The new phase of NLDAS attempts to bridge this gap by assimilating all land relevant datasets in the NLDAS configuration using the NASA Land Information System (LIS). The results from individually assimilating the soil moisture, snow and terrestrial water storage datasets indicate that improvements can be obtained not only in soil moisture and snow states, but also on evapotranspiration and streamflow estimates. The results from the multivariate, multisensor assimilation of the above-mentioned remote sensing datasets in NLDAS and an evaluation of the resulting improvements and trends in soil moisture, snowpack, evapotranspiration and streamflow will also be presented. Through this talk, I will describe the advances made towards the effective utilization of remote sensing data for hydrologic

  8. Land Surface Microwave Emissivity Dynamics: Observations, Analysis and Modeling

    NASA Technical Reports Server (NTRS)

    Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Kumar, Sujay; Ringerud, Sarah

    2014-01-01

    Land surface microwave emissivity affects remote sensing of both the atmosphere and the land surface. The dynamical behavior of microwave emissivity over a very diverse sample of land surface types is studied. With seven years of satellite measurements from AMSR-E, we identified various dynamical regimes of the land surface emission. In addition, we used two radiative transfer models (RTMs), the Community Radiative Transfer Model (CRTM) and the Community Microwave Emission Modeling Platform (CMEM), to simulate land surface emissivity dynamics. With both CRTM and CMEM coupled to NASA's Land Information System, global-scale land surface microwave emissivities were simulated for five years, and evaluated against AMSR-E observations. It is found that both models have successes and failures over various types of land surfaces. Among them, the desert shows the most consistent underestimates (by approx. 70-80%), due to limitations of the physical models used, and requires a revision in both systems. Other snow-free surface types exhibit various degrees of success and it is expected that parameter tuning can improve their performances.

  9. The Complicate Observations and Multi-Parameter Land Information Constructions on Allied Telemetry Experiment (COMPLICATE)

    PubMed Central

    Tian, Xin; Li, Zengyuan; Chen, Erxue; Liu, Qinhuo; Yan, Guangjian; Wang, Jindi; Niu, Zheng; Zhao, Shaojie; Li, Xin; Pang, Yong; Su, Zhongbo; van der Tol, Christiaan; Liu, Qingwang; Wu, Chaoyang; Xiao, Qing; Yang, Le; Mu, Xihan; Bo, Yanchen; Qu, Yonghua; Zhou, Hongmin; Gao, Shuai; Chai, Linna; Huang, Huaguo; Fan, Wenjie; Li, Shihua; Bai, Junhua; Jiang, Lingmei; Zhou, Ji

    2015-01-01

    The Complicate Observations and Multi-Parameter Land Information Constructions on Allied Telemetry Experiment (COMPLICATE) comprises a network of remote sensing experiments designed to enhance the dynamic analysis and modeling of remotely sensed information for complex land surfaces. Two types of experimental campaigns were established under the framework of COMPLICATE. The first was designed for continuous and elaborate experiments. The experimental strategy helps enhance our understanding of the radiative and scattering mechanisms of soil and vegetation and modeling of remotely sensed information for complex land surfaces. To validate the methodologies and models for dynamic analyses of remote sensing for complex land surfaces, the second campaign consisted of simultaneous satellite-borne, airborne, and ground-based experiments. During field campaigns, several continuous and intensive observations were obtained. Measurements were undertaken to answer key scientific issues, as follows: 1) Determine the characteristics of spatial heterogeneity and the radiative and scattering mechanisms of remote sensing on complex land surfaces. 2) Determine the mechanisms of spatial and temporal scale extensions for remote sensing on complex land surfaces. 3) Determine synergist inversion mechanisms for soil and vegetation parameters using multi-mode remote sensing on complex land surfaces. Here, we introduce the background, the objectives, the experimental designs, the observations and measurements, and the overall advances of COMPLICATE. As a result of the implementation of COMLICATE and for the next several years, we expect to contribute to quantitative remote sensing science and Earth observation techniques. PMID:26332035

  10. Advancing an Information Model for Environmental Observations

    NASA Astrophysics Data System (ADS)

    Horsburgh, J. S.; Aufdenkampe, A. K.; Hooper, R. P.; Lehnert, K. A.; Schreuders, K.; Tarboton, D. G.; Valentine, D. W.; Zaslavsky, I.

    2011-12-01

    have been modified to support data management for the Critical Zone Observatories (CZOs). This paper will present limitations of the existing information model used by the CUAHSI HIS that have been uncovered through its deployment and use, as well as new advances to the information model, including: better representation of both in situ observations from field sensors and observations derived from environmental samples, extensibility in attributes used to describe observations, and observation provenance. These advances have been developed by the HIS team and the broader scientific community and will enable the information model to accommodate and better describe wider classes of environmental observations and to better meet the needs of the hydrologic science and CZO communities.

  11. Applications of Land Surface Temperature from Microwave Observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST) is a key input for physically-based retrieval algorithms of hydrological states and fluxes. Yet, it remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observation...

  12. Battery Carpenter Observation Station, view down from tower stair landing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Battery Carpenter Observation Station, view down from tower stair landing on west side; view northwest - Fort McKinley, Battery Carpenter Observation Station, West side of East Side Drive, approximately 275 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

  13. Advanced Earth Observation System Instrumentation Study (aeosis)

    NASA Technical Reports Server (NTRS)

    White, R.; Grant, F.; Malchow, H.; Walker, B.

    1975-01-01

    Various types of measurements were studied for estimating the orbit and/or attitude of an Earth Observation Satellite. An investigation was made into the use of known ground targets in the earth sensor imagery, in combination with onboard star sightings and/or range and range rate measurements by ground tracking stations or tracking satellites (TDRSS), to estimate satellite attitude, orbital ephemeris, and gyro bias drift. Generalized measurement equations were derived for star measurements with a particular type of star tracker, and for landmark measurements with a multispectral scanner being proposed for an advanced Earth Observation Satellite. The use of infra-red horizon measurements to estimate the attitude and gyro bias drift of a geosynchronous satellite was explored.

  14. Advanced Short Takeoff and Vertical Landing (ASTOVL) Concepts Tested

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In this cooperative program between NASA, Lockheed Corporation, and the Advanced Research and Projects Agency (ARPA), an advanced short takeoff and vertical landing (ASTOVL) model was tested in the 9- by 15-Foot Low-Speed Wind Tunnel at the NASA Lewis Research Center. The 10-percent scaled model was tested over a range of headwind velocities from 25 to 120 kn. This inlet/forebody test was a key part of an important Department of Defense program investigation enabling technologies for future high-performance ASTOVL aircraft. The Lockheed concept is focused on a shaft-coupled lift fan system centered around Pratt & Whitney's F119 power plant. As envisioned, a conventional takeoff and landing version (CTOL) would replace the U.S. Air Force's F-16's. The ASTOVL version would eventually replace Marine and, possibly, British Harrier aircraft. The ASTOVL and CTOL versions are scheduled to begin their manufacturing development phases in 2000. The purpose of this test was to acquire data pertinent to the inlet-forebody model. The test was very successful. Both steady-state and dynamic data were obtained. This small-scale testing, which is directed at reducing risks, may greatly reduce the risks on a full-scale aircraft.

  15. The Cold Land Process Experiment's (CLPX) Local Scale Observation Site

    NASA Astrophysics Data System (ADS)

    Hardy, J. P.; Cline, D.; Elder, K.; Davis, R. E.; Pomeroy, J.; Koh, Y.; Armstrong, R.; Koike, T.; McDonald, K.

    2002-12-01

    The Local Scale Observation Site (LSOS) is the smallest study site of the Cold Land Processes Experiment (CLPX) and is located within the Fraser Meso-cell Study Area (MSA), near the Fraser Experimental Forest Headquarters Facility, in Fraser, Colorado USA. The 100- x 100-m site consists of a small, open field, a managed dense canopy, and an open, mixed age canopy. Unlike the other components of the experiment, which focus on spatial distributions at relatively brief "snapshots" in time, measurements at the local-scale site focused on the temporal domain. Measurements made at the LSOS were designed to produce a comprehensive assessment of the snow, soil, and vegetation characteristics viewed by the ground-based remote sensing instruments. The objective of ground-based microwave remote sensing was to collect time series of active and passive microwave spectral signatures over snow, soil, and forest, coincident with intensive physical characterization of these features. Ground-based remote sensing instruments included Frequency Modulated Continuous Wave (FMCW) radars operating over multiple microwave bandwidths, the Ground-Based Microwave Radiometer (GBMR-7) (Advanced Microwave Scanning Radiometer (AMSR) Simulator; channels 18.7, 23.8, 36.5, and 89.0-GHz), and in 2003, an L/C/X/Ku-band scatterometer radar system. Snow and soil measurements included standard snow physical properties, snow surface roughness, snow depth transects, and soil moisture. The stem and canopy temperature, and xylem flux of several trees within the area, were monitored continuously. Two micrometeorological towers, one located in the open snow area and the other in the forested area, monitored ambient conditions and provided forcing data sets for 1-D snow/soil models. Arrays of radiometers (0.3-3 μm) and a scanning thermal radiometer (8-12 μm) characterized the variability of radiative receipt in the forests. These measurements, together with the ground-based remote sensing, provide the

  16. Earth Observing System (EOS) advanced altimetry

    NASA Technical Reports Server (NTRS)

    Parsons, C. L.; Walsh, E. J.

    1988-01-01

    In the post-TOPEX era, satellite radar altimeters will be developed with the capability of measuring the earth's surface topography over a wide swath of coverage, rather than just at the satellite's nadir. The identification of potential spacecraft flight missions in the future was studied. The best opportunity was found to be the Earth Observing System (EOS). It is felt that an instrument system that has a broad appeal to the earth sciences community stands a much better chance of being selected as an EOS instrument. Consequently, the Topography and Rain Radar Imager (TARRI) will be proposed as a system that has the capability to profile the Earth's topography regardless of the surface type. The horizontal and height resolutions of interest are obviously significantly different over land, ice, and water; but, the use of radar to provide an all-weather observation capability is applicable to the whole earth. The scientific guidance for the design and development of this instrument and the eventual scientific utilization of the data produced by the TARRI will be provided by seven science teams. The teams are formed around scientific disciplines and are titled: Geology/Geophysics, Hydrology/Rain, Oceanography, Ice/Snow, Geodesy/Orbit/Attitude, Cartography, and Surface Properties/Techniques.

  17. Earth Observing System (EOS) advanced altimetry

    NASA Astrophysics Data System (ADS)

    Parsons, C. L.; Walsh, E. J.

    In the post-TOPEX era, satellite radar altimeters will be developed with the capability of measuring the earth's surface topography over a wide swath of coverage, rather than just at the satellite's nadir. The identification of potential spacecraft flight missions in the future was studied. The best opportunity was found to be the Earth Observing System (EOS). It is felt that an instrument system that has a broad appeal to the earth sciences community stands a much better chance of being selected as an EOS instrument. Consequently, the Topography and Rain Radar Imager (TARRI) will be proposed as a system that has the capability to profile the Earth's topography regardless of the surface type. The horizontal and height resolutions of interest are obviously significantly different over land, ice, and water; but, the use of radar to provide an all-weather observation capability is applicable to the whole earth. The scientific guidance for the design and development of this instrument and the eventual scientific utilization of the data produced by the TARRI will be provided by seven science teams. The teams are formed around scientific disciplines and are titled: Geology/Geophysics, Hydrology/Rain, Oceanography, Ice/Snow, Geodesy/Orbit/Attitude, Cartography, and Surface Properties/Techniques.

  18. New Advances in Observations Around the Turbopause

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.; Yuan, T.; Woods, T. N.; Eparvier, F. G.; Sulzer, M. P.; Aponte, N.; Gonzalez, S. A.; Nicolls, M. J.

    2013-12-01

    The aeronomy of the turbopause is rich in both chemistry and physics, but has avoided detailed exploration. In this regime, both neutral and plasma processes coexist and interact but this region, centered around 100 km altitude, is almost unreachable from below or above. Our observational knowledge depends upon remote sensing from either below or above augmented by a smattering of in situ measurements from sounding rockets. A comparison of almost any parameter measured in situ from these sounding rocket flights attests to the complexity, the variability, and above all unexplained aeronomy of the turbopause. In this presentation, three complimentary improvements in remote sensing observations will be discussed focusing on how they contribute to new insights on the aeronomy of the turbopause and its dynamics. The first is the improvement in observation of the solar irradiance obtained from the EVE instrument on the NASA SDO satellite. This measurement, with a cadence of at least 10 seconds, has enabled the E-region's response to solar dynamics to be studied for a first time. Note the E-region lies at or just above the turbopause. A second advancement in experimental technique is the coordination between incoherent scatter radars to observe with altitude resolution of better than 2 km the ionosphere straddling the turbopause--upper D-region and E-region. A third development is the coordination between collocated sodium Lidar and ionosondes to study the dynamics and longer term variability of the metal neutral and metal ion layers that are prevalent around the turbopause.

  19. Observations of land-atmosphere interactions using satellite data

    NASA Astrophysics Data System (ADS)

    Green, Julia; Gentine, Pierre; Konings, Alexandra; Alemohammad, Hamed; Kolassa, Jana

    2016-04-01

    Observations of land-atmosphere interactions using satellite data Julia Green (1), Pierre Gentine (1), Alexandra Konings (1,2), Seyed Hamed Alemohammad (3), Jana Kolassa (4) (1) Columbia University, Earth and Environmental Engineering, NY, NY, USA, (2) Stanford University, Environmental Earth System Science, Stanford, CA, USA, (3) Massachusetts Institute of Technology, Civil and Environmental Engineering, Cambridge, MA, USA, (4) National Aeronautics and Space Administration/Goddard Space Flight Center, Greenbelt, MD, USA. Previous studies of global land-atmosphere hotspots have often relied solely on data from global models with the consequence that they are sensitive to model error. On the other hand, by only analyzing observations, it can be difficult to distinguish causality from mere correlation. In this study, we present a general framework for investigating land-atmosphere interactions using Granger Causality analysis applied to remote sensing data. Based on the near linear relationship between chlorophyll sun induced fluorescence (SIF) and photosynthesis (and thus its relationship with transpiration), we use the GOME-2 fluorescence direct measurements to quantify the surface fluxes between the land and atmosphere. By using SIF data to represent the flux, we bypass the need to use soil moisture data from FLUXNET (limited spatially and temporally) or remote sensing (limited by spatial resolution, canopy interference, measurement depth, and radio frequency interference) thus eliminating additional uncertainty. The Granger Causality analysis allows for the determination of the strength of the two-way causal relationship between SIF and several climatic variables: precipitation, radiation and temperature. We determine that warm regions transitioning from water to energy limitation exhibit strong feedbacks between the land surface and atmosphere due to their high sensitivity to climate and weather variability. Tropical rainforest regions show low magnitudes of

  20. Potential for Landing Gear Noise Reduction on Advanced Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Nickol, Craig L.; Burley, Casey L.; Guo, Yueping

    2016-01-01

    The potential of significantly reducing aircraft landing gear noise is explored for aircraft configurations with engines installed above the wings or the fuselage. An innovative concept is studied that does not alter the main gear assembly itself but does shorten the main strut and integrates the gear in pods whose interior surfaces are treated with acoustic liner. The concept is meant to achieve maximum noise reduction so that main landing gears can be eliminated as a major source of airframe noise. By applying this concept to an aircraft configuration with 2025 entry-into-service technology levels, it is shown that compared to noise levels of current technology, the main gear noise can be reduced by 10 EPNL dB, bringing the main gear noise close to a floor established by other components such as the nose gear. The assessment of the noise reduction potential accounts for design features for the advanced aircraft configuration and includes the effects of local flow velocity in and around the pods, gear noise reflection from the airframe, and reflection and attenuation from acoustic liner treatment on pod surfaces and doors. A technical roadmap for maturing this concept is discussed, and the possible drag increase at cruise due to the addition of the pods is identified as a challenge, which needs to be quantified and minimized possibly with the combination of detailed design and application of drag reduction technologies.

  1. Initial CRISM Observations of the Candidate 2007 Phoenix Landing Sites

    NASA Astrophysics Data System (ADS)

    Seelos, K. D.; Murchie, S.; Arvidson, R. E.; Seelos, F. P.

    2006-12-01

    The Mars Reconnaissance Orbiter (MRO) Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) will acquire multispectral and targeted hyperspectral visible and near infrared data of the candidate Phoenix landing sites during the first few months of primary mission operations (beginning early November). Three 150 x 75 km candidate Phoenix landing sites are located in the high northern plains of Mars within a region from 65-72° N and 120-140° E. Geomorphologic characterization of this region indicates a relatively homogeneous terrain primarily composed of multiple kilometer-scale polygonal plains with superposed degraded craters. At decameter spatial scales, the area is ubiquitously covered by patterned ground in the form of basketball terrain, stripes, and small polygons. Spectral variation of these different types of landforms and materials that are detected by CRISM at 100- or 200-meter scales (multispectral) or ~20-meter scales (targeted hyperspectral) will be analyzed and initial results presented. Implications for Phoenix landing site selection and in situ measurements will also be discussed. CRISM observations along with other MRO data will be critical to the selection of the final landing site prior to launch in August of 2007.

  2. Big Earth observation data analytics for land use and land cover change information

    NASA Astrophysics Data System (ADS)

    Câmara, Gilberto

    2015-04-01

    Current scientific methods for extracting information for Earth observation data lag far behind our capacity to build complex satellites. In response to this challenge, our work explores a new type of knowledge platform to improve the extraction of land use and land cover change information from big Earth Observation data sets. We take a space-time perspective of Earth Observation data, considering that each sensor revisits the same place at regular intervals. Sensor data can, in principle, be calibrated so that observations of the same place in different times are comparable and each measure from a sensor is mapped into a three dimensional array in space-time. To fully enable the use of space-time arrays for working with Earth Observation data, we use the SciDB array database. Arrays naturally fit the data structure of Earth Observation images, breaking the image-as-a-snapshot paradigm. Thus, entire collections of images can be stored as multidimensional arrays. However, array databases do not understand the specific nature of geographical data, and do not capture the meaning and the differences between spatial and temporal dimensions. In our work, we have extended SciDB to include additional information about satellite image metadata, cartographical projections, and time. We are currently developing methods to extract land use and land cover information based on space-time analysis on array databases. Our experiments show these space-time methods give us significant improvements over current space-only remote sensing image processing methods. We have been able to capture tropical forest degradation and forest regrowth and also to distinguish between single-cropping and double-cropping practices in tropical agriculture.

  3. Effect of surface BRDF of various land cover types on geostationary observations of tropospheric NO2

    NASA Astrophysics Data System (ADS)

    Noguchi, K.; Richter, A.; Rozanov, V.; Rozanov, A.; Burrows, J. P.; Irie, H.; Kita, K.

    2014-10-01

    We investigated the effect of surface reflectance anisotropy, bidirectional reflectance distribution function (BRDF), on satellite retrievals of tropospheric NO2. We assume the geometry of geostationary measurements over Tokyo, which is one of the worst air-polluted regions in East Asia. We calculated air mass factors (AMF) and box AMFs (BAMF) for tropospheric NO2 to evaluate the effect of BRDF by using the radiative transfer model SCIATRAN. To model the BRDF effect, we utilized the Moderate Resolution Imaging Spectroradiometer (MODIS) products (MOD43B1 and MOD43B2), which provide three coefficients to express the RossThick-LiSparse reciprocal model, a semi-empirical and kernel-based model of BRDF. Because BRDF depends on the land cover type, we also utilized the High Resolution Land-Use and Land-Cover Map of the Advanced Land Observing Satellite (ALOS)/Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2), which classifies the ground pixels over Tokyo into six main types: water, urban, paddy, crop, deciduous forest, and evergreen forest. We first develop an empirical model of the three BRDF coefficients for each land cover type over Tokyo and then apply the model to the calculation of land-cover-type-dependent AMFs and BAMFs. Results show that the variability of AMF among the land types is up to several tens of percent, and if we neglect the reflectance anisotropy, the difference with AMFs based on BRDF reaches 10% or more. The evaluation of the BAMFs calculated shows that not considering BRDF will cause large errors if the concentration of NO2 is high close to the surface, although the importance of BRDF for AMFs decreases for large aerosol optical depth (AOD).

  4. Observationally based analysis of land-atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Catalano, F.; Alessandri, A.; De Felice, M.; Zhu, Z.; Myneni, R. B.

    2015-10-01

    The variance of soil moisture, vegetation and evapotranspiration over land has been recognized to be strongly connected to the variance of precipitation. However, the feedbacks and couplings between these variables are still not well understood and quantified. Furthermore, soil moisture and vegetation processes are associated to a memory and therefore they may have important implications for predictability. In this study we apply a generalized linear method, specifically designed to assess the reciprocal forcing between connected fields, to the latest available observational datasets of global precipitation, evapotranspiration, vegetation and soil moisture content. For the first time a long global observational dataset is used to investigate the spatial and temporal land variability and to characterize the relationships and feedbacks between land and precipitation. The variables considered show a significant coupling among each other. The analysis of the response of precipitation to soil moisture evidences a robust coupling between these two variables. In particular, the first two modes of variability of the precipitation forced by soil moisture appear to have a strong link with volcanic eruptions and ENSO cycles, respectively, and these links are modulated by the effects of evapotranspiration and vegetation. It is suggested that vegetation state and soil moisture provide a biophysical memory of ENSO and major volcanic eruptions, revealed through delayed feedbacks on rainfall patterns. The third mode of variability reveals a trend very similar to the trend of the inter-hemispheric contrast in SST and appears to be connected to greening/browning trends of vegetation over the last three decades.

  5. A role for AVIRIS in the Landsat and Advanced Land Remote Sensing Systems program

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Simmonds, John J.

    1993-01-01

    As a calibrated imaging spectrometer flying at a 20 km altitude, AVIRIS may contribute to the Landsat and the Advanced Land Remote Sensing System efforts. These contributions come in the areas of: (1) on-orbit calibration, (2) specification of new spectral bands, (3) validation of algorithms, and (4) investigation of an imaging spectrometer of the Advanced Land Remote Sensing System.

  6. Role of the advanced IR sounder in land surface remote sensing

    NASA Astrophysics Data System (ADS)

    Knuteson, Robert O.

    2005-09-01

    A new era of Earth remote sensing began with the launch of the NASA EOS Aqua platform with the Atmospheric InfraRed Sounder (AIRS) in May 2002. The EOS AIRS instrument is the first in a series of high spectral resolution infrared spectrometers that will allow improved characterization of the global atmospheric temperature and water vapor structure. Follow-on operational sensors with similar sounding capability include the Cross-track InfraRed Sounder (CrIS) on the NPP/NPOESS satellites and the Infrared Advanced Sounding Interferometer (IASI) on the European METOP series. These so-called advanced infrared sounders will have a vital role to play in the remote sensing of land ecosystems. This paper describes how the use of Advanced IR Sounder data can be used to improve the accuracy of atmospheric corrections in the thermal IR and provide detailed information on the spectral dependence of the infrared land surface emissivity. Radiance observations from AIRS have been obtained over a large, uniform sandy desert region in the Libyan Desert suitable for evaluation of the 15-km footprints of the NASA AIRS advanced sounder. Analysis of this data indicates a spectral contrast of more than 30% between 12 mm and 9 mm in the surface infrared emissivity due to the presence of the mineral quartz with somewhat smaller contrast at 4 mm. Results of a method for separation of infrared surface emissivity and effective surface skin temperature are presented also.

  7. Investigating Land Memory Characteristics Using Observations and Modeling

    NASA Astrophysics Data System (ADS)

    Amenu, G. G.; Kumar, P.

    2004-12-01

    It has been speculated that understanding land memory dynamics may provide a basis for hydrologic and climate prediction at seasonal to longer time-scales. In this study the characteristics of land memory are explored using observed soil-moisture data from the Illinois Climate Network stations and corresponding simulated soil temperature. The soil moisture data is observed for 11 layers from the surface to a depth of 2 meters and spans 23 years, 1981 to 2003. The soil temperature profile is obtained using the numerical solution of the heat transfer equation, constrained by observed soil-moisture, and driven by observed surface variables which include air temperature, relative humidity, solar radiation, wind speed, and snow depth. Spatio-temporal variability of soil moisture and soil temperature with depth is explored. Depth-wise variability of the magnitudes of amplitude, phase-lag, and temporal scales are quantified for both soil moisture and soil temperature. Dominant signals are identified using spectral analysis techniques and their variability with depth is investigated. Linkage between the inter-annual signals of soil moisture, soil temperature, and ENSO is explored. Further, the sensitivity of surface temperature and surface energy fluxes to the variability of soil moisture at different depths is demonstrated.

  8. Experimental and analytical studies of advanced air cushion landing systems

    NASA Technical Reports Server (NTRS)

    Lee, E. G. S.; Boghani, A. B.; Captain, K. M.; Rutishauser, H. J.; Farley, H. L.; Fish, R. B.; Jeffcoat, R. L.

    1981-01-01

    Several concepts are developed for air cushion landing systems (ACLS) which have the potential for improving performance characteristics (roll stiffness, heave damping, and trunk flutter), and reducing fabrication cost and complexity. After an initial screening, the following five concepts were evaluated in detail: damped trunk, filled trunk, compartmented trunk, segmented trunk, and roll feedback control. The evaluation was based on tests performed on scale models. An ACLS dynamic simulation developed earlier is updated so that it can be used to predict the performance of full-scale ACLS incorporating these refinements. The simulation was validated through scale-model tests. A full-scale ACLS based on the segmented trunk concept was fabricated and installed on the NASA ACLS test vehicle, where it is used to support advanced system development. A geometrically-scaled model (one third full scale) of the NASA test vehicle was fabricated and tested. This model, evaluated by means of a series of static and dynamic tests, is used to investigate scaling relationships between reduced and full-scale models. The analytical model developed earlier is applied to simulate both the one third scale and the full scale response.

  9. Contextualizing the global relevance of local land change observations

    NASA Astrophysics Data System (ADS)

    Magliocca, N. R.; Ellis, E. C.; Oates, T.; Schmill, M.

    2014-02-01

    To understand global changes in the Earth system, scientists must generalize globally from observations made locally and regionally. In land change science (LCS), local field-based observations are costly and time consuming, and generally obtained by researchers working at disparate local and regional case-study sites chosen for different reasons. As a result, global synthesis efforts in LCS tend to be based on non-statistical inferences subject to geographic biases stemming from data limitations and fragmentation. Thus, a fundamental challenge is the production of generalized knowledge that links evidence of the causes and consequences of local land change to global patterns and vice versa. The GLOBE system was designed to meet this challenge. GLOBE aims to transform global change science by enabling new scientific workflows based on statistically robust, globally relevant integration of local and regional observations using an online social-computational and geovisualization system. Consistent with the goals of Digital Earth, GLOBE has the capability to assess the global relevance of local case-study findings within the context of over 50 global biophysical, land-use, climate, and socio-economic datasets. We demonstrate the implementation of one such assessment - a representativeness analysis - with a recently published meta-study of changes in swidden agriculture in tropical forests. The analysis provides a standardized indicator to judge the global representativeness of the trends reported in the meta-study, and a geovisualization is presented that highlights areas for which sampling efforts can be reduced and those in need of further study. GLOBE will enable researchers and institutions to rapidly share, compare, and synthesize local and regional studies within the global context, as well as contributing to the larger goal of creating a Digital Earth.

  10. Who launched what, when and why; trends in global land-cover observation capacity from civilian earth observation satellites

    NASA Astrophysics Data System (ADS)

    Belward, Alan S.; Skøien, Jon O.

    2015-05-01

    This paper presents a compendium of satellites under civilian and/or commercial control with the potential to gather global land-cover observations. From this we show that a growing number of sovereign states are acquiring capacity for space based land-cover observations and show how geopolitical patterns of ownership are changing. We discuss how the number of satellites flying at any time has progressed as a function of increased launch rates and mission longevity, and how the spatial resolutions of the data they collect has evolved. The first such satellite was launched by the USA in 1972. Since then government and/or private entities in 33 other sovereign states and geopolitical groups have chosen to finance such missions and 197 individual satellites with a global land-cover observing capacity have been successfully launched. Of these 98 were still operating at the end of 2013. Since the 1970s the number of such missions failing within 3 years of launch has dropped from around 60% to less than 20%, the average operational life of a mission has almost tripled, increasing from 3.3 years in the 1970s to 8.6 years (and still lengthening), the average number of satellites launched per-year/per-decade has increased from 2 to 12 and spatial resolution increased from around 80 m to less than 1 m multispectral and less than half a meter for panchromatic; synthetic aperture radar resolution has also fallen, from 25 m in the 1970s to 1 m post 2007. More people in more countries have access to data from global land-cover observing spaceborne missions at a greater range of spatial resolutions than ever before. We provide a compendium of such missions, analyze the changes and shows how innovation, the need for secure data-supply, national pride, falling costs and technological advances may underpin the trends we document.

  11. Observationally based analysis of land-atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Catalano, Franco; Alessandri, Andrea; De Felice, Matteo; Zhu, Zaichun; Myneni, Ranga B.

    2016-03-01

    The temporal variance of soil moisture, vegetation and evapotranspiration over land has been recognized to be strongly connected to the temporal variance of precipitation. However, the feedbacks and couplings between these variables are still not well understood and quantified. Furthermore, soil moisture and vegetation processes are associated with a memory and therefore they may have important implications for predictability. In this study we apply a generalized linear method, specifically designed to assess the reciprocal forcing between connected fields, to the latest available observational data sets of global precipitation, evapotranspiration, vegetation and soil moisture content. For the first time a long global observational data set is used to investigate the spatial and temporal land variability and to characterize the relationships and feedbacks between land and precipitation. The variables considered show a significant coupling among each other. The analysis of the response of precipitation to soil moisture evidences a robust coupling between these two variables. In particular, the first two modes of variability in the precipitation forced by soil moisture appear to have a strong link with volcanic eruptions and El Niño-Southern Oscillation (ENSO) cycles, respectively, and these links are modulated by the effects of evapotranspiration and vegetation. It is suggested that vegetation state and soil moisture provide a biophysical memory of ENSO and major volcanic eruptions, revealed through delayed feedbacks on rainfall patterns. The third mode of variability reveals a trend very similar to the trend of the inter-hemispheric contrast in sea surface temperature (SST) and appears to be connected to greening/browning trends of vegetation over the last three decades.

  12. Technology needs of advanced Earth observation spacecraft

    NASA Technical Reports Server (NTRS)

    Herbert, J. J.; Postuchow, J. R.; Schartel, W. A.

    1984-01-01

    Remote sensing missions were synthesized which could contribute significantly to the understanding of global environmental parameters. Instruments capable of sensing important land and sea parameters are combined with a large antenna designed to passively quantify surface emitted radiation at several wavelengths. A conceptual design for this large deployable antenna was developed. All subsystems required to make the antenna an autonomous spacecraft were conceptually designed. The entire package, including necessary orbit transfer propulsion, is folded to package within the Space Transportation System (STS) cargo bay. After separation, the antenna, its integral feed mast, radiometer receivers, power system, and other instruments are automatically deployed and transferred to the operational orbit. The design resulted in an antenna with a major antenna dimension of 120 meters, weighing 7650 kilograms, and operating at an altitude of 700 kilometers.

  13. A framework for the specification of modeling and observation uncertainties for land data assimilation of remote sensing retrievals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent advances in the development of sequential land data assimilation techniques have demonstrated that remote sensing observations of surface soil moisture can improve the dynamic representation of root-zone soil moisture in hydrologic models. However, much of the available evidence is based on ...

  14. Observation of Parametric Instability in Advanced LIGO.

    PubMed

    Evans, Matthew; Gras, Slawek; Fritschel, Peter; Miller, John; Barsotti, Lisa; Martynov, Denis; Brooks, Aidan; Coyne, Dennis; Abbott, Rich; Adhikari, Rana X; Arai, Koji; Bork, Rolf; Kells, Bill; Rollins, Jameson; Smith-Lefebvre, Nicolas; Vajente, Gabriele; Yamamoto, Hiroaki; Adams, Carl; Aston, Stuart; Betzweiser, Joseph; Frolov, Valera; Mullavey, Adam; Pele, Arnaud; Romie, Janeen; Thomas, Michael; Thorne, Keith; Dwyer, Sheila; Izumi, Kiwamu; Kawabe, Keita; Sigg, Daniel; Derosa, Ryan; Effler, Anamaria; Kokeyama, Keiko; Ballmer, Stefan; Massinger, Thomas J; Staley, Alexa; Heinze, Matthew; Mueller, Chris; Grote, Hartmut; Ward, Robert; King, Eleanor; Blair, David; Ju, Li; Zhao, Chunnong

    2015-04-24

    Parametric instabilities have long been studied as a potentially limiting effect in high-power interferometric gravitational wave detectors. Until now, however, these instabilities have never been observed in a kilometer-scale interferometer. In this Letter, we describe the first observation of parametric instability in a gravitational wave detector, and the means by which it has been removed as a barrier to progress. PMID:25955042

  15. A flexible approach to an Operational Land Observing System

    NASA Technical Reports Server (NTRS)

    Driver, J. M.

    1981-01-01

    This paper presents a concept for an Operational Land Observing System (OLOS) formulated to satisfy a broad spectrum of perceived user needs for a diverse discipline community. The concept formulated will allow continuous orthographic imaging across multiple spectral bands, near-global stereoscopic imaging, and next-day oblique imaging of any desired spot on earth. Imaging parameters will be adaptable to known phenomena characteristics to facilitate information extraction including optional onboard theme selection. The conceptual system will provide 6- to 12-hour quick-look capability, 48-hour turnaround on all standard imaging products, and a guaranteed data flow schedule reliability for 10 to 20 years. A fleet of successive operational satellites will be used.

  16. Characterizing user requirements for future land observing satellites

    NASA Technical Reports Server (NTRS)

    Barker, J. L.; Cressy, P. J.; Schnetzler, C. C.; Salomonson, V. V.

    1981-01-01

    The objective procedure was developed for identifying probable sensor and mission characteristics for an operational satellite land observing system. Requirements were systematically compiled, quantified and scored by type of use, from surveys of federal, state, local and private communities. Incremental percent increases in expected value of data were estimated for critical system improvements. Comparisons with costs permitted selection of a probable sensor system, from a set of 11 options, with the following characteristics: 30 meter spatial resolution in 5 bands and 15 meters in 1 band, spectral bands nominally at Thematic Mapper (TM) bands 1 through 6 positions, and 2 day data turn around for receipt of imagery. Improvements are suggested for both the form of questions and the procedures for analysis of future surveys in order to provide a more quantitatively precise definition of sensor and mission requirements.

  17. An Earth Observation Land Data Assimilation System (EO-LDAS)

    NASA Astrophysics Data System (ADS)

    Gomez-Dans, Jose; Lewis, Philip; Quaife, Tristan; Kaminski, Tomas; Styles, Jon

    2013-04-01

    In order to monitor the land surface, EO data provides the means of achieving global coverage in a timely fashion. Different sensors orbit the Earth acquiring data at different times and with different spectral and spatial properties. Blending all these observations presents a considerable challenge. Purely statistical methods based on machine learning techniques require accurate and extensive ground truth for "training" models. The complexities of the processes that take place in the scene result in limited usefulness of these models outside their training region or period. Models that describe the physical processes that give rise to the measurements, based on radiative transfer theory, offer a more robust way of interpreting the recorded data and relating it to surface properties such as leaf area index, chlorophyll concentration, etc. Unfortunately, the information content in the signals is rarely sufficient to unambigously determine the many parameters that are required in typical radiative transfer models. To improve on this, the use of prior information is required. Typically, this information is given as parameter ranges, or maybe even distributions, which can have a positive effect in the so-called "inverse problem". Data assimilation techniques allow one to use models of the land surface as priors, to constrain the inverse problem. These models can be very useful in improving the ability of inverting the observations, as the models can give very valuable information on the dynamics of some parameters, like LAI. However, some parameters that have a strong bearing on the observations (some pigments, leaf angle distributions...) have no analogues in typical DGVMs. In this work, we introduce and demonstrate the use of weak constraint 4DVAR data assimilation to the problem of inverting optical RT models. We demonstrate that the use of this technique results in important gains in parameter uncertainty reduction for a typical satellite mission, including

  18. Development of Advanced Earth Observing Satellite (ADEOS)

    NASA Astrophysics Data System (ADS)

    Tsuzuki, Toshiyuki; Iwasaki, Nobuo; Hara, Norikazu

    ADEOS ia a large satellite which could be called a polar orbiting platform. The weight is 3.5 tons and power is 4.5 KW at the end of three years of mission life. It is scheduled to be launched in early 1995 by the H-II launch vehicle from Tanegashima Space Center. ADEOS carries two core sensors and six Announcement Opportunity (AO) sensors. The core sensors are called the Ocean Color and Temperature Scanner (OCTS) and the Advanced Visible and Near Infrared Radiometer (ANVIR), which are being developed by NASDA. The AO sensors are the NASA Scatterometer (NSCAT), the NASA Total Ozone Mapping Spectrometer (TOMS), the Polarization and Directionality of Earth's Reflectances of CNES, the Interferometric Monitor for Greenhouse gases of MITI, the Improved Limb Atmospheric Spectrometer of Environment Agency (EA) of the Japanese government, and the EA Retroreflector In Space. This paper discusses the present status of the design and development of ADEOS putting emphasis on several features incorporated in the ADEOS bus system and several issues imposed at the system Preliminary Design Review.

  19. Advanced Diagnostic System on Earth Observing One

    NASA Technical Reports Server (NTRS)

    Hayden, Sandra C.; Sweet, Adam J.; Christa, Scott E.; Tran, Daniel; Shulman, Seth

    2004-01-01

    In this infusion experiment, the Livingstone 2 (L2) model-based diagnosis engine, developed by the Computational Sciences division at NASA Ames Research Center, has been uploaded to the Earth Observing One (EO-1) satellite. L2 is integrated with the Autonomous Sciencecraft Experiment (ASE) which provides an on-board planning capability and a software bridge to the spacecraft's 1773 data bus. Using a model of the spacecraft subsystems, L2 predicts nominal state transitions initiated by control commands, monitors the spacecraft sensors, and, in the case of failure, isolates the fault based on the discrepant observations. Fault detection and isolation is done by determining a set of component modes, including most likely failures, which satisfy the current observations. All mode transitions and diagnoses are telemetered to the ground for analysis. The initial L2 model is scoped to EO-1's imaging instruments and solid state recorder. Diagnostic scenarios for EO-1's nominal imaging timeline are demonstrated by injecting simulated faults on-board the spacecraft. The solid state recorder stores the science images and also hosts: the experiment software. The main objective of the experiment is to mature the L2 technology to Technology Readiness Level (TRL) 7. Experiment results are presented, as well as a discussion of the challenging technical issues encountered. Future extensions may explore coordination with the planner, and model-based ground operations.

  20. Advances in Lunar Science and Observational Opportunities

    NASA Technical Reports Server (NTRS)

    Heldmann, Jennifer

    2012-01-01

    Lunar science is currently undergoing a renaissance as our understanding of our Moon continues to evolve given new data from multiple lunar mission and new analyses. This talk will overview NASA's recent and future lunar missions to explain the scientific questions addressed by missions such as the Lunar Reconnaissance Orbiter (LRO), Lunar Crater Observation and Sensing Satellite (LCROSS), Gravity Recovery and Interior Laboratory (Grail), Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS), and the Lunar Atmosphere and Dust Environment Explorer (LADEE). The talk will also overview opportunities for participatory exploration whereby professional and amateur astronomers are encouraged to participate in lunar exploration in conjunction with NASA.

  1. Observation-based investigation of land-precipitation coupling

    NASA Astrophysics Data System (ADS)

    Guillod, B. P.; Orlowsky, B.; Seneviratne, S. I.; Reichstein, M.; Ciais, P.; Teuling, A. J.; Buchmann, N.; Findell, K. L.

    2012-04-01

    Interactions between land-surface and precipitation are an important component of the climate system and have been the subject of numerous studies. However, in particular the feedback between soil moisture and convective rainfall through indirect mechanisms (e.g., boundary-layer growth and convection triggering related to evapotranspiration) remains poorly understood. Although most modelling studies find positive feedbacks, observational studies are inconclusive up to now, questioning even the sign of the feedback. Here we explore the relationship between the evaporative fraction and precipitation on the daily time scale using data from FLUXNET sites from the US. An (apparent) positive relationship is found, with higher conditional probabilities of afternoon rainfall for higher values of evaporative fraction. However, we identify that this behaviour could be induced by large-scale precipitation or other confounding variables and also depends on the atmospheric conditions, which merits further investigation. Therefore, we extend our analysis using additional observational data (precipitation data from radar measurements and early-morning radio-soundings) and a reanalysis product (NARR). This enables us to better identify and analyze convective situations and also to perform a first cross-validation of the different data sources.

  2. Advanced Earth Observation System Instrumentation Study (AEOSIS)

    NASA Technical Reports Server (NTRS)

    Var, R. E.

    1976-01-01

    The feasibility, practicality, and cost are investigated for establishing a national system or grid of artificial landmarks suitable for automated (near real time) recognition in the multispectral scanner imagery data from an earth observation satellite (EOS). The intended use of such landmarks, for orbit determination and improved mapping accuracy is reviewed. The desirability of using xenon searchlight landmarks for this purpose is explored theoretically and by means of experimental results obtained with LANDSAT 1 and LANDSAT 2. These results are used, in conjunction with the demonstrated efficiency of an automated detection scheme, to determine the size and cost of a xenon searchlight that would be suitable for an EOS Searchlight Landmark Station (SLS), and to facilitate the development of a conceptual design for an automated and environmentally protected EOS SLS.

  3. Development of advanced entry, descent, and landing technologies for future Mars Missions

    NASA Technical Reports Server (NTRS)

    Chu, Cheng-Chih (Chester)

    2006-01-01

    Future Mars missions may need the capability to land much closer to a desired target and/or advanced methods of detecting, avoiding, or tolerating landing hazards. Therefore, technologies that enable 'pinpoint landing' (within tens of meters to 1 km of a target site) will be crucial to meet future mission requirements. As part of NASA Research Announcement, NRA 03-OSS-01, NASA solicited proposals for technology development needs of missions to be launched to Mars during or after the 2009 launch opportunity. Six technology areas were identified as of high priority including advanced entry, descent, and landing (EDL) technologies. In May 2004, 11 proposals with PIs from universities, industries, and NASA centers, were awarded in the area of advanced EDL by NASA for further study and development. This paper presents an overview of these developing technologies.

  4. Advances in Thermal Infrared Remote Sensing for Land Surface Modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 10 years ago, John Norman and co-authors proposed a thermal-based land surface modeling strategy that treated the energy exchange and kinetic temperatures of the soil and vegetated components in a unique “Two-Source Model” (TSM) approach. The TSM formulation addresses key factors affecting the...

  5. Acquiring observation error covariance information for land data assimilation systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent work has presented the initial application of adaptive filtering techniques to land surface data assimilation systems. Such techniques are motivated by our current lack of knowledge concerning the structure of large-scale error in either land surface modeling output or remotely-sensed estimat...

  6. Detecting and Simulating Urban-induced Climate Changes via EOS observations and NCAR Community Land Model

    NASA Astrophysics Data System (ADS)

    Jin, M.; Peters-Lidard, C.

    2003-12-01

    Advanced EOS observations provide us an unique opportunity to detect and simulate urban induced climate changes. Using 5km EOS MODIS-observed skin temperature, land cover, albedo, emissivity, LAI, aerosol optical depth, and cloud properties, we examine the surface-atmosphere interactions and urban heat island effects from selected big cities (New York, Beijing, Phoenix, and Houston) to global coverage. These analyses address physical processes modified by urban constructions as well as the general features of urban climate. We find the largest urban impacts in terms of temperature are observed over 30-60N, where most cities are located. In addition, urban regions overall decrease surface albedo by 3-5% and decrease surface emissivity by 1-2%. Focusing on Houston, we develop an urban scheme and couple it into NCAR Community Land Model (CLM-urban) to simulate urban climate. CLM-urban can improve the simulation of water and energy cycles over Houston with the use of observed LAI, albedo and emissivity, as well as urban thermal properties.

  7. NASA's Earth Observing System (EOS): Observing the Atmosphere, Land, Oceans, and Ice from Space

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2005-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by whch scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During this year, the last of the first series of EOS missions, Aura, was launched. Aura is designed exclusively to conduct research on the composition, chemistry, and dynamics of the Earth's upper and lower atmosphere, employing multiple instruments on a single spacecraft. Aura is the third in a series of major Earth observing satellites to study the environment and climate change and is part of NASA's Earth Science Enterprise. The first and second missions, Terra and Aqua, are designed to study the land, oceans, atmospheric constituents (aerosols, clouds, temperature, and water vapor), and the Earth's radiation budget. The other seven EOS spacecraft include satellites to study (i) land cover & land use change, (ii) solar irradiance and solar spectral variation, (iii) ice volume, (iv) ocean processes (vector wind and sea surface topography), and (v) vertical variations of clouds, water vapor, and aerosols up to and including the stratosphere. Aura's chemistry measurements will also follow up on measurements that began with NASA's Upper Atmosphere Research Satellite and continue the record of satellite ozone data collected from the TOMS missions. In this presentation I will describe how scientists are using EOS data to examine the health of the earth's atmosphere, including atmospheric chemistry, aerosol properties, and cloud properties, with a special look at the latest earth observing mission, Aura.

  8. NASA's Earth Observing System (EOS): Observing the Atmosphere, Land, Oceans, and Ice from Space

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2004-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During this year, the last of the first series of EOS missions, Aura, was launched. Aura is designed exclusively to conduct research on the composition, chemistry, and dynamics of the Earth's upper and lower atmosphere, employing multiple instruments on a single spacecraft. Aura is the third in a series of major Earth observing satellites to study the environment and climate change and is part of NASA's Earth Science Enterprise. The first and second missions, Terra and Aqua, are designed to study the land, oceans, atmospheric constituents (aerosols, clouds, temperature, and water vapor), and the Earth's radiation budget. The other seven EOS spacecraft include satellites to study (i) land cover & land use change, (ii) solar irradiance and solar spectral variation, (iii) ice volume, (iv) ocean processes (vector wind and sea surface topography), and (v) vertical variations of clouds, water vapor, and aerosols up to and including the stratosphere. Aura's chemistry measurements will also follow up on measurements that began with NASA's Upper Atmosphere Research Satellite and continue the record of satellite ozone data collected from the TOMS missions. In this presentation I will describe how scientists are using EOS data to examine the health of the earth's atmosphere, including atmospheric chemistry, aerosol properties, and cloud properties, with a special but not exclusive look at the latest earth observing mission, Aura.

  9. Global scale hydrology - Advances in land surface modeling

    SciTech Connect

    Wood, E.F. )

    1991-01-01

    Research into global scale hydrology is an expanding area that includes researchers from the meteorology, climatology, ecology and hydrology communities. This paper reviews research in this area carried out in the United States during the last IUGG quadrennial period of 1987-1990. The review covers the representation of land-surface hydrologic processes for general circulation models (GCMs), sensitivity analysis of these representations on global hydrologic fields like precipitation, regional studies of climate that have global hydrologic implications, recent field studies and experiments whose aims are the improved understanding of land surface-atmospheric interactions, and the use of remotely sensed data for the further understanding of the spatial variability of surface hydrologic processes that are important at regional and global climate scales. 76 refs.

  10. A geometric performance assessment of the EO-1 advanced land imager

    USGS Publications Warehouse

    Storey, J.C.; Choate, M.J.; Meyer, D.J.

    2004-01-01

    The Earth Observing 1 (EO-1) Advanced Land Imager (ALI) demonstrates technology applicable to a successor system to the Landsat Thematic Mapper series. A study of the geometric performance characteristics of the ALI was conducted under the auspices of the EO-1 Science Validation Team. This study evaluated ALI performance with respect to absolute pointing knowledge, focal plane sensor chip assembly alignment, and band-to-band registration for purposes of comparing this new technology to the heritage Landsat systems. On-orbit geometric calibration procedures were developed that allowed the generation of ALI geometrically corrected products that compare favorably with their Landsat 7 counterparts with respect to absolute geodetic accuracy, internal image geometry, and band registration.

  11. Sensing, Spectra and Scaling: What's in Store for Land Observations

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.

    2001-01-01

    Bill Pecora's 1960's vision of the future, using spacecraft-based sensors for mapping the environment and exploring for resources, is being implemented today. New technology has produced better sensors in space such as the Landsat Thematic Mapper (TM) and SPOT, and creative researchers are continuing to find new applications. However, with existing sensors, and those intended for launch in this century, the potential for extracting information from the land surface is far from being exploited. The most recent technology development is imaging spectrometry, the acquisition of images in hundreds of contiguous spectral bands, such that for any pixel a complete reflectance spectrum can be acquired. Experience with Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has shown that, with proper attention paid to absolute calibration, it is possible to acquire apparent surface reflectance to 5% accuracy without any ground-based measurement. The data reduction incorporates in educated guess of the aerosol scattering, development of a precipitable water vapor map from the data and mapping of cirrus clouds in the 1.38 micrometer band. This is not possible with TM. The pixel size in images of the earth plays and important role in the type and quality of information that can be derived. Less understood is the coupling between spatial and spectral resolution in a sensor. Recent work has shown that in processing the data to derive the relative abundance of materials in a pixel, also known is unmixing, the pixel size is an important parameter. A variance in the relative abundance of materials among the pixels is necessary to be able to derive the endmembers or pure material constituent spectra. In most cases, the 1 km pixel size for the Earth Observing System Moderate Resolution Imaging Spectroradiometer (MODIS) instrument is too large to meet the variance criterion. A pointable high spatial and spectral resolution imaging spectrometer in orbit will be necessary to make the

  12. Land-cover observations as part of a Global Earth Observation System of Systems (GEOSS): progress, activities, and prospects

    USGS Publications Warehouse

    Herold, M.; Woodcock, C.E.; Loveland, Thomas R.; Townshend, J.; Brady, M.; Steenmans, C.; Schmullius, C. C.

    2008-01-01

    The international land-cover community has been working with GEO since 2005 to build the foundations for land-cover observations as an integral part of a Global Earth Observation System of Systems (GEOSS). The Group on Earth Observation (GEO) has provided the platform to elevate the societal relevance of land cover monitoring and helped to link a diverse set of global, regional, and national activities. A dedicated 2007-2009 GEO work plan task has resulted in achievements on the strategic and implementation levels. Integrated Global Observations of the Land (IGOL), the land theme of the Integrated Global Observation Strategy (IGOS), has been approved and is now in the process of transition into GEO implementation. New global land-cover maps at moderate spatial resolutions (i.e., GLOBCOVER) are being produced using guidelines and standards of the international community. The Middecadal Global Landsat Survey for 2005-2006 is extending previous 1990 and 2000 efforts for global, high-quality Landsat data. Despite this progress, essential challenges for building a sustained global land-cover-observing system remain, including: international cooperation on the continuity of global observations; ensuring consistency in land monitoring approaches; community engagement and country participation in mapping activities; commitment to ongoing quality assurance and validation; and regional networking and capacity building.

  13. Hyperspectral Observations of Land Surfaces Using Ground-based, Airborne, and Satellite Sensors

    NASA Astrophysics Data System (ADS)

    Knuteson, R. O.; Best, F. A.; Revercomb, H. E.; Tobin, D. C.

    2006-12-01

    The University of Wisconsin-Madison Space Science and Engineering Center (UW-SSEC) has helped pioneer the use of high spectral resolution infrared spectrometers for application to atmospheric and surface remote sensing. This paper is focused on observations of land surface infrared emission from high spectral resolution measurements collected over the past 15 years using airborne, ground-based, and satellite platforms. The earliest data was collected by the High-resolution Interferometer Sounder (HIS), an instrument designed in the 1980s for operation on the NASA ER-2 high altitude aircraft. The HIS was replaced in the late 1990s by the Scanning-HIS instrument which has flown on the NASA ER-2, WB-57, DC-8, and Scaled Composites Proteus aircraft and continues to support field campaigns, such as those for EOS Terra, Aqua, and Aura validation. Since 1995 the UW-SSEC has fielded a ground-based Atmospheric Emitted Radiance Interferometer (AERI) in a research vehicle (the AERIBAGO) which has allowed for direct field measurements of land surface emission from a height of about 16 ft above the ground. Several ground-based and aircraft campaigns were conducted to survey the region surrounding the ARM Southern Great Plains site in north central Oklahoma. The ground- based AERIBAGO has also participated in surface emissivity campaigns in the Western U.S.. Since 2002, the NASA Atmospheric InfraRed Sounder (AIRS) has provided similar measurements from the Aqua platform in an afternoon sun-synchronous polar orbit. Ground-based and airborne observations are being used to validate the land surface products derived from the AIRS observations. These cal/val activities are in preparation for similar measurements anticipated from the operational Cross-track InfraRed Sounder (CrIS) on the NPOESS Preparatory Platform (NPP), expected to be launched in 2008. Moreover, high spectral infrared observations will soon be made by the Infrared Atmospheric Sounder Interferometer (IASI) on the

  14. Astrophysical Implications Drawn from Advanced LIGO's First Observing Run

    NASA Astrophysics Data System (ADS)

    Kalogera, Vassiliki; Nelemans, Gijs; LIGO Scientific Collaboration; Virgo Collaboration

    2016-03-01

    Following a major instrumentation upgrade, the Advanced LIGO detectors recently completed the first observing run. In this talk I will highlight constraints expected to be drawn from the analysis of this observational data set, in the context of astrophysical models for the formation and eventual mergers of binary compact objects in a wide range of stellar environments.

  15. A framework for global diurnally-resolved observations of Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Ghent, Darren; Remedios, John

    2014-05-01

    Land surface temperature (LST) is the radiative skin temperature of the land, and is one of the key parameters in the physics of land-surface processes on regional and global scales. Being a key boundary condition in land surface models, which determine the surface to atmosphere fluxes of heat, water and carbon; thus influencing cloud cover, precipitation and atmospheric chemistry predictions within Global models, the requirement for global diurnal observations of LST is well founded. Earth Observation satellites offer an opportunity to obtain global coverage of LST, with the appropriate exploitation of data from multiple instruments providing a capacity to resolve the diurnal cycle on a global scale. Here we present a framework for the production of global, diurnally resolved, data sets for LST which is a key request from users of LST data. We will show how the sampling of both geostationary and low earth orbit data sets could conceptually be employed to build combined, multi-sensor, pole-to-pole data sets. Although global averages already exist for individual instruments and merging of geostationary based LST is already being addressed operationally (Freitas, et al., 2013), there are still a number of important challenges to overcome. In this presentation, we will consider three of the issues still open in LST remote sensing: 1) the consistency amongst retrievals; 2) the clear-sky bias and its quantification; and 3) merging methods and the propagation of uncertainties. For example, the combined use of both geostationary earth orbit (GEO) and low earth orbit (LEO) data, and both infra-red and microwave data are relatively unexplored but are necessary to make the most progress. Hence this study will suggest what is state-of-the-art and how considerable advances can be made, accounting also for recent improvements in techniques and data quality. The GlobTemperature initiative under the Data User Element of ESA's 4th Earth Observation Envelope Programme (2013

  16. A framework for global diurnally-resolved observations of Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Ghent, D.; Remedios, J.; Pinnock, S.

    2013-12-01

    Land surface temperature (LST) is the radiative skin temperature of the land, and is one of the key parameters in the physics of land-surface processes on regional and global scales. Being a key boundary condition in land surface models, which determine the surface to atmosphere fluxes of heat, water and carbon; thus influencing cloud cover, precipitation and atmospheric chemistry predictions within Global models, the requirement for global diurnal observations of LST is well founded. Earth Observation satellites offer an opportunity to obtain global coverage of LST, with the appropriate exploitation of data from multiple instruments providing a capacity to resolve the diurnal cycle on a global scale. Here we present a framework for the production of global, diurnally resolved, data sets for LST which is a key request from users of LST data. We will show how the sampling of both geostationary and low earth orbit data sets could conceptually be employed to build combined, multi-sensor, pole-to-pole data sets. Although global averages already exist for individual instruments and merging of geostationary based LST is already being addressed operationally (Freitas, et al., 2013), there are still a number of important challenges to overcome. In this presentation, we will consider three of the issues still open in LST remote sensing: 1) the consistency amongst retrievals; 2) the clear-sky bias and its quantification; and 3) merging methods and the propagation of uncertainties. For example, the combined use of both geostationary earth orbit (GEO) and low earth orbit (LEO) data, and both infra-red and microwave data are relatively unexplored but are necessary to make the most progress. Hence this study will suggest what is state-of-the-art and how considerable advances can be made, accounting also for recent improvements in techniques and data quality. The GlobTemperature initiative under the Data User Element of ESA's 4th Earth Observation Envelope Programme (2013

  17. The enhanced NOAA global land dataset from the advanced very high resolution radiometer

    SciTech Connect

    Gutman, G.; Tarpley, D.; Ignatov, A.

    1995-07-01

    Global mapped data of reflected radiation in the visible (0.63 {mu}m) and near-infrared (0.85 {mu}m) wavebands on the Advanced Very High Resolution Radiometer (AVHRR) onboard National Oceanic and Atmospheric Administration satellites have been collected as the global vegetation index (GVI) dataset since 1982. Its primary objective has been vegetation studies (hence its title) using the normalized difference vegetation index (NDVI) calculated from the visible and near-IR data. The second-generation GVI, which started in April 1985, has also included brightness temperatures in the thermal IR (11 and 12 {mu}m) and the associated observation-illumination geometry. This multiyear, multispectral, multisatellite dataset is a unique tool for global land studies. At the same time, it raises challenging remote sensing and data management problems with respect to uniformity in time, enhancement of signal-to-noise ratio, retrieval of geophysical parameters from satellite radiances, and large data volumes. The authors explored a four-level generic structure for processing AVHRR data-the first two levels being remote sensing oriented and the other two directed at environmental studies-and will describe the present status of each level. The uniformity of GVI data was improved by applying an updated calibration, and noise was reduced by applying a more accurate cloud-screening procedure. In addition to the enhanced weekly data (recalibrated with appended quality/cloud flags), the available land environmental products include monthly 0-15{degrees}-resolution global maps of top-of-the-atmosphere visible and near-IR reflectances, NDVI, brightness temperatures, and a precipitable water index for April 1985-September 1994. For the first time, a 5-yr monthly climatology (means and standard deviations) of each quantity was produced. These products show strong potential for detecting and analyzing large-scale spatial and seasonal land variability. 57 refs., 8 figs.

  18. Advances in POST2 End-to-End Descent and Landing Simulation for the ALHAT Project

    NASA Technical Reports Server (NTRS)

    Davis, Jody L.; Striepe, Scott A.; Maddock, Robert W.; Hines, Glenn D.; Paschall, Stephen, II; Cohanim, Babak E.; Fill, Thomas; Johnson, Michael C.; Bishop, Robert H.; DeMars, Kyle J.; Sostaric, Ronald r.; Johnson, Andrew E.

    2008-01-01

    Program to Optimize Simulated Trajectories II (POST2) is used as a basis for an end-to-end descent and landing trajectory simulation that is essential in determining design and integration capability and system performance of the lunar descent and landing system and environment models for the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. The POST2 simulation provides a six degree-of-freedom capability necessary to test, design and operate a descent and landing system for successful lunar landing. This paper presents advances in the development and model-implementation of the POST2 simulation, as well as preliminary system performance analysis, used for the testing and evaluation of ALHAT project system models.

  19. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    SciTech Connect

    Varughese, Byji; Dayananda, G. N.; Rao, M. Subba

    2008-07-29

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with.

  20. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    NASA Astrophysics Data System (ADS)

    Varughese, Byji; Dayananda, G. N.; Rao, M. Subba

    2008-07-01

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with.

  1. DISAGGREGATION OF GOES-LAND SURFACE TEMPERATURES USING MODIS OBSERVATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate temporal and spatial estimation of land surface temperatures (LST) is important for modeling the hydrological cycle at field to global scales because LSTs can improve estimates of soil moisture and evapotranspiration. Using remote sensing satellites, accurate LSTs could be routine, but unfo...

  2. Observations of atmosphere and ocean/land surfaces using UAVs in Ny-Alesund

    NASA Astrophysics Data System (ADS)

    Inoue, J.; Storvold, R.

    2008-12-01

    Using a Norwegian small robotic aircraft called the Cryowing, atmospheric and ocean/land surface observations were made over Ny-Alesund, Svalbard, Norway from 31 July to 17 August 2008. The aircraft has meteorological sensors to observe dynamic and static air pressures, air temperature, and relative humidity, infrared thermometer to observe surface temperature, and digital camera to record the surface characteristics. From the results of surface mapping, the atmosphere responded differently with different types of surface (i.e., grass, crust, glacier, and ocean). The continuous observation at the same region showed that the time change in incoming solar radiation affects the variation of surface temperature due to difference in surface albedo, resulting in spacial distribution of air temperature in the boundary layer. While in the long ocean flight, the strong SST gradient was observed between the warm Atlantic water and melted water of sea ice near the Fram Strait. The air temperature above 150-m level observed by the UAV was clearly high over the warm current. These results demonstrate the utility of recent advances in UAV technology for monitoring and interpreting the spatial variations in cryosphere.

  3. HiRISE observations of potential MSL landing sites

    NASA Astrophysics Data System (ADS)

    Griffes, J. L.; Grant, J.; McEwen, A.; Golombek, M.; HiRISE Team

    2007-12-01

    The Mars Reconnaissance Orbiter's (MRO) High Resolution Imaging Science Experiment (HiRISE) began acquiring data in the fall of 2006. Some of the images of the past year of operations include support for the 2009 Mars Science Laboratory (MSL) potential landing sites, which were proposed at the first landing site workshop in October of 2006. There are 28 proposed sites that were prioritized at the first workshop and they are located across elevations and latitudes ranging from -6 km to approximately +1 km, and 29.3°N to 48.5°S respectively. These sites emphasize a range of science themes including mineralogy (i.e. phyllosilicates, sulfates, or hematite), layered materials, or presence of fluvial, erosional or depositional landforms. Each site was originally proposed with a 20 km landing ellipse in an area that appeared smooth and flat in pre-HiRISE images. Many of the sites are "go to" sites where there is a proposed landing ellipse adjacent to a nearby science target of interest. HiRISE has acquired images at ~30 cm/pixel for all the proposed sites, including a few additional images of the northern hemisphere landing ellipses at low sun, used to better constrain the distribution of slopes at small scales. Each HiRISE image is approximately 6 km wide by at least 10 km long and includes a 1.2 km-wide blue-green and NIR swath down the middle of the image. For each HiRISE footprint, there is also a co-located Context Image (CTX) and CRISM hyperspectral image. The HiRISE images show a variety of landforms at high resolution, such as layered deposits, dunes, channels, ridges, rocks, polygonal terrain and craters. Each of these sites will be extensively studied to assess the safest landing site, as well as what is best suited to achieving mission science objectives. The acquired images have been released to the PDS and are available to all interested parties, including MSL project and science advocates for the purpose of characterizing potential hazards to safe landing

  4. Retrieval of land parameters by multi-sensor information using the Earth Observation Land Data Assimilation System

    NASA Astrophysics Data System (ADS)

    Chernetskiy, Maxim; Gobron, Nadine; Gomez-Dans, Jose; Disney, Mathias

    2016-07-01

    Upcoming satellite constellations will substantially increase the amount of Earth Observation (EO) data, and presents us with the challenge of consistently using all these available information to infer the state of the land surface, parameterised through Essential Climate Variables (ECVs). A promising approach to this problem is the use of physically based models that describe the processes that generate the images, using e.g. radiative transfer (RT) theory. However, these models need to be inverted to infer the land surface parameters from the observations, and there is often not enough information in the EO data to satisfactorily achieve this. Data assimilation (DA) approaches supplement the EO data with prior information in the form of models or prior parameter distributions, and have the potential for solving the inversion problem. These methods however are computationally expensive. In this study, we show the use of fast surrogate models of the RT codes (emulators) based on Gaussian Processes (Gomez-Dans et al, 2016) embedded with the Earth Observation Land Data Assimilation System (EO-LDAS) framework (Lewis et al 2012) in order to estimate the surface of the land surface from a heterogeneous set of optical observations. The study uses time series of moderate spatial resolution observations from MODIS (250 m), MERIS (300 m) and MISR (275 m) over one site to infer the temporal evolution of a number of land surface parameters (and associated uncertainties) related to vegetation: leaf area index (LAI), leaf chlorophyll content, etc. These parameter estimates are then used as input to an RT model (semidiscrete or PROSAIL, for example) to calculate fluxes such as broad band albedo or fAPAR. The study demonstrates that blending different sensors in a consistent way using physical models results in a rich and coherent set of land surface parameters retrieved, with quantified uncertainties. The use of RT models also allows for the consistent prediction of fluxes

  5. North American vegetation patterns observed with the NOAA-7 advanced very high resolution radiometer. [North America

    NASA Technical Reports Server (NTRS)

    Goward, S. N.; Tucker, C. J.; Dye, D. G.

    1985-01-01

    Spectral vegetation index measurements derived from remotely sensed observations show great promise as a means to improve knowledge of land vegetation patterns. The daily, global observations acquired by the advanced very high resolution radiometer, a sensor on the current series of U.S. National Oceanic and Atmospheric Administration meteorological satellites, may be particularly well suited for global studies of vegetation. Preliminary results from analysis of North American observations, extending from April to November 1982, show that the vegetation index patterns observed correspond to the known seasonality of North American natural and cultivated vegetation. Integration of the observations over the growing season produced measurements that are related to net primary productivity patterns of the major North American natural vegetation formations. Regions of intense cultivation were observed as anomalous areas in the integrated growing season measurements. Significant information on seasonality, annual extent and interannual variability of vegetation photosynthetic activity at continental and global scales can be derived from these satellite observations.

  6. Satellite-based land use mapping: comparative analysis of Landsat-8, Advanced Land Imager, and big data Hyperion imagery

    NASA Astrophysics Data System (ADS)

    Pervez, Wasim; Uddin, Vali; Khan, Shoab Ahmad; Khan, Junaid Aziz

    2016-04-01

    Until recently, Landsat technology has suffered from low signal-to-noise ratio (SNR) and comparatively poor radiometric resolution, which resulted in limited application for inland water and land use/cover mapping. The new generation of Landsat, the Landsat Data Continuity Mission carrying the Operational Land Imager (OLI), has improved SNR and high radiometric resolution. This study evaluated the utility of orthoimagery from OLI in comparison with the Advanced Land Imager (ALI) and hyperspectral Hyperion (after preprocessing) with respect to spectral profiling of classes, land use/cover classification, classification accuracy assessment, classifier selection, study area selection, and other applications. For each data source, the support vector machine (SVM) model outperformed the spectral angle mapper (SAM) classifier in terms of class discrimination accuracy (i.e., water, built-up area, mixed forest, shrub, and bare soil). Using the SVM classifier, Hyperion hyperspectral orthoimagery achieved higher overall accuracy than OLI and ALI. However, OLI outperformed both hyperspectral Hyperion and multispectral ALI using the SAM classifier, and with the SVM classifier outperformed ALI in terms of overall accuracy and individual classes. The results show that the new generation of Landsat achieved higher accuracies in mapping compared with the previous Landsat multispectral satellite series.

  7. Accessing Recent Trend of Land Surface Temperature from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Shen, Suhung; Leptoukh, Gregory G.; Romanov, Peter

    2011-01-01

    Land surface temperature (Ts) is an important element to measure the state of terrestrial ecosystems and to study surface energy budgets. In support of the land cover/land use change-related international program MAIRS (Monsoon Asia Integrated Regional Study), we have collected global monthly Ts measured by MODIS since the beginning of the missions. The MODIS Ts time series have approximately 11 years of data from Terra since 2000 and approximately 9 years of data from Aqua since 2002, which makes possible to study the recent climate, such as trend. In this study, monthly climatology from two platforms are calculated and compared with that from AIRS. The spatial patterns of Ts trends are accessed, focusing on the Eurasia region. Furthermore, MODIS Ts trends are compared with those from AIRS and NASA's atmospheric assimilation model, MERRA (Modern Era Retrospective-analysis for Research and Applications). The preliminary results indicate that the recent 8-year Ts trend shows an oscillation-type spatial variation over Eurasia. The pattern is consistent for data from MODIS, AIRS, and MERRA, with the positive center over Eastern Europe, and the negative center over Central Siberia. The calculated climatology and anomaly of MODIS Ts will be integrated into the online visualization system, Giovanni, at NASA GES DISC for easy use by scientists and general public.

  8. Accessing Recent Trend of Land Surface Temperature from Satellite Observations

    NASA Astrophysics Data System (ADS)

    Shen, S.; Leptoukh, G. G.; Romanov, P.

    2011-12-01

    Land surface temperature (LST) is an important element to measure the state of the terrestrial ecosystems and to study the surface energy budgets. In support of the land cover/land use change related international program MAIRS (Monsoon Asia Integrated Regional Study), we have collected the global monthly LST measured by MODIS since the beginning of the missions. The MODIS LST time series have ~11 years of data from Terra since 2000 and ~9 years of data from Aqua since 2002, which makes possible to study the recent climate, such as trend and variability. In this study, monthly climatology from two satellite platforms are calculated and compared. The spatial patterns of LST trends are accessed, focusing on the Asian Monsoon region. Furthermore, the MODIS LST trends are compared with the skin temperature trend from the NASA's atmospheric assimilation model, MERRA (MODERN ERA RETROSPECTIVE-ANALYSIS FOR RESEARCH AND APPLICATIONS), which has longer data record since 1979. The calculated climatology and anomaly of MODIS LST will be integrated into the online visualization system, Giovanni, at NASA GES DISC for easy access and use by scientists and general public.

  9. Offshore marine observation of Willow Ptarmigan, including water landings, Kuskokwim Bay, Alaska

    USGS Publications Warehouse

    Zimmerman, C.E.; Hillgruber, N.; Burril, S.E.; St., Peters, M. A.; Wetzel, J.D.

    2005-01-01

    We report an observation of Willow Ptarmigan (Lagopus lagopus) encountered 8 to 17 km from the nearest shoreline on Kuskokwim Bay, Alaska, on 30 August 2003. The ptarmigan were observed flying, landing on our research vessel, and landing and taking off from the water surface. We also report on one other observation of ptarmigan sitting on the water surface and other marine observations of ptarmigan from the North Pacific Pelagic Seabird Database. These observations provide evidence that Willow Ptarmigan are capable of dispersing across large bodies of water and landing and taking off from the water surface.

  10. Effect of surface BRDF of various land cover types on the geostationary observations of tropospheric NO2

    NASA Astrophysics Data System (ADS)

    Noguchi, K.; Richter, A.; Rozanov, V.; Rozanov, A.; Burrows, J. P.; Irie, H.; Kita, K.

    2014-04-01

    We investigated the effect of surface reflectance anisotropy, Bidirectional Reflectance Distribution Function (BRDF), on satellite retrievals of tropospheric NO2. We assume the geometry of geostationary measurements over Tokyo, which is one of the worst air-polluted regions in the East Asia. We calculated air mass factors (AMF) and box AMFs (BAMF) for tropospheric NO2 to evaluate the effect of BRDF by using the radiative transfer model SCIATRAN. To model the BRDF effect, we utilized the Moderate Resolution Imaging Spectroradiometer (MODIS) products (MOD43B1 and MOD43B2), which provide three coefficients to express the RossThick-LiSparseReciprocal model, a semi-empirical and kernel-based model of BRDF. Because BRDF depends on the land cover type, we also utilized the High Resolution Land-Use and Land-Cover Map by the Advanced Land Observing Satellite (ALOS)/Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2), which classifies the ground pixels over Tokyo into six main types: water, urban, paddy, crop, deciduous forest and evergreen forest. We first develop an empirical model of the three BRDF coefficients for each land cover type over Tokyo, and then apply the model to the calculation of land cover type dependent AMFs and BAMFs. Results show that the variability of AMF among the land types is up to several tens percent, and if we neglect the reflectance anisotropy, the difference from BRDF's AMF reaches 10% or more. The evaluation of the BAMFs calculated shows that not to consider variations in BRDF will cause large errors if the concentration of NO2 is high close to the surface, although the importance of BRDF for AMFs decreases for large aerosol optical depth (AOD).

  11. Advanced entry guidance algorithm with landing footprint computation

    NASA Astrophysics Data System (ADS)

    Leavitt, James Aaron

    The design and performance evaluation of an entry guidance algorithm for future space transportation vehicles is presented. The algorithm performs two functions: on-board trajectory planning and trajectory tracking. The planned longitudinal path is followed by tracking drag acceleration, as is done by the Space Shuttle entry guidance. Unlike the Shuttle entry guidance, lateral path curvature is also planned and followed. A new trajectory planning function for the guidance algorithm is developed that is suitable for suborbital entry and that significantly enhances the overall performance of the algorithm for both orbital and suborbital entry. In comparison with the previous trajectory planner, the new planner produces trajectories that are easier to track, especially near the upper and lower drag boundaries and for suborbital entry. The new planner accomplishes this by matching the vehicle's initial flight path angle and bank angle, and by enforcing the full three-degree-of-freedom equations of motion with control derivative limits. Insights gained from trajectory optimization results contribute to the design of the new planner, giving it near-optimal downrange and crossrange capabilities. Planned trajectories and guidance simulation results are presented that demonstrate the improved performance. Based on the new planner, a method is developed for approximating the landing footprint for entry vehicles in near real-time, as would be needed for an on-board flight management system. The boundary of the footprint is constructed from the endpoints of extreme downrange and crossrange trajectories generated by the new trajectory planner. The footprint algorithm inherently possesses many of the qualities of the new planner, including quick execution, the ability to accurately approximate the vehicle's glide capabilities, and applicability to a wide range of entry conditions. Footprints can be generated for orbital and suborbital entry conditions using a pre

  12. The Land Potential Knowledge System: Application of earth observation data for sustainable land management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Africa is facing numerous challenges including a rapidly growing population, soil erosion, declining soil fertility and climate change. In the face of all these problems, the need to feed the growing population has led to expansion of land for agriculture and pasture production rather than increasin...

  13. Evaluation of various LandFlux evapotranspiration algorithms using the LandFlux-EVAL synthesis benchmark products and observational data

    NASA Astrophysics Data System (ADS)

    Michel, Dominik; Hirschi, Martin; Jimenez, Carlos; McCabe, Mathew; Miralles, Diego; Wood, Eric; Seneviratne, Sonia

    2014-05-01

    Research on climate variations and the development of predictive capabilities largely rely on globally available reference data series of the different components of the energy and water cycles. Several efforts aimed at producing large-scale and long-term reference data sets of these components, e.g. based on in situ observations and remote sensing, in order to allow for diagnostic analyses of the drivers of temporal variations in the climate system. Evapotranspiration (ET) is an essential component of the energy and water cycle, which can not be monitored directly on a global scale by remote sensing techniques. In recent years, several global multi-year ET data sets have been derived from remote sensing-based estimates, observation-driven land surface model simulations or atmospheric reanalyses. The LandFlux-EVAL initiative presented an ensemble-evaluation of these data sets over the time periods 1989-1995 and 1989-2005 (Mueller et al. 2013). Currently, a multi-decadal global reference heat flux data set for ET at the land surface is being developed within the LandFlux initiative of the Global Energy and Water Cycle Experiment (GEWEX). This LandFlux v0 ET data set comprises four ET algorithms forced with a common radiation and surface meteorology. In order to estimate the agreement of this LandFlux v0 ET data with existing data sets, it is compared to the recently available LandFlux-EVAL synthesis benchmark product. Additional evaluation of the LandFlux v0 ET data set is based on a comparison to in situ observations of a weighing lysimeter from the hydrological research site Rietholzbach in Switzerland. These analyses serve as a test bed for similar evaluation procedures that are envisaged for ESA's WACMOS-ET initiative (http://wacmoset.estellus.eu). Reference: Mueller, B., Hirschi, M., Jimenez, C., Ciais, P., Dirmeyer, P. A., Dolman, A. J., Fisher, J. B., Jung, M., Ludwig, F., Maignan, F., Miralles, D. G., McCabe, M. F., Reichstein, M., Sheffield, J., Wang, K

  14. Land cover change impacts on surface ozone: an observation-based study

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Lin, Jintai

    2016-04-01

    Ozone air quality is a critical global environmental issue. Although it is clear that industrialization and urbanization has increased surface ozone through enhanced emissions of its precursors, much less is known about the role of changes in land cover and land use. Human activities have substantially altered the global land cover and land use through agriculture, urbanization, deforestation, and afforestation. Changes in Land cover and land use affect the ozone levels by altering soil emissions of nitrogen oxides (NOx), biogenic emissions of volatile organic compounds (VOCs), and dry deposition of ozone itself. This study performs a series of experiments with a chemical transport model based on satellite observation of land types to analyze the influences of changes in land cover/land use and their impact on surface ozone concentration. Our results indicate that land cover change explains 1-2 ppbv of summertime surface ozone increase in the Western United States and 1-6 ppbv of increase in Southern China between 2001 and 2012. This is largely driven by enhanced isoprene emissions and soil NOx emissions. It is also found that land cover change itself elevates summertime surface zone in Canadian coniferous forests by up to 4 ppbv mainly through substantial decreases in ozone dry deposition associated with increased vegetation density in a warmer climate.

  15. Observed Land Impacts on Clouds, Water Vapor, and Rainfall at Continental Scales

    NASA Technical Reports Server (NTRS)

    Jin, Menglin; King, Michael D.

    2005-01-01

    How do the continents affect large-scale hydrological cycles? How important can one continent be to the climate system? To address these questions, 4-years of National Aeronautics and Space Administration (NASA) Terra Moderate Resolution Imaging Spectroradiometer (MODIS) observations, Tropical Rainfall Measuring Mission (TRMM) observations, and the Global Precipitation Climatology Project (GPCP) global precipitation analysis, were used to assess the land impacts on clouds, rainfall, and water vapor at continental scales. At these scales, the observations illustrate that continents are integrated regions that enhance the seasonality of atmospheric and surface hydrological parameters. Specifically, the continents of Eurasia and North America enhance the seasonality of cloud optical thickness, cirrus fraction, rainfall, and water vapor. Over land, both liquid water and ice cloud effective radii are smaller than over oceans primarily because land has more aerosol particles. In addition, different continents have similar impacts on hydrological variables in terms of seasonality, but differ in magnitude. For example, in winter, North America and Eurasia increase cloud optical thickness to 17.5 and 16, respectively, while in summer, Eurasia has much smaller cloud optical thicknesses than North America. Such different land impacts are determined by each continent s geographical condition, land cover, and land use. These new understandings help further address the land-ocean contrasts on global climate, help validate global climate model simulated land-atmosphere interactions, and help interpret climate change over land.

  16. Radar Observations of Snowpack Changes from the Second Cold Land Processes Experiment

    NASA Astrophysics Data System (ADS)

    Cline, D.; Yueh, S.; Elder, K.

    2007-12-01

    To support the NASA Snow and Cold Land Processes (SCLP) and the ESA Cold Regions High-Resolution Hydrologic Observatory (CoRe-H2O) missions and advance observation of the global water cycle, NASA is supporting the second Cold Land Processes Experiment (CLPX-II). The experiment is being conducted in two parts over two winter seasons (Colorado 2006-2007, and Alaska 2007-2008). The focus of CLPX-II is on testing and development of advanced snow measurement using high-frequency radar through repeat observations of changing snow conditions using airborne and spaceborne radars and intensive in situ measurements. During 2006-2007 three field campaigns were conducted in a 90-km x 9-km study area in north-central Colorado. The campaigns were carried out in December, January and February to observe significant changes in snowpack characteristics. In each campaign, the Jet Propulsion Laboratory's conically scanning Ku- band polarimetric scatterometer (POLSCAT) was flown on a Twin Otter aircraft to collect radar data over the study area. Multiple complete images of the entire study area were acquired during each campaign, enabling examination of short-term changes in radar response as well as long-term changes between campaigns. In each campaign, intensive in situ observations of snow depth, water equivalent, stratigraphy, and grain size were made in each of 16 target sites. All of the target sites shared similar backgrounds (flat terrain with a ground cover of grasses and sedges) but exhibited a wide range of snowpack characteristics. Preliminary analyses of the POLSCAT data acquired from the CLPX-II in winter 2006-2007 are described. The data showed response of the Ku-band radar echoes to snowpack changes for various types of background vegetation. There was about 0.4 dB increase in backscatter for every 1 cm SWE accumulation for sage brush and pasture fields. The data also showed the impact of freeze/thaw cycles, which appeared to create depth hoar and ice lenses with large

  17. LOTOS: A Proposed Lower Tropospheric Observing System from the Land Surface through the Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Cohn, S. A.; Lee, W. C.; Carbone, R. E.; Oncley, S.; Brown, W. O. J.; Spuler, S.; Horst, T. W.

    2015-12-01

    Advances in sensor capabilities, but also in electronics, optics, RF communication, and off-the-grid power are enabling new measurement paradigms. NCAR's Earth Observing Laboratory (EOL) is considering new sensors, new deployment modes, and integrated observing strategies to address challenges in understanding within the atmospheric boundary layer and the underlying coupling to the land surface. Our vision is of a network of deployable observing sites, each with a suite of complementary instruments that measure surface-atmosphere exchange, and the state and evolution of the boundary layer. EOL has made good progress on distributed surface energy balance and flux stations, and on boundary layer remote sensing of wind and water vapor, all suitable for deployments of combined instruments and as network of such sites. We will present the status of the CentNet surface network development, the 449-MHz modular wind profiler, and a water vapor and temperature profiling differential absorption lidar (DIAL) under development. We will further present a concept for a test bed to better understand the value of these and other possible instruments in forming an instrument suite flexible for multiple research purposes.

  18. Forcing a Global, Offline Land Surface Modeling System with Observation-Based Fields

    NASA Technical Reports Server (NTRS)

    Rodell, Matthew; Houser, Paul R.; Jambor, U.; Gottschalck, J.; Radakovich, J.; Arsenault, K.; Meng, C.-J.; Mitchell, K. E.

    2002-01-01

    The Global Land Data Assimilation System (GLDAS) drives multiple uncoupled land surface models in order to produce optimal output fields of surface states in near-real time, globally, at 1/4 degree spatial resolution. These fields are then made available for coupled atmospheric model initialization and further research. One of the unique aspects of GLDAS is its ability to ingest both modeled and observation-derived forcing for running global scale land surface models. This paper compares results of runs forced by modeled and observed precipitation and shortwave radiation fields. Differences are examined and the impact of the observations on model skill is assessed.

  19. Observations of Supernovae and Gamma-Ray Bursts as Cooperative Observing Exercises for Advanced Astronomy Classes

    NASA Astrophysics Data System (ADS)

    Durig, Douglas T.

    For my advanced astronomy class, Physics 251, many of our laboratory exercises were cooperative assignments where each student contributed observations and data towards a common goal. Observations of supernovae and gamma-ray burst afterglow candidates were natural targets of opportunity. This past Spring Semester we observed SN 2002ap and GRB020406. We observed the supernova with R and V filters and unfiltered several nights near maximum. We also observed the error region near GRB020406 and found some new, dim, vary cool infrared rich stars. The results from these observations will be reported. These targets provided excellent, applied examples of the material being covered in lecture.

  20. Radiometric calibration stability of the EO-1 advanced land imager: 5 years on-orbit

    USGS Publications Warehouse

    Markham, B.L.; Ong, L.; Barsi, J.A.; Mendenhall, J.A.; Lencioni, D.E.; Helder, D.L.; Hollaren, D.M.; Morfitt, R.

    2006-01-01

    The Advanced Land Imager (ALI) was developed as a prototype sensor for follow on missions to Landsat-7. It was launched in November 2000 on the Earth Observing One (EO-1) satellite as a nominal one-year technology demonstration mission. As of this writing, the sensor has continued to operate in excess of 5 years. Six of the ALl's nine multi-spectral (MS) bands and the panchromatic band have similar spectral coverage as those on the Landsat-7 ETM+. In addition to on-board lamps, which have been significantly more stable than the lamps on ETM+, the ALI has a solar diffuser and has imaged the moon monthly since launch. This combined calibration dataset allows understanding of the radiometric stability of the ALI system, its calibrators and some differentiation of the sources of the changes with time. The solar dataset is limited as the mechanism controlling the aperture to the solar diffuser failed approximately 18 months after launch. Results over 5 years indicate that: the shortest wavelength band (443 nm) has degraded in response about 2%; the 482 nm and 565 nm bands decreased in response about 1%; the 660 nm, 790 nm and 868 nm bands each degraded about 5%; the 1250 nm and 1650 nm bands did not change significantly and the 2215 nm band increased in response about 2%.

  1. Mediterranean desertification and land degradation: Mapping related land use change syndromes based on satellite observations

    NASA Astrophysics Data System (ADS)

    Hill, J.; Stellmes, M.; Udelhoven, Th.; Röder, A.; Sommer, S.

    2008-12-01

    In past decades, the European Mediterranean has undergone widespread land use transformations. These are largely driven by changes of socio-economic conditions, such as accession to the European Community, and had strong effects on the way the land is being used. Aiming at a systematic description of such change processes on a global level, the syndrome concept was proposed to describe archetypical, co-evolutionary patterns of human-nature interactions, and has been specifically linked to the desertification issue. In this study, we present an adaptation of the syndrome approach to the Iberian Peninsula. We suggest a data processing and interpretation framework to map the spatial extent of specific syndromes. The mapping approach is based on the time series analysis of satellite data. We have characterized vegetation dynamics using NDVI estimates from the coarse scale, hyper-temporal 1-km MEDOKADS archive, which is based on calibrated NOAA-AVHRR images. Results indicate that local patches of abrupt disturbance, mainly caused by fire, are contrasted by a widespread increase in vegetation, which is in large parts attributed to the abandonment of rural areas. Although this questions the dominance of classical desertification traits, i.e. decline of productivity after disturbance, it is concluded that the recent greening presents a different sort of environmental risk, as it may negatively impact on fire regimes and the hydrological cycle.

  2. Use of NOMADSS Observations to Improve Our Understanding of the Land and Ocean Fluxes of Mercury

    NASA Astrophysics Data System (ADS)

    Song, S.; Selin, N. E.; Jaffe, D. A.; Jaegle, L.; Gratz, L.; Ambrose, J. L., II; Shah, V.; Giang, A.

    2014-12-01

    We use measurements during the 2013 Nitrogen Oxidants Mercury and Aerosol Distributions Sources and Sinks (NOMADSS) campaign to constrain the land and ocean emissions of mercury, using a combination of forward and inverse modeling. Mercury emissions from land and ocean drive the global cycling of mercury. A recent bottom-up assessment of global mercury emissions estimated that the land and ocean sources release about 1500 and 2700 Mg yr-1 of mercury into the atmosphere, respectively. Thus, the average emission per unit area from the land is thought to exceed the ocean (Pirrone et al., Atmos. Chem. Phys., 10, 5951-5964, 2010). Considering that there are additional mercury sources from the land (e.g., anthropogenic emission and biomass burning), this emission difference should lead to higher observed mercury levels over the land compared to over the ocean. However, several very recent measurement and modeling studies challenge such understanding. The NOMADSS campaign provided a first opportunity to measure speciated mercury concentrations over both land and ocean surfaces. As shown in Table 1, the median Total Mercury (TM) concentration in 0-1 km (within the planetary boundary layer) for over-ocean flights is 0.11 ng m-3 higher (p < 0.05) than for over-land flights, whereas the over-ocean flights have lower TM concentrations in > 1 km than the over-land flights. We combine analysis of NOMADDS mercury measurements with the GEOS-Chem model, to better constrain land and ocean mercury sources. The standard GEOS-Chem model cannot reproduce the mercury concentration differences between over the land and the ocean. We improve the GEOS-Chem model's ability to reproduce these observations by implementing updated air-sea and air-land exchange mechanisms. We find that increased ocean emissions are necessary to explain this discrepancy. These results are consistent with the inverse analysis of global GEM concentrations.

  3. Advances in Land Data Assimilation at the NASA Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf

    2009-01-01

    Research in land surface data assimilation has grown rapidly over the last decade. In this presentation we provide a brief overview of key research contributions by the NASA Goddard Space Flight Center (GSFC). The GSFC contributions to land assimilation primarily include the continued development and application of the Land Information System (US) and the ensemble Kalman filter (EnKF). In particular, we have developed a method to generate perturbation fields that are correlated in space, time, and across variables and that permit the flexible modeling of errors in land surface models and observations, along with an adaptive filtering approach that estimates observation and model error input parameters. A percentile-based scaling method that addresses soil moisture biases in model and observational estimates opened the path to the successful application of land data assimilation to satellite retrievals of surface soil moisture. Assimilation of AMSR-E surface soil moisture retrievals into the NASA Catchment model provided superior surface and root zone assimilation products (when validated against in situ measurements and compared to the model estimates or satellite observations alone). The multi-model capabilities of US were used to investigate the role of subsurface physics in the assimilation of surface soil moisture observations. Results indicate that the potential of surface soil moisture assimilation to improve root zone information is higher when the surface to root zone coupling is stronger. Building on this experience, GSFC leads the development of the Level 4 Surface and Root-Zone Soil Moisture (L4_SM) product for the planned NASA Soil-Moisture-Active-Passive (SMAP) mission. A key milestone was the design and execution of an Observing System Simulation Experiment that quantified the contribution of soil moisture retrievals to land data assimilation products as a function of retrieval and land model skill and yielded an estimate of the error budget for the

  4. Estimating model and observation error covariance information for land data assimilation systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to operate efficiently, data assimilation systems require accurate assumptions concerning the statistical magnitude and cross-correlation structure of error in model forecasts and assimilated observations. Such information is seldom available for the operational implementation of land data ...

  5. Improving land surface emissivty parameter for land surface models using portable FTIR and remote sensing observation in Taklimakan Desert

    NASA Astrophysics Data System (ADS)

    Liu, Yongqiang; Mamtimin, Ali; He, Qing

    2014-05-01

    Because land surface emissivity (ɛ) has not been reliably measured, global climate model (GCM) land surface schemes conventionally set this parameter as simply assumption, for example, 1 as in the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) model, 0.96 for soil and wetland in the Global and Regional Assimilation and Prediction System (GRAPES) Common Land Model (CoLM). This is the so-called emissivity assumption. Accurate broadband emissivity data are needed as model inputs to better simulate the land surface climate. It is demonstrated in this paper that the assumption of the emissivity induces errors in modeling the surface energy budget over Taklimakan Desert where ɛ is far smaller than original value. One feasible solution to this problem is to apply the accurate broadband emissivity into land surface models. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument has routinely measured spectral emissivities in six thermal infrared bands. The empirical regression equations have been developed in this study to convert these spectral emissivities to broadband emissivity required by land surface models. In order to calibrate the regression equations, using a portable Fourier Transform infrared (FTIR) spectrometer instrument, crossing Taklimakan Desert along with highway from north to south, to measure the accurate broadband emissivity. The observed emissivity data show broadband ɛ around 0.89-0.92. To examine the impact of improved ɛ to radiative energy redistribution, simulation studies were conducted using offline CoLM. The results illustrate that large impacts of surface ɛ occur over desert, with changes up in surface skin temperature, as well as evident changes in sensible heat fluxes. Keywords: Taklimakan Desert, surface broadband emissivity, Fourier Transform infrared spectrometer, MODIS, CoLM

  6. Physical properties (particle size, rock abundance) from thermal infrared remote observations: Implications for Mars landing sites

    NASA Technical Reports Server (NTRS)

    Christensen, P. R.; Edgett, Kenneth S.

    1994-01-01

    Critical to the assessment of potential sites for the 1997 Pathfinder landing is estimation of general physical properties of the martian surface. Surface properties have been studied using a variety of spacecraft and earth-based remote sensing observations, plus in situ studies at the Viking lander sites. Because of their value in identifying landing hazards and defining scientific objectives, we focus this discussion on thermal inertia and rock abundance derived from middle-infrared (6 to 30 microns) observations. Used in conjunction with other datasets, particularly albedo and Viking orbiter images, thermal inertia and rock abundance provide clues about the properties of potential Mars landing sites.

  7. Viking landing sites, remote-sensing observations, and physical properties of Martian surface materials

    NASA Technical Reports Server (NTRS)

    Moore, Henry J.; Jakosky, Bruce M.

    1989-01-01

    Consideration is given to the relations between the physical properties of the surface materials at Viking landing sites, the physical properties of other Martian surfaces inferred from radar observations from earth and thermal observations from orbit, and the geological processes that formed the materials and shaped the surfaces. The radar and thermal remote-sensing signatures of the landing site surface materials are estimated and compared with the thermal and radar measurements for the entire planet. It is shown that the surface materials at the landing sites are good analogs for the materials in most of the Martian equatorial regions.

  8. Viking landing sites, remote-sensing observations, and physical properties of Martian surface materials

    NASA Astrophysics Data System (ADS)

    Moore, H. J.; Jakosky, B. M.

    1989-09-01

    Consideration is given to the relations between the physical properties of the surface materials at Viking landing sites, the physical properties of other Martian surfaces inferred from radar observations from earth and thermal observations from orbit, and the geological processes that formed the materials and shaped the surfaces. The radar and thermal remote-sensing signatures of the landing site surface materials are estimated and compared with the thermal and radar measurements for the entire planet. It is shown that the surface materials at the landing sites are good analogs for the materials in most of the Martian equatorial regions.

  9. Approximating tasseled cap values to evaluate brightness, greenness, and wetness for the Advanced Land Imager (ALI)

    USGS Publications Warehouse

    Yamamoto, Kristina H.; Finn, Michael P.

    2012-01-01

    The Tasseled Cap transformation is a method of image band conversion to enhance spectral information. It primarily is used to detect vegetation using the derived brightness, greenness, and wetness bands. An approximation of Tasseled Cap values for the Advanced Land Imager was investigated and compared to the Landsat Thematic Mapper Tasseled Cap values. Despite sharing similar spectral, temporal, and spatial resolution, the two systems are not interchangeable with regard to Tasseled Cap matrices.

  10. Ellerman bombs: Advances driven by high-resolution observations

    NASA Astrophysics Data System (ADS)

    Vissers, Gregal

    Ellerman bombs, transient brightenings that have traditionally been observed in the wings of the Balmer Halpha line, are a ubiquitous phenomenon in the lower atmosphere of active regions with considerable flux emergence. These explosive events display sub-arcsecond fine structure, fast dynamical evolution and their energies tend to fall in the nanoflare ballpark. Over the past decade and a half, several high-resolution ground-based and space-based telescopes have contributed greatly to further characterising Ellerman bombs, offering a view in spectral diagnostics ranging from the UV to the infrared. I will highlight some of the recent advances that have been made - both observationally and from a theoretical point of view - in determining their properties (quantitative morphology, energies, flows and proper motion, driving mechanism, etc.), and discuss the potential of observations from relatively new space-based telescopes, such as SDO and IRIS, to add to our understanding of this phenomenon.

  11. Advanced Microwave Precipitation Radiometer (AMPR) for remote observation of precipitation

    NASA Technical Reports Server (NTRS)

    Galliano, J. A.; Platt, R. H.

    1990-01-01

    The design, development, and tests of the Advanced Microwave Precipitation Radiometer (AMPR) operating in the 10 to 85 GHz range specifically for precipitation retrieval and mesoscale storm system studies from a high altitude aircraft platform (i.e., ER-2) are described. The primary goals of AMPR are the exploitation of the scattering signal of precipitation at frequencies near 10, 19, 37, and 85 GHz together to unambiguously retrieve precipitation and storm structure and intensity information in support of proposed and planned space sensors in geostationary and low earth orbit, as well as storm-related field experiments. The development of AMPR will have an important impact on the interpretation of microwave radiances for rain retrievals over both land and ocean for the following reasons: (1) A scanning instrument, such as AMPR, will allow the unambiguous detection and analysis of features in two dimensional space, allowing an improved interpretation of signals in terms of cloud features, and microphysical and radiative processes; (2) AMPR will offer more accurate comparisons with ground-based radar data by feature matching since the navigation of the ER-2 platform can be expected to drift 3 to 4 km per hour of flight time; and (3) AMPR will allow underflights of the SSM/I satellite instrument with enough spatial coverage at the same frequencies to make meaningful comparisons of the data for precipitation studies.

  12. Open-Source Data Assimilation for Land Models and Multiscale Observations.

    NASA Astrophysics Data System (ADS)

    Hoar, T. J.; Fox, A. M.; Zhang, Y.; Rosolem, R.; Toure, A. M.; Evans, B. J.; McCreight, J. L.

    2014-12-01

    The Data Assimilation Research Testbed (DART) has been coupled to severalland models including the Community Land Model (CLM),the Community Noah Land Surface Model (Noah LSM), WRF-Hydro, andthe CSIRO Atmosphere Biosphere Land Exchange (CABLE) model. Many typesof observational data ranging from in-situ soil moisture probes totower-based fluxes to satellite estimates of moisture have been successfully assimilated to produce model-based estimates of quantities that are moreconsistent with the information content of the observations and yet havethe desirable spatio-temporal attributes of the gridded model output. Examples of assimilation research with each of the models will be shown. One of the challenges for land data assimilation systems is the collectionand integration of the observational data given multiple datastreams andcollection agencies. The challenges and considerations of ingesting andusing a wide variety of data in many different formats will be discussedwith a view of what is needed for a community resource.

  13. Recent Advances in Magnetoseismology Using Network Observations by Ground Magnetometers

    NASA Astrophysics Data System (ADS)

    Chi, P. J.; Russell, C. T.

    2011-12-01

    The rise of modern, synchronized networks of ground magnetometers in recent years has inspired and advanced research and development in magnetoseismology. Like the practice in other geophysical disciplines, magnetoseismology can infer the structure of the magnetosphere from the observations of normal-mode frequencies of the magnetic field. It can also time and locate impulsive events by measuring the signal arrival time at multiple ground stations. We highlight recent advances in using network observations by ground magnetometers for both types of magnetoseismic research. In the area of normal-mode magnetoseismology the increase in ground magnetometers has enabled ever more station pairs suitable for the gradient analysis. We demonstrate progress in automatic detection of field line resonance frequencies and the results that reveal longitudinal structure of the plasmasphere. As a relatively young research topic, travel-time magnetoseismology has shown its capability to time and locate sudden impulses and substorm onsets by using ground-based magnetometer observations. These initial successes in turn motivated detailed examination of MHD wave propagation in the magnetosphere. In the end we discuss how these magnetoseismic studies shed light on the regions in the world where future establishment of ground magnetometers is desirable.

  14. Global Survey and Statistics of Radio-Frequency Interference in AMSR-E Land Observations

    NASA Technical Reports Server (NTRS)

    Njoku, Eni G.; Ashcroft, Peter; Chan, Tsz K.; Li, Li

    2005-01-01

    Radio-frequency interference (RFI) is an increasingly serious problem for passive and active microwave sensing of the Earth. To satisfy their measurement objectives, many spaceborne passive sensors must operate in unprotected bands, and future sensors may also need to operate in unprotected bands. Data from these sensors are likely to be increasingly contaminated by RFI as the spectrum becomes more crowded. In a previous paper we reported on a preliminary investigation of RFI observed over the United States in the 6.9-GHz channels of the Advanced Microwave Scanning Radiometer (AMSR-E) on the Earth Observing System Aqua satellite. Here, we extend the analysis to an investigation of RFI in the 6.9- and 10.7-GHz AMSR-E channels over the global land domain and for a one-year observation period. The spatial and temporal characteristics of the RFI are examined by the use of spectral indices. The observed RFI at 6.9 GHz is most densely concentrated in the United States, Japan, and the Middle East, and is sparser in Europe, while at 10.7 GHz the RFI is concentrated mostly in England, Italy, and Japan. Classification of RFI using means and standard deviations of the spectral indices is effective in identifying strong RFI. In many cases, however, it is difficult, using these indices, to distinguish weak RFI from natural geophysical variability. Geophysical retrievals using RFI-filtered data may therefore contain residual errors due to weak RFI. More robust radiometer designs and continued efforts to protect spectrum allocations will be needed in future to ensure the viability of spaceborne passive microwave sensing.

  15. Monitoring multi-decadal satellite earth observation of soil moisture using era-land global land water resources dataset

    NASA Astrophysics Data System (ADS)

    Albergel, Clement; Dorigo, Wouter; Balsamo, Gianpaolo; de Rosnay, Patricia; Muñoz-Sabater, Joaquin; Isaksen, Lars; Brocca, Luca; de Jeu, Richard; Wagner, Wolfgang

    2014-05-01

    It has been widely recognized that soil moisture is one of the main drivers of the water, energy and carbon cycles. It is a crucial variable for Numerical Weather Prediction (NWP) and climate projections because it plays a key role in hydro-meteorological processes. A good representation of soil moisture conditions can help improving the forecasting of precipitation, temperature, droughts and floods. For many applications global or continental scale soil moisture maps are needed. As a consequence, a signi?cant amount of studies have been conducted to obtain such information. For that purpose, land surface modeling, remote sensing techniques or a combination of both through Land Data Assimilation Systems are used. Assessing the quality of these products is required and for instance, the release of a new -long term- harmonized soil moisture product (SM-MW hereafter) from remote sensing within the framework of the European Space Agency's Water Cycle Multi-mission Observation Strategy (WACMOS) and Climate Change Initiative (CCI) projects in 2012 (more information at http://www.esa-soilmoisture-cci.org/) triggered several evaluation activities. The typical validation approach for model and satellite based data products is to compare them to in situ observations. However the evaluation of soil moisture products using ground measurements is not trivial. Even if in the recent years huge efforts were made to make such observations available in contrasting biomes and climate conditions, long term and large scale ground measurements networks are still sparse. Additionally, different networks will present different characteristics (e.g. measurement methods, installation depths and modes, calibration techniques, measurement interval, and temporal and spatial coverage). Finally using in situ measurements, the quality of retrieved soil moisture can be accurately assessed for the locations of the stations. That is why it is of interest to conceive new validation methods

  16. Land-Use/Land Cover Change as Driver of Earth System Dynamics: past progress, future priorities, and new data and models for advancing the science

    NASA Astrophysics Data System (ADS)

    Hurtt, G. C.; Lawrence, D. M.; Brovkin, V.; Calvin, K. V.; Chini, L. P.; Fisk, J.; Frolking, S. E.; Jones, C.; de Noblet-Ducoudre, N.; Pongratz, J.; Seneviratne, S. I.; Shevliakova, E.

    2014-12-01

    Human land-use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth surface, with impacts on climate. The activities which alter vegetation cover, biomass, and phenology, directly influence regional to global climate through modification of surface biophysical properties and the surface energy balance. Land-use activities are also impact climate through changes in carbon and nitrogen balances and greenhouse gas emissions. Moreover, land-use activities are likely to expand and/or intensify further to meet future demands for food, feed, fiber, and energy. The fifth phase of the Coupled Model Intercomparison Project (CMIP5) achieved a qualitative scientific advance in studying the effects of land-use on climate, for the first time explicitly accounting for the effects of global gridded land-use changes (past-future) in coupled carbon-climate model projections. Enabling this advance, the first consistent gridded land-use dataset (past-future) was developed, linking historical land-use data to future projections from Integrated Assessment Models, in a standard format required by climate models ("Land-use Harmonization"). Results from climate models indicate that the effects of land-use on climate, while uncertain, are sufficiently large and complex to warrant an expanded treatment of land-use. Here, we review past progress, future priorities, and present on new data and models designed to improve the understanding of the effects of land-use on climate (past-future). The work is organized through the Land Use Model Intercomparison Project (LUMIP) in preparation for CMIP6.

  17. Land surface water cycles observed with satellite sensors

    NASA Technical Reports Server (NTRS)

    Nghiem, Son V.; Njoku, E. G.; Brakenridge, G. R.; Kim, Y.

    2005-01-01

    Acceleration of the global water cycle may lead to increased global precipitation, faster evaporation and a consequent exacerbation of hydrologic extreme. In the U.S. national assessment of the potential consequences of climate variability and change, two GCMs (CGCM1 and HadCM2) show a large increase in precipitation in the future over the southwestern U.S. particularly during winter (Felzer and Heard, 1999). Increased precipitation potentially has important impacts on agricultural and water use in the southeast U.S. (Hatch et al., 1999) and in the central Great Plains (Nielsen, 1997). A hurricane model predicts a 40% precipitation increase for severe hurricanes affecting southeastern Florida, which provokes substantially greater flooding that could negate most of the benefits of present water-management practices in this basin (Gutowski et al., 1994). Thus, it is important to observe the hydroclimate on a continuous longterm basis to address the question of increased precipitation in the enhanced water cycle.

  18. Economic Value of an Advanced Climate Observing System

    NASA Astrophysics Data System (ADS)

    Wielicki, B. A.; Cooke, R.; Young, D. F.; Mlynczak, M. G.

    2013-12-01

    Scientific missions increasingly need to show the monetary value of knowledge advances in budget-constrained environments. For example, suppose a climate science mission promises to yield decisive information on the rate of human caused global warming within a shortened time frame. How much should society be willing to pay for this knowledge today? The US interagency memo on the social cost of carbon (SCC) creates a standard yardstick for valuing damages from carbon emissions. We illustrate how value of information (VOI) calculations can be used to monetize the relative value of different climate observations. We follow the SCC, setting uncertainty in climate sensitivity to a truncated Roe and Baker (2007) distribution, setting discount rates of 2.5%, 3% and 5%, and using one of the Integrated Assessment Models sanctioned in SCC (DICE, Nordhaus 2008). We consider three mitigation scenarios: Business as Usual (BAU), a moderate mitigation response DICE Optimal, and a strong response scenario (Stern). To illustrate results, suppose that we are on the BAU emissions scenario, and that we would switch to the Stern emissions path if we learn with 90% confidence that the decadal rate of temperature change reaches or exceeds 0.2 C/decade. Under the SCC assumptions, the year in which this happens, if it happens, depends on the uncertain climate sensitivity and on the emissions path. The year in which we become 90% certain that it happens depends, in addition, on our Earth observations, their accuracy, and their completeness. The basic concept is that more accurate observations can shorten the time for societal decisions. The economic value of the resulting averted damages depends on the discount rate, and the years in which the damages occur. A new climate observation would be economically justified if the net present value (NPV) of the difference in averted damages, relative to the existing systems, exceeds the NPV of the system costs. Our results (Cooke et al. 2013

  19. Modeling and Observational Framework for Diagnosing Local Land-Atmosphere Coupling on Diurnal Time Scales

    NASA Technical Reports Server (NTRS)

    Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kumar, Sujay V.; Alonge, Charles; Tao, Wei-Kuo

    2009-01-01

    Land-atmosphere interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed due to the complex interactions and feedbacks present across a range of scales. Further, uncoupled systems or experiments (e.g., the Project for Intercomparison of Land Parameterization Schemes, PILPS) may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land-atmosphere coupling is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during field experiments in the U. S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to the Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. Within this framework, the coupling established by each pairing of the available PBL schemes in WRF with the LSMs in LIS is evaluated in terms of the diurnal temperature and humidity evolution in the mixed layer. The co-evolution of these variables and the convective PBL is sensitive to and, in fact, integrative of the dominant processes that govern the PBL budget, which are synthesized through the use of mixing diagrams. Results show how the sensitivity of land-atmosphere interactions to the specific choice of PBL scheme and LSM varies across surface moisture regimes and can be quantified and evaluated against observations. As such, this methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate

  20. Stochastic control of light UAV at landing with the aid of bearing-only observations

    NASA Astrophysics Data System (ADS)

    Miller, Alexander; Miller, Boris

    2015-12-01

    This work considers the tracking of the UAV (unmanned aviation vehicle) at landing on unprepared field. Despite the advantages in UAV guidance the autonomous landing remains to be one of most serious problems. The principal difficulties are the absence of the precise UAV position measurements with respect to the landing field and the action of external atmospheric perturbations (turbulence and wind). So the control problem for UAV landing is the nonlinear stochastic one with incomplete information. The aim of the article is the development of stochastic control algorithms based on pseudomeasurement Kalman filter in the problem of the UAV autonomous landing with the aid of ground-based optical/radio radars in the case of strong wind and large initial error of the UAV entrance into the area covered by radars. The novelty of the article is the joint control-observation algorithm based on unbiased pseudomeasurement Kalman filter which provides the quadratic characteristics of the estimation errors. The later property is highly important for the UAV control based on the data fusion from INS (inertial navigation system) and the bearing observations obtained from external terrain based locators. The principal difficulty in the UAV landing control is the absence of the direct control tools at the terrain end, so the possible control can be based on the angular-range data obtained by terrain locators which must be transmitted from terrain location station to the UAV control unit. Thus the stochastic approach looks very effective in this challenging problem of the UAV landing.

  1. Summer-Fall Seasonal Ices at the Mars Phoenix Landing Site: Results from CRISM Observations

    NASA Astrophysics Data System (ADS)

    Cull, S.; Arvidson, R. E.; Morris, R. V.; Wolff, M. J.; Mellon, M. T.; Lemmon, M. T.

    2009-12-01

    We combine ground observations from the Mars Phoenix lander with orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to chart the onset of seasonal ice at the landing site from late spring (solar longitude [Ls] ~ 84) to late summer (Ls] ~ 117) . We use 25 CRISM observations acquired directly over the landing site and 13 acquired near the landing site. We find that summer ice-free spectra at the Phoenix landing site are approximated by scattering properties similar to Gusev Crater soils. Summer spectra have the strong water absorption at 3 μm, indicating a low level of hydration or adsorption of water, an effect previously observed throughout the northern hemisphere. Patches of permanent water ice appear on the shadowed sides of Heimdal Crater and on the shadowed sides of large mountains to the northeast. These patches were monitored throughout the summer and did not appear to grow or shrink; however, the ice patches darken between Ls~119 and Ls~160, possibly due to the sublimation or sintering of fine-grained ices cold-trapped onto the ice deposits during the spring defrost period. Mobile patches of summertime ice were observed to follow the shadow of a crater wall on an ~85-m crater located ~6.5 km northeast of the landing site. Widespread surface ice was first observed at the Phoenix landing site during the night (3 a.m. Local True Solar Time [LTST]) at Ls~104, and water ice was first observed in the afternoon (3 p.m. LTST) at Ls~154. CRISM observations show the first afternoon water ice clouds at Ls~157. Phoenix Surface Stereo Imager (SSI) images first show evidence of afternoon (1 p.m. LTST) water ice in the shadows of large rocks on operations sol 80 (Ls~112), but did not observe widespread afternoon ice during the mission, which ended at Ls~149.

  2. Using microwave observations to estimate land surface temperature during cloudy conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST), a key ingredient for physically-based retrieval algorithms of hydrological states and fluxes, remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observations and...

  3. A Physical Model to Estimate Snowfall over Land using AMSU-B Observations

    NASA Technical Reports Server (NTRS)

    Kim, Min-Jeong; Weinman, J. A.; Olson, W. S.; Chang, D.-E.; Skofronick-Jackson, G.; Wang, J. R.

    2008-01-01

    In this study, we present an improved physical model to retrieve snowfall rate over land using brightness temperature observations from the National Oceanic and Atmospheric Administration's (NOAA) Advanced Microwave Sounder Unit-B (AMSU-B) at 89 GHz, 150 GHz, 183.3 +/- 1 GHz, 183.3 +/- 3 GHz, and 183.3 +/- 7 GHz. The retrieval model is applied to the New England blizzard of March 5, 2001 which deposited about 75 cm of snow over much of Vermont, New Hampshire, and northern New York. In this improved physical model, prior retrieval assumptions about snowflake shape, particle size distributions, environmental conditions, and optimization methodology have been updated. Here, single scattering parameters for snow particles are calculated with the Discrete-Dipole Approximation (DDA) method instead of assuming spherical shapes. Five different snow particle models (hexagonal columns, hexagonal plates, and three different kinds of aggregates) are considered. Snow particle size distributions are assumed to vary with air temperature and to follow aircraft measurements described by previous studies. Brightness temperatures at AMSU-B frequencies for the New England blizzard are calculated using these DDA calculated single scattering parameters and particle size distributions. The vertical profiles of pressure, temperature, relative humidity and hydrometeors are provided by MM5 model simulations. These profiles are treated as the a priori data base in the Bayesian retrieval algorithm. In algorithm applications to the blizzard data, calculated brightness temperatures associated with selected database profiles agree with AMSU-B observations to within about +/- 5 K at all five frequencies. Retrieved snowfall rates compare favorably with the near-concurrent National Weather Service (NWS) radar reflectivity measurements. The relationships between the NWS radar measured reflectivities Z(sub e) and retrieved snowfall rate R for a given snow particle model are derived by a histogram

  4. GRASP Algorithm: retrieval of the aerosol properties over land surface from satellite observations (solicited)

    NASA Astrophysics Data System (ADS)

    Dubovik, Oleg; Litvinov, Pavel; Lapyonok, Tatyana; Ducos, Fabrice; Aspetsberger, Michael; Planer, Wolfgang; Federspiel, Christian; Fuertes, David

    The GRASP (Generalized Retrieval of Aerosol and Surface Properties) algorithm has been developed for enhanced characterization of the properties of both aerosol and land surface from diverse remote sensing observations. The concept of the algorithm is described in details by Dubovik et al. (2011). The algorithm is based on highly advanced statistically optimized fitting implemented as Multi-Term Least Square minimization (Dubovik, 2004) and deduces nearly 50 unknowns for each observed site. The algorithm derives a set of aerosol parameters similar to that derived by AERONET including detailed particle size distribution, the spectral dependence on the complex index of refraction and the fraction of non-spherical particles. The algorithm uses detailed aerosol and surface models and fully accounts for all multiple interactions of scattered solar light with aerosol, gases and the underlying surface. All calculations are done on-line without using traditional look-up tables. In addition, the algorithm can use the new multi-pixel concept - a simultaneous fitting of a large group of pixels with additional constraints limiting the time variability of surface properties and spatial variability of aerosol properties. This principle provides a possibility to improve retrieval for multiple observations even if the observations are not exactly co-incident or co-located. Significant efforts have been spent for optimization and speedup of the GRASP computer routine and retrievals from satellite observations. For example, the routine has been adapted for running at GPGPUs accelerators. Originally GRASP has been developed for POLDER/PARASOL multi-viewing imager and later adapted to a number of other satellite sensors such as MERIS at polar-orbiting platform and COCI/GOMS geostationary observations. The results of numerical tests and results of applications to real data will be presented. REFERENCES: Dubovik, et al.,“Statistically optimized inversion algorithm for enhanced

  5. Recent advances on the study of land-atmospheric interaction on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ma, Y.

    2009-04-01

    As a unique geological and geographical unit, the Tibetan Plateau dramatically impacts the world's environment and especially controls climatic and environmental changes in China, Asia and even in the Northern Hemisphere. Tibetan Plateau, therefore, provides a field laboratory for studying global change. With support from various agencies in the People's Republic of China, a Tibetan Observation and Research Platform (TORP) is now implementing. Firstly the background of the establishment of the TORP, the establishing and monitoring plan of long-term scale (5-10 years) of the TORP has been introduced. Then the preliminary observational analysis results, such as the characteristics of land surface heat fluxes and CO2 flux partitioning (diurnal variation, inter-monthly variation and vertical variation etc), the characteristics of atmospheric and soil variables, the structure of the Atmospheric Boundary Layer (ABL) and the turbulent characteristics have also been shown in this paper. The study on the regional distribution of land surface heat fluxes of paramount importance over heterogeneous landscape of the Tibetan Plateau. Therefore, here the parameterization methods based on satellite data (NOAA/AVHRR, Landsat-7 ETM, ASTER and MODIS) and Atmospheric Boundary Layer (ABL) observations have been proposed and tested for deriving surface reflectance, surface temperature, NDVI, MSAVI, vegetation coverage, LAI, net radiation flux, soil heat flux, sensible heat flux and latent heat flux over heterogeneous landscape. As cases study, the methods were applied to the experimental area of the CAMP/Tibet (CEOP (Coordinated Enhanced Observing Period) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau), which located at the central Tibetan Plateau and the whole Tibetan Plateau area. Five scenes of Landsat-7 ETM data, four scenes of NOAA/AVHRR data, three scenes of ASTER data and four MODIS data were used in this study. To validate the proposed methods, the ground

  6. Land Surface and Atmosphere Impacts on Spaceborne Passive Microwave Observations for Snowfall Estimation

    NASA Astrophysics Data System (ADS)

    Kraatz, S. G.; Zahraei, A.; Mahani, S. E.; Khanbilvardi, R.

    2013-12-01

    Accurate global estimates of precipitation rate will lead to a better understanding of atmospheric circulation and to improve climatology, weather forecasting and climate change studies. Sensitivity of microwave (MW) range of electromagnetic spectra to ice particles and snowflakes might lead us to use satellite-based MW brightness temperature (BT) to study snowfall. However, MW-BT significantly varies in regards to atmosphere and ground conditions (e.g. land coverage). This study will address how remotely sensed MW-BT measurements are affected by ground surface (snow covered vs. no-snow) and atmospheric conditions (hydrometeors vs. clear sky). The study area is located in the Northeastern United States. Multi MW frequencies from the Advanced Microwave Sounding Unit (AMSU), the NOAA-CREST in-situ snow measurement unit - CREST-SAFE (Snow Analysis and Field Experiment), ISCCP (International Satellite Cloud Climatology project), etc, will be used to show the interrelationship between satellite and ground-based retrieved MW observations. A statistical model has been developed to classify different ground and atmosphere scenarios, and derive relationships among different MW frequencies from satellite and in-situ measurements given ground and atmospheric conditions. We concluded that 89, 150, and 183×7 GHz bands are less affected by atmosphere humidity and can be used to measure ground surface and hydrometeors (e.g. ice particles) impacts. While satellite-based 89 GHz has shown a robust relationship with ground conditions, 68% correlation between satellite and ground observations; 150 and 183×7 GHz are 57% and 46% correlated with hydrometeors. Satellite-based 183×1 GHz has the weakest correlation with ground and atmosphere conditions.

  7. Global observation-based diagnosis of soil moisture control on land surface flux partition

    NASA Astrophysics Data System (ADS)

    Gallego-Elvira, Belen; Taylor, Christopher M.; Harris, Phil P.; Ghent, Darren; Veal, Karen L.; Folwell, Sonja S.

    2016-04-01

    Soil moisture plays a central role in the partition of available energy at the land surface between sensible and latent heat flux to the atmosphere. As soils dry out, evapotranspiration becomes water-limited ("stressed"), and both land surface temperature (LST) and sensible heat flux rise as a result. This change in surface behaviour during dry spells directly affects critical processes in both the land and the atmosphere. Soil water deficits are often a precursor in heat waves, and they control where feedbacks on precipitation become significant. State-of-the-art global climate model (GCM) simulations for the Coupled Model Intercomparison Project Phase 5 (CMIP5) disagree on where and how strongly the surface energy budget is limited by soil moisture. Evaluation of GCM simulations at global scale is still a major challenge owing to the scarcity and uncertainty of observational datasets of land surface fluxes and soil moisture at the appropriate scale. Earth observation offers the potential to test how well GCM land schemes simulate hydrological controls on surface fluxes. In particular, satellite observations of LST provide indirect information about the surface energy partition at 1km resolution globally. Here, we present a potentially powerful methodology to evaluate soil moisture stress on surface fluxes within GCMs. Our diagnostic, Relative Warming Rate (RWR), is a measure of how rapidly the land warms relative to the overlying atmosphere during dry spells lasting at least 10 days. Under clear skies, this is a proxy for the change in sensible heat flux as soil dries out. We derived RWR from MODIS Terra and Aqua LST observations, meteorological re-analyses and satellite rainfall datasets. Globally we found that on average, the land warmed up during dry spells for 97% of the observed surface between 60S and 60N. For 73% of the area, the land warmed faster than the atmosphere (positive RWR), indicating water stressed conditions and increases in sensible heat flux

  8. Seasonal ice cycle at the Mars Phoenix landing site: 2. Postlanding CRISM and ground observations

    NASA Astrophysics Data System (ADS)

    Cull, Selby; Arvidson, R. E.; Morris, R. V.; Wolff, M.; Mellon, M. T.; Lemmon, M. T.

    2010-05-01

    The combination of ground observations from the Mars Phoenix Lander and orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) provided a detailed view of the formation of late summer surface water ice at the landing site and surrounding regions. CRISM observations of the landing site during and immediately after Phoenix operations were analyzed to track the seasonal and diurnal ice cycles during the late spring to late summer, and a nonlinear mixing model was used to estimate grain sizes and relative abundances of water ice and dust. The surface around the Phoenix landing site was ice-free from late spring through midsummer, although transient patches of mobile ices were observed in an 85 m diameter crater to the northeast of the landing site. At the ˜10 km diameter Heimdal Crater, located ˜10 km east of the landing site, permanent patches of water ice were observed to brighten during the late spring and darken during the summer, possibly as fine-grained water ice that was cold trapped onto the ice during late spring sintered into larger grains or finally sublimated, exposing larger-grained ice. CRISM spectra first show evidence of widespread ice during the night at solar longitude (Ls) ˜ 109°, ˜9 sols before Phoenix’s Surface Stereo Imager detected it. CRISM spectra first show evidence of afternoon surface ice and water ice clouds after Ls ˜ 155°, after Phoenix operations ended.

  9. Assimilation of Freeze-Thaw Observations into the NASA Catchment Land Surface Model

    NASA Astrophysics Data System (ADS)

    Farhadi, L.; Reichle, R. H.; De Lannoy, G. J.; Kimball, J. S.

    2013-12-01

    The land surface freeze/thaw (F/T) state plays a key role in the hydrological and carbon cycles and thus affects water and energy exchanges and net primary productivity at the land surface. To support the level 4 soil moisture and carbon products (value-added, i.e. using a combination of remote sensing data and modeling) for the planned NASA Soil Moisture Active Passive (SMAP) mission, an F/T assimilation algorithm is developed for the NASA Goddard Earth Observing System, version 5 (GEOS-5) modeling and assimilation framework. The algorithm includes a newly developed observation operator that diagnoses the landscape F/T state in the GEOS-5 Catchment land surface model. A rule-based approach that incorporates model and observational errors is developed and used for assimilating the categorical F/T measurements into the land surface model (F/T analysis). An Observing System Simulation Experiment is conducted using synthetically generated measurements of the F/T state for a region in North America (90-110oW longitude, 45-55oN latitude). The synthetic 'truth' is generated using the NASA Catchment land surface model forced with surface meteorological fields from the Modern-Era Retrospective Reanalysis for Research and Applications (MERRA). To generate synthetic measurements, the true categorical F/T state is corrupted with a prescribed amount of F/T classification error. The assimilation experiment employs the same Catchment model except that forcing errors (relative to truth) are introduced via the application of meteorological forcing fields from the Global Land Data Assimilation System (GLDAS). The effect of the F/T analysis and classification error on land surface temperature and soil temperature predictions is examined in this research.

  10. Combining GOSAT XCO2 observations over land and ocean to improve regional CO2 flux estimates

    NASA Astrophysics Data System (ADS)

    Deng, Feng; Jones, Dylan B. A.; O'Dell, Christopher W.; Nassar, Ray; Parazoo, Nicholas C.

    2016-02-01

    We used the GEOS-Chem data assimilation system to examine the impact of combining Greenhouse Gases Observing Satellite (GOSAT) XCO2 data over land and ocean on regional CO2 flux estimates for 2010-2012. We found that compared to assimilating only land data, combining land and ocean data produced an a posteriori CO2 distribution that is in better agreement with independent data and fluxes that are in closer agreement with existing top-down and bottom-up estimates. Adding XCO2 data over oceans changed the tropical land regions from a source of 0.64 Pg C/yr to a sink of -0.60 Pg C/yr and produced a corresponding reduction in the estimated sink in northern and southern land regions by 0.49 Pg C/yr and 0.80 Pg C/yr, respectively. This highlights the importance of improved observational coverage in the tropics to better quantify the latitudinal distribution of the terrestrial fluxes. Based only on land XCO2 data, we estimated a strong source in northern tropical South America, which experienced wet conditions in 2010-2012. In contrast, with the land and ocean data, we estimated a sink for this wet region in the north, and a source for the seasonally dry regions in the south and east, which is consistent with our understanding of the impact of moisture availability on the carbon balance of the region. Our results suggest that using satellite data with a more zonally balanced observational coverage could help mitigate discrepancies in CO2 flux estimates; further improvement could be expected with the greater observational coverage provided by the Orbiting Carbon Observatory-2.

  11. Are deep-ocean-generated surface-wave microseisms observed on land?

    NASA Astrophysics Data System (ADS)

    Bromirski, Peter D.; Stephen, Ralph A.; Gerstoft, Peter

    2013-07-01

    studies attribute land double-frequency (DF) microseism observations to deep water generation. Here we show that near-coastal generation is generally the dominant source region. This determination is based on observations at land and ocean seismic stations, buoys, gravity-wave hindcasts, and on beamforming results from continental seismic arrays. Interactions between opposing ocean wave components generate a pressure excitation pulse at twice the ocean wave frequency that excites pseudo-Rayleigh (pRg) wave DF microseisms. pRg generated in shallow coastal waters have most of their energy in the solid Earth ("elastic" pRg) and are observed by land-based and seafloor seismometers as DF microseisms. pRg generated in the deep ocean have most of their energy in the ocean ("acoustic" pRg) and are continuously observed on the ocean bottom, but acoustic pRg does not efficiently transition onto continents. High-amplitude DF signals over the [0.2, 0.3] Hz band observed on the deep seafloor are uncorrelated with continental observations and are not clearly detectable at individual continental stations or by land seismic-array beamforming. Below 0.2 Hz, modeling and some observations suggest that some deep water-generated elastic pRg energy can reach continental stations, providing that losses from scattering and transition across the continental-shelf boundary to the shore are not substantial. However, most observations indicate that generally little deep-ocean-generated DF microseism energy reaches continental stations. Effectively, DF land observations are dominated by near-coastal wave activity.

  12. A Modeling and Observational Framework for Diagnosing Local Land-Atmosphere Coupling on Diurnal Time Scales

    NASA Astrophysics Data System (ADS)

    Santanello, J. A.; Peters-Lidard, C. D.; Kumar, S.

    2009-12-01

    Land-atmosphere interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed due to the complex interactions and feedbacks present across a range of scales. Further, uncoupled systems or experiments (e.g., the Project for Intercomparison of Land Parameterization Schemes, PILPS) may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land-atmosphere coupling is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during the summer of 2006 and 2007 in the Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to the Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. Mixing diagram diagnostics based on the evolution of 2m temperature and humidity are examined for the dry/wet extremes of this region, along with the sensitivity of PBL-LSM coupling to perturbations in soil moisture. As such, this methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate coupling diagnostics within the community.

  13. Consistent estimate of ocean warming, land ice melt and sea level rise from Observations

    NASA Astrophysics Data System (ADS)

    Blazquez, Alejandro; Meyssignac, Benoît; Lemoine, Jean Michel

    2016-04-01

    Based on the sea level budget closure approach, this study investigates the consistency of observed Global Mean Sea Level (GMSL) estimates from satellite altimetry, observed Ocean Thermal Expansion (OTE) estimates from in-situ hydrographic data (based on Argo for depth above 2000m and oceanic cruises below) and GRACE observations of land water storage and land ice melt for the period January 2004 to December 2014. The consistency between these datasets is a key issue if we want to constrain missing contributions to sea level rise such as the deep ocean contribution. Numerous previous studies have addressed this question by summing up the different contributions to sea level rise and comparing it to satellite altimetry observations (see for example Llovel et al. 2015, Dieng et al. 2015). Here we propose a novel approach which consists in correcting GRACE solutions over the ocean (essentially corrections of stripes and leakage from ice caps) with mass observations deduced from the difference between satellite altimetry GMSL and in-situ hydrographic data OTE estimates. We check that the resulting GRACE corrected solutions are consistent with original GRACE estimates of the geoid spherical harmonic coefficients within error bars and we compare the resulting GRACE estimates of land water storage and land ice melt with independent results from the literature. This method provides a new mass redistribution from GRACE consistent with observations from Altimetry and OTE. We test the sensibility of this method to the deep ocean contribution and the GIA models and propose best estimates.

  14. Aerodynamic performance of conventional and advanced design labyrinth seals with solid-smooth abradable, and honeycomb lands. [gas turbine engines

    NASA Technical Reports Server (NTRS)

    Stocker, H. L.; Cox, D. M.; Holle, G. F.

    1977-01-01

    Labyrinth air seal static and dynamic performance was evaluated using solid, abradable, and honeycomb lands with standard and advanced seal designs. The effects on leakage of land surface roughness, abradable land porosity, rub grooves in abradable lands, and honeycomb land cell size and depth were studied using a standard labyrinth seal. The effects of rotation on the optimum seal knife pitch were also investigated. Selected geometric and aerodynamic parameters for an advanced seal design were evaluated to derive an optimized performance configuration. The rotational energy requirements were also measured to determine the inherent friction and pumping energy absorbed by the various seal knife and land configurations tested in order to properly assess the net seal system performance level. Results indicate that: (1) seal leakage can be significantly affected with honeycomb or abradable lands; (2) rotational energy absorption does not vary significantly with the use of a solid-smooth, an abradable, or a honeycomb land; and (3) optimization of an advanced lab seal design produced a configuration that had leakage 25% below a conventional stepped seal.

  15. Evaluation of the uncertainty due to land cover observation and conversion into plant functional types

    NASA Astrophysics Data System (ADS)

    Georgievski, Goran; Hartley, Andrew; MacBean, Natasha; Hagemann, Stefan

    2016-04-01

    Land surface processes represented in the latest generation of climate models (IPCC AR5) use the concept of Plant Functional Types (PFTs) to group different vegetation types and species according to similar physiological, biochemical and structural characteristics. The 5th IPCC Assessment Report recognizes the role of the Land Surface Models (LSMs) as one of the key contributors to uncertainty in climate change impacts projections. In the frame of the European Space Agency (ESA) Climate Change Initiative (CCI), a new global land cover (LC) data set was derived. We aim to investigate two sources of uncertainties in LSMs and their ranges: (i) uncertainty of ESA-CCI state of the art satellite observation of LC classes, and (ii) uncertainty due to LC conversion ("cross-walking (CW) procedure") into PFTs. Therefore, we have derived 5 perturbations of PFTs maps: (i) reference map (REF), (ii) map that minimizes biomass in LC observation and CW procedure (MinLC MinCW), (iii) map that minimizes biomass in LC observation with reference CW procedure (MinLC RefCW), (iv) map that maximizes biomass in LC observation with reference CW procedure (MaxLC RefCW), and (v) map that maximizes biomass in LC observation and CW procedure (MaxLC MaxCW). Our analysis demonstrates that there is still considerable uncertainty in the methods used to convert LC classes into the PFTs used by LSMs. Furthermore, uncertainty in the labelling of LC classes has an equal magnitude compared to the cross-walking uncertainty. In the next phase, we aim to quantify the sensitivity of the carbon, hydrological and energy cycles to LC and CW uncertainty with 3 LSMs (JSBACH, JULES, and ORHCIDEE). This work will enable us to both advice the land cover mapping community about the accuracy requirements for land cover maps, and to provide insights to the earth system modelling community on the implications of decisions taken when converting from land cover classes to PFTs.

  16. Global observational diagnosis of soil moisture control on the land surface energy balance

    NASA Astrophysics Data System (ADS)

    Gallego-Elvira, Belen; Taylor, Christopher M.; Harris, Phil P.; Ghent, Darren; Veal, Karen L.; Folwell, Sonja S.

    2016-03-01

    An understanding of where and how strongly the surface energy budget is constrained by soil moisture is hindered by a lack of large-scale observations, and this contributes to uncertainty in climate models. Here we present a new approach combining satellite observations of land surface temperature and rainfall. We derive a Relative Warming Rate (RWR) diagnostic, which is a measure of how rapidly the land warms relative to the overlying atmosphere during 10 day dry spells. In our dry spell composites, 73% of the land surface between 60°S and 60°N warms faster than the atmosphere, indicating water-stressed conditions, and increases in sensible heat. Higher RWRs are found for shorter vegetation and bare soil than for tall, deep-rooted vegetation, due to differences in aerodynamic and hydrological properties. We show how the variation of RWR with antecedent rainfall helps to identify different evaporative regimes in the major nonpolar climate zones.

  17. Comparison of the EO-1 Advanced Land Imager Performance With the Landsat Data Continuity Mission Specification

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.; Hearn, D. R.; Lencioni, D. E.

    2002-01-01

    The performance requirements for the Advanced Land Imager were developed under NASA's New Millennium Program and were intended to facilitate the validation of new sensor technologies and architectures for potential application in future remote sensing missions. The Advanced Land Imager (ALI) was designed and flown well before the Landsat Data Continuity Mission (LDCM) specifications were developed. Nevertheless, the science focus of the ALI technology validation was Landsat data continuity. Therefore, although exact compliance by ALI is not expected, the performance should demonstrate a path to a compliant sensor system. The performance of the ALI, as determined from preflight and flight data, is compared to the LDCM specification. Twenty-one noncompliances have been identified: four data collection, four spectral, six spatial, and seven radiometric (Table I). All but six of these are considered minor. The six major noncompliances are the result of stray light, leaky detectors, and contamination. Appendix A replicates the LDCM specification and contains ALI compliance notes where appropriate. Details of the ALI stray light, contamination, and leaky detectors are provided in Appendix B, C, and D respectively. Additional information pertaining to the calculation of the ALI edge response and coherent noise is presented in Appendix E and F. A list of ALI related publications is provided in Appendix G.

  18. Utilizing NASA Earth Observations to Monitor Land Management Practices and the Development of Marshlands to Rice Fields in Rwanda

    NASA Astrophysics Data System (ADS)

    Dusabimana, M. R.; Blach, D.; Mwiza, F.; Muzungu, E.; Swaminathan, R.; Tate, Z.

    2014-12-01

    Rwanda, a small country with the highest population density in Sub-Saharan Africa, is one of the world's poorest countries. Although agriculture is the backbone of Rwandan economy, agricultural productivity is extremely low. Over 90 % of the population is engaged in subsistence farming and only 52 % of the total land surface area is arable. Of this land, approximately 165,000 hectares are marshlands, of which only 57 % has been cultivated. Rwandan government has invested in the advancement of agriculture with activities such as irrigation, marshland reclamation, and crop regionalization. In 2001, Ministry of Agriculture and Animal Resources (MINAGRI) released the Rural Sector Support Program (RSSP), which aimed at converting marshlands into rice fields at various development sites across the country. The focus of this project was to monitor rice fields in Rwanda utilizing NASA Earth observations such as Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager. Modified Normalized Difference Water Index (MNDWI) was used to depict the progress of marshland to rice field conversion as it highlights the presence of irrigated rice fields from the surrounding area. Additionally, Decision Support System for Agrotechnology Transfer (DSSAT) was used to estimate rice yield at RSSP sites. Various simulations were run to find perfect conditions for cultivating the highest yield for a given farm. Furthermore, soil erosion susceptibility masks were created by combining factors derived from ASTER, MERRA, and ground truth data using Revised Universal Soil Loss Equation (RUSLE). The end results, maps, and tutorials were delivered to the partners and policy makers in Rwanda to help make informed decisions. It can be clearly seen that Earth observations can be successfully used to monitor agricultural and land management practices as a cost effective method that will enable farmers to improve crop yield production and food security.

  19. Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

    NASA Astrophysics Data System (ADS)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Amariutei, D. V.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Belczynski, C.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Bork, R.; Boschi, V.; Bose, S.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.; DeRosa, R.; De Rosa, R.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Lieto, A.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J. M.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gatto, A.; Gaur, G.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, A.; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.

    2016-02-01

    We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg^2 to 20 deg^2 will require at least three detectors of sensitivity within a factor of ~2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

  20. Advanced Methods of Observing Surface Plasmon Polaritons and Magnons

    NASA Astrophysics Data System (ADS)

    Moghaddam, Abolghasem Mobaraki

    Available from UMI in association with The British Library. Requires signed TDF. The primary objectives of this thesis are the investigation of the theoretical and experimental aspects of the design and construction of advanced techniques for the excitation of surface plasmon-polaritons, surface magneto -plasmon-polaritons and surface magnons. They involve on -line observation of these phenomena and to accomplish these goals, analytical studies of the characteristic behaviour of these phenomena have been undertaken. For excitations of surface plasmon- and surface magneto-plasmon-polaritons the most robust and conventional configuration, namely Prism-Medium-Air, coupled to a novel angle scan (prism spinning) method was employed. The system to be described here can automatically measure the reflectivity of a multilayer system over a range of angles that includes the resonance angle in an Attenuated Total Reflection (ATR) experiment. The computer procedure that controls the system is quite versatile so that it allows any right-angle prism of different angle or refractive index to be utilised. It also provided probes to check for optical alignment within the system. Moreover, it performs the angular scan many times and then averages the results in order to reduce the environmental and other possible sources of noise within the system. The mechanical side of the system is unique and could eventually be adopted as a marketable piece of equipment. It consists of a turntable for holding the prism-sample assembly and a drive motor in conjunction with a servo-potentiometer whose output not only operates the turntable but also sends a signal to a computer to measure accurately its position. The interface unit enables a computer to control automatically an angular scan ATR experiment for measuring the resonance reflectivity spectrum of a multilayer system. The interface unit uses an H-bridge switch formed by four bipolar power transistor and two small signal MOSFETs to convert

  1. Comparison of land surface temperature measurements at NOAA CRN sites with airborne and satellite observations

    NASA Astrophysics Data System (ADS)

    Krishnan, P.; Kochendorfer, J.; Baker, B.; Dumas, E.; Meyers, T. P.; Guillevic, P.; Corda, S.; Muratore, J.; Martos, B.

    2011-12-01

    Land surface temperature (LST) is a key variable for studying global or regional land surface processes and the energy and water vapor exchange at the biosphere-atmosphere interface. In an effort to better quantify the spatial variability and overall representativeness of single-point surface temperature measurement being recorded at NOAA's Climate Reference Network (CRN) sites and to improve the accuracy of satellite land surface temperature measurements, airborne flight campaigns were conducted over two vegetated sites in Tennessee, USA during 2010 to 2011. During the campaign, multiple measurements of land surface temperature were made using Infra-Red temperature sensors at micrometeorological tower sites and onboard an instrumented Piper Navajo airborne research aircraft. In addition to this, coincident Moderate Resolution Imaging Spectroradiometer (MODIS) LST observations, onboard the NASA Terra and Aqua Earth Observing System satellites were used. The aircraft-based and satellite based land surface temperature measurements were compared to in situ, tower based LST measurements. Preliminary results show good agreement between in situ, aircraft and satellite measurements.

  2. COSMIC-2: A Platform for Advanced Ionospheric Observations

    NASA Astrophysics Data System (ADS)

    Straus, P. R.; Betz, D. A.

    2013-12-01

    The equatorial component of the COSMIC-2 program will consist of 6 satellites to be flown in a 24 degree inclination/520 km altitude orbit. In addition to the primary GNSS radio occultation (RO) payload, to be provided by JPL, the USAF plans to fly a pair of space weather sensors: a multi-frequency radio beacon and the Velocity, Ion Density and Irregularities (VIDI) in-situ plasma sensor package. Together, these three instruments will provide data to address key issues related to the specification and forecast of ionospheric densities and the instabilities/irregularities associated with ionospheric scintillation. The TriG GNSS receiver will provide a substantial increase in the number of daily ionospheric observations relative to COSMIC-1, both in the RO limb-viewing and overhead geometries. These data will provide a significant improvement of assimilative model capabilities for providing accurate ionospheric specifications in the important equatorial region. In addition, TriG will make routine measurements of ionospheric scintillation at L-band frequencies, as pioneered by the CORISS instrument on C/NOFS. The radio beacon, together with a network of ground receivers, will enable direct measurement of scintillation effects on trans-ionospheric signal propagation across the UHF to S-band frequency spectrum. The VIDI sensors will measure the in-situ density depletions associated with scintillation-producing irregularities. Together, the beacon, TriG, and VIDI will provide an unprecedented ability to map equatorial ionospheric instabilities and their effects. The in-situ package will also provide observations of plasma drifts from which electric fields, the most important physical driver for equatorial ionospheric structure, can be inferred. This will enable advancements in ionospheric models to further improve specifications and forecasts. In addition to discussing ionospheric science and operational support aspects of the COSMIC-2 mission, this presentation will

  3. Global patterns of annual actual evapotranspiration with land-cover type: knowledge gained from a new observation-based database

    NASA Astrophysics Data System (ADS)

    Ambrose, S. M.; Sterling, S. M.

    2014-10-01

    The process of evapotranspiration (ET) plays a critical role in the earth system, driving key land-surface processes in the energy, water and carbon cycles. Land-cover (LC) exerts multiple controls on ET, yet the global distribution of ET by LC and the related physical variables are poorly understood. The lack of quantitative understanding of global ET variation with LC begets considerable uncertainties regarding how ET and key land-surface processes will change alongside ongoing anthropogenic LC transformations. Here we apply statistical analysis and models to a new global ET database to advance our understanding of how annual actual ET varies with LC type. We derive global fields for each LC using linear mixed effect models (LMMs) that use geographical and meteorological variables as possible independent regression variables. Our inventory of ET observations reveals important gaps in spatial coverage that overlie hotpots of global change. There is a spatial bias of observations towards the mid latitudes, and LCs with large areas in the high latitudes (lakes, wetlands and barren land) are poorly represented. From the distribution of points as well as the uncertainty analysis completed by bootstrapping we identify high priority regions in need of more data collection. Our analysis of the new database provides new insights into how ET varies globally, providing more robust estimates of global ET rates for a broad range of LC types. Results reveal that different LC types have distinct global patterns of ET. Furthermore, zonal ET means among LCs reveal new patterns: ET rates in low latitudinal bands are more sensitive to LC change than in higher latitude bands; LCs with a higher evaporation component show higher variability of ET at the global scale; and LCs with dispersed rather than contiguous global locations have a higher variability of ET at the global scale. Results from this study indicate two major advancements are required to improve our ability to predict

  4. Variability and Predictability of Land-Atmosphere Interactions: Observational and Modeling Studies

    NASA Technical Reports Server (NTRS)

    Roads, John; Oglesby, Robert; Marshall, Susan; Robertson, Franklin R.

    2002-01-01

    The overall goal of this project is to increase our understanding of seasonal to interannual variability and predictability of atmosphere-land interactions. The project objectives are to: 1. Document the low frequency variability in land surface features and associated water and energy cycles from general circulation models (GCMs), observations and reanalysis products. 2. Determine what relatively wet and dry years have in common on a region-by-region basis and then examine the physical mechanisms that may account for a significant portion of the variability. 3. Develop GCM experiments to examine the hypothesis that better knowledge of the land surface enhances long range predictability. This investigation is aimed at evaluating and predicting seasonal to interannual variability for selected regions emphasizing the role of land-atmosphere interactions. Of particular interest are the relationships between large, regional and local scales and how they interact to account for seasonal and interannual variability, including extreme events such as droughts and floods. North and South America, including the Global Energy and Water Cycle Experiment Continental International Project (GEWEX GCIP), MacKenzie, and LBA basins, are currently being emphasized. We plan to ultimately generalize and synthesize to other land regions across the globe, especially those pertinent to other GEWEX projects.

  5. Integrating remotely sensed land cover observations and a biogeochemical model for estimating forest ecosystem carbon dynamics

    USGS Publications Warehouse

    Liu, J.; Liu, S.; Loveland, T.R.; Tieszen, L.L.

    2008-01-01

    Land cover change is one of the key driving forces for ecosystem carbon (C) dynamics. We present an approach for using sequential remotely sensed land cover observations and a biogeochemical model to estimate contemporary and future ecosystem carbon trends. We applied the General Ensemble Biogeochemical Modelling System (GEMS) for the Laurentian Plains and Hills ecoregion in the northeastern United States for the period of 1975-2025. The land cover changes, especially forest stand-replacing events, were detected on 30 randomly located 10-km by 10-km sample blocks, and were assimilated by GEMS for biogeochemical simulations. In GEMS, each unique combination of major controlling variables (including land cover change history) forms a geo-referenced simulation unit. For a forest simulation unit, a Monte Carlo process is used to determine forest type, forest age, forest biomass, and soil C, based on the Forest Inventory and Analysis (FIA) data and the U.S. General Soil Map (STATSGO) data. Ensemble simulations are performed for each simulation unit to incorporate input data uncertainty. Results show that on average forests of the Laurentian Plains and Hills ecoregion have been sequestrating 4.2 Tg C (1 teragram = 1012 gram) per year, including 1.9 Tg C removed from the ecosystem as the consequences of land cover change. ?? 2008 Elsevier B.V.

  6. Thermal barrier coatings issues in advanced land-based gas turbines

    NASA Technical Reports Server (NTRS)

    Parks, W. P.; Lee, W. Y.; Wright, I. G.

    1995-01-01

    The Department of Energy's Advanced Turbine System (ATS) program is aimed at forecasting the development of a new generation of land-based gas turbine systems with overall efficiencies significantly beyond those of current state-of-the-art machines, as well as greatly increased times between inspection and refurbishment, improved environmental impact, and decreased cost. The proposed duty cycle of ATS turbines will require the use of different criteria in the design of the materials for the critical hot gas path components. In particular, thermal barrier coatings will be an essential feature of the hot gas path components in these machines. While such coatings are routinely used in high-performance aircraft engines and are becoming established in land-based turbines, the requirements of the ATS turbine application are sufficiently different that significant improvements in thermal barrier coating technology will be necessary. In particular, it appears that thermal barrier coatings will have to function on all airfoil sections of the first stage vanes and blades to provide the significant temperature reduction required. In contrast, such coatings applied to the blades and vances of advanced aircraft engines are intended primarily to reduce air cooling requirements and extend component lifetime; failure of those coatings can be tolerated without jeopardizing mechanical or corrosion performance. A major difference is that in ATS turbines these components will be totally reliant on thermal barrier coatings which will, therefore, need to be highly reliable even over the leading edges of first stage blades. Obviously, the ATS program provides a very challenging opportunity for TBC's, and involves some significant opportunities to extend this technology.

  7. A Method to Retrieve Rainfall Rate Over Land from TRMM Microwave Imager Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Over tropical land regions, rain rate maxima in mesoscale convective systems revealed by the Precipitation Radar (PR) flown on the Tropical Rainfall Measuring Mission (TRMM) satellite are found to correspond to thunderstorms, i.e., Cbs. These Cbs are reflected as minima in the 85 GHz brightness temperature, T85, observed by the TRMM Microwave Imager (TMI) radiometer. Because the magnitude of TMI observations do not discriminate satisfactorily convective and stratiform rain, we developed here a different TMI discrimination method. In this method, two types of Cbs, strong and weak, are inferred from the Laplacian of T85 at minima. Then, to retrieve rain rate, where T85 is less than 270 K, a weak (background) rain rate is deduced using T85 observations. Furthermore, over a circular area of 10 km radius centered at the location of each T85 minimum, an additional Cb component of rain rate is added to the background rain rate. This Cb component of rain rate is estimated with the help of (T19-T37) and T85 observations. Initially, our algorithm is calibrated with the PR rain rate measurements from 20 MCS rain events. After calibration, this method is applied to TMI data taken from several tropical land regions. With the help of the PR observations, we show that the spatial distribution and intensity of rain rate over land estimated from our algorithm are better than those given by the current TMI-Version-5 Algorithm. For this reason, our algorithm may be used to improve the current state of rain retrievals on land.

  8. Assimilation of Freeze - Thaw Observations into the NASA Catchment Land Surface Model

    NASA Technical Reports Server (NTRS)

    Farhadi, Leila; Reichle, Rolf H.; DeLannoy, Gabrielle J. M.; Kimball, John S.

    2014-01-01

    The land surface freeze-thaw (F-T) state plays a key role in the hydrological and carbon cycles and thus affects water and energy exchanges and vegetation productivity at the land surface. In this study, we developed an F-T assimilation algorithm for the NASA Goddard Earth Observing System, version 5 (GEOS-5) modeling and assimilation framework. The algorithm includes a newly developed observation operator that diagnoses the landscape F-T state in the GEOS-5 Catchment land surface model. The F-T analysis is a rule-based approach that adjusts Catchment model state variables in response to binary F-T observations, while also considering forecast and observation errors. A regional observing system simulation experiment was conducted using synthetically generated F-T observations. The assimilation of perfect (error-free) F-T observations reduced the root-mean-square errors (RMSE) of surface temperature and soil temperature by 0.206 C and 0.061 C, respectively, when compared to model estimates (equivalent to a relative RMSE reduction of 6.7 percent and 3.1 percent, respectively). For a maximum classification error (CEmax) of 10 percent in the synthetic F-T observations, the F-T assimilation reduced the RMSE of surface temperature and soil temperature by 0.178 C and 0.036 C, respectively. For CEmax=20 percent, the F-T assimilation still reduces the RMSE of model surface temperature estimates by 0.149 C but yields no improvement over the model soil temperature estimates. The F-T assimilation scheme is being developed to exploit planned operational F-T products from the NASA Soil Moisture Active Passive (SMAP) mission.

  9. Contributions of Precipitation and Soil Moisture Observations to the Skill of Soil Moisture Estimates in a Land Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; Liu, Qing; Bindlish, Rajat; Cosh, Michael H.; Crow, Wade T.; deJeu, Richard; DeLannoy, Gabrielle J. M.; Huffman, George J.; Jackson, Thomas J.

    2011-01-01

    The contributions of precipitation and soil moisture observations to the skill of soil moisture estimates from a land data assimilation system are assessed. Relative to baseline estimates from the Modern Era Retrospective-analysis for Research and Applications (MERRA), the study investigates soil moisture skill derived from (i) model forcing corrections based on large-scale, gauge- and satellite-based precipitation observations and (ii) assimilation of surface soil moisture retrievals from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E). Soil moisture skill is measured against in situ observations in the continental United States at 44 single-profile sites within the Soil Climate Analysis Network (SCAN) for which skillful AMSR-E retrievals are available and at four CalVal watersheds with high-quality distributed sensor networks that measure soil moisture at the scale of land model and satellite estimates. The average skill (in terms of the anomaly time series correlation coefficient R) of AMSR-E retrievals is R=0.39 versus SCAN and R=0.53 versus CalVal measurements. The skill of MERRA surface and root-zone soil moisture is R=0.42 and R=0.46, respectively, versus SCAN measurements, and MERRA surface moisture skill is R=0.56 versus CalVal measurements. Adding information from either precipitation observations or soil moisture retrievals increases surface soil moisture skill levels by IDDeltaR=0.06-0.08, and root zone soil moisture skill levels by DeltaR=0.05-0.07. Adding information from both sources increases surface soil moisture skill levels by DeltaR=0.13, and root zone soil moisture skill by DeltaR=0.11, demonstrating that precipitation corrections and assimilation of satellite soil moisture retrievals contribute similar and largely independent amounts of information.

  10. Moderate resolution imaging spectroradiometer (MODIS) and observations of the land surface

    NASA Technical Reports Server (NTRS)

    Salomonson, V. V.; Toll, D. L.; Lawrence, W. T.

    1992-01-01

    The moderate resolution imaging spectroradiometer (MODIS) is a NASA facility instrument that is being designed for flight on the Earth Observing System (EOS) series of missions. It is designed to measure biophysical states and dynamics of the land, atmosphere, and ocean. Plans are required for use of other instruments that will be accompanying MODIS on the EOS missions, such as the High-Resolution Imaging Spectrometer (HIRIS) and the Multi-angle Imaging Spectro-Radiometer (MISR). The HIRIS instrument, a spectrometer operating in the visible to shortwave infrared parts of the spectrum, would be employed in combination with the MODIS to understand the impact of sampling the spectrum and the effects of land cover mixtures within the MODIS pixel. The MISR will help in understanding the effects of anisotropy in reflected solar radiation. Both instruments will work in combination with MODIS to better quantify the effects of the atmosphere on observations of surface properties.

  11. Daytime sensible heat flux estimation over heterogeneous surfaces using multitemporal land-surface temperature observations

    NASA Astrophysics Data System (ADS)

    Castellví, F.; Cammalleri, C.; Ciraolo, G.; Maltese, A.; Rossi, F.

    2016-05-01

    Equations based on surface renewal (SR) analysis to estimate the sensible heat flux (H) require as input the mean ramp amplitude and period observed in the ramp-like pattern of the air temperature measured at high frequency. A SR-based method to estimate sensible heat flux (HSR-LST) requiring only low-frequency measurements of the air temperature, horizontal mean wind speed, and land-surface temperature as input was derived and tested under unstable conditions over a heterogeneous canopy (olive grove). HSR-LST assumes that the mean ramp amplitude can be inferred from the difference between land-surface temperature and mean air temperature through a linear relationship and that the ramp frequency is related to a wind shear scale characteristic of the canopy flow. The land-surface temperature was retrieved by integrating in situ sensing measures of thermal infrared energy emitted by the surface. The performance of HSR-LST was analyzed against flux tower measurements collected at two heights (close to and well above the canopy top). Crucial parameters involved in HSR-LST, which define the above mentioned linear relationship, were explained using the canopy height and the land surface temperature observed at sunrise and sunset. Although the olive grove can behave as either an isothermal or anisothermal surface, HSR-LST performed close to H measured using the eddy covariance and the Bowen ratio energy balance methods. Root mean square differences between HSR-LST and measured H were of about 55 W m-2. Thus, by using multitemporal thermal acquisitions, HSR-LST appears to bypass inconsistency between land surface temperature and the mean aerodynamic temperature. The one-source bulk transfer formulation for estimating H performed reliable after calibration against the eddy covariance method. After calibration, the latter performed similar to the proposed SR-LST method.

  12. Local Scale Radiobrightness Modelling during Intensive Observing Period-4 of the Cold Land Processes Experiment-1

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco; deRoo, Roger; England, Anthony W.; Gu, Haoyu; Pham, Hanh; Boprie, David; Graf, Tobias; Koike, Toshio; Armstrong, Richard

    2004-01-01

    The NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and frozen ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in the spring of 2003 in Colorado, USA. Initial forward model validation work is concentrating on the Local-Scale Observation Site (LSOS), a 0.8 ha study site consisting of open meadows separated by trees where the most detailed measurements were made of snow depth and temperature, density, and grain size profiles. This paper will focus on the ability of forward Dense Medium Radiative Transfer (DMRT) modelling, combined with snowpack measurements to reproduce the radiobrightness signatures observed by the University of Michigan s Truck-Mounted Radiometer System at 19 and 37 GHz during the 4th Intensive Observing Period (IOP4) in March, 2003. Unlike the earlier IOP3, conditions during IOP4 include both wet and dry periods, providing a valuable test of DMRT model performance. Observations of upwelling and downwelling tree radiobrightness will be used to formulate a simple model for the effect of trees within the field of view. In addition, a comparison will be made for the one day of coincident observations by the University of Tokyo s Ground- Based Microwave Radiometer-7 (GBMR-7). These analyses will help guide the choice of future snow retrieval algorithms and the design of future Cold Lands observing systems.

  13. Interactive Computing and Processing of NASA Land Surface Observations Using Google Earth Engine

    NASA Technical Reports Server (NTRS)

    Molthan, Andrew; Burks, Jason; Bell, Jordan

    2016-01-01

    Google's Earth Engine offers a "big data" approach to processing large volumes of NASA and other remote sensing products. h\\ps://earthengine.google.com/ Interfaces include a Javascript or Python-based API, useful for accessing and processing over large periods of record for Landsat and MODIS observations. Other data sets are frequently added, including weather and climate model data sets, etc. Demonstrations here focus on exploratory efforts to perform land surface change detection related to severe weather, and other disaster events.

  14. Using observed dry spell land surface temperature to investigate simulated European heat waves

    NASA Astrophysics Data System (ADS)

    Harris, Phil; Folwell, Sonja; Taylor, Christopher; Rodríguez, José

    2014-05-01

    There is increasing evidence that European summer temperature extremes can be enhanced by soil moisture- induced land-atmosphere feedback. Moreover, climate model projections indicate that heat wave events could become more frequent in the future. The surface energy partition into latent and sensible heat flux exerts an important control over this feedback, but quite how it responds to soil moisture remains uncertain. For example, climate models disagree to what extent current central European summer evaporation is limited by soil moisture or incident radiation. In situ observations are improving our understanding of these dry down processes, but they are limited to relatively few locations. Alternatively, satellite observations of land surface temperature (LST) provide indirect information about the surface energy partition across the whole of Europe. Here, we improve dry spell dynamics in the JULES land surface model using satellite observations of LST, and evaluate the corresponding impact on temperatures simulated by the parent climate model, MetUM. We use a spatially and temporally aggregated diagnostic derived from 1 km daytime MODIS-Terra LST observations to describe the composite response of LST during surface dry down in rain-free periods. This diagnostic is produced for Europe at 0.5° spatial resolution to allow comparison with the equivalent values simulated by the land surface scheme. For Mediterranean grasslands, JULES exhibits warming rates during the first 15 days of dry down that compare well with observations, whereas outside of the Mediterranean the simulated warming rates are much weaker than observed. The composite diagnostic is then used to train spatially-invariant JULES parameters that are known to affect the modelled soil moisture control of evaporation on sub-seasonal time scales. The trained parameters are then applied to climate simulations using the Met Office Unified Model (MetUM GA5.0) to examine their effect in the coupled land

  15. Land and Atmosphere Near-Real-Time Capability for Earth Observing System

    NASA Technical Reports Server (NTRS)

    Murphy, Kevin J.

    2011-01-01

    LANCE (Land, Atmosphere Near-Real-Time Capability for EOS) in 2009. LANCE consists of special processing elements, co-located with selected EOSDIS data centers and processing facilities. A primary goal of LANCE is to bring multiple near-real-time systems under one umbrella, offering commonality in data access, quality control, and latency. LANCE now processes and distributes data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Atmospheric Infrared Sounder (AIRS), Advanced Microwave Scanning Radiometer Earth Observing System (AMSR-E), Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) instruments within 3 hours of satellite observation. The Rapid Response System and the Fire Information for Resource Management System (FIRMS) capabilities will be incorporated into LANCE in 2011. LANCE maintains a central website to facilitate easy access to data and user services. LANCE products are extensively tested and compared with science products before being made available to users. Each element also plans to implement redundant network, power and server infrastructure to ensure high availability of data and services. Through the user registration system, users are informed of any data outages and when new products or services will be available for access. Building on a significant investment by NASA in developing science algorithms and products, LANCE creates products that have a demonstrated utility for applications requiring near-real-time data. From lower level data products such as calibrated geolocated radiances to higher-level products such as sea ice extent, snow cover, and cloud cover, users have integrated LANCE data into forecast models and decision support systems. The table above shows the current near-real-time product categories by instrument. The ESDIS Project continues to improve the LANCE system and use the experience gained through practice to seek adjustments to improve the quality and performance of the system. For example, an

  16. Observation on internal waves propagation during Land breeze event in Northern Tyrrhenian coast

    NASA Astrophysics Data System (ADS)

    Martellucci, Riccardo; Pierattini, Alberto; Paladini de Mendoza, Francesco; Melchiorri, Cristiano; Piermattei, Viviana; Ciampa, Francesco; Marcelli, Marco

    2015-04-01

    Internal wave propagation and water column mixing phenomena play an important role in many marine ecosystem coastal process. In Northern Tyrrhenian coast the experimental proposed approach is aimed to identify these type of oscillation in presence of breeze circulation. Along the Tyrrhenian coast summer period climate conditions allow the generations of high frequency land-sea breeze events. This local circulation, land-sea breeze indeed, may generate significant modifications of the sea waters physical parameters. Thay often appear as internal gravity waves especially in presence of stratified water and stable thermocline. Since the whole investigated process evolves on diurnal scale and in the space of a few miles the sampling plan was operated with a series of oceanographic surveys at 40 meters depth with 20 minutes interval one from another between 5 a.m. and 11 a.m. and they were repeted during each summers between 2012 - 2014. Coupled with the acquisition of physical parameters current data were collected with 500 kHz ADCP every 20s, the resolution of vertical profiles of CTD matches the ADCP 1 meter magnitude vertical resolution. in order to investigate the water column layers dynamics behavior, Brunt-Vaisala and Richardson number were computed using the sampled physical parameters. Coastal surveys analysis highlights the presence of temperature oscillation in proximity of the thermocline and bottom layers; these oscillations have been observed during all measure surveys, when the land breeze was over. Indeed the land breeze tends to generate an offshore transport causing bottom layers to lift. At the same time solar radiation heating causes a sink of the surface layers which flatten the layers in proximity of the thermocline. Therefore the oscillations of temperature observed during the oceanographic surveys have to considered as internal waves, as during earlier studies conducted in the Tyrrhenian Sea has been observed.

  17. Recent Advances in Modeling of the Atmospheric Boundary Layer and Land Surface in the Coupled WRF-CMAQ Model

    EPA Science Inventory

    Advances in the land surface model (LSM) and planetary boundary layer (PBL) components of the WRF-CMAQ coupled meteorology and air quality modeling system are described. The aim of these modifications was primarily to improve the modeling of ground level concentrations of trace c...

  18. Using Microwave Observations to Estimate Land Surface Temperature during Cloudy Conditions

    NASA Astrophysics Data System (ADS)

    Holmes, T. R.; Crow, W. T.; Hain, C.; Anderson, M. C.

    2014-12-01

    Land surface temperature (LST), a key ingredient for physically-based retrieval algorithms of hydrological states and fluxes, remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observations and passive microwave observations (MW). TIR is the most commonly used approach and the method of choice to provide standard LST products for various satellite missions. MW-based LST retrievals on the other hand are not as widely adopted for land applications; currently their principle use is in soil moisture retrieval algorithms. MW and TIR technologies present two highly complementary and independent means of measuring LST. MW observations have a high tolerance to clouds but a low spatial resolution, and TIR has a high spatial resolution with temporal sampling restricted to clear skies. The nature of the temperature at the very surface layer of the land makes it difficult to combine temperature estimates between different methods. The skin temperature is characterized by a strong diurnal cycle that is dependant in timing and amplitude on the exact sensing depth and thermal properties of the vegetation. This paper builds on recent progress in characterizing the main structural components of the DTC that explain differences in TIR and MW estimates of LST. Spatial patterns in DTC timing (phase lag with solar noon) and DTC amplitude have been calculated for TIR, MW and compared to weather prediction estimates. Based on these comparisons MW LST can be matched to the TIR record. This paper will compare in situ measurements of LST with satellite estimates from (downscaled) TIR and (reconciled) MW products. By contrasting the validation results of clear sky days with those of cloudy days the expected tolerance to clouds of the MW observations will be tested. The goal of this study is to determine the weather conditions in which MW can supplement the TIR LST record.

  19. Inverse modeling of interbed storage parameters using land subsidence observations, Antelope Valley, California

    USGS Publications Warehouse

    Hoffmann, J.; Galloway, D.L.; Zebker, H.A.

    2003-01-01

    We use land-subsidence observations from repeatedly surveyed benchmarks and interferometric synthetic aperture radar (InSAR) in Antelope Valley, California, to estimate spatially varying compaction time constants, ??, and inelastic specific skeletal storage coefficients, Skv*, in a previously calibrated regional groundwater flow and subsidence model. The observed subsidence patterns reflect both the spatial distribution of head declines and the spatially variable inelastic skeletal storage coefficient. Using the nonlinear parameter estimation program UCODE we estimate compaction time constants between 3.8 and 285 years. The Skv* values are estimated by linear estimation and range from 0 to almost 0.09. We find that subsidence observations over long time periods are necessary to constrain estimates of the large compaction time constants in Antelope Valley. The InSAR data used in this study cover only a three-year period, limiting their usefulness in constraining these time constants. This problem will be alleviated as more SAR data become available in the future or where time constants are small. By incorporating the resulting parameter estimates in the previously calibrated regional model of groundwater flow and land subsidence we can significantly improve the agreement between simulated and observed land subsidence both in terms of magnitude and spatial extent. The sum of weighted squared subsidence residuals, a common measure of model fit, was reduced by 73% with respect to the original model. However, the ability of the model to adequately reproduce the subsidence observed over only a few years is impaired by the fact that the simulated hydraulic heads over small time periods are often not representative of the actual aquifer hydraulic heads. Errors in the simulated hydraulic aquifer heads constitute the primary limitation of the approach presented here.

  20. Observational Evaluation of Simulated Land-Atmosphere Coupling on the U.S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Phillips, T. J.; Klein, S. A.

    2014-12-01

    In a recent study of observed features of land-atmosphere coupling (LAC) at the ARM Southern Great Plains (ARM SGP) site in northern Oklahoma (Phillips and Klein, 2014 Journal of Geophysical Research), we identified statistically significant interactions between 1997-2008 summertime daily averages of soil moisture (at 10 cm depth) and a number of surface atmospheric variables, such as surface evaporation, relative humidity, and temperature. Here we will report on an evaluation of similar features of LAC simulated by version 5 of the global Community Atmosphere Model (CAM5), coupled to its native CLM4 land model, and downscaled to the vicinity of the ARM SGP site. In these case studies, the CAM5 was initialized from a 6-hourly atmospheric reanalysis for each day of the years 2008 and 2009 (where the CLM4 land state was equilibrated to the atmospheric model state), thus permitting a close comparison of the modeled and observed summer daily average features of the LAC in these years. Correlation coefficients R and "sensitivity indices" I (a measure of the comparative change of an atmospheric variable for a one-standard-deviation change in soil moisture) provided quantitative measures of the respective coupling strengths. Such a comparison of observed versus modeled LAC is complicated by differences in atmospheric forcings of the land; for example, the CAM5's summertime precipitation is too scant, and thus the model's upper soil layer often is drier than observed. The modeled daily average covariations of soil moisture with lower atmospheric variables also display less coherence (lower R values), but sometimes greater "sensitivity" (higher I values) than are observed at the ARM SGP site. Since the observational estimate of LAC may itself be sensitive to soil moisture measurement biases, we also will report on a planned investigation of the dependence of LAC on several alternative choices of soil moisture data sets local to the ARM SGP site. AcknowledgmentsThis work was

  1. Land Surface Microwave Emissivities Derived from AMSR-E and MODIS Measurements with Advanced Quality Control

    NASA Technical Reports Server (NTRS)

    Moncet, Jean-Luc; Liang, Pan; Galantowicz, John F.; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    A microwave emissivity database has been developed with data from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and with ancillary land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the same Aqua spacecraft. The primary intended application of the database is to provide surface emissivity constraints in atmospheric and surface property retrieval or assimilation. An additional application is to serve as a dynamic indicator of land surface properties relevant to climate change monitoring. The precision of the emissivity data is estimated to be significantly better than in prior databases from other sensors due to the precise collocation with high-quality MODIS LST data and due to the quality control features of our data analysis system. The accuracy of the emissivities in deserts and semi-arid regions is enhanced by applying, in those regions, a version of the emissivity retrieval algorithm that accounts for the penetration of microwave radiation through dry soil with diurnally varying vertical temperature gradients. These results suggest that this penetration effect is more widespread and more significant to interpretation of passive microwave measurements than had been previously established. Emissivity coverage in areas where persistent cloudiness interferes with the availability of MODIS LST data is achieved using a classification-based method to spread emissivity data from less-cloudy areas that have similar microwave surface properties. Evaluations and analyses of the emissivity products over homogeneous snow-free areas are presented, including application to retrieval of soil temperature profiles. Spatial inhomogeneities are the largest in the vicinity of large water bodies due to the large water/land emissivity contrast and give rise to large apparent temporal variability in the retrieved emissivities when satellite footprint locations vary over time. This issue will be dealt with in the future by

  2. A Method to Retrieve Rainfall Rate over Land from TRMM Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.

    2002-01-01

    Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) observations over mesoscale convective systems (MCSs) reveal that there are localized maxima in the rain rate with a scale of about 10 to 20 km that represent thunderstorms (Cbs). Some of these Cbs are developing or intense, while others are decaying or weak. These Cbs constitute only about 20 % of the rain area of a given MCS. Outside of Cbs, the average rain rate is much weaker than that within Cbs. From an analysis of the PR data, we find that the spatial distribution of rain and its character, convective or stratiform, is highly inhomogeneous. This complex nature of rain exists on a scale comparable to that of a Cb. The 85 GHz brightness temperature, T85, observations of the TRMM Microwave Imager (TMI) radiometer taken over an MCS reflect closely the PR rain rate pattern over land. Local maxima in rain rate shown by PR are observed as local minima in T85. Where there are no minima in T85, PR observations indicate there is light rain. However, the TMI brightness temperature measurements (Tbs) have poor ability to discriminate convective rain from stratiform rain. For this reason, a TMI rain retrieval procedure that depends primarily on the magnitude of Tbs performs poorly. In order to retrieve rain rate from TMI data on land one has to include the spatial distribution information deduced from the T85 data in the retrieval method. Then, quantitative estimation of rain rate can be accomplished. A TMI rain retrieval method developed along these lines can yield estimates of rain rate and its frequency distribution which agree closely with that given by PR. We find the current TRMM project TMI (Version 5) rain retrieval algorithm on land could be improved with the retrieval scheme developed here. To support the conceptual frame work of the rain retrieval method developed here, a theoretical analysis of the TMI brightness temperatures in convective and stratiform regions is presented.

  3. Integrated Assessment Modeling of Carbon Sequestration and Land Use Emissions Using Detailed Model Results and Observations

    SciTech Connect

    Dr. Atul Jain

    2005-04-17

    This report outlines the progress on the development and application of Integrated Assessment Modeling of Carbon Sequestrations and Land Use Emissions supported by the DOE Office of Biological and Environmental Research (OBER), U.S. Department of Energy, Grant No. DOE-DE-FG02-01ER63069. The overall objective of this collaborative project between the University of Illinois at Urbana-Champaign (UIUC), Oak Ridge National Laboratory (ORNL), Lawrence Livermore National Laboratory (LLNL), and Pacific Northwest National Laboratory (PNNL) was to unite the latest advances in carbon cycle research with scientifically based models and policy-related integrated assessment tools that incorporate computationally efficient representations of the latest knowledge concerning science and emission trajectories, and their policy implications. As part of this research we accomplished the following tasks that we originally proposed: (1) In coordination with LLNL and ORNL, we enhanced the Integrated Science Assessment Model's (ISAM) parametric representation of the ocean and terrestrial carbon cycles that better represent spatial and seasonal variations, which are important to study the mechanisms that influence carbon sequestration in the ocean and terrestrial ecosystems; (2) Using the MiniCAM modeling capability, we revised the SRES (IPCC Special Report on Emission Scenarios; IPCC, 2000) land use emission scenarios; and (3) On the application front, the enhanced version of ISAM modeling capability is applied to understand how short- and long-term natural carbon fluxes, carbon sequestration, and human emissions contribute to the net global emissions (concentrations) trajectories required to reach various concentration (emission) targets. Under this grant, 21 research publications were produced. In addition, this grant supported a number of graduate and undergraduate students whose fundamental research was to learn a disciplinary field in climate change (e.g., ecological dynamics and

  4. Observing Nutrient Dynamics in Streams Draining Varied Land Uses Using In Situ Optical Sensors

    NASA Astrophysics Data System (ADS)

    Vaughan, M.; Schroth, A. W.; Bowden, W. B.; Jerram, A.; Shanley, J. B.; Vermilyea, A.

    2014-12-01

    In recent years, in situ optical water quality sensors have been applied to advance the understanding of biogeochemical changes in aquatic systems at temporal scales impracticable for traditional grab sampling. Optical sensor technology was used in northern Vermont to measure watershed response to seasonal- and event-based fluctuations in various water quality parameters using measurements every 15 minutes. An in-stream UV-Vis spectrometer measured turbidity and nitrate, total organic carbon, and dissolved organic carbon concentrations using turbidity compensated spectra at wavelengths from 200 nm to 700 nm. Sensors were placed in streams whose watersheds represent urban-suburban, agricultural, forested, and mixed land uses in order to understand varied chemical responses based on a variety of natural and anthropogenic influences. Salt dilution and velocity-area discharge measurements were made in concert with pressure transducer measurements to develop robust rating curves for streams where no US Geological Survey discharge data was available so that loads could be calculated. Findings will deepen the understanding of (1) the behavior of dissolved organic carbon, nitrate, and sediment across watersheds of different land uses, focusing on seasonal climatic drivers and response to extreme events, (2) the changes in the absorbance and fluorescence character of dissolved organic carbon over diurnal, event-based, and seasonal temporal scales, and (3) how high-frequency water quality data can be used to better calculate nutrient loads to receiving water bodies.

  5. Transient land breeze: Eclipse induced wind flow modifications—Observations over plant canopy

    NASA Astrophysics Data System (ADS)

    Murthy, B. S.; Latha, R.; Sreeja, P.; Dharmaraj, T.

    2012-11-01

    An experiment is conducted over Cassava plant canopy at a coastal station at CTCRI, Thiruvananthapuram (8°29'N, 76°59E) to study the response of meteorological parameters and land-sea breeze circulations to the annular solar eclipse on January 15, 2010. Observations reveal decrease of solar radiation to a minimum of 96 W m-2 during the peak eclipse period. Air temperature drops by 4 °C and relative humidity increases by 20%. Sensible heat flux reduces to zero. Transient land breeze occurs for a few minutes with a time lag of about 1 h possibly due to outflow from the umbra region or temperature gradient over land with the eclipse progressing in the eastward direction. Sea breeze is delayed by about 3 h on the next day of eclipse. Spectral energy density of wind (u, v, w) and temperature attains a minimum value during totality and increases later, attributable to reduction in turbulence due to eclipse-induced stability.

  6. GPS observations of seasonal crustal deformation and long-term land subsidence in response to water storage changes in California

    NASA Astrophysics Data System (ADS)

    Anderson, K. J.; De Linage, C.; Famiglietti, J. S.

    2011-12-01

    Observations of vertical land surface height from Scripps Orbit and Permanent Array Center (SOPAC) GPS stations throughout California and the Western United States reveal significant seasonal and long-term land surface responses to water storage changes. Long-term land surface subsidence in the Central Valley is due to aquifer compaction resulting from ongoing groundwater depletion. Seasonal motion of the land surface due to elastic crustal loading provides insight about seasonal surface water loads such as snow water equivalent, soil moisture, and reservoir storage. This research explores the relationship between water storage changes observed by GRACE and Snotel and the land surface responses observed by GPS, and the potential for new applications of GPS for monitoring various components of water storage.

  7. Role of land atmosphere interactions in WCRP - overview of the terrestrial component of GEWEX and the observing networks and field campaigns

    NASA Astrophysics Data System (ADS)

    Try, P.

    2002-06-01

    The Global Energy and Water Cycle Experiment (GEWEX) of the World Climate Research Programme (WCRP) has been designed to observe and model the hydrologic cycle and energy fluxes in the atmosphere, at the land surface, and in the upper oceans. GEWEX is an integrated program of research, observations, and science activities ultimately leading to the prediction of global and regional climate change. The objectives of the GEWEX Program are to: -- determine the hydrological cycle and energy fluxes by means of global measurements of atmospheric and surface properties; -- model the global hydrological cycle and its impact on the atmosphere, oceans and land surfaces; -- develop the ability to predict the variations of global and regional hydrological processes and water resources, and their response to environmental change; and, -- advance the development of observing techniques, data management, and assimiliation systems for operational application to long-range weather forecasts, hydrology, and climate predictions. The primary activities of GEWEX are a) global data set development, b) process studies, c) model development support. To accomplish this, GEWEX has many components to address the critical elements with roles in the energy and water cycles. The data projects focus on global distribution and variability of clouds, water vapour, aerosols, surface radiation, precipitation and the features of the land surface and near surface meteorology that couple the land to the atmosphere. The modelling projects focus on the cloud, land-atmosphere and boundary layer parameterizations necessary to drive our regional and global predictive models. Coupling the land-atmosphere at the mesoscale has been the initial strategy for GEWEX and five major continental-scale field campaigns have been underway to provide new process and modelling understanding in the Amazon, Baltic Sea, Mississippi River Basin, MacKenzie River Basin, and four basins in Asia (Thailand, Tibet, Siberia and China

  8. Chang'e 3 and Jade Rabbit's: observations and the landing zone

    NASA Astrophysics Data System (ADS)

    Ping, Jinsong

    Chang’E-3 was launched and landed on the near side of the Moon in December 2013. It is realizing the 2nd phase of Chinese lunar scientific exploration projects. Together with the various in-situ optical observations around the landing sites, the mission carried 4 kinds of radio science experiments, cover the various lunar scientific disciplines as well as lunar surface radio astronomy studies. The key payloads onboard the lander and rover include the near ultraviolet telescope, extreme ultraviolet cameras, ground penetrating radar, very low frequency radio spectrum analyzer, which have not been used in earlier lunar landing missions. Optical spectrometer, Alpha Paticle X-ray spectrometer and Gama Ray spectrometer is also used. The mission is using extreme ultraviolet camera to observe the sun activity and geomagnetic disturbances on geo-space plasma layer of extreme ultraviolet radiation, studying space weather in the plasma layer role in the process; the mission also carries the first time lunar base optical astronomical observations. Most importantly, the topography, landforms and geological structure has been explored in detail. Additionally, the very precise Earth-Moon radio phase ranging technique was firstly tested and realized in this mission. It may increase the study of lunar dyanmics together with LLR technique. Similar to Luna-Glob landers, together with the VLBI radio beacons, the radio transponders are also set on the Chang’E-3. Transponder will receive the uplink X band radio wave transmitted from the two newly constructed Chinese deep space stations, where the high quality hydrogen maser atomic clocks have been used as local time and frequency standard. Radio science receivers have been developed by updating the multi-channel open loop Doppler receiver developed for VLBI and Doppler tracking in Yinghuo-1 and Phobos-Glob Martian missions. This experiment will improve the study of lunar dynamics, by means of measuring the lunar physical liberations

  9. Real-time infrared target processor for advanced land fire control applications

    NASA Astrophysics Data System (ADS)

    Lithopoulos, Erik; Sevigny, Leandre; Laurent, John

    1994-10-01

    The infrared target processor (IRTP) is a real-time processor capable of automatic and operator-aided detection, lock-on and tracking of multiple targets in infrared imagery. The IRTP has been developed under a feeder project to the advanced land fire control system (ALFCS) program, a project to develop accurate fire on the move capability for Canadian tanks. The IRTP is built around the datacube pipelined architecture using commercially available image processing and general purpose components. Presently, the IRTP is capable of real-time detection and tracking of up to five targets at video rates (30 frames/sec), and its operation is controlled via a single monitor that contains graphical control panels and a real- time video display. To augment the operation of the target detection/tracking and the gun fire control operations of the ALFCS a position orientation system (POS) can be used to provide accurate vertical reference measurements of the turret. The POS is built around an inertial measurement unit (IMU) and specialized real-time software implemented on a general purpose CPU card. Although the IRTP is currently being developed for ALFCS applications, the testbed architecture and algorithms are flexible and the system has been used to test and develop algorithms for general target processing applications.

  10. Radiometric calibration of Advanced Land Imager using reflectance-based results between 2001 and 2005

    NASA Astrophysics Data System (ADS)

    McCorkel, J.; Thome, K.; Biggar, S.; Kuester, M.

    2006-08-01

    The Landsat series of sensors have supplied the remote sensing community with a continuous data set dating to the early 1970s. An important aspect of retaining the continuity of these data is that a Landsat follow-on as well as current Landsat instruments must be understood radiometrically throughout their mission. The Advanced Land Imager (ALI), for example, was developed as a prototype for the next generation of Landsat Instruments, and as such there was a significant effort to understand its radiometric characteristics as well as how it compares with previous Landsat sensors. The Remote Sensing Group at the University of Arizona has been part of this effort since the late 2000 launch of ALI through the use of the reflectance-based method of vicarious calibration. The reflectance-based approach consists of ground-based measurements of atmospheric conditions and surface reflectance at the time of satellite overpass to predict the at-sensor radiance seen by the sensor under study. The work compares results from the reflectance-based approach obtained from well-characterized test sites such as Railroad Valley Playa in Nevada and Ivanpah Playa in California as applied to ALI, Landsat-5 TM, and Landsat-7 EMT+. The results from the comparison use a total of 14 ALI dates spanning in time from 2001 to late 2005 and show that ALI agrees with the current radiometric results from TM and ETM+ to within 5%.

  11. Thermal barrier coatings issues in advanced land-based gas turbines

    NASA Astrophysics Data System (ADS)

    Parks, W. P.; Hoffman, E. E.; Lee, W. Y.; Wright, I. G.

    1997-06-01

    The Department of Energy’s Advanced Turbine Systems (ATS) program is aimed at fostering the devel-opment of a new generation of land-based gas turbine systems with overall efficiencies significantly be-yond those of current state-of-the-art machines, as well as greatly increased times between inspection and refurbishment, improved environmental impact, and decreased cost. The proposed duty cycle of ATS ma-chines will emphasize different criteria in the selection of materials for the critical components. In par-ticular, thermal barrier coatings (TBCs) will be an essential feature of the hot gas path components in these machines. The goals of the ATS will require significant improvements in TBC technology, since these turbines will be totally reliant on TBCs, which will be required to function on critical components such as the first-stage vanes and blades for times considerably longer than those experienced in current applications. Important issues include the mechanical and chemical stability of the ceramic layer and the metallic bond coat, the thermal expansion characteristics and compliance of the ceramic layer, and the thermal conductivity across the thickness of the ceramic layer.

  12. Wind tunnel results of advanced high speed propellers in the takeoff, climb, and landing operating regimes

    NASA Technical Reports Server (NTRS)

    Stefko, G. L.; Jeracki, R. J.

    1985-01-01

    Low speed wind tunnel performance tests of two advanced propellers were completed. The 62.2 cm diameter adjustable pitch models were tested at Mach numbers typical of takeoff, initial climbout, and landing speeds in the 10 by 10 ft Supersonic Wind Tunnel. Both models had eight blades and a cruise design point operating condition of 0.80 Mach number, 10.668 km S.A. altitude, 243.8 m/s tip speed and a high power loading of 301 kW sq m. No adverse or unusual low speed operating conditions were found during the test with either the straight blade SR-2 or the 45 deg swept SR-3 propellers. The 45 deg swept propeller efficiency exceeded the straight blade efficiency by 4 to 5 percent. Typical net efficiencies of the straight and 45 deg swept propeller at a Mach 0.20 takeoff condition were 50.2 and 54.9 percent respectively. At a Mach 0.34 climb condition, the efficiencies were 53.7 and 59.1 percent. Reverse thrust data indicates that these propellers are capable of producing more reverse thrust at Mach 0.20 than a high bypass turbofan engine at Mach 0.20.

  13. Wind tunnel results of advanced high speed propellers in the takeoff, climb and landing operating regimes

    NASA Technical Reports Server (NTRS)

    Stefko, G. L.; Jeracki, R. J.

    1985-01-01

    Low speed wind tunnel performance tests of two advanced propellers were completed. The 62.2 cm diameter adjustable pitch models were tested at Mach numbers typical of takeoff, initial climbout, and landing speeds in the 10 by 10 ft Supersonic Wind Tunnel. Both models had eight blades and a cruise design point operating condition of 0.80 Mach number, 10.668 km S.A. altitude, 243.8 m/s tip speed and a high power loading of 301 kW sq m. No adverse or unusual low speed operating conditions were found during the test with either the straight blade SR-2 or the 45 deg swept SR-3 propellers. The 45 deg swept propeller efficiency exceeded the straight blade efficiency by 4 to 5%. Typical net efficiencies of the straight and 45 deg swept propeller at a Mach 0.20 takeoff condition were 50.2 and 54.9% respectively. At a Mach 0.34 climb condition, the efficiencies were 53.7 and 59.1%. Reverse thrust data indicates that these propellers are capable of producing more reverse thrust at Mach 0.20 than a high bypass turbofan engine at Mach 0.20.

  14. Evaluation of Four Advanced Nozzle Concepts for Short Takeoff and Landing Performance

    NASA Technical Reports Server (NTRS)

    Quinto, P. Frank; Kemmerly, Guy T.; Paulson, John W., Jr.

    1993-01-01

    Four advanced nozzle concepts were tested on a canard-wing fighter in the Langley 14- by 22-Foot Subsonic Tunnel. The four vectoring-nozzle concepts were as follows: (1) an axisymmetric nozzle (AXI); (2) an asymmetric, load balanced exhaust nozzle (ALBEN); (3) a low aspect ratio, single expansion ramp nozzle (LASERN); and (4) a high aspect ratio, single expansion ramp nozzle (HASERN). The investigation was conducted to determine the most suitable nozzle concept for short takeoff and landing (STOL) performance. The criterion for the best STOL performance was a takeoff ground roll of less than 1000 ft. At approach, the criteria were high lift and sufficient drag to maintain a glide slope of -3 to -6 deg with enough pitching-moment control from the canards. The test was performed at a dynamic pressure of 45 lb/sq ft and an angle-of-attack range of 0 to 20 deg. The nozzle pressure ratio was varied from 1.0 to 4.3 at both dry power and after burning nozzle configurations with nozzle vectoring to 60 deg. In addition, the model was tested in and out of ground effects. The ALBEN concept was the best of the four nozzle concepts tested for STOL performance.

  15. Enhancing Global Land Surface Hydrology Estimates from the NASA MERRA Reanalysis Using Precipitation Observations and Model Parameter Adjustments

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf; Koster, Randal; DeLannoy, Gabrielle; Forman, Barton; Liu, Qing; Mahanama, Sarith; Toure, Ally

    2011-01-01

    The Modern-Era Retrospective analysis for Research and Applications (MERRA) is a state-of-the-art reanalysis that provides. in addition to atmospheric fields. global estimates of soil moisture, latent heat flux. snow. and runoff for J 979-present. This study introduces a supplemental and improved set of land surface hydrological fields ('MERRA-Land') generated by replaying a revised version of the land component of the MERRA system. Specifically. the MERRA-Land estimates benefit from corrections to the precipitation forcing with the Global Precipitation Climatology Project pentad product (version 2.1) and from revised parameters in the rainfall interception model, changes that effectively correct for known limitations in the MERRA land surface meteorological forcings. The skill (defined as the correlation coefficient of the anomaly time series) in land surface hydrological fields from MERRA and MERRA-Land is assessed here against observations and compared to the skill of the state-of-the-art ERA-Interim reanalysis. MERRA-Land and ERA-Interim root zone soil moisture skills (against in situ observations at 85 US stations) are comparable and significantly greater than that of MERRA. Throughout the northern hemisphere, MERRA and MERRA-Land agree reasonably well with in situ snow depth measurements (from 583 stations) and with snow water equivalent from an independent analysis. Runoff skill (against naturalized stream flow observations from 15 basins in the western US) of MERRA and MERRA-Land is typically higher than that of ERA-Interim. With a few exceptions. the MERRA-Land data appear more accurate than the original MERRA estimates and are thus recommended for those interested in using '\\-tERRA output for land surface hydrological studies.

  16. Assimilation of Satellite-Derived Skin Temperature Observations into Land Surface Models

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; Kumar, Sujay V.; Mahanama, P. P.; Koster, Randal D.; Liu, Q.

    2010-01-01

    Land surface (or "skin") temperature (LST) lies at the heart of the surface energy balance and is a key variable in weather and climate models. Here we assimilate LST retrievals from the International Satellite Cloud Climatology Project (ISCCP) into the Noah and Catchment (CLSM) land surface models using an ensemble-based, off-line land data assimilation system. LST is described very differently in the two models. A priori scaling and dynamic bias estimation approaches are applied because satellite and model LST typically exhibit different mean values and variability. Performance is measured against 27 months of in situ measurements from the Coordinated Energy and Water Cycle Observations Project at 48 stations. LST estimates from Noah and CLSM without data assimilation ("open loop") are comparable to each other and superior to that of ISCCP retrievals. For LST, RMSE values are 4.9 K (CLSM), 5.6 K (Noah), and 7.6 K (ISCCP), and anomaly correlation coefficients (R) are 0.62 (CLSM), 0.61 (Noah), and 0.52 (ISCCP). Assimilation of ISCCP retrievals provides modest yet statistically significant improvements (over open loop) of up to 0.7 K in RMSE and 0.05 in anomaly R. The skill of surface turbulent flux estimates from the assimilation integrations is essentially identical to the corresponding open loop skill. Noah assimilation estimates of ground heat flux, however, can be significantly worse than open loop estimates. Provided the assimilation system is properly adapted to each land model, the benefits from the assimilation of LST retrievals are comparable for both models.

  17. NPP VIIRS Land Surface Temperature EDR validation using NOAA's observation networks

    NASA Astrophysics Data System (ADS)

    Guillevic, P. C.; Privette, J. L.

    2012-12-01

    NOAA will soon use the new Visible Infrared Imager Radiometer Suite (VIIRS) on the Joint Polar Satellite System (JPSS) as its primary polar-orbiting satellite imager. Employing a near real-time processing system, NOAA will generate a series of Environmental Data Records (EDRs) from VIIRS data. For example, the VIIRS Land Surface Temperature (LST) EDR will estimate the surface skin temperature over all global land areas and provide key information for monitoring Earth surface energy and water fluxes. Because both VIIRS and its processing algorithms are new, NOAA is conducting a rigorous calibration and validation program to understand and improve product quality. This work presents a new validation methodology to estimate the quantitative uncertainty in the LST EDR, and contribute to improving the retrieval algorithm. It employs a physically-based approach to scaling up point LST measurements currently made operationally at many field and weather stations around the world. The scaling method consists of the merging information collected at different spatial resolutions within a land surface model to fully characterize large area (km x km scale) satellite products. The approach can be used to explore scaling issues over terrestrial surfaces spanning a large range of climate regimes and land cover types, including forests and mixed vegetated areas. First results show that VIIRS and MODIS (collection 5) LST products are very consistent. Over vegetated areas, VIIRS LST EDRs verify JPSS program quality requirements - bias and precision specifications of VIIRS LST EDRs are 1.5K and 2.5K. However, VIIRS agrees better with scaled-up field data than with non-scaled field observations. Over desert areas, current VIIRS LST EDRs do not verify JPSS specifications. VIIRS and MODIS LST products tend to underestimate surface temperature at night. Ultimately, this validation approach should lead to an accurate and continuously-assessed VIIRS LST products suitable to support weather

  18. Thermal movement of the regolith. [seismic event observed at Apollo 17 landing site

    NASA Technical Reports Server (NTRS)

    Duennebier, F.

    1976-01-01

    High-frequency seismic events observed at the Apollo landing sites indicate that the regolith moves in response to diurnal variations of thermal stresses. While these events (thermal moonquakes) are observed by each of the Passive Seismic Experiment stations, the location of their sources was not possible until they were observed by the Lunar Surface Profiling Experiment (LSPE) array at the Apollo 17 site. Comparison of source locations with topographic features near the LSPE array indicate that thermal moonquakes are associated to some degree with large rocks and to a larger degree with craters. They are not associated with man-made disturbances of the lunar surface. It is suggested that thermal moonquakes are the seismic expression of a phenomenon that is actively degrading slopes on the lunar surface.

  19. Connecting Satellite Observations with Water Cycle Variables Through Land Data Assimilation: Examples Using the NASA GEOS-5 LDAS

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Forman, Barton A.; Draper, Clara S.; Liu, Qing

    2013-01-01

    A land data assimilation system (LDAS) can merge satellite observations (or retrievals) of land surface hydrological conditions, including soil moisture, snow, and terrestrial water storage (TWS), into a numerical model of land surface processes. In theory, the output from such a system is superior to estimates based on the observations or the model alone, thereby enhancing our ability to understand, monitor, and predict key elements of the terrestrial water cycle. In practice, however, satellite observations do not correspond directly to the water cycle variables of interest. The present paper addresses various aspects of this seeming mismatch using examples drawn from recent research with the ensemble-based NASA GEOS-5 LDAS. These aspects include (1) the assimilation of coarse-scale observations into higher-resolution land surface models, (2) the partitioning of satellite observations (such as TWS retrievals) into their constituent water cycle components, (3) the forward modeling of microwave brightness temperatures over land for radiance-based soil moisture and snow assimilation, and (4) the selection of the most relevant types of observations for the analysis of a specific water cycle variable that is not observed (such as root zone soil moisture). The solution to these challenges involves the careful construction of an observation operator that maps from the land surface model variables of interest to the space of the assimilated observations.

  20. Heavy thunderstorms observed over land by the Nimbus 7 scanning multichannel microwave radiometer

    NASA Technical Reports Server (NTRS)

    Spencer, R. W.; Olson, W. S.; Martin, D. W.; Weinman, J. A.; Santek, D. A.; Wu, R.

    1983-01-01

    Brightness temperatures obtained through examination of microwave data from the Nimbus 7 satellite are noted to be much lower than those expected on the strength of radiation emanating from rain-producing clouds. Very cold brightness temperature cases all coincided with heavy thunderstorm rainfall, with the cold temperatures being attributable to scattering by a layer of ice hydrometeors in the upper parts of the storms. It is accordingly suggested that brightness temperatures observed by satellite microwave radiometers can sometimes distinguish heavy rain over land.

  1. Remote Sensing of Aerosol Over the Land from the Earth Observing System MODIS Instrument

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Tanre, Didier; Remer, Lorraine; Einaudi, Franco (Technical Monitor)

    2000-01-01

    On Dec 18, 1999, NASA launched the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument on the Earth Observing System (EOS) Terra mission, in a spectacular launch. The mission will provide morning (10:30 AM) global observations of aerosol and other related parameters. It will be followed a year later by a MODIS instrument on EOS Aqua for afternoon observations (1:30 PM). MODIS will measure aerosol over land and ocean with its eight 500 m and 250 m channels in the solar spectrum (0-41 to 2.2 micrometers). Over the land MODIS will measure the total column aerosol loading, and distinguish between submicron pollution particles and large soil particles. Standard daily products of resolution of ten kilometers and global mapped eight day and monthly products on a 1x1 degree global scale will be produced routinely and make available for no or small reproduction charge to the international community. Though the aerosol products will not be available everywhere over the land, it is expected that they will be useful for assessments of the presence, sources and transport of urban pollution, biomass burning aerosol, and desert dust. Other measurements from MODIS will supplement the aerosol information, e.g., land use change, urbanization, presence and magnitude of biomass burning fires, and effect of aerosol on cloud microphysics. Other instruments on Terra, e.g. Multi-angle Imaging SpectroRadiometer (MISR) and the Clouds and the Earth's Radiant Energy System (CERES), will also measure aerosol, its properties and radiative forcing in tandem with the MODIS measurements. During the Aqua period, there are plans to launch in 2003 the Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission for global measurements of the aerosol vertical structure, and the PARASOL mission for aerosol characterization. Aqua-MODIS, PICASSO and PARASOL will fly in formation for detailed simultaneous characterization of the aerosol three-dimensional field, which

  2. Flight evaluation of advanced controls and displays for transition and landing on the NASA V/STOL systems research aircraft

    NASA Technical Reports Server (NTRS)

    Franklin, James A.; Stortz, Michael W.; Borchers, Paul F.; Moralez, Ernesto, III

    1996-01-01

    Flight experiments were conducted on Ames Research Center's V/STOL Systems Research Aircraft (VSRA) to assess the influence of advanced control modes and head-up displays (HUD's) on flying qualities for precision approach and landing operations. Evaluations were made for decelerating approaches to hover followed by a vertical landing and for slow landings for four control/display mode combinations: the basic YAV-8B stability augmentation system; attitude command for pitch, roll, and yaw; flightpath/acceleration command with translational rate command in the hover; and height-rate damping with translational-rate command. Head-up displays used in conjunction with these control modes provided flightpath tracking/pursuit guidance and deceleration commands for the decelerating approach and a mixed horizontal and vertical presentation for precision hover and landing. Flying qualities were established and control usage and bandwidth were documented for candidate control modes and displays for the approach and vertical landing. Minimally satisfactory bandwidths were determined for the translational-rate command system. Test pilot and engineer teams from the Naval Air Warfare Center, the Boeing Military Airplane Group, Lockheed Martin, McDonnell Douglas Aerospace, Northrop Grumman, Rolls-Royce, and the British Defense Research Agency participated in the program along with NASA research pilots from the Ames and Lewis Research Centers. The results, in conjunction with related ground-based simulation data, indicate that the flightpath/longitudinal acceleration command response type in conjunction with pursuit tracking and deceleration guidance on the HUD would be essential for operation to instrument minimums significantly lower than the minimums for the AV-8B. It would also be a superior mode for performing slow landings where precise control to an austere landing area such as a narrow road is demanded. The translational-rate command system would reduce pilot workload for

  3. Soil moisture retrieval using L-band time-series radar observations over shrub lands

    NASA Astrophysics Data System (ADS)

    Kim, S.; Das, N. N.; Jackson, T. J.; Njoku, E. G.

    2012-12-01

    A time-series algorithm was applied to retrieve surface (from the surface down to a ~5 cm depth) soil moisture over shrub land using airborne L-band radar observations. The goal is to develop and assess algorithms as a part of the global soil moisture retrieval at 3-km spatial resolution by the Soil Moisture Active and Passive (SMAP) mission (due for launch in 2014). Shrub lands cover 20% of the global land surface, and reliable retrieval over this land cover is important for providing a global product. To systematically separate the effect of soil moisture from those of surface roughness and vegetation, the retrieval algorithm inverts a generalized forward model for radar scattering from vegetation-covered soil surfaces. The forward model consists of the small perturbation model for smooth bare surface, and the discrete scattering model for the scattering from vegetation and vegetation-ground interaction. The time-series measurements of co-polarized radar backscatter coefficients and ground-based vegetation water contents are inputs to the retrieval and used as initial guess of their values. These input parameters are further adjusted during the retrieval through least-square minimization. In addition to soil moisture, the roughness of the soil surface is retrieved. A constraint is imposed that the surface roughness is time-invariant, which resolves ambiguities in the soil moisture solution search. In comparison, a conventional retrieval relying on snapshot observations may not resolve the ambiguities, resulting in soil moisture retrieval error. The radar data were obtained by the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) over the San Joaquin Valley on 8 days between May 2011 and November 2011. Each of two study regions covers an area of about 1 km x 0.5 km. Ground-based soil moisture and vegetation information were collected. Details of the vegetation structure were recorded and used to train the forward model for radar scattering. The proposed

  4. Rainfall estimation over-land using SMOS soil moisture observations: SM2RAIN, LMAA and SMART algorithms

    NASA Astrophysics Data System (ADS)

    Massari, Christian; Brocca, Luca; Pellarin, Thierry; Kerr, Yann; Crow, Wade; Cascon, Carlos; Ciabatta, Luca

    2016-04-01

    Recent advancements in the measurement of precipitation from space have provided estimates at scales that are commensurate with the needs of the hydrological and land-surface model communities. However, as demonstrated in a number of studies (Ebert et al. 2007, Tian et al. 2007, Stampoulis et al. 2012) satellite rainfall estimates are characterized by low accuracy in certain conditions and still suffer from a number of issues (e.g., bias) that may limit their utility in over-land applications (Serrat-Capdevila et al. 2014). In recent years many studies have demonstrated that soil moisture observations from ground and satellite sensors can be used for correcting satellite precipitation estimates (e.g. Crow et al., 2011; Pellarin et al., 2013), or directly estimating rainfall (SM2RAIN, Brocca et al., 2014). In this study, we carried out a detailed scientific analysis in which these three different methods are used for: i) estimating rainfall through satellite soil moisture observations (SM2RAIN, Brocca et al., 2014); ii) correcting rainfall through a Land surface Model Assimilation Algorithm (LMAA) (an improvement of a previous work of Crow et al. 2011 and Pellarin et al. 2013) and through the Soil Moisture Analysis Rainfall Tool (SMART, Crow et al. 2011). The analysis is carried within the ESA project "SMOS plus Rainfall" and involves 9 sites in Europe, Australia, Africa and USA containing high-quality hydrometeorological and soil moisture observations. Satellite soil moisture data from Soil Moisture and Ocean Salinity (SMOS) mission are employed for testing their potential in deriving a cumulated rainfall product at different temporal resolutions. The applicability and accuracy of the three algorithms is investigated also as a function of climatic and soil/land use conditions. A particular attention is paid to assess the expected limitations soil moisture based rainfall estimates such as soil saturation, freezing/snow conditions, SMOS RFI, irrigated areas

  5. Automated ground data acquisition and processing system for calibration and performance assessment of the EO-1 Advanced Land Imager

    NASA Astrophysics Data System (ADS)

    Viggh, Herbert E. M.; Mendenhall, Jeffrey A.; Sayer, Ronald W.; Stuart, J. S.; Gibbs, Margaret D.

    1999-09-01

    The calibration and performance assessment of the Earth Observing-1 (EO-1) Advanced Land Imager (ALI) required a ground data system for acquiring and processing ALI data. In order to meet tight schedule and budget requirements, an automated system was developed that could be run by a single operator. This paper describes the overall system and the individual Electrical Ground Support Equipment (EGSE) and computer components used. The ALI Calibration Control Node (ACCN) serves as a test executive with a single graphical user interface to the system, controlling calibration equipment and issuing data acquisition and processing requests to the other EGSE and computers. EGSE1, a custom data acquisition syste, collects ALI science data and also passes ALI commanding and housekeeping telemetry collection requests to EGSE2 and EGSE3 which are implemented on an ASIST workstation. The performance assessment machine, stores and processes collected ALI data, automatically displaying quick-look processing results. The custom communications protocol developed to interface these various machines and to automate their interactions is described, including the various modes of operation needed to support spatial, radiometric, spectral, and functional calibration and performance assessment of the ALI.

  6. Geographic bias of field observations of soil carbon stocks with tropical land-use changes precludes spatial extrapolation

    PubMed Central

    Powers, Jennifer S.; Corre, Marife D.; Twine, Tracy E.; Veldkamp, Edzo

    2011-01-01

    Accurately quantifying changes in soil carbon (C) stocks with land-use change is important for estimating the anthropogenic fluxes of greenhouse gases to the atmosphere and for implementing policies such as REDD (Reducing Emissions from Deforestation and Degradation) that provide financial incentives to reduce carbon dioxide fluxes from deforestation and land degradation. Despite hundreds of field studies and at least a dozen literature reviews, there is still considerable disagreement on the direction and magnitude of changes in soil C stocks with land-use change. We conducted a meta-analysis of studies that quantified changes in soil C stocks with land use in the tropics. Conversion from one land use to another caused significant increases or decreases in soil C stocks for 8 of the 14 transitions examined. For the three land-use transitions with sufficient observations, both the direction and magnitude of the change in soil C pools depended strongly on biophysical factors of mean annual precipitation and dominant soil clay mineralogy. When we compared the distribution of biophysical conditions of the field observations to the area-weighted distribution of those factors in the tropics as a whole or the tropical lands that have undergone conversion, we found that field observations are highly unrepresentative of most tropical landscapes. Because of this geographic bias we strongly caution against extrapolating average values of land-cover change effects on soil C stocks, such as those generated through meta-analysis and literature reviews, to regions that differ in biophysical conditions. PMID:21444813

  7. Geographic bias of field observations of soil carbon stocks with tropical land-use changes precludes spatial extrapolation.

    PubMed

    Powers, Jennifer S; Corre, Marife D; Twine, Tracy E; Veldkamp, Edzo

    2011-04-12

    Accurately quantifying changes in soil carbon (C) stocks with land-use change is important for estimating the anthropogenic fluxes of greenhouse gases to the atmosphere and for implementing policies such as REDD (Reducing Emissions from Deforestation and Degradation) that provide financial incentives to reduce carbon dioxide fluxes from deforestation and land degradation. Despite hundreds of field studies and at least a dozen literature reviews, there is still considerable disagreement on the direction and magnitude of changes in soil C stocks with land-use change. We conducted a meta-analysis of studies that quantified changes in soil C stocks with land use in the tropics. Conversion from one land use to another caused significant increases or decreases in soil C stocks for 8 of the 14 transitions examined. For the three land-use transitions with sufficient observations, both the direction and magnitude of the change in soil C pools depended strongly on biophysical factors of mean annual precipitation and dominant soil clay mineralogy. When we compared the distribution of biophysical conditions of the field observations to the area-weighted distribution of those factors in the tropics as a whole or the tropical lands that have undergone conversion, we found that field observations are highly unrepresentative of most tropical landscapes. Because of this geographic bias we strongly caution against extrapolating average values of land-cover change effects on soil C stocks, such as those generated through meta-analysis and literature reviews, to regions that differ in biophysical conditions. PMID:21444813

  8. Inverse optimization of the land surface model JSBACH using multiple constraints and long term observations

    NASA Astrophysics Data System (ADS)

    Carvalhais, N.; Zaehle, S.; Schürmann, G. J.; Beer, C.; Granier, A.; Loustau, D.; Papale, D.; Reick, C.; Reichstein, M.

    2012-04-01

    Terrestrial ecosystems play a key role in the global carbon cycle. The characterization and understanding of ecosystem level responses to climatic drivers is essential for diagnostic purposes as well as improving the representation of land-atmosphere feedbacks in climate projections of coupled carbon-cycle climate models. The combination of biogeochemical models with multiple observations of ecosystem carbon and water fluxes through a model-data integration framework enables the recognition of potential limitations of modeling approaches. Here, we evaluate the performance of the land surface scheme (JSBACH 2.0) of the Max Planck Institute Earth System Model (MPI-ESM) to simulate ecosystem carbon and water fluxes for two forest sites monitored using the eddy covariance technique since 1996: a beech (Hesse) and a pine (Le Bray) forest. An inverse optimization approach was performed considering daily carbon and water fluxes, as well as observations of vegetation and soil carbon stocks. Our results show that multiple-constraints approaches including information about ecosystem states and ecosystem carbon and water fluxes provide a significant support in evaluating model structures as opposed to assimilation approaches only considering ecosystem flux measurements. Further, this work emphasizes the relevance of long time series to address the model performance of inter annual variability.

  9. Power law distributions of wildfires across Europe: benchmarking a land surface model with observed data

    NASA Astrophysics Data System (ADS)

    Di Mauro, B.; Fava, F.; Frattini, P.; Camia, A.; Colombo, R.; Migliavacca, M.

    2015-11-01

    Monthly wildfire burned area frequency is here modeled with a power law distribution and scaling exponent across different European biomes are estimated. Data sets, spanning from 2000 to 2009, comprehend the inventory of monthly burned areas from the European Forest Fire Information System (EFFIS) and simulated monthly burned areas from a recent parameterization of a Land Surface Model (LSM), that is the Community Land Model (CLM). Power law exponents are estimated with a Maximum Likelihood Estimation (MLE) for different European biomes. The characteristic fire size (CFS), i.e. the area that most contributes to the total burned area, was also calculated both from EFFIS and CLM data set. We used the power law fitting and the CFS analysis to benchmark CLM model against the EFFIS observational wildfires data set available for Europe. Results for the EFFIS data showed that power law fittings holds for 2-3 orders of magnitude in the Boreal and Continental ecoregions, whereas the distribution of the Alpine, Atlantic are fitted only in the upper tail. Power law instead is not a suitable model for fitting CLM simulations. CLM benchmarking analysis showed that the model strongly overestimates burned areas and fails in reproducing size-frequency distribution of observed EFFIS wildfires. This benchmarking analysis showed that some refinements in CLM structure (in particular regarding the anthropogenic influence) are needed for predicting future wildfires scenarios, since the low spatial resolution of the model and differences in relative frequency of small and large fires can affect the reliability of the predictions.

  10. Inverse Modeling of Hydrologic Parameters Using Surface Flux and Streamflow Observations in the Community Land Model

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Hou, Z.; Huang, M.; Tian, F.; Leung, L.

    2012-12-01

    This study aims at demonstrating the possibility of calibrating hydrologic parameters using surface flux and streamflow observations in version 4 of the Community Land Model (CLM4). Previously we showed that surface flux and streamflow calculations are sensitive to several key hydrologic parameters in CLM4, and discussed the necessity and possibility of parameter calibration. In this study, we evaluate performances of several different inversion strategies, including least-square fitting, quasi Monte-Carlo (QMC) sampling based Bayesian updating, and a Markov-Chain Monte-Carlo (MCMC) Bayesian inversion approach. The parameters to be calibrated include the surface and subsurface runoff generation parameters and vadose zone soil water parameters. We discuss the effects of surface flux and streamflow observations on the inversion results and compare their consistency and reliability using both monthly and daily observations at various flux tower and MOPEX sites. We find that the sampling-based stochastic inversion approaches behaved consistently - as more information comes in, the predictive intervals of the calibrated parameters as well as the misfits between the calculated and observed observations decrease. In general, the parameters that are identified to be significant through sensitivity analyses and statistical tests are better calibrated than those with weak or nonlinear impacts on flux or streamflow observations. We also evaluated the possibility of probabilistic model averaging for more consistent parameter estimation.

  11. Rapid groundwater-related land subsidence in Yemen observed by multi-temporal InSAR

    NASA Astrophysics Data System (ADS)

    Abdullin, Ayrat; Xu, Wenbin; Kosmicki, Maximillian; Jonsson, Sigurjon

    2015-04-01

    Several basins in Yemen are suffering from a rapid drawdown of groundwater, which is the most important water source for agricultural irrigation, industry and domestic use. However, detailed geodetic measurements in the region have been lacking and the extent and magnitude of groundwater-related land subsidence has been poorly known. We used 13 ascending ALOS and 15 descending Envisat images to study land subsidence of several basins in Yemen, with a special focus on the Sana'a and Mabar basins. From multitemporal synthetic aperture radar interferometric analysis (persistent scatterers (PS) and small baseline subsets (SBAS)) we examined the spatio-temporal behavior of the subsidence induced by depletion of groundwater aquifer systems from November 2003 to February 2011. In the interferometric data processing, we carefully chose interferogram pairs to minimize spatial and temporal decorrelation, because of high subsidence rates and the type of land cover. Our results show that the spatial pattern of subsidence remained quite stable during the observation period in both the Sana'a and Mabar basins. In the Sana'a basin, the maximum subsidence rate exceeded 14 cm/year in the radar line-of-sight (LOS) direction between 2003 and 2008 in an agricultural area just north of Sana'a city, where water wells have been drying up according to the well data. The subsidence rate was lower in the urban areas, or approximately 1 cm/year, exhibiting annual variations. The main subsidence was found in the center and southern parts of the city, while deformation in the northern part is less obvious. For the Mabar basin, the subsidence rate exceeded 30 cm/year in the agricultural area north of the town of Mabar during 2007 - 2011. The southern part of the Mabar basin also experienced high subsidence rates, although somewhat lower than to the north. Excessive water pumping is the main cause of the ground subsidence and it has already led to extensive ground fracturing at the edge of some

  12. First observation of beryllium-7 solar neutrinos with KamLAND

    NASA Astrophysics Data System (ADS)

    Keefer, Gregory J.

    2009-09-01

    The international KamLAND collaboration operates a 1 kton liquid scintillation detector in the Kamioka mine in Gifu, Japan. KamLAND's main scientific results are the precision measurement of the solar Dm 2 12 = 7.58[Special characters omitted.] (stat) [Special characters omitted.] (syst) and tan 2 [straight theta] 12 = 0.56[Special characters omitted.] (stat) [Special characters omitted.] (syst) utilizing reactor n e and first evidence for the observation of geologically produced anti-neutrinos. In an effort to extend KamLAND's scientific reach, extensive research has been performed on preparing a spectroscopic measurement of 7 Be solar n e s. This work provides the first inclusive analysis of KamLAND's backgrounds below 1 MeV. 85 Kr and 210 Pb, dissolved in KamLAND liquid scintillator, were found to be the dominant source of low energy backgrounds. The concentration of these ultra-trace contaminants were determined to be 10 -20 g/g. This is more than 6 orders of magnitude lower than commercially available ultra-pure liquids. To attain a signal-to-background ratio suitable for the detection of 7 Be solar n e s, the concentration of these contaminants had to be reduced by 5 orders of magnitude. A comprehensive study of 210 Pb removal was undertaken over the course of this thesis. This work further covers techniques for the removal of 220 Rn, 222 Rn and their daughter nuclei from liquid scintillator at concentrations of 10^-18 g/g. Purification techniques studied in this work include water extraction, isotope exchange, adsorption, and distillation. These laboratory studies guided the design and implementation of a large scale purification system in the Kamioka mine. The purification system's design and operation is discussed in detail as well as specific experiments devised to control scintillator quality and radio-purity. The purification system's effectiveness in removing radioactive trace impurities is analyzed in detail. The total scintillator purified over two

  13. River flow and inundation in African river systems: results from a new pan-African land-surface model validated against Earth observations

    NASA Astrophysics Data System (ADS)

    Dadson, Simon

    2015-04-01

    The role of surface-water flooding in controlling fluxes of water and carbon between the land and the atmosphere is increasingly recognized in studies of the Earth system. Simultaneous advances in remote earth observation and large-scale land-surface and hydrological modeling promise improvements in our ability to understand these linkages, and suggest that improvements in prediction of river flow and inundation extents may result. Here we present an analysis of newly-available observational estimates of surface water inundation obtained through satellite Earth observation with results from simulations produced by using the Joint UK Land Environment Simulator (JULES) land-surface model operating at 0.5 degree resolution over the African continent. The model was forced with meteorological input from the WATCH Forcing Data for the period 1981-2001 and sensitivity to various model configurations and parameter settings were tested. Both the PDM and TOPMODEL sub-grid scale runoff generation schemes were tested for parameter sensitivities, with the evaluation focussing on simulated river discharge in sub-catchments of the Congo, Nile, Niger, Orange, Okavango and Zambezi rivers. It was found that whilst the water balance in each of the catchments can be simulated with acceptable accuracy, the individual responses of each river vary between model configurations so that there is no single runoff parameterization scheme or parameter values that yields optimal results across all catchments. We trace these differences to the model's representation of sub-surface flow and make some suggestions to improve the performance of large-scale land-surface models for use in similar applications. These findings suggest that the use of Earth observation data together with improved models of large-scale hydrology have the potential to improve our ability to predict surface-water flooding and to develop our understanding of the role of flooding in driving components of the water and carbon

  14. Current Land Subsidence in the Houston Metropolitan Area, Texas, Derived from GPS Observations (1993-2012)

    NASA Astrophysics Data System (ADS)

    Kearns, T.; Wang, G.; Jia, X.; Jiang, J.; Lee, D.

    2014-12-01

    This article summarizes recent land subsidence that has occurred in the Houston metropolitan area. Subsidence measurements derived from observations at 11 borehole extensometers and 90 GPS sites during the past 20 years (1993-2012) were investigated in this study. Precise Point Positioning with Single Receiver Phase Ambiguity (PPP-SRPA) resolution employed by the GIPSY-OASIS software package (V6.2) was applied to calculate daily positions of GPS antennas. GPS and extensometer observations indicate that the overall subsidence rate in the Houston metropolitan area has been decreasing since the 1970s, which was when groundwater withdrawal regulations started to be enforced by the Harris-Galveston Subsidence District (HGSD). Currently, the subsidence in the southeast of the Houston metropolitan area has almost ceased. Slight rebound has been observed at several sites along the Houston Ship Channel area since 2005. Nonetheless, a relatively small area within the Houston Ship Channel area that runs northwest from approximately Texas City to League City has continued to subside. There is some evidence that suggest that this subsidence is the result of local oil and gas withdrawal rather than groundwater withdrawal. Subsidence also continues in the west and northwest of the Houston metropolitan area, where groundwater regulations have only recently been implemented. The maximum rate is 2.5 cm/year. It is evident that the groundwater withdrawal regulations enforced by HGSD have successfully reduced the subsidence in the Houston metropolitan area. Long-term GPS observations also indicate that subsidence rates vary spatially and temporally depending on local groundwater withdrawals and the clay-to-sand ratio in subsurface sediments. The ground water and aquifer systems respond slowly to human actions. It took almost two decades (1980s and 1990s) to halt the subsidence in the east part of the Houston metropolitan area after groundwater regulations were implemented in the late

  15. Global land cover mapping using Earth observation satellite data: Recent progresses and challenges

    NASA Astrophysics Data System (ADS)

    Ban, Yifang; Gong, Peng; Giri, Chandra

    2015-05-01

    Land cover is an important variable for many studies involving the Earth surface, such as climate, food security, hydrology, soil erosion, atmospheric quality, conservation biology, and plant functioning. Land cover not only changes with human caused land use changes, but also changes with nature. Therefore, the state of land cover is highly dynamic. In winter snow shields underneath various other land cover types in higher latitudes. Floods may persist for a long period in a year over low land areas in the tropical and subtropical regions. Forest maybe burnt or clear cut in a few days and changes to bare land. Within several months, the coverage of crops may vary from bare land to nearly 100% crops and then back to bare land following harvest. The highly dynamic nature of land cover creates a challenge in mapping and monitoring which remains to be adequately addressed. As economic globalization continues to intensify, there is an increasing trend of land cover/land use change, environmental pollution, land degradation, biodiversity loss at the global scale, timely and reliable information on global land cover and its changes is urgently needed to mitigate the negative impact of global environment change.

  16. Observational and theoretical advances in cosmological foreground emission

    NASA Astrophysics Data System (ADS)

    Stevenson, Matthew A.

    Observational and theoretical work towards the separation of foreground emission from the cosmic microwave background is described. The bulk of this work is in the design, construction, and commissioning of the C-Band All-Sky Survey (C-BASS), an experiment to produce a template of the Milky Way Galaxy's polarized synchrotron emission. Theoretical work is the derivation of an analytical approximation to the emission spectrum of spinning dust grains. The performance of the C-BASS experiment is demonstrated through a preliminary, deep survey of the North Celestial Pole region. A comparison to multiwavelength data is performed, and the thermal and systematic noise properties of the experiment are explored. The systematic noise has been minimized through careful data processing algorithms, implemented both in the experiment's Field Programmable Gate Array (FPGA) based digital backend and in the data analysis pipeline. Detailed descriptions of these algorithms are presented. The analytical function of spinning dust emission is derived through the application of careful approximations, with each step tested against numerical calculations. This work is intended for use in the parameterized separation of cosmological foreground components and as a framework for interpreting and comparing the variety of anomalous microwave emission observations.

  17. Advanced meteor wind observations using meteor and MST radars

    NASA Astrophysics Data System (ADS)

    Tsutsumi, M.; Aso, T.; Hall, C.; Nakamura, T.; Sato, K.; Sato, T.

    A few topics from recent developments of radio meteor observation techniques are presented The Nippon Norway Tromsoe Meteor Radar NTMR has been in continuous operation since November 2003 in Tromsoe 69N One of the major advantages of the present meteor radar is its high echo rate 6000-20000 echoes a day despite the relatively small transmitting power 7 5kW peak From ambipolar diffusion coefficients we have successfully extracted atmospheric temperature fluctuations due to gravity waves assuming the Boussinesq approximation The time and height resolutions of horizontal winds and temperature fluctuations at the altitude of 90 km are 1 hour and 2km high enough for the study of gravity waves with a period longer than a few hours Horizontal propagation characteristics of gravity waves are further studied using a theoretical phase relation between the wind and temperature fluctuations MST radars in the VHF band have a great potential in meteor echo observations due to their high transmitting power The meteor measurement can be conducted throughout a day and complement the turbulent echo measurement in the mesosphere which is limited to daylight hours only The MU radar of Kyoto University is one of those radars and has been successfully applied to meteor studies by utilizing its very high versatility The MU radar was recently renewed Its signal processing unit is up-graded from a 4 analog receiver system to a 25 digital receiver system In the present study we try to improve the MU radar meteor measurement

  18. Advances in understanding particle acceleration and loss from Cluster observations

    NASA Astrophysics Data System (ADS)

    Escoubet, C. Philippe; Laakso, Harri; Goldstein, Mevlyn; Masson, Arnaud

    2016-07-01

    The main science targets of the Cluster mission, originally proposed in 1982, were the bow shock, the cusp, the magnetopause and the plasmasheet. The inner magnetosphere was not a prime target and thanks to the low perigee, around 4 RE geocentric distance, that decreased down to a few 100s of kilometers altitude in 2011, this region could be studied for the first time with four spacecraft. We will present science highlights obtained both in the plasmasphere and in the radiation belts such as the localization of the source of non-thermal continuum radiation both through triangulation and through the tilt of one spacecraft, plasmasphere density structures, interplanetary shock electron acceleration in the inner magnetosphere, discovery of the plasmaspheric wind, interaction between the plasmasphere and the radiation belts, multi-point observations of equatorial noise as well as many multi-point observations of chorus emissions. We will also present the distribution of data through the Cluster Science Data System (CSDS), and the Cluster Science Archive (CSA). CSA was implemented to provide, for the first time for a plasma physics mission, a permanent and public archive of all the high-resolution data from all instruments.

  19. Assimilation of gridded terrestrial water storage observations from GRACE into a land surface model

    NASA Astrophysics Data System (ADS)

    Girotto, Manuela; De Lannoy, Gabriëlle J. M.; Reichle, Rolf H.; Rodell, Matthew

    2016-05-01

    Observations of terrestrial water storage (TWS) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission have a coarse resolution in time (monthly) and space (roughly 150,000 km2 at midlatitudes) and vertically integrate all water storage components over land, including soil moisture and groundwater. Data assimilation can be used to horizontally downscale and vertically partition GRACE-TWS observations. This work proposes a variant of existing ensemble-based GRACE-TWS data assimilation schemes. The new algorithm differs in how the analysis increments are computed and applied. Existing schemes correlate the uncertainty in the modeled monthly TWS estimates with errors in the soil moisture profile state variables at a single instant in the month and then apply the increment either at the end of the month or gradually throughout the month. The proposed new scheme first computes increments for each day of the month and then applies the average of those increments at the beginning of the month. The new scheme therefore better reflects submonthly variations in TWS errors. The new and existing schemes are investigated here using gridded GRACE-TWS observations. The assimilation results are validated at the monthly time scale, using in situ measurements of groundwater depth and soil moisture across the U.S. The new assimilation scheme yields improved (although not in a statistically significant sense) skill metrics for groundwater compared to the open-loop (no assimilation) simulations and compared to the existing assimilation schemes. A smaller impact is seen for surface and root-zone soil moisture, which have a shorter memory and receive smaller increments from TWS assimilation than groundwater. These results motivate future efforts to combine GRACE-TWS observations with observations that are more sensitive to surface soil moisture, such as L-band brightness temperature observations from Soil Moisture Ocean Salinity (SMOS) or Soil Moisture Active Passive

  20. Advanced Chinese NiTi alloy wire and clinical observations.

    PubMed

    Chen, R; Zhi, Y F; Arvystas, M G

    1992-01-01

    Chinese NiTi wire was studied on the bench with six other nickel-titanium-alloy wires. Bending and torsional tests were conducted and temperatures of phase transformation compared. The Chinese NiTi wire was found to have a low stiffness, high springback and constant bending and torsional moments on unloading, in a very large deformation region. It can produce a gentle, nearly constant force. These factors make it desirable for clinical application. Included in this paper are clinical observations of case selected from over 100 patients in current treatment with Chinese NiTi wires. Chinese NiTi wire reduced the leveling and alignment phase of treatment without discomfort to the patient. Chinese NiTi wire can be used in both children and adults. PMID:1445516

  1. Spatial distribution of Sahelian land surface properties from airborne POLDER multiangular observations

    NASA Astrophysics Data System (ADS)

    Lacaze, Roselyne; Roujean, Jean-Louis; Goutorbe, Jean-Paul

    1999-05-01

    This paper presents the spatial distribution of land surface parameters in southwestern Niger, a region composed mainly of shrub and grassland fallows, millet crop, and tiger bush. The regional patterns of the surface albedo, the leaf area index, the fractional vegetation cover, and the fraction of absorbed photosynthetically active radiation are estimated through the growing season from airborne POLDER (Polarization and Directionality of Earth Reflectances) data acquired during the Hydrologic Atmospheric Pilot Experiment in Sahel (HAPEX-Sahel). The retrieval of these parameters is via a bidirectional reflectance model, appropriate vegetation indices, and Sun-view geometries. Comparison of the POLDER-derived surface parameters with airborne and ground measurements shows that the procedure generally performs well, enhancing the ability to constrain soil-vegetation-atmosphere transfer (SVAT) models in the Sahel area by providing spatially averaged and updated information. This will enable a more valid assessment of the role of the land surface in determining the Sahelian climate, with a better determination of the scaling effect of surface processes. Although the algorithms described in this work rely primarily on multiangular observations, such as those provided by spaceborne POLDER data sets, they should be useful in a number of remote sensing applications.

  2. Pathfinder Landing Site Observed by Mars Orbiter Camera - 'Big Crater' in Stereo View

    NASA Technical Reports Server (NTRS)

    1998-01-01

    On its 256th orbit of Mars, the camera on-board the Mars Global Surveyor spacecraft successfully observed the vicinity of the Pathfinder landing site. The images shown are a stereoscopic image pair in anaglyph format, made from the overlapping area of MOC 25603 and 23703. This image is reproduced at a scale of 5 m (16.4 feet) per pixel. Image 23703 was acquired on 13 April at 7:50 AM PDT; Image 25603 was acquired on 22 April at 1:11 PM PDT. The P237 observation was made from a distance of 675 km while the P256 measurement was made from 800 km. The viewing angle for 23703 was 21.2o, for 25603, 30.67o, giving an angular difference of about 9.5o. Owing to the relief on 'Big Crater,' this relatively small angular difference was in this case sufficient to show good stereo parallax.

    The resolution of the MOC image that covered the Pathfinder landing site (MOC 25603) was about 3.3 m or 11 feet per pixel. The Pathfinder lander and airbags form a roughly equilateral triangle 5 m on a side. Noting that the camera has not yet been focussed (it needs to be in the stable temperature conditions of the low altitude, circular mapping orbit in order to achieve best focus) and the hazy atmospheric conditions, the effective scale of the image is probably closer to 5 m (16.4 feet). Thus, the scale of the image was insufficient to resolve the lander (more than one pixel is needed to resolve a feature). In addition, the relatively high sun angle of the image (the sun was 40o above the horizon) reduced the length of shadows (for example, only a few boulders are seen), also decreasing the ability to discriminate small features. Work continues to locate intermediate-scale features in the lander and orbiter images in the hope of identifying the precise landing site based on these comparisons.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego

  3. Satellite observation of aerosol - cloud interactions over semi-arid and arid land regions

    NASA Astrophysics Data System (ADS)

    Klüser, L.; Holzer-Popp, T.

    2012-04-01

    Satellite observations from three different sources are used to study the interactions between aerosol and ice clouds in five semi-arid and arid land regions over Africa and Asia, reaching from the South-African Kalahari to the Taklimakan and Gobi in Mongolia. (1) Six years of Aqua MODIS cloud and aerosol observations (including "Deep Blue" retrievals) which contain a qualitative separation into coarse and fine mode aerosol are analysed. (2) Five years of APOLLO cloud observations and SYNAER aerosol retrievals which allow discriminating between mineral dust and soot dominated cases from AATSR and SCIAMACHY on ENVISAT are exploited. (3) Moreover IASI provides one year of ice cloud and mineral dust observations over land retrieved with a newly developed method based on singular vector decomposition. Cloud top temperature observations are used to asses the state of convection and to statistically re-project observation distributions of cloud properties to background conditions. Then the difference between observation density distributions of background and re-projected aerosol-contaminated samples can be evaluated. By such way of analysis the influence of different cloud development stages, which also manifest in seasonal cycles of cloud properties, can be minimised. The analysis of the various observation density distributions shows that liquid water and ice effective radius is mainly decreased for increased total aerosol content for both aerosol types, biomass burning aerosols and mineral dust, separately. Two different modes of aerosol impacts on cloud optical depth can be shown. Optical depth is mainly increased, directly following the theory of the so-called "Twomey effect". In the West African Sahel a decrease of cloud water path (for both liquid water and ice) under the influence of absorbing aerosols results also in decreased optical depth. As at the same time the cloud fraction does not decrease under aerosol influence, the statistical decrease of mean

  4. 76 FR 81906 - Advance Notice of Proposed Rulemaking Regarding a Competitive Process for Leasing Public Lands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... a Competitive Process for Leasing Public Lands for Solar and Wind Energy Development AGENCY: Bureau... public lands for solar and wind energy development. DATES: The BLM will accept comments and suggestions...) leases for solar and wind energy development that is based upon the Agency's authority under the...

  5. Advancing an Urban Agenda: Principles and Experiences of an Urban Land Grant University

    ERIC Educational Resources Information Center

    Maruyama, Geoffrey; Jones, Robert J.; Finnegan, John R., Jr.

    2009-01-01

    Our urban-located land grant institution has long been committed to engaged research, teaching, and service. This paper describes efforts to articulate and implement a strategic urban land grant vision that places urban/metropolitan engagement at the center of our institution's "urban age" future. We describe intentional and broad-based efforts in…

  6. Mapping urban land cover from space: Some observations for future progress

    NASA Technical Reports Server (NTRS)

    Gaydos, L.

    1982-01-01

    The multilevel classification system adopted by the USGS for operational mapping of land use and land cover at levels 1 and 2 is discussed and the successes and failures of mapping land cover from LANDSAT digital data are reviewed. Techniques used for image interpretation and their relationships to sensor parameters are examined. The requirements for mapping levels 2 and 3 classes are considered.

  7. Land subsidence caused by the East Mesa geothermal field, California, observed using SAR interferometry

    USGS Publications Warehouse

    Massonnet, D.; Holzer, T.; Vadon, H.

    1997-01-01

    Interferometric combination of pairs of synthetic aperture radar (SAR) images acquired by the ERS-1 satellite maps the deformation field associated with the activity of the East Mesa geothermal plant, located in southern California. SAR interferometry is applied to this flat area without the need of a digital terrain model. Several combinations are used to ascertain the nature of the phenomenon. Short term interferograms reveal surface phase changes on agricultural fields similar to what had been observed previously with SEASAT radar data. Long term (2 years) interferograms allow the study of land subsidence and improve prior knowledge of the displacement field, and agree with existing, sparse levelling data. This example illustrates the power of the interferometric technique for deriving accurate industrial intelligence as well as its potential for legal action, in cases involving environmental damages. Copyright 1997 by the American Geophysical Union.

  8. A Model for Estimation of Rain Rate on Tropical Land from TRMM Microwave Imager Radiometer Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Kim, Kyu-Myong

    2004-01-01

    Over the tropical land regions observations of the 85 GHz brightness temperature (T(sub 85v)) made by the TRMM Microwave Imager (TMI) radiometer when analyzed with the help of rain rate (R(sub pR)) deduced from the TRMM Precipitation Radar (PR) indicate that there are two maxima in rain rate. One strong maximum occurs when T(sub 85) has a value of about 220 K and the other weaker one when T(sub 85v) is much colder approx. 150 K. Together with the help of earlier studies based on airborne Doppler Radar observations and radiative transfer theoretical simulations, we infer the maximum near 220 K is a result of relatively weak scattering due to super cooled rain drops and water coated ice hydrometeors associated with a developing thunderstorm (Cb) that has a strong updraft. The other maximum is associated with strong scattering due to ice particles that are formed when the updraft collapses and the rain from the Cb is transit2oning from convective type to stratiform type. Incorporating these ideas and with a view to improve the estimation of rain rate from existing operational method applicable to the tropical land areas, we have developed a rain retrieval model. This model utilizes two parameters, that have a horizontal scale of approx. 20km, deduced from the TMI measurements at 19, 21 and 37 GHz (T(sub 19v), T(sub 21v), T(sub 37v). The third parameter in the model, namely the horizontal gradient of brightness temperature within the 20 km scale, is deduced from TMI measurements at 85 GHz. Utilizing these parameters our retrieval model is formulated to yield instantaneous rain rate on a scale of 20 km and seasonal average on a mesoscale that agree well with that of the PR.

  9. Land-atmosphere coupling manifested in warm-season observations on the U.S. southern great plains

    SciTech Connect

    Phillips, Thomas J.; Klein, Stephen A.

    2014-01-28

    This study examines several observational aspects of land-atmosphere coupling on daily average time scales during warm seasons of the years 1997 to 2008 at the Department of Energy Atmospheric Radiation Measurement Program’s Southern Great Plains (SGP) Central Facility site near Lamont, Oklahoma. Characteristics of the local land-atmosphere coupling are inferred by analyzing the covariability of selected land and atmospheric variables that include precipitation and soil moisture, surface air temperature, relative humidity, radiant and turbulent fluxes, as well as low-level cloud base height and fractional coverage. For both the energetic and hydrological aspects of this coupling, it is found that large-scale atmospheric forcings predominate, with local feedbacks of the land on the atmosphere being comparatively small much of the time. The weak land feedbacks are manifested by 1) the inability of soil moisture to comprehensively impact the coupled land-atmosphere energetics, and 2) the limited recycling of local surface moisture under conditions where most of the rainfall derives from convective cells that originate at remote locations. There is some evidence, nevertheless, of the local land feedback becoming stronger as the soil dries out in the aftermath of precipitation events, or on days when the local boundary-layer clouds are influenced by thermal updrafts known to be associated with convection originating at the surface. Finally, we also discuss potential implications of these results for climate-model representation of regional land-atmosphere coupling.

  10. Evaluation of the Community Land Model simulated carbon and water fluxes against observations over ChinaFLUX sites

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Mao, J.; Shi, X.; Ricciuto, D. M.; He, H.; Thornton, P. E.; Yu, G.; Han, S.; Li, Y.; Yan, J.; Hao, Y.; Wang, H.

    2014-12-01

    The Community Land Model (CLM) is an advanced process-based land surface model that simulates the complicated carbon, water vapor and energy exchanges between the terrestrial ecosystem and the atmosphere at various spatial-temporal scales. We for the first time use eddy-covariance observations of CO2 and water vapor exchange and soil respiration measurements at five representative Chinese Terrestrial Ecosystem Flux Observational Network (ChinaFLUX) tower sites to systematically evaluate the latest versions of CLM, the CLM4.0 and CLM4.5, and comprehensively examine the similarities and differences between the observational and simulated results. The CLM4.5 underestimates annual carbon sink at three forest sites and one alpine grassland site but overestimates the carbon sink at a semi-arid grassland site. The underestimation in annual carbon sink at a deciduous dominated forest site is resulted from underestimated daytime carbon sequestration in summer and overestimated nighttime carbon emission in spring and autumn. Compared with the CLM4.0, the bias of annual Gross Primary Production (GPP) is reduced by 24% and 28% in CLM4.5 at two subtropical forest sites. However, CLM4.5 still has a large positive bias in annual GPP. The improvement in NEE is limited, although the bias of soil respiration decreases by 16%-43% at three forest sites. The CLM4.5 has lower soil water content in dry season than this simulated by the CLM4.0 at two grassland sites. These lead to the significant drop in leaf area index and GPP, and the increase in respiration for the CLM4.5. The new fire parameterization in CLM4.5 causes incorrect fire estimation at Changbaishan forest site, which results in unexpected underestimation of NEE, vegetation carbon, and soil organic carbon by 46%, 95%, and 87%, respectively. Our study with the ChinaFLUX sites indicates a significant improvement of the CLM4.5 than the CLM4, and suggests further developments on the parameterization of seasonal GPP and

  11. Using NASA Earth Observing Satellites and Statistical Model Analysis to Monitor Vegetation and Habitat Rehabilitation in Southwest Virginia's Reclaimed Mine Lands

    NASA Astrophysics Data System (ADS)

    Tate, Z.; Dusenge, D.; Elliot, T. S.; Hafashimana, P.; Medley, S.; Porter, R. P.; Rajappan, R.; Rodriguez, P.; Spangler, J.; Swaminathan, R. S.; VanGundy, R. D.

    2014-12-01

    The majority of the population in southwest Virginia depends economically on coal mining. In 2011, coal mining generated $2,000,000 in tax revenue to Wise County alone. However, surface mining completely removes land cover and leaves the land exposed to erosion. The destruction of the forest cover directly impacts local species, as some are displaced and others perish in the mining process. Even though surface mining has a negative impact on the environment, land reclamation efforts are in place to either restore mined areas to their natural vegetated state or to transform these areas for economic purposes. This project aimed to monitor the progress of land reclamation and the effect on the return of local species. By incorporating NASA Earth observations, such as Landsat 8 Operational Land Imager (OLI) and Landsat 5 Thematic Mapper (TM), re-vegetation process in reclamation sites was estimated through a Time series analysis using the Normalized Difference Vegetation Index (NDVI). A continuous source of cloud free images was accomplished by utilizing the Spatial and Temporal Adaptive Reflectance Fusion Model (STAR-FM). This model developed synthetic Landsat imagery by integrating the high-frequency temporal information from Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and high-resolution spatial information from Landsat sensors In addition, the Maximum Entropy Modeling (MaxENT), an eco-niche model was used to estimate the adaptation of animal species to the newly formed habitats. By combining factors such as land type, precipitation from Tropical Rainfall Measuring Mission (TRMM), and slope from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the MaxENT model produced a statistical analysis on the probability of species habitat. Altogether, the project compiled the ecological information which can be used to identify suitable habitats for local species in reclaimed mined areas.

  12. Preliminary results of land subsidence monitoring project in Konya Closed Basin between 2006-2009 by means of GNSS observations

    NASA Astrophysics Data System (ADS)

    Ustun, A.; Tusat, E.; Yalvac, S.

    2010-06-01

    One of the potential dangers that might arise as a result of bringing excessive amounts of groundwater to the surface of the Earth is land subsidence. Such surface deformations - these velocities may vary from a few millimetres to a few metres per year - do the greatest damage to infrastructure facilities and buildings in residential units. Agricultural lands, in which excessive irrigation is performed, and densely populated cities are more likely to suffer from land subsidence. Konya Closed Basin (KCB), where a rapid groundwater withdrawal has been observed during the last 30-40 years, is faced with such a threat. In this study, the possibility of the occurrence of land subsidence, related to groundwater withdrawal for the KCB, is assessed and the geodetic studies conducted up to now, with the intention of identifying land subsidence, are introduced. The vertical displacements of between -12 and -52 mm/year have been detected through GNSS observations collected on the 6-point test network. The land subsidence phenomenon has been developing in the areas where the groundwater is extensively used for irrigation and daily life. The results support the findings derived from the historical leveling records and point out the need of an extended study based on both GNSS and InSAR techniques for spatial and temporal mapping of land subsidence in the KCB.

  13. Coordinated Orbital and Landed Observations for Understanding Martian Soil and Rock Mineralogy and Textures

    NASA Astrophysics Data System (ADS)

    Arvidson, R. E.; Wolff, M.; Morris, R. V.; Poulet, F.; Seelos, F.; Murchie, S.

    2008-12-01

    Coordinated observations between the orbiting Mars Express OMEGA hyperspectral imager (0.4 to 5 micrometers) and the MER rovers Spirit and Opportunity have provided a self-consistent view of surface materials at the rover traverse sites and beyond. Coordinated observations now include the Mars Reconnaissance Orbiter CRISM hyperspectral imager (0.4 to 4 micrometers), the two rovers, and the Phoenix Lander (touched down 5/25/08). Coordinated observations with Phoenix include dozens of near simultaneous and simultaneous measurements of the atmosphere and surface, spaced throughout the northern hemisphere summer period. For Spirit the results show that the Gusev plains are dominated by weakly altered basaltic sands with a variable cover of nanophase iron oxide-rich dust. The hydrated sulfate and opaline silica deposits found by Spirit could not be seen using orbital data because of their small areal extent and subsurface provenance (exposed by rover wheels). Opportunity joint observations show that the Meridiani Plains are covered by aeolian deposits dominated by basaltic sand, hematitic concretions, and outcrops with orbital spectral signatures consistent with weakly hydrated nanophase iron oxides, although jarosite (OH-bearing) and hydrated phases were detected by Moessbauer and, on surfaces excavated by the Rock Abrasion Tool, by Mini-TES. Phoenix joint observations show that water ice frost is retained during the summer in a nearby small (~6 km) bowl-shaped crater and on the north facing slopes of the ~10 km wide Heimdall Crater. The landing site and immediate surroundings are on the differentially eroded ejecta deposits from Heimdall, and the soil exposures are dominated by basaltic sandy silt deposits mixed with nanophase iron oxide-rich dust. No carbonates, sulfates, nitrates, or phyllosilicates are evident in the orbit- based spectra, but ice is present in the subsurface. Monitoring of the Phoenix site during the transition from summer to fall will allow us to

  14. Land Surface Temperature Forecasting using spectral observations of MODIS and Modular Neural Networks

    NASA Astrophysics Data System (ADS)

    Taghavi, Farahnaz; Zargaran, Zahrah; Ahmadi, Abbas

    Land Surface Temperature (LST) is a significant parameter for many applications including numerical weather prediction, climate and environmental studies. The goal of this study is using a combination of Modular neural networks and satellite image as input to predict the LST in Tehran ,Iran.In this study, two MLP and RBF neural networks and an algorithm for calculating of LST based spectral observations of MODerate resolution Imaging Spectra-radiometer (MODIS) are used This algorithm include Brightness Temperature of channel 31(BT31) and 32(BT32) on thermal band of MODIS. The algorithm are written using Hierarchical Data Format (HDF) calibrated data which has the spatial resolution of 1km by ENVI (Environment for Visualizing Images) software, and output products are in HDF format. Initial results show that modular neural network helps to improve networks' generalization and learning speed and the main reason for selecting these networks is their good performance in this problem.The model has a modular learning and structure. Since the task decomposition at first and the combination of results to get the final prediction at the end are key and effective points on the performance of modular neural network, in this study we propose a new approach to this issue. This method uses the Self-Organizing Map (SOM) Neural Network and Particle Swarm Optimization(PSO) algorithm for task decomposition. The proposed model combines this neural networks and optimization algorithms. Results indicate that use of PSO algorithm has caused suitable distribution of clusters obtained from SOM algorithm. In addition to the use of satellite images has improved the performance of the proposed model. Finally, the results obtained from this model will be compared with some other methods with non-modular structure and learning and it is shown that this proposed model is able to produce accurate results. The result of this comparison show that training time of model in the forecasting of land

  15. Advanced Land Use Classification for Nigeriasat-1 Image of Lake Chad Basin

    NASA Astrophysics Data System (ADS)

    Babamaaji, R.; Park, C.; Lee, J.

    2009-12-01

    Lake Chad is a shrinking freshwater lake that has been significantly reduced to about 1/20 of its original size in the 1960’s. The severe draughts in 1970’s and 1980’s and following overexploitations of water resulted in the shortage of surface water in the lake and the surrounding rivers. Ground water resources are in scarcity too as ground water recharge is mostly made by soil infiltration through soil and land cover, but this surface cover is now experiencing siltation and expansion of wetland with invasive species. Large changes in land use and water management practices have taken place in the last 50 years including: removal of water from river systems for irrigation and consumption, degradation of forage land by overgrazing, deforestation, replacing natural ecosystems with mono-cultures, and construction of dams. Therefore, understanding the change of land use and its characteristics must be a first step to find how such changes disturb the water cycle around the lake and affect the shrinkage of the lake. Before any useful thematic information can be extracted from remote sensing data, a land cover classification system has to be developed to obtain the classes of interest. A combination of classification systems used by Global land cover, Water Resources eAtlass and Lake Chad Basin Commission gave rise to 7 land cover classes comprising of - Cropland, vegetation, grassland, water body, shrub-land, farmland ( mostly irrigated) and bareland (i.e. clear land). Supervised Maximum likelihood classification method was used with 15 reference points per class chosen. At the end of the classification, the overall accuracy is 93.33%. Producer’s accuracy for vegetation is 40% compare to the user’s accuracy that is 66.67 %. The reason is that the vegetation is similar to shrub land, it is very hard to differentiate between the vegetation and other plants, and therefore, most of the vegetation is classified as shrub land. Most of the waterbodies are occupied

  16. Inverse modeling of hydrologic parameters using surface flux and runoff observations in the Community Land Model

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Hou, Z.; Huang, M.; Tian, F.; Leung, L. R.

    2013-04-01

    This study demonstrates the possibility of inverting hydrologic parameters using surface flux and runoff observations in version 4 of the Community Land Model (CLM4). Previous studies showed that surface flux and runoff calculations are sensitive to major hydrologic parameters in CLM4 over different watersheds, and illustrated the necessity and possibility of parameter calibration. Two inversion strategies, the deterministic least-square fitting and stochastic Markov-Chain Monte-Carlo (MCMC) Bayesian inversion approaches, are evaluated by applying them to CLM4 at selected sites. The unknowns to be estimated include surface and subsurface runoff generation parameters and vadose zone soil water parameters. We find that using model parameters calibrated by the least-square fitting provides little improvements in the model simulations but the sampling-based stochastic inversion approaches are consistent - as more information comes in, the predictive intervals of the calibrated parameters become narrower and the misfits between the calculated and observed responses decrease. In general, parameters that are identified to be significant through sensitivity analyses and statistical tests are better calibrated than those with weak or nonlinear impacts on flux or runoff observations. Temporal resolution of observations has larger impacts on the results of inverse modeling using heat flux data than runoff data. Soil and vegetation cover have important impacts on parameter sensitivities, leading to different patterns of posterior distributions of parameters at different sites. Overall, the MCMC-Bayesian inversion approach effectively and reliably improves the simulation of CLM under different climates and environmental conditions. Bayesian model averaging of the posterior estimates with different reference acceptance probabilities can smooth the posterior distribution and provide more reliable parameter estimates, but at the expense of wider uncertainty bounds.

  17. Global CO2 Distributions over Land from the Greenhouse Gases Observing Satellite (GOSAT)

    NASA Technical Reports Server (NTRS)

    Hammerling, Dorit M.; Michalak, Anna M.; O'Dell, Christopher; Kawa, Randolph S.

    2012-01-01

    January 2009 saw the successful launch of the first space-based mission specifically designed for measuring greenhouse gases, the Japanese Greenhouse gases Observing SATellite (GOSAT). We present global land maps (Level 3 data) of column-averaged CO2 concentrations (X(sub CO2)) derived using observations from the GOSAT ACOS retrieval algorithm, for July through December 2009. The applied geostatistical mapping approach makes it possible to generate maps at high spatial and temporal resolutions that include uncertainty measures and that are derived directly from the Level 2 observations, without invoking an atmospheric transport model or estimates of CO2 uptake and emissions. As such, they are particularly well suited for comparison studies. Results show that the Level 3 maps for July to December 2009 on a lO x 1.250 grid, at six-day resolution capture much of the synoptic scale and regional variability of X(sub CO2), in addition to its overall seasonality. The uncertainty estimates, which reflect local data coverage, X(sub CO2) variability, and retrieval errors, indicate that the Southern latitudes are relatively well-constrained, while the Sahara Desert and the high Northern latitudes are weakly-constrained. A probabilistic comparison to the PCTM/GEOS-5/CASA-GFED model reveals that the most statistically significant discrepancies occur in South America in July and August, and central Asia in September to December. While still preliminary, these results illustrate the usefulness of a high spatiotemporal resolution, data-driven Level 3 data product for direct interpretation and comparison of satellite observations of highly dynamic parameters such as atmospheric CO2.

  18. Inverse Modeling of Hydrologic Parameters Using Surface Flux and Runoff Observations in the Community Land Model

    SciTech Connect

    Sun, Yu; Hou, Zhangshuan; Huang, Maoyi; Tian, Fuqiang; Leung, Lai-Yung R.

    2013-12-10

    This study demonstrates the possibility of inverting hydrologic parameters using surface flux and runoff observations in version 4 of the Community Land Model (CLM4). Previous studies showed that surface flux and runoff calculations are sensitive to major hydrologic parameters in CLM4 over different watersheds, and illustrated the necessity and possibility of parameter calibration. Two inversion strategies, the deterministic least-square fitting and stochastic Markov-Chain Monte-Carlo (MCMC) - Bayesian inversion approaches, are evaluated by applying them to CLM4 at selected sites. The unknowns to be estimated include surface and subsurface runoff generation parameters and vadose zone soil water parameters. We find that using model parameters calibrated by the least-square fitting provides little improvements in the model simulations but the sampling-based stochastic inversion approaches are consistent - as more information comes in, the predictive intervals of the calibrated parameters become narrower and the misfits between the calculated and observed responses decrease. In general, parameters that are identified to be significant through sensitivity analyses and statistical tests are better calibrated than those with weak or nonlinear impacts on flux or runoff observations. Temporal resolution of observations has larger impacts on the results of inverse modeling using heat flux data than runoff data. Soil and vegetation cover have important impacts on parameter sensitivities, leading to the different patterns of posterior distributions of parameters at different sites. Overall, the MCMC-Bayesian inversion approach effectively and reliably improves the simulation of CLM under different climates and environmental conditions. Bayesian model averaging of the posterior estimates with different reference acceptance probabilities can smooth the posterior distribution and provide more reliable parameter estimates, but at the expense of wider uncertainty bounds.

  19. DIAGNOSTIC EVALUATION OF AIR QUALITY MODELS USING ADVANCED METHODS WITH SPECIALIZED OBSERVATIONS OF SELECTED AMBIENT SPECIES -PART II

    EPA Science Inventory

    This is Part 2 of "Diagnostic Evaluation of Air Quality Models Using Advanced Methods with Specialized Observations of Selected Ambient Species". A limited field campaign to make specialized observations of selected ambient species using advanced and innovative instrumentation f...

  20. Variational assimilation of land surface temperature observations for enhanced river flow predictions

    NASA Astrophysics Data System (ADS)

    Ercolani, Giulia; Castelli, Fabio

    2016-04-01

    Data assimilation (DA) has the potential of improving hydrologic forecasts. However, many issues arise in case it is employed for spatially distributed hydrologic models that describes processes in various compartments: large dimensionality of the inverse problem, layers governed by different equations, non-linear and discontinuous model structure, complex topology of domains such as surface drainage and river network.On the other hand, integrated models offer the possibility of improving prediction of specific states by exploiting observations of quantities belonging to other compartments. In terms of forecasting river discharges, and hence for their enhancement, soil moisture is a key variable, since it determines the partitioning of rainfall into infiltration and surface runoff. However, soil moisture measurements are affected by issues that could prevent a successful DA and an actual improvement of discharge predictions.In-situ measurements suffer a dramatic spatial scarcity, while observations from satellite are barely accurate and provide spatial information only at a very coarse scale (around 40 km).Hydrologic models that explicitly represent land surface processes of coupled water and energy balance provide a valid alternative to direct DA of soil moisture.They gives the possibility of inferring soil moisture states through DA of remotely sensed Land Surface Temperature (LST), whose measurements are more accurate and with a higher spatial resolution in respect to those of soil moisture. In this work we present the assimilation of LST data in a hydrologic model (Mobidic) that is part of the operational forecasting chain for the Arno river, central Italy, with the aim of improving flood predictions. Mobidic is a raster based, continuous in time and distributed in space hydrologic model, with coupled mass and energy balance at the surface and coupled groundwater and surface hydrology. The variational approach is adopted for DA, since it requires less

  1. Drought, Fire and Insects in Western US Forests: Observations to Improve Regional Land System Modeling

    NASA Astrophysics Data System (ADS)

    Law, B. E.; Yang, Z.; Berner, L. T.; Hicke, J. A.; Buotte, P.; Hudiburg, T. W.

    2015-12-01

    Drought, fire and insects are major disturbances in the western US, and conditions are expected to get warmer and drier in the future. We combine multi-scale observations and modeling with CLM4.5 to examine the effects of these disturbances on forests in the western US. We modified the Community Land Model, CLM4.5, to improve simulated drought-related mortality in forests, and prediction of insect outbreaks under future climate conditions. We examined differences in plant traits that represent species variation in sensitivity to drought, and redefined plant groupings in PFTs. Plant traits, including sapwood area: leaf area ratio and stemwood density were strongly correlated with water availability during the ecohydrologic year. Our database of co-located observations of traits for 30 tree species was used to produce parameterization of the model by species groupings according to similar traits. Burn area predicted by the new fire model in CLM4.5 compares well with recent years of GFED data, but has a positive bias compared with Landsat-based MTBS. Biomass mortality over recent decades increased, and was captured well by the model in general, but missed mortality trends of some species. Comparisons with AmeriFlux data showed that the model with dynamic tree mortality only (no species trait improvements) overestimated GPP in dry years compared with flux data at semi-arid sites, and underestimated GPP at more mesic sites that experience dry summers. Simulations with both dynamic tree mortality and species trait parameters improved estimates of GPP by 17-22%; differences between predicted and observed NEE were larger. Future projections show higher productivity from increased atmospheric CO2 and warming that somewhat offsets drought and fire effects over the next few decades. Challenges include representation of hydraulic failure in models, and availability of species trait and carbon/water process data in disturbance- and drought-impacted regions.

  2. Observational study of land-surface-cloud-atmosphere coupling on daily timescales

    NASA Astrophysics Data System (ADS)

    Betts, Alan; Desjardins, Raymond; Beljaars, Anton; Tawfik, Ahmed

    2015-04-01

    Our aim is to provide an observational reference for the evaluation of the surface and boundary layer parameterizations used in large-scale models using the remarkable long-term Canadian Prairie hourly dataset. First we use shortwave and longwave data from the Baseline Surface Radiation Network (BSRN) station at Bratt’s Lake, Saskatchewan, and clear sky radiative fluxes from ERA-Interim, to show the coupling between the diurnal cycle of temperature and relative humidity and effective cloud albedo and net longwave flux. Then we calibrate the nearby opaque cloud observations at Regina, Saskatchewan in terms of the BSRN radiation fluxes. We find that in the warm season, we can determine effective cloud albedo to ±0.08 from daytime opaque cloud, and net long-wave radiation to ±8 W/m2 from daily mean opaque cloud and relative humidity. This enables us to extend our analysis to the 55 years of hourly observations of opaque cloud cover, temperature, relative humidity, and daily precipitation from 11 climate stations across the Canadian Prairies. We show the land-surface-atmosphere coupling on daily timescales in summer by stratifying the Prairie data by opaque cloud, relative humidity, surface wind, day-night cloud asymmetry and monthly weighted precipitation anomalies. The multiple linear regression fits relating key diurnal climate variables, the diurnal temperature range, afternoon relative humidity and lifting condensation level, to daily mean net longwave flux, wind-speed and precipitation anomalies have R2 values between 0.61 and 0.69. These fits will be a useful guide for evaluating the fully coupled system in models.

  3. Battery Performance of ADEOS (Advanced Earth Observing Satellite) and Ground Simulation Test Results

    NASA Technical Reports Server (NTRS)

    Koga, K.; Suzuki, Y.; Kuwajima, S.; Kusawake, H.

    1997-01-01

    The Advanced Earth Observing Satellite (ADEOS) is developed with the aim of establishment of platform technology for future spacecraft and inter-orbit communication technology for the transmission of earth observation data. ADEOS uses 5 batteries, consists of two packs. This paper describes, using graphs and tables, the ground simulation tests and results that are carried to determine the performance of the ADEOS batteries.

  4. THEMIS Observations, Discoveries and Predictions for the MER A Landing Site in Gusev Crater

    NASA Astrophysics Data System (ADS)

    Rice, J. W.; Christensen, P. R.

    2003-12-01

    THEMIS has "followed the water" and discovered the youngest water flow into the MER A landing site in Gusev crater. This flow has a rumpled looking texture and is interpreted to be viscous material emanating from the mouth of Ma'adim Vallis. The flow can be traced for over 150 km across the floor of Gusev. This flow is emplaced on top of the smooth plains material and covers the whole western half of the landing ellipse. The flow does not show up in THEMIS IR indicating that it is mantled with at least a few cm of dust. This flow is either a debris flow (15-40% water volume content) or hyperconcentrated flow (40-80% water volume content) and not a lava flow based on its morphology, geologic setting, and lack of nearby volcanic sources. Debris flow deposits can be differentiated from hyperconcentrated flows on the basis of particle sorting, sedimentary structures, and inferred rheological properties. Access to this deposit will allow sampling of the most recent water related sediment in the basin. A very interesting relationship has been found to exist for many craters in the region of Gusev. These craters contain stacks of layered sedimentary deposits. It should be noted that these craters lack a large inflowing channel system. A similar layered morphology is seen on the floor of Gusev, especially the SE portion of the crater, where a 190 m thick deposit is being eroded. We propose that this material in Gusev is the remnant of a formerly more extensive regional unit related to the layered deposits seen in the many nearby craters. This observation suggests that the region was formerly buried by several hundred meters of material that is now being exhumed. This also implies that Ma'adim Vallis was a superposed channel that cut down from above and across Gusev. We also offer another scenario for Gusev in that it received periodic outwash deposits and may have contained shallow ephemeral playas with short lifetimes and not deep long lived lakes as suggested by some

  5. Observed impacts of wind farms on land surface temperature in Inner Mongolia

    NASA Astrophysics Data System (ADS)

    Tang, B.; Zhao, X.; Wu, D.; Zhao, W.; Wei, H.

    2015-12-01

    Abstract: The wind turbine industry in china has experienced a dramatic increase in recent years and wind farms (WFs) have an impact on the underlying surface conditions of climate system. This paper assesses the impacts of wind farms by analyzing the variations of the land surface temperature (LST) data for the period of 2003-2014 over a region consisted of 1097 turbines in the Huitengxile Wind Farm, the largest wind farm in Asia. We first compare the spatial coupling between the geographic layouts of the WFs and the spatial patterns of LST changes of two periods (post- versus pre- wind turbines construction) and then employ the difference of LST between WF pixels and surrounding non-WF pixels to quantify the effects of WFs. The results reveal that the LST at daytime increases by 0.52-0.86°C in winter, spring and autumn and decreases by about 0.56°C in summer over the WFs on average, with the spatial pattern of this warming or cooling generally coupled with the geographic distribution of the wind turbines, while the changes in LST at nighttime are much noisier. The daytime LST warming or cooling effects vary with seasons, and the strongest warming and tightest spatial coupling are in autumn months of September-November. The seasonal variations in albedo due to the construction of wind turbines are primarily responsible for the daytime LST changes. Areal mean decreases in winter, spring and autumn and increase in summer in albedo are observed over the WFs and the spatial pattern and magnitude of the changes in albedo couple very well with the layouts of the wind turbines. The increase (decrease) in albedo over the WFs indicates that WFs across the Huitengxile grassland absorb less (more) incoming radiation, thus resulting in a decrease (increase) in LST at daytime. The inter-annual variations in areal mean LST differences at daytime are highly correlated with those in areal mean albedo differences for all four seasons (R2=0.48~0.67). Our findings are in contrast

  6. Benchmarking global land surface models against the observed mean annual runoff from 150 large basins

    NASA Astrophysics Data System (ADS)

    Zhou, Xinyao; Zhang, Yongqiang; Wang, Yingping; Zhang, Huqiang; Vaze, Jai; Zhang, Lu; Yang, Yonghui; Zhou, Yanchun

    2012-11-01

    SummaryUsing the observed mean annual runoff for 1986-1995 from 150 large basins globally, we evaluate the performance of the 14 global land surface models (LSMs) and six Budyko-type hydrological models that are forced by the meteorological data from the second phase of the Global Soil Wetness Project (GSWP-2). The results show that both the 14 LSMs and six Budyko-type models can explain 55-70% of the spatial variations of mean annual runoff across the selected 150 basins. However, the 14 LSMs show larger biases in the simulated mean annual runoff than the Budyko-type models. The LSMs biases are caused by errors in forcing data, model structure and model parameterisation. The errors in the precipitation forcing data are found to be the main cause for biases in the simulated mean annual runoffs by the Budyko-types models, and most likely for biases in the 14 global land surface models too. The GSWP-2 precipitation is noticeably overestimated at Northern high-latitudes, which causes large positive biases for the LSMs in simulating mean annual runoff in these regions. The most LSMs show large biases in the regions with low mean annual precipitation. Underestimation of the GSWP-2 precipitation in Amazon and Orinoco basins results in significant underestimation in the simulated mean annual runoff by all LSMs and Budyko-type models for these regions. The LSMs with smaller biases generally show larger baseflow ratio in wet basins than in dry basins while the LSMs with larger biases generally show smaller baseflow ratio in wet basins than in dry basins. This indicates that errors in model structure can result in large biases in the simulated runoff. Several parameter sensitivity experiments for one LSM are carried out to investigate impacts on simulated mean runoff. The result indicates that ±20% changes in five key model parameters have relatively smaller impacts on the simulated mean annual runoff across the 150 basins, compared to errors in model structure.

  7. Agriculture, Food Production, and Rural Land Use in Advanced Placement® Human Geography

    ERIC Educational Resources Information Center

    Moseley, William G.; Watson, Nancy H.

    2016-01-01

    ''Agriculture, Food, and Rural Land Use" constitutes a major part of the AP Human Geography course outline. This article explores challenging topics to teach, emerging research trends in agricultural geography, and sample teaching approaches for concretizing abstract topics. It addresses content identified as "essential knowledge"…

  8. Recent advances in land data assimilation at the NASA Global Modeling and Assimilation Office

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research in land surface data assimilation has grown rapidly over the last decade. We provide a brief overview of key research contributions by the NASA Global Modeling and Assimilation Office (GMAO). The GMAO contributions primarily include the continued development and application of the Ensembl...

  9. Advanced multispectral sensor requirements for remote sensing of agriculture and land cover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern agricultural and land cover monitoring programs require frequent data acquisitions and increased spectral resolution to acquire a greater number of parameters in a more accurate manner. Whereas hyperspectral sensors could provide the required information, agriculture's biggest need is for fr...

  10. Boundary-layer cumulus over land: Some observations and conceptual models

    SciTech Connect

    Stull, R.B.

    1993-09-01

    Starting in 1980, the Boundary Layer Research Team at the University of Wisconsin has been systematically studying the formation and evolution of nonprecipitating boundary-layer cumulus clouds (BLCu) in regions of fair weather (anticyclones) over land (Stull, 1980). Our approach is to quantify the average statistical characteristics of the surface, thermals, boundary layer, and clouds over horizontal regions of roughly 20 km in diameter. Within such a region over land, there is typically quite a variation in land use, and associated variations in surface albedo and moisture.

  11. Mars Delay-Doppler Radar Observations With GSSR: Global Analysis for Landing Site Selection and Characterization

    NASA Technical Reports Server (NTRS)

    Haldemann, A. F. C.; Jurgens, R. F.; Slade, M. A.; Thompson, T. W.; Rojas, F.

    1997-01-01

    Earth-based radar data remain an important part of the information set used to select and certify spacecraft landing sites on Mars. Constraints on robotic landings on Mars include: terrain elevation, radar reflectivity. regional and local slopes, rock distribution and coverage, and surface roughness, all of which are addressed by radar data. Indeed, the usefulness of radar data for Mars exploration has been demonstrated in the past. Radar data were critical in assessing the Viking Lander I site, and more recently, the Mars Pathfinder landing site.

  12. Alteration zone Mapping in the Meiduk and Sar Cheshmeh Porphyry Copper Mining Districts of Iran using Advanced Land Imager (ALI) Satellite Data

    NASA Astrophysics Data System (ADS)

    Beiranvand Pour, A.; Hashim, M.

    2015-10-01

    This study evaluates the capability of Earth Observing-1 (EO1) Advanced Land Imager (ALI) data for hydrothermal alteration mapping in the Meiduk and Sar Cheshmeh porphyry copper mining districts, SE Iran. Feature-oriented principal components selection, 4/2, 8/9, 5/4 band ratioing were applied to ALI data for enhancing the hydrothermally altered rocks associated with porphyry copper mineralization, lithological units and vegetation. Mixture-tuned matched-filtering (MTMF) was tested to discriminate the hydrothermal alteration areas of porphyry copper mineralization from surrounding environment using the shortwave infrared bands of ALI. Results indicate that the tested methods are able to yield spectral information for identifying vegetation, iron oxide/hydroxide and clay minerals, lithological units and the discrimination of hydrothermally altered rocks from unaltered rocks using ALI data.

  13. Classification of leafy spurge with earth o;bserving-1 advanced land imager

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a series of research studies sponsored by The Ecological Area-Wide Management of Leafy Spurge program, and as part of the 1998 DOI/NASA joint demonstration project, various remote sensing sensors were tested for their ability to map the invasive weed, leafy spurge (Euphorbia esula L). This study ...

  14. Land Use Change Mapping from Multi-Temporal Earth Observation Data in the Siberian Kulunda Steppe

    NASA Astrophysics Data System (ADS)

    Walde, I.; Hese, S.; Schmullius, C.

    2014-12-01

    Most of the temperate grassland of the Siberian Kulunda Steppe in the Altai Krai region of Russia was converted into intensely used farmland in the 1950`s following the directives of the 'virgin lands campaign' (russ. Zelina). The area under investigation comprises around 80.000 km² and belongs to the 'granary' of Russia, which is elementary for food supply of the increasing population. On the other hand inadequate and antiquated cultivation and agricultural management practices, e.g. acceptance of precipitation values of less than 250mm/year for farming, have caused ecological and socio-economic problems, e.g. degradation, desertification, and yield losses. The aim of the KULUNDA project is the development of sustainable land management policies and practices to stabilize agricultural yields and minimize the ongoing degradation and desertification processes. The focus of the study is the quantification and assessment of land use and land cover change. Therefore multi-temporal and multi-sensor satellite images were used to classify the land cover and perform change detection on specific land cover classes. For the earliest acquisition Landsat 4/5 TM scenes from 1989 with a medium ground resolution of 30 m were chosen and mosaicked. The second time step is a Landsat 7 ETM+ mosaic from the years 1999 and 2000 with 30 m ground resolution. The third acquisition represents the actual situation, acquired in 2013/14 by the RapidEye satellites (mosaicked and resampled to 30 m pixel size). The three mosaics were classified with an object-based approach into six land cover classes: Cropland, Woody vegetation, Herbaceous vegetation, Water areas, Salinization & Clouds, and Settlements. Afterwards a post-classification change detection identified areas of change and no change especially for cropland and steppe regions. Final statistics were provided for districts (russ. Rajon) and steppe types quantifying the change within the past 25 years.

  15. Mapping of land use changes in Poland using Earth observation data

    NASA Astrophysics Data System (ADS)

    Ciolkosz, A.

    2012-06-01

    Mapping of land use for the needs of reconstruction of the country was one of the main tasks of the Head Office of the Land Surveying set up after the Second World War. Up to present day such map has not been made despite of many attempts and the high demand for this type of map primarily by the spatial economy. The main reason was the lack of raw materials and high cost of f eld works. The situation changed with the launch of Landsat satellite. Images taken by this satellite were used for the preparation of land use map covering the entire country. They were also used to compilation the land cover databases developed within the three CORINE Land Cover (CLC) projects in 1990, 2000 and 2006. Comparison of these databases allowed an analysis of land use changes occurred within 16 years. These changes were relatively small, far below expectations. CLC database was also compared with a map of land use developed on the basis of topographic maps from the 1930's. The comparison showed changes that have occurred on the surface representing almost 10% of the total area of the country. They reveal both some effects of hostilities, the current expansion of the country, as well as the effects of natural disasters which hit Poland in recent years. Images taken by Landsat have also been applied to study the damage of forests in the Sudety Mountains. Several degrees of damage to spruce stands have been distinguished on the basis of satellite images. They were also used to study the development of brown coal mine and its impact on dropping the groundwater level in the vicinity of mine as well as to determine the development of Warsaw built-up areas in the last 80 years.

  16. Assimilation of soil moisture retrievals or brightness temperature observations from SMOS and SMAP into the GEOS-5 land surface model

    NASA Astrophysics Data System (ADS)

    De Lannoy, G. J. M.; Reichle, R. H.

    2015-12-01

    Two L-band microwave missions are currently collecting passive microwave observations and aiming at an improved estimation of soil moisture. The ESA Soil Moisture Ocean Salinity (SMOS) mission and the NASA Soil Moisture Active Passive (SMAP) mission both provide Level 1 brightness temperature products and derived Level 2 soil moisture retrieval products. The assimilation of these products into land surface models has potential to improve global estimates of soil moisture and other land surface variables. This presentation investigates the benefits and challenges of assimilating either retrievals or brightness temperature observations from either SMOS or SMAP into the Goddard Earth Observing System (GEOS-5) land surface model. It will be shown that the seasonal corrections introduced by retrieval assimilation are slightly different from those with brightness temperature assimilation as a result of the technical implementation of the assimilation scheme. Various resulting land surface variables will also be evaluated against the results from the operational SMAP Level 4 Soil Moisture (L4_SM) product, which assimilates SMAP brightness temperature data.

  17. Earth Observing System(EOS). Advanced Microwave Sounding Unit-A: Firmware Test Report

    NASA Technical Reports Server (NTRS)

    Schwantje, R.

    1998-01-01

    This document is the Firmware Test Report for the firmware to be used in the Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) instrument. It describes the firmware results of the Formal Qualification Test (FQT)/Demonstrations conducted on Mar. 21, 1997, Apr. 8, 1998, and July 14, 1998, for the EOS/AMSU-A instrument.

  18. The Advanced X-Ray Astrophysics Facility. Observing the Universe in X-Rays

    NASA Technical Reports Server (NTRS)

    Neal, V.

    1984-01-01

    An overview of the Advanced X ray Astronophysics Facility (AXAF) program is presented. Beginning with a brief introduction to X ray astrophysics, the AXAF observatory is described including the onboard instrumentation and system capabilities. Possible X ray sources suitable for AXAF observation are identified and defined.

  19. Observations of albedo and radiation balance over postforest land surfaces in the eastern Amazon Basin

    SciTech Connect

    Giambelluca, T.W.; Nullet, M.A.; Ziegler, A.D.

    1997-05-01

    Regional climatic change, including significant reductions in Amazon Basin evaporation and precipitation, has been predicted by numerical simulations of total tropical forest removal. These results have been shown to be very sensitive to the prescription of the albedo shift associated with conversion from forest to a replacement land cover. Modelers have so far chosen to use an {open_quotes}impoverished grassland{close_quotes} scenario to represent the postforest land surface. This choice maximizes the shifts in land surface parameters, especially albedo (fraction of incident shortwave radiation reflected by the surface). Recent surveys show secondary vegetation to be the dominant land cover for some deforested areas of the Amazon. This paper presents the results of field measurements of radiation flux over various deforested surfaces on a small farm in the eastern Amazonian state of Para. The albedo of fields in active use was as high as 0.176, slightly less than the 0.180 recently determined for Amazonian pasture and substantially less than the 0.19 commonly used in GCM simulations of deforestation. For 10-yr-old secondary vegetation, albedo was 0.135, practically indistinguishable from the recently published mean primary forest albedo of 0.134. Measurements of surface temperature and net radiation show that, despite similarity in albedo, secondary vegetation differs from primary forest in energy and mass exchange. The elevation of midday surface temperature above air temperature was found to be greatest for actively and recently farmed land, declining with time since abandonment. Net radiation was correspondingly lower for fields in active or recent use. Using land cover analyses of the region surrounding the study area for 1984, 1988, and 1991, the pace of change in regional-mean albedo is estimated to have declined and appears to be leveling at a value less than 0.03 above that of the original forest cover. 41 refs., 3 figs., 8 tabs.

  20. Improving the Representation of Land in Climate Models by Application of EOS Observations

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The PI's IDS current and previous investigation has focused on the applications of the land data toward the improvement of climate models. The previous IDS research identified the key factors limiting the accuracy of climate models to be the representation of albedos, land cover, fraction of landscape covered by vegetation, roughness lengths, surface skin temperature and canopy properties such as leaf area index (LAI) and average stomatal conductance. Therefore, we assembled a team uniquely situated to focus on these key variables and incorporate the remotely sensed measures of these variables into the next generation of climate models.

  1. A System for Monitoring and Forecasting Land Surface Phenology Using Time Series of JPSS VIIRS Observations and Its Applications

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Yu, Y.; Liu, L.

    2015-12-01

    Land surface phenology quantifies seasonal dynamics of vegetation properties including the timing and magnitude of vegetation greenness from satellite observations. Over the last decade, historical time series of AVHRR and MODIS data has been used to characterize the seasonal and interannual variation in terrestrial ecosystems and their responses to a changing and variable climate. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on board the operational JPSS satellites provides land surface observations in a timely fashion, which has the capability to monitor phenological development in near real time. This capability is particularly important for assisting agriculture, natural resource management, and land modeling for weather prediction systems. Here we introduce a system to monitor in real time and forecast in the short term phenological development based on daily VIIRS observations available with a one-day latency. The system integrates a climatological land surface phenology from long-term MODIS data and available VIIRS observations to simulate a set of potential temporal trajectories of greenness development at a given time and pixel. The greenness trajectories, which are qualified using daily two-band Enhanced Vegetation Index (EVI2), are applied to identify spring green leaf development and autumn color foliage status in real time and to predict the occurrence of future phenological events. This system currently monitors vegetation development across the North America every three days and makes prediction to 10 days ahead. We further introduce the applications of near real time spring green leaf and fall color foliage. Specifically, this system is used for tracing the crop progress across the United States, guiding the field observations in US National Phenology Network, servicing tourists for the observation of color fall foliage, and parameterizing seasonal surface physical conditions for numerical weather prediction models.

  2. Observational analysis of the atmosphere-land surface interactions over the TERENO pre-alpine region

    NASA Astrophysics Data System (ADS)

    Soltani, Mohsen; Mauder, Matthias; Laux, Patrick; Kunstmann, Harald

    2016-04-01

    In order to examine the variability of heat fluxes and energy partitioning over complex terrain in the TERrestrial ENvironmental Observatories (TERENO) pre-alpine region, the turbulent heat fluxes and moisture at the surface layer were calculated using the eddy covariance technique. To better understand the principle characteristics of the land-surface energy balance, monthly and seasonal variations of radiation components, heat fluxes and moisture contents in the region, the measurements obtained from three eddy-covariance towers from January 2013 to December 2014 were analyzed. The diurnal, monthly and seasonal variations observed in all the radiation components as a result of the seasonal variation in the solar radiation. The diurnal variations in shortwave radiation were larger than those of longwave radiations. The highest daily value of incoming shortwave radiation (ISR, 344.2 W/m2), incoming longwave radiation (ILR, 389.3 W/m2) and outgoing longwave radiation (OLR, 439.2 W/m2) were measured in summer, while the highest daily value of outgoing shortwave radiation (OSR, 120.7 W/m2) occurred in winter due to the snow cover in the region. The ISR and OLR had the strongest seasonal and interannual variability, in particular during the summertime. The maximum (extreme) surface albedo value was measured in winter 2013 due to the heavy snowfall event. By contrast, it was lower during the warm seasons because of a darker surface (i.e. high vegetation fraction and wetter soil). The seasonal variation of the sensible heat flux (H) was stronger than that of the latent heat flux (LE) in winter, while LE had a stronger variation in summer and considered as the main consumer of available energy in summer, while the soil heat flux (G) indicated the least variation over the experimental time. In addition, the range of the seasonal diurnal cycle of net radiation (Rn) increased from winter to summer and decreased in-turned position indicating a high variation of Rn in summer

  3. Analysis of impacts of urban land use and land cover on air quality in the Las Vegas region using remote sensing information and ground observations

    USGS Publications Warehouse

    Xian, G.

    2007-01-01

    Urban development in the Las Vegas Valley of Nevada (USA) has expanded rapidly over the past 50 years. The air quality in the valley has suffered owing to increases from anthropogenic emissions of carbon monoxide, ozone and criteria pollutants of particular matter. Air quality observations show that pollutant concentrations have apparent heterogeneous characteristics in the urban area. Quantified urban land use and land cover information derived from satellite remote sensing data indicate an apparent local influence of urban development density on air pollutant distributions. Multi-year observational data collected by a network of local air monitoring stations specify that ozone maximums develop in the May and June timeframe, whereas minimum concentrations generally occur from November to February. The fine particulate matter maximum occurs in July. Ozone concentrations are highest on the west and northwest sides of the valley. Night-time ozone reduction contributes to the heterogeneous features of the spatial distribution for average ozone levels in the Las Vegas metropolitan area. Decreased ozone levels associated with increased urban development density suggest that the highest ozone and lowest nitrogen oxides concentrations are associated with medium to low density urban development in Las Vegas.

  4. Flight test evaluation of advanced symbology for general aviation approach to landing displays

    NASA Technical Reports Server (NTRS)

    Downing, D. R.; Bryant, W. H.; Yenni, K. R.

    1981-01-01

    This paper describes a set of flight test experiments which were designed to evaluate the relative utility of candidate displays with advanced symbology for General Aviation IFR operations in the terminal area. This symbology was previously evaluated as part of the NASA Langley Research Center's Terminal Configured Vehicle Program for use in commercial airlines. The advanced symbology included vehicle track-angle, flight path angle and a perspective representation of the runway. These symbols were selectively drawn on a CRT display along with the roll attitude, pitch attitude, localizer-deviation and glideslope deviation. In addition to the CRT display, the instrument panel contained standard turn and bank, altimeter, rate of climb, airspeed, heading and engine instruments. The symbology was evaluated using tracking performance and pilot subjective ratings for an ILS capture and tracking task.

  5. WindSat passive microwave polarimetric observations of soil moisture and land variables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    WindSat is a spaceborne multi-frequency polarimetric microwave radiometer and has the potential of contributing to the retrieval of land variables and complementing efforts directed at the Aqua AMSR-E. In this study, a previously established algorithm was applied to WindSat data to estimate global s...

  6. Observations of Land Surface Passive Polarimetry with the WindSat Instrument

    Technology Transfer Automated Retrieval System (TEKTRAN)

    WindSat provides an opportunity to explore the passive microwave polarimetric signatures of land surfaces. In order to accommodate the large sensor footprint, large homogeneous regions with unique features were used. These included forest, rangeland, desert and agricultural conditions. WindSat obser...

  7. Using ARM Observations to Evaluate Model Predictions of Land-Atmosphere Coupling on the U.S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Phillips, T. J.; Klein, S. A.; Ma, H. Y.

    2015-12-01

    Statistically significant interactions between summertime soil moisture and a number of atmospheric surface and boundary-layer variables have been observed at the U.S. Southern Great Plains Central Facility (SGP CF) site that is maintained by the Department of Energy's Atmospheric Radiation Measurement (ARM) program in northern Oklahoma (Phillips and Klein, 2014 JGR). The observed land-atmosphere coupling (LAC) strength was assessed by means of correlation coefficients R and "sensitivity indices" I (a measure of the comparative change in an atmospheric variable for a one-standard-deviation change in soil moisture). In the current study, we evaluate similar features of LAC in global predictions generated by version 5.1 of the Community Atmosphere Model (CAM5.1), when coupled to the CLM4 land model and downscaled to the ARM SGP site. Each day's prediction was made after initializing the CAM5 atmosphere with ERA Interim reanalysis state variables, while other needed variables were obtained from a nudging simulation. In addition, the CLM4 daily initial conditions were determined by running the land model offline using observed surface net radiation, precipitation, and wind as forcings. Different aspects of LAC in the CAM5 will be compared with those found in the ARM observations during the summers of 2003-2011, when 3 independent measurements of soil moisture are available to provide an estimate of the inherent uncertainties in the LAC strengths determined from the ARM observations. This evaluation may uncover some unrealistic aspects of LAC in the CAM5 model that point toward potential deficiencies in its land or atmospheric model parameterizations. AcknowledgmentsThis work was funded by the U.S. Department of Energy Office of Science and was performed at the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  8. Earth Observation for monitoring phenology for european land use and ecosystems over 1998-2011

    NASA Astrophysics Data System (ADS)

    Ceccherini, Guido; Gobron, Nadine

    2013-04-01

    Long-term measurements of plant phenology have been used to track vegetation responses to climate change but are often limited to particular species and locations and may not represent synoptic patterns. Given the limitations of working directly with in-situ data, many researchers have instead used available satellite remote sensing. Remote sensing extends the possible spatial coverage and temporal range of phenological assessments of environmental change due to the greater availability of observations. Variations and trends of vegetation dynamics are important because they alter the surface carbon, water and energy balance. For example, the net ecosystem CO2 exchange of vegetation is strongly linked to length of the growing season: extentions and decreases in length of growing season modify carbon uptake and the amount of CO2 in the atmosphere. Advances and delays in starting of growing season also affect the surface energy balance and consequently transpiration. The Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) is a key climate variable identified by Global Terrestrial Observing System (GTOS) that can be monitored from space. This dimensionless variable - varying between 0 and 1- is directly linked to the photosynthetic activity of vegetation, and therefore, can monitor changes in phenology. In this study, we identify the spatio/temporal patterns of vegetation dynamics using a long-term remotely sensed FAPAR dataset over Europe. Our aim is to provide a quantitative analysis of vegetation dynamics relevant to climate studies in Europe. As part of this analysis, six vegetation phenological metrics have been defined and made routinely in Europe. Over time, such metrics can track simple, yet critical, impacts of climate change on ecosystems. Validation has been performed through a direct comparison against ground-based data over ecological sites. Subsequently, using the spatio/temporal variability of this suite of metrics, we classify areas with

  9. Satellite observations of changes in snow-covered land surface albedo during spring in the Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Atlaskina, K.; Berninger, F.; de Leeuw, G.

    2015-05-01

    Thirteen years of MODIS surface albedo data for the Northern Hemisphere during the spring months (March-May) were analysed to determine temporal and spatial changes over snow-covered land surfaces. Tendencies in land surface albedo change north of 50° N were analysed using data on snow cover fraction, air temperature, vegetation index and precipitation. To this end, the study domain was divided into six smaller areas, based on their geographical position and climate similarity. Strong differences were observed between these areas. As expected, snow cover fraction (SCF) has a strong influence on the albedo in the study area and can explain 56% of variation of albedo in March, 76% in April and 92% in May. Therefore the effects of other parameters were investigated only for areas with 100% SCF. The second largest driver for snow-covered land surface albedo changes is the air temperature when it exceeds -15 °C. At monthly mean air temperatures below this value no albedo changes are observed. Enhanced vegetation index (EVI) and precipitation amount and frequency were independently examined as possible candidates to explain observed changes in albedo for areas with 100% SCF. Amount and frequency of precipitation were identified to influence the albedo over some areas in Eurasia and North America, but no clear effects were observed in other areas. EVI is positively correlated with albedo in Chukotka Peninsula and negatively in Eastern Siberia. For other regions the spatial variability of the correlation fields is too high to reach any conclusions.

  10. The development of advanced automatic flare and decrab for powered lift short haul aircraft using a microwave landing system

    NASA Technical Reports Server (NTRS)

    Gevaert, G.; Feinreich, B.

    1977-01-01

    Advanced automatic flare and decrab control laws were developed for future powered lift STOL aircraft using the NASA-C-8A augmentor wing vehicle as the aircraft model. The longitudinal control laws utilize the throttle for flight path control and use the direct lift augmentor flap chokes for flight path augmentation. The elevator is used to control airspeed during the approach phase and to enhance path control during the flare. The forward slip maneuver was selected over the flat decrab technique for runway alignment because it can effectively handle the large crab angles obtained at STOL approach speeds. Performance evaluation of selected system configurations were obtained over the total landing environment. Limitations were defined and critical failure modes assessed. Pilot display concepts are discussed.

  11. The ``Uberbank'': A search for compact binary coalescences in the first Observing run of Advanced LIGO

    NASA Astrophysics Data System (ADS)

    Capano, Collin; LIGO Scientific Collaboration; Virgo Collaboration

    2016-03-01

    Modeled searches for gravitational waves from compact binary coalescence (CBC) use a ``bank'' of template waveforms to search the wide range of parameters that binaries may have. Recent advances in waveform modeling and template placement techniques have opened up the possibility to efficiently search for systems with non-precessing spin, using waveforms that model the inspiral, merger, and ringdown of coalescing binaries. I discuss how these advances were combined to produce the template bank used to search for CBCs in the first observing run of Advanced LIGO. This bank covered the full range of plausible masses and non-precessing spins of binary neutron stars, stellar-mass binary black holes, and binaries consisting of a neutron star and a stellar-mass black hole.

  12. A Physical Method for Generating the Surface Temperature from Passive Microwave Observations by Addressing the Thermal Sampling Depth for Barren Land

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Zhou, J.; Dai, F.

    2015-12-01

    The land surface temperature (LST) is an important parameter in studying the global and regional climate change. Passive microwave (PMW) remote sensing is less influenced by the atmosphere and has a unique advantage in cloudy regions compared to satellite thermal infrared (TIR) remote sensing. However, the accuracy of LST estimation of many PMW remote sensing models, especially in barren land, is unsatisfactory due to the neglected discrepancy of thermal sampling depth between PMW and TIR. Here, a physical method for PMW remote sensing is proposed to generate the surface temperature, which has the same physically meaning as the TIR surface temperature, by addressing the thermal sampling depth over barren land surface. The method was applied to the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) data. Validation with the synchronous Moderate Resolution Imaging Spectroradiometer (MODIS) LSTs demonstrates that the method has better performances in estimating LSTs than another two methods that neglect the thermal sampling depth. In Northwest China and a part of Mongolia, the root mean squared errors (RMSEs) the physical method were 3.9 K and 3.7K for daytime and nighttime cases, respectively. In the region of western Namibia, the corresponding RMSEs were 3.8 K and 4.5 K. Further comparison with the in-situ measured LST temperatures at a ground station confirmed the better performance of the proposed method, compared with another two methods. The proposed method will be beneficial for improving the accuracies of the LSTs estimated from PMW observations and integrating the LST products generated from both the TIR and PMW remote sensing.

  13. Earth Observing-1 Advanced Imager Flight Performance Assessment: Investigating Dark Current Stability Over One-Half Orbit Period during the First 60 Days

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.

    2001-01-01

    The stability of the EO-1 Advanced Land Imager dark current levels over the period of one-half orbit is investigated. A series of two-second dark current collections, over the course of 40 minutes, was performed during the first sixty days the instrument was in orbit. Analysis of this data indicates only two dark current reference periods, obtained entering and exiting eclipse, are required to remove ALI dark current offsets for 99.9% of the focal plane to within 1.5 digital numbers for any observation on the solar illuminated portion of the orbit.

  14. Seasonal-scale Observational Data Analysis and Atmospheric Phenomenology for the Cold Land Processes Experiment

    NASA Technical Reports Server (NTRS)

    Poulos, Gregory S.; Stamus, Peter A.; Snook, John S.

    2005-01-01

    The Cold Land Processes Experiment (CLPX) experiment emphasized the development of a strong synergism between process-oriented understanding, land surface models and microwave remote sensing. Our work sought to investigate which topographically- generated atmospheric phenomena are most relevant to the CLPX MSA's for the purpose of evaluating their climatic importance to net local moisture fluxes and snow transport through the use of high-resolution data assimilation/atmospheric numerical modeling techniques. Our task was to create three long-term, scientific quality atmospheric datasets for quantitative analysis (for all CLPX researchers) and provide a summary of the meteorologically-relevant phenomena of the three MSAs (see Figure) over northern Colorado. Our efforts required the ingest of a variety of CLPX datasets and the execution an atmospheric and land surface data assimilation system based on the Navier-Stokes equations (the Local Analysis and Prediction System, LAPS, and an atmospheric numerical weather prediction model, as required) at topographically- relevant grid spacing (approx. 500 m). The resulting dataset will be analyzed by the CLPX community as a part of their larger research goals to determine the relative influence of various atmospheric phenomena on processes relevant to CLPX scientific goals.

  15. Advanced ceramics for land-based gas turbine applications. Final report

    SciTech Connect

    Schneibel, J.H.; Ludeman, E.; Sabol, S.M.

    1997-05-23

    In order to increase the efficiency of land-based gas turbines, inlet gas temperatures have to be increased, and the amount of air which cools the turbine vanes has to be reduced, to the maximum extent possible. Presently, thermal barrier coatings (TBC`s) are the state of the art in achieving these goals. However, since TBC`s are very thin (typically 100 {mu}m), they have clearly limitations. Since all-ceramic turbine vanes would be a very large and risky development step, Westinghouse is considering to protect the leading edges of turbine vanes with high-performance ceramics. This might be done by either replacing the leading edge with a suitably shaped ceramic part, or by modifying the vanes such that they can accommodate ceramic inserts. Among the most important criteria for the success of ceramics in such applications are (a) thermodynamic compatibility with the turbine vane alloy, (b) sufficient thermal shock resistance to survive the thermal cycling during operation and in particular during emergency shut-down, and a design considering the thermal expansion mismatch of the metallic and ceramic components. This paper presents results of work performed on SiC, SiN, and aluminas.

  16. An advanced generation land mobile satellite system and its critical technologies

    NASA Technical Reports Server (NTRS)

    Naderi, F.

    1982-01-01

    A conceptual design for a Land Mobile Satellite System (LMSS) for the 1990s is presented. LMSS involves small tranceivers accessing satellites directly, with ground reception through small car-top antennas. The satellite would have a large antenna and blanket coverage areas in the UHF. The call may originate from a home, be carried by wire to a gateway, transmitted to satellite on the S-band, converted to UHF on the satellite, and transmitted to the vehicle. The system design is constrained by the number of users in an area during the busiest hours, Shuttle storage, controllability factors, and the total area served. A 55-m antenna has been selected, with 87 spot beams and two 10 MHz UHF bands in the 806-890 MHz band. A 17 dB interbeam isolation level is required, implying that sufficient sub-bands can be generated to assure 8265 total channels. The mobile satellite (MSAT) would have an 83 m mast lower segment, a 34 m upper segment, and a second, 10 m antenna made of a deployable mesh. Various antenna function modes are considered.

  17. A Dynamic Approach to Addressing Observation-Minus-Forecast Mean Differences in a Land Surface Skin Temperature Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Draper, Clara; Reichle, Rolf; De Lannoy, Gabrielle; Scarino, Benjamin

    2015-01-01

    In land data assimilation, bias in the observation-minus-forecast (O-F) residuals is typically removed from the observations prior to assimilation by rescaling the observations to have the same long-term mean (and higher-order moments) as the corresponding model forecasts. Such observation rescaling approaches require a long record of observed and forecast estimates, and an assumption that the O-F mean differences are stationary. A two-stage observation bias and state estimation filter is presented, as an alternative to observation rescaling that does not require a long data record or assume stationary O-F mean differences. The two-stage filter removes dynamic (nonstationary) estimates of the seasonal scale O-F mean difference from the assimilated observations, allowing the assimilation to correct the model for synoptic-scale errors without adverse effects from observation biases. The two-stage filter is demonstrated by assimilating geostationary skin temperature (Tsk) observations into the Catchment land surface model. Global maps of the O-F mean differences are presented, and the two-stage filter is evaluated for one year over the Americas. The two-stage filter effectively removed the Tsk O-F mean differences, for example the GOES-West O-F mean difference at 21:00 UTC was reduced from 5.1 K for a bias-blind assimilation to 0.3 K. Compared to independent in situ and remotely sensed Tsk observations, the two-stage assimilation reduced the unbiased Root Mean Square Difference (ubRMSD) of the modeled Tsk by 10 of the open-loop values.

  18. Simulation studies of the impact of advanced observing systems on numerical weather prediction

    NASA Technical Reports Server (NTRS)

    Atlas, R.; Kalnay, E.; Susskind, J.; Reuter, D.; Baker, W. E.; Halem, M.

    1984-01-01

    To study the potential impact of advanced passive sounders and lidar temperature, pressure, humidity, and wind observing systems on large-scale numerical weather prediction, a series of realistic simulation studies between the European Center for medium-range weather forecasts, the National Meteorological Center, and the Goddard Laboratory for Atmospheric Sciences is conducted. The project attempts to avoid the unrealistic character of earlier simulation studies. The previous simulation studies and real-data impact tests are reviewed and the design of the current simulation system is described. Consideration is given to the simulation of observations of space-based sounding systems.

  19. Maximizing the Use of Satellite Thermal Infrared Data for Advancing Land Surface Temperature Analysis

    NASA Astrophysics Data System (ADS)

    Weng, Q.; Fu, P.; Gao, F.

    2014-12-01

    Land surface temperature (LST) is a crucial parameter in investigating environmental, ecological processes and climate change at various scales, and is also valuable in the studies of evapotranspiration, soil moisture conditions, surface energy balance, and urban heat islands. These studies require thermal infrared (TIR) images at both high temporal and spatial resolution to retrieve LST. However, currently, no single satellite sensors can deliver TIR data at both high temporal and spatial resolution. Thus, various algorithms/models have been developed to enhance the spatial or the temporal resolution of TIR data, but rare of those can enhance both spatial and temporal details. This paper presents a new data fusion algorithm for producing Landsat-like LST data by blending daily MODIS and periodic Landsat TM datasets. The original Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) was improved and modified for predicting thermal radiance and LST data by considering annual temperature cycle (ATC) and urban thermal landscape heterogeneity. The technique of linear spectral mixture analysis was employed to relate the Landsat radiance with the MODIS one, so that the temporal changes in radiance can be incorporated in the fusion model. This paper details the theoretical basis and the implementation procedures of the proposed data fusion algorithm, Spatio-temporal Adaptive Data Fusion Algorithm for Temperature mapping (SADFAT). A case study was conducted that predicted LSTs of five dates in 2005 from July to October in Los Angeles County, California. The results indicate that the prediction accuracy for the whole study area ranged from 1.3 K to 2 K. Like existing spatio-temporal data fusion models, the SADFAT method has a limitation in predicting LST changes that were not recorded in the MODIS and/or Landsat pixels due to the model assumption.

  20. Transitioning MODIS to VIIRS observations for Land: Surface Reflectance results, Status and Long-term Prospective

    NASA Astrophysics Data System (ADS)

    Vermote, E.

    2015-12-01

    Surface reflectance is one of the key products from VIIRS and as with MODIS, is used in developing several higher-order land products. The VIIRS Surface Reflectance (SR) IP is based on the heritage MODIS Collection 5 product (Vermote et al. 2002). The quality and character of surface reflectance depends on the accuracy of the VIIRS Cloud Mask (VCM) and aerosol algorithms and of course on the adequate calibration of the sensor. Early evaluation of the VIIRS SR product in the context of the maturity of the operational processing system known as the Interface Data Processing System (IDPS), has been a major focus of work to-date, but is now evolving into the development of a VIIRS suite of Climate Data Records produced by the NASA Land Science Investigator Processing System (SIPS). We will present the calibration performance and the role of the surface reflectance in calibration monitoring, the performance of the cloud mask with a focus on vegetation monitoring (no snow conditions), the performance of the aerosol input used in the atmospheric correction with quantitative results of the performance of the SR product over AERONET sites. Based on those elements and further assessment, we will address the readiness of the SR product for the production of higher-order land products such as Vegetation Indices, Albedo and LAI/FPAR, the its application to agricultural monitoring and in particular the integration of VIIRS data into the global agricultural monitoring (GLAM) system developed at UMd. Finally from the lessons learned, we will articulate a set of critical recommendations to ensure consistency and continuity of the JPSS mission with the MODIS data record.

  1. Quantifying the Representation Error of Land Biosphere Models using High Resolution Footprint Analyses and UAS Observations

    NASA Astrophysics Data System (ADS)

    Hanson, C. V.; Schmidt, A.; Law, B. E.; Moore, W.

    2015-12-01

    The validity of land biosphere model outputs rely on accurate representations of ecosystem processes within the model. Typically, a vegetation or land cover type for a given area (several Km squared or larger resolution), is assumed to have uniform properties. The limited spacial and temporal resolution of models prevents resolving finer scale heterogeneous flux patterns that arise from variations in vegetation. This representation error must be quantified carefully if models are informed through data assimilation in order to assign appropriate weighting of model outputs and measurement data. The representation error is usually only estimated or ignored entirely due to the difficulty in determining reasonable values. UAS based gas sensors allow measurements of atmospheric CO2 concentrations with unprecedented spacial resolution, providing a means of determining the representation error for CO2 fluxes empirically. In this study we use three dimensional CO2 concentration data in combination with high resolution footprint analyses in order to quantify the representation error for modelled CO2 fluxes for typical resolutions of regional land biosphere models. CO2 concentration data were collected using an Atlatl X6A hexa-copter, carrying a highly calibrated closed path infra-red gas analyzer based sampling system with an uncertainty of ≤ ±0.2 ppm CO2. Gas concentration data was mapped in three dimensions using the UAS on-board position data and compared to footprints generated using WRF 3.61. Chad Hanson, Oregon State University, Corvallis, OR Andres Schmidt, Oregon State University, Corvallis, OR Bev Law, Oregon State University, Corvallis, OR

  2. Initializing Weather Research and Forecasting (WRF) model with land surface conditions from the Terrestrial Observation and PredictionSystem (TOPS)

    NASA Astrophysics Data System (ADS)

    Hashimoto, H.; Wang, W.; Melton, F.; Milesi, C.; Michaellis, A.; Nemani, R.

    2008-12-01

    Weather forecasting models have been shown to exhibit a strong sensitivity to land surface conditions, particularly soil moisture. However, the lack of robust estimates of soil moisture at appropriate time and space scales has been a persistent problem. Terrestrial Observation and Prediction System (TOPS) integrates surface weather observations and satellite data with ecosystem simulation models to produce spatially and temporally consistent nowcasts and forecasts of land surface conditions such as soil moisture, evapotranspiration, vegetation stress and photosynthesis. To extend TOPS capabilities beyond estimating ecosystem rocesses, we integrated TOPS with Weather Research Forecasting (WRF) model to evaluate the utility of TOPS-derived surface conditions such as soil moisture in weather forecasting. TOPS land surface schemes are based on a well-calibrated ecosystem model, Biome-BGC, for simulating water and carbon budgets. One of the advantages of TOPS is its flexibility, which enables it to ingest data from a variety of sensors and surface networks, and thus we can provide the surface conditions to users from historical to near real-time, and for spatial scales ranging from 1km and up. We ran the TOPS-WRF system over California for several days during 2007. The results show TOPS-WRF simulations are consistently better than default WRF simulations, particularly over the dry season when spatial variability in soil moisture becomes a significant factor in influencing local energy balance.

  3. Viking landing sites, remote-sensing observations, and physical properties of Martian surface materials

    USGS Publications Warehouse

    Moore, H.J.; Jakosky, B.M.

    1989-01-01

    Important problems that confront future scientific exploration of Mars include the physical properties of Martian surface materials and the geologic processes that formed the materials. The design of landing spacecraft, roving vehicles, and sampling devices and the selection of landing sites, vehicle traverses, and sample sites will be, in part, guided by the physical properties of the materials. Four materials occur in the sample fields of the Viking landers: (1) drift, (2) crusty to cloddy, (3) blocky, and (4) rock. The first three are soillike. Drift materials is weak, loose, and porous. We estimate that it has a dielectric constant near 2.4 and a thermal inertia near 1 ?? 10-3 to 3 ?? 10-3 (cal cm-2 sec 1 2 K-1) because of its low bulk density, fine grain size, and small cohesion. Crusty to cloddy material is expected to have a dielectric constant near 2.8 and a thermal inertia near 4 ?? 10-3 to 7 ?? 10-3 because of its moderate bulk density and cementation of grains. Blocky material should have a dielectric constant near 3.3 and a thermal inertia near 7 ?? 10-3 to 9 ?? 10-3 because of its moderate bulk density and cementation. Common basaltic rocks have dielectric constans near 8 and thermal inertias near 30 ?? 10-3 to 60 ?? 10-3. Comparisons of estimated dielectric constants and thermal inertias of the materials at the landing sites with those obtained remotely by Earth-based radars and Viking Orbiter thermal sensors suggest that the materials at the landing sites are good analogs for materials elsewhere on Mars. Correlation of remotely estimated dielectric constant and thermal inertias indicates two modal values for paired values of dielectric constants and thermal inertias near (A) 2 and 2 ?? 10-3 and (B) 3 and 6 ?? 10-3, respectively. These two modes are comparable to the dielectric constants and thermal inertias for drift and crusty to cloddy material, respectively. Dielectric constants and thermal inertias for blocky material are larger but conistent

  4. Advancing the science for active surveillance: rationale and design for the Observational Medical Outcomes Partnership.

    PubMed

    Stang, Paul E; Ryan, Patrick B; Racoosin, Judith A; Overhage, J Marc; Hartzema, Abraham G; Reich, Christian; Welebob, Emily; Scarnecchia, Thomas; Woodcock, Janet

    2010-11-01

    The U.S. Food and Drug Administration (FDA) Amendments Act of 2007 mandated that the FDA develop a system for using automated health care data to identify risks of marketed drugs and other medical products. The Observational Medical Outcomes Partnership is a public-private partnership among the FDA, academia, data owners, and the pharmaceutical industry that is responding to the need to advance the science of active medical product safety surveillance by using existing observational databases. The Observational Medical Outcomes Partnership's transparent, open innovation approach is designed to systematically and empirically study critical governance, data resource, and methodological issues and their interrelationships in establishing a viable national program of active drug safety surveillance by using observational data. This article describes the governance structure, data-access model, methods-testing approach, and technology development of this effort, as well as the work that has been initiated. PMID:21041580

  5. Regional-scale evaluation of a land surface scheme from atmospheric boundary layer observations

    NASA Astrophysics Data System (ADS)

    Noilhan, J.; Donier, S.; LacarrèRe, P.; Sarrat, C.; Le Moigne, P.

    2011-01-01

    The study describes an evaluation of three configurations of the Interactions Soil-Biosphere-Atmosphere (ISBA) land surface scheme fully coupled with the Meso-NH mesoscale atmospheric model. The ability of the modeling system to correctly reproduce the screen-level variables as well as the boundary layer characteristics is examined for more than 30 clear convective days monitored during the CERES 2005 and 2007 field campaigns. For the horizontal resolution considered (8 km), this study shows that the boundary layer characteristics and the low-level variables are better simulated when the subgrid-scale surface process variability is simulated explicitly using the so-called "tiling method." An additional improvement is brought when the CO2 diurnal cycle is used interactively because of the physical link between the stomatal conductance used both for CO2 assimilation and plant transpiration. The parameterization of this link between CO2 and evaporation fluxes improves the simulation of the Bowen ratio and therefore of the atmospheric boundary layer. The last part of the paper discusses the realism of the simulated regional field of CO2 when the carbon configuration is activated in the mesoscale model. Large regional variability of CO2 within the atmospheric boundary layer is found in response to the spatial and seasonal variability of CO2 surface fluxes with respect to the three main land covers in the area: pine forest, extensive winter (wheat), and summer (maize) crops.

  6. Satellite observations of changes in snow-covered land surface albedo during spring in the Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Atlaskina, K.; Berninger, F.; de Leeuw, G.

    2015-09-01

    Thirteen years of Moderate Resolution Imaging Spectroradiometer (MODIS) surface albedo data for the Northern Hemisphere during the spring months (March-May) were analyzed to determine temporal and spatial changes over snow-covered land surfaces. Tendencies in land surface albedo change north of 50° N were analyzed using data on snow cover fraction, air temperature, vegetation index and precipitation. To this end, the study domain was divided into six smaller areas, based on their geographical position and climate similarity. Strong differences were observed between these areas. As expected, snow cover fraction (SCF) has a strong influence on the albedo in the study area and can explain 56 % of variation of albedo in March, 76 % in April and 92 % in May. Therefore the effects of other parameters were investigated only for areas with 100 % SCF. The second largest driver for snow-covered land surface albedo changes is the air temperature when it exceeds a value between -15 and -10 °C, depending on the region. At monthly mean air temperatures below this value no albedo changes are observed. The Enhanced Vegetation Index (EVI) and precipitation amount and frequency were independently examined as possible candidates to explain observed changes in albedo for areas with 100 % SCF. Amount and frequency of precipitation were identified to influence the albedo over some areas in Eurasia and North America, but no clear effects were observed in other areas. EVI is positively correlated with albedo in Chukotka Peninsula and negatively in eastern Siberia. For other regions the spatial variability of the correlation fields is too high to reach any conclusions.

  7. Global Monitoring for Food Security and Sustainable Land Management - Recent Advances of Remote Sensing Applications to African and Siberian Show Cases

    NASA Astrophysics Data System (ADS)

    Komp, K. U.; Haub, C.

    2012-07-01

    After four decades of space borne remote sensing, the unmapped white patches have mostly disappeared. Those basic information give the foundations to the observation of changes and even the introduction of monitoring programmes for a various number of features in the natural and human landscape of our planet. Recent indicators for climatic change together with worrisome alterations in regional food production versus the constantly increase of human population demand the design and implementation of reliable land management tools which will serve the food security as well as the sustainable use of resources of the ecosystem in its respective regional context. The positive responses and convincing results of ESA service elements in the efforts towards food security in several African countries have been the basis for the transfer of the methods into another region, the Western Siberian corn-belt. The large extends of cropping schemes in West Siberia demand advanced remote sensing methods to be applied in order to compare the impacts of climatic change not only on the agricultural production but also on risks for the ecosystem. A multi scale approach of remote sensing methods is introduced in analogy to the African activities. An adopted monitoring concept is developed using a nearly daily product of medium resolution for wide areas, high resolution sensors for stratified sample areas and in-situ observations. Beyond methodological research, the ability of remote sensing is contributing to operational solutions that can ensure the nutritional and ecological future of our planet.

  8. Evaluation of Flying Qualities and Guidance Displays for an Advanced Tilt-Wing STOL Transport Aircraft in Final Approach and Landing

    NASA Technical Reports Server (NTRS)

    Frost, Chad R.; Franklin, James A.; Hardy, Gordon H.

    2002-01-01

    A piloted simulation was performed on the Vertical Motion Simulator at NASA Ames Research Center to evaluate flying qualities of a tilt-wing Short Take-Off and Landing (STOL) transport aircraft during final approach and landing. The experiment was conducted to assess the design s handling qualities, and to evaluate the use of flightpath-centered guidance for the precision approach and landing tasks required to perform STOL operations in instrument meteorological conditions, turbulence, and wind. Pilots rated the handling qualities to be satisfactory for all operations evaluated except those encountering extreme crosswinds and severe windshear; even in these difficult meteorological conditions, adequate handling qualities were maintained. The advanced flight control laws and guidance displays provided consistent performance and precision landings.

  9. Mineralogy of the MSL Curiosity landing site in Gale crater as observed by MRO/CRISM

    NASA Astrophysics Data System (ADS)

    Seelos, Kimberly D.; Seelos, Frank P.; Viviano-Beck, Christina E.; Murchie, Scott L.; Arvidson, Raymond E.; Ehlmann, Bethany L.; Fraeman, Abigail A.

    2014-07-01

    Orbital data acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and High Resolution Imaging Science Experiment instruments on the Mars Reconnaissance Orbiter (MRO) provide a synoptic view of compositional stratigraphy on the floor of Gale crater surrounding the area where the Mars Science Laboratory (MSL) Curiosity landed. Fractured, light-toned material exhibits a 2.2 µm absorption consistent with enrichment in hydroxylated silica. This material may be distal sediment from the Peace Vallis fan, with cement and fracture fill containing the silica. This unit is overlain by more basaltic material, which has 1 µm and 2 µm absorptions due to pyroxene that are typical of Martian basaltic materials. Both materials are partially obscured by aeolian dust and basaltic sand. Dunes to the southeast exhibit differences in mafic mineral signatures, with barchan dunes enhanced in olivine relative to pyroxene-containing longitudinal dunes. This compositional difference may be related to aeolian grain sorting.

  10. Observed trends in light precipitation events over global land during 1961-2010

    NASA Astrophysics Data System (ADS)

    Wen, Guanhuan; Huang, Gang; Tao, Weichen; Liu, Chunxia

    2016-07-01

    Based on daily station precipitation data, this study investigates the trends in light precipitation events (less than the 50th percentile) over global land during 1961-2010. It is found that the frequency of light precipitation events decreases over East China (EC) and northern Eurasia (NE) but increases over the United States of America (US), Australia (AU), and the Iberian Peninsula (IP). However, the trends in the intensity of light precipitation events are opposite to those in frequency. We find that the trends in light precipitation events are possibly associated with the changes in static stability. Over EC and NE (US, AU, and IP), the static stability weakens (strengthens) during 1961-2010. The weakening (strengthening) of static stability leads to increase (decrease) in precipitation intensity due to the enhancement (reduction) of upward motion; light (relatively heavier) precipitation events accordingly shift toward relatively heavier (light) precipitation, and the frequency of light precipitation events decreases (increases) consequently.

  11. Urban land-cover classification based on airborne hyperspectral data and field observation

    NASA Astrophysics Data System (ADS)

    Yamazaki, Fumio; Hara, Konomi; Liu, Wen

    2014-10-01

    Using a dataset from the 2013 IEEE data fusion contest, a basic study to classify urban land-cover was carried out. The spectral reflectance characteristics of surface materials were investigated from the airborne hyperspectral (HS) data acquired by CASI-1500 imager over Houston, Texas, USA. The HS data include 144 spectral bands in the visible to near-infrared (380 nm to 1050 nm) regions. A multispectral (MS) image acquired by WorldView-2 satellite was also introduced in order to compare it with the HS image. A field measurement in the Houston's test site was carried out using a handheld spectroradiometer by the present authors. The reflectance of surface materials obtained by the measurement was also compared with the pseudo-reflectance of the HS data and they showed good agreement. Finally a principal component analysis was conducted for the HS and MS data and the result was discussed.

  12. Observed trends in light precipitation events over global land during 1961-2010

    NASA Astrophysics Data System (ADS)

    Wen, Guanhuan; Huang, Gang; Tao, Weichen; Liu, Chunxia

    2015-05-01

    Based on daily station precipitation data, this study investigates the trends in light precipitation events (less than the 50th percentile) over global land during 1961-2010. It is found that the frequency of light precipitation events decreases over East China (EC) and northern Eurasia (NE) but increases over the United States of America (US), Australia (AU), and the Iberian Peninsula (IP). However, the trends in the intensity of light precipitation events are opposite to those in frequency. We find that the trends in light precipitation events are possibly associated with the changes in static stability. Over EC and NE (US, AU, and IP), the static stability weakens (strengthens) during 1961-2010. The weakening (strengthening) of static stability leads to increase (decrease) in precipitation intensity due to the enhancement (reduction) of upward motion; light (relatively heavier) precipitation events accordingly shift toward relatively heavier (light) precipitation, and the frequency of light precipitation events decreases (increases) consequently.

  13. Cassini/VIMS hyperspectral observations of the HUYGENS landing site on Titan

    USGS Publications Warehouse

    Rodriguez, S.; Le, Mouelic S.; Sotin, C.; Clenet, H.; Clark, R.N.; Buratti, B.; Brown, R.H.; McCord, T.B.; Nicholson, P.D.; Baines, K.H.

    2006-01-01

    Titan is one of the primary scientific objectives of the NASA-ESA-ASI Cassini-Huygens mission. Scattering by haze particles in Titan's atmosphere and numerous methane absorptions dramatically veil Titan's surface in the visible range, though it can be studied more easily in some narrow infrared windows. The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini spacecraft successfully imaged its surface in the atmospheric windows, taking hyperspectral images in the range 0.4-5.2 ??m. On 26 October (TA flyby) and 13 December 2004 (TB flyby), the Cassini-Huygens mission flew over Titan at an altitude lower than 1200 km at closest approach. We report here on the analysis of VIMS images of the Huygens landing site acquired at TA and TB, with a spatial resolution ranging from 16 to14.4 km/pixel. The pure atmospheric backscattering component is corrected by using both an empirical method and a first-order theoretical model. Both approaches provide consistent results. After the removal of scattering, ratio images reveal subtle surface heterogeneities. A particularly contrasted structure appears in ratio images involving the 1.59 and 2.03 ??m images north of the Huygens landing site. Although pure water ice cannot be the only component exposed at Titan's surface, this area is consistent with a local enrichment in exposed water ice and seems to be consistent with DISR/Huygens images and spectra interpretations. The images show also a morphological structure that can be interpreted as a 150 km diameter impact crater with a central peak. ?? 2006 Elsevier Ltd. All rights reserved.

  14. Predictions for Swift Follow-up Observations of Advanced LIGO/Virgo Gravitational Wave Sources

    NASA Astrophysics Data System (ADS)

    Racusin, Judith; Evans, Phil; Connaughton, Valerie

    2015-04-01

    The likely detection of gravitational waves associated with the inspiral of neutron star binaries by the upcoming advanced LIGO/Virgo observatories will be complemented by searches for electromagnetic counterparts over large areas of the sky by Swift and other observatories. As short gamma-ray bursts (GRB) are the most likely electromagnetic counterpart candidates to these sources, we can make predictions based upon the last decade of GRB observations by Swift and Fermi. Swift is uniquely capable of accurately localizing new transients rapidly over large areas of the sky in single and tiled pointings, enabling ground-based follow-up. We describe simulations of the detectability of short GRB afterglows by Swift given existing and hypothetical tiling schemes with realistic observing conditions and delays, which guide the optimal observing strategy and improvements provided by coincident detection with observatories such as Fermi-GBM.

  15. Validation Of The Earth Observation Land Data Assimilation System By The Field Data Of ESA SPARC Field Campaign

    NASA Astrophysics Data System (ADS)

    Chernetskiy, Maxim; Gomez-Dans, Jose; Lewis, Philip

    2013-12-01

    The Earth Observation Land Data Assimilation System (EO-LDAS) project is uses the weak constraint variational data assimilation (DA) technique for the estimation of land surface parameters and their uncertainties by the remote sensing data. The main goal of the project is to make full use of different sources of optical sensors data, to provide improved estimation of structural and biophysical parameters of land surface. Therefore a software tool - the EO-LDAS prototype - was developed. Within the frame of this work, the possibilities of EO- LDAS have been demonstrated for MERIS/Envisat and CHRIS/Proba data acquired during ESA SPARC 2004 field campaign over an agricultural test-site near Barrax (Spain). We have used a regularization approach and conditions of spatial smoothness in order to better constrain the problem. The EO-LDAS prototype has been used to implement the weak constrain data assimilation (DA) system, to estimate leaf area index (LAI) and Chlorophyll (a + b) concentration as well as their uncertainties.

  16. Wind-Tunnel Results of Advanced High-Speed Propellers at Takeoff, Climb, and Landing Mach Numbers

    NASA Technical Reports Server (NTRS)

    Stefko, George L.; Jeracki, Robert J.

    1985-01-01

    Low-speed wind-tunnel performance tests of two advanced propellers have been completed at the NASA Lewis Research Center as part of the NASA Advanced Turboprop Program. The 62.2 cm (24.5 in.) diameter adjustable-pitch models were tested at Mach numbers typical of takeoff, initial climbout, and landing speeds (i.e., from Mach 0.10 to 0.34) at zero angle of attack in the NASA Lewis 10 by 10 Foot Supersonic Wind Tunnel. Both models had eight blades and a cruise-design-point operating condition of Mach 0.80, and 10.668 km (35,000 ft) I.S.A. altitude, a 243.8 m/s (800 ft/sec) tip speed, and a high power loading of 301 kW/sq m (37.5 shp/sq ft). Each model had its own integrally designed area-ruled spinner, but used the same specially contoured nacelle. These features reduced blade-section Mach numbers and relieved blade-root choking at the cruise condition. No adverse or unusual low-speed operating conditions were found during the test with either the straight blade SR-2 or the 45 deg swept SR-3 propeller. Typical efficiencies of the straight and 45 deg swept propellers were 50.2 and 54.9 percent, respectively, at a takeoff condition of Mach 0.20 and 53.7 and 59.1 percent, respectively, at a climb condition of Mach 0.34.

  17. Runoff production in a small agricultural catchment in Lao PDR : influence of slope, land-use and observation scale.

    NASA Astrophysics Data System (ADS)

    Patin, J.; Ribolzi, O.; Mugler, C.; Valentin, C.; Mouche, E.

    2009-04-01

    We study the surface and sub-surface hydrology of a small agricultural catchment (60ha) located in the Luang Prabang province of Lao PDR. This catchment is representative of the rural mountainous south east Asia. It exhibits steep slopes (up to 100% and more) under a monsoon climate. After years of traditional slash and burn cultures, it is now under high land pressures due to population resettling and environment preservation policies. This evolution leads to rapid land-use changes such as shifting cultivation reduction or growing of teak forest instead of classical crops. This catchment is a benchmark site of the Managing Soil Erosion Consortium since 1998. The international consortium aims to understand the effects of agricultural changes on the catchment hydrology and soil erosion in south east Asia. The Huay Pano catchment is subdivided into small sub-catchments that are gauged and monitored. Differ- ent agricultural practices where tested along the years. At a smaller scale, plot of 1m2 are instrumented to follow runoff and detachment of soil under natural rainfall along the monsoon season. Our modeling work aims to develop a distributed hydrological model integrating experimental data at the different scales. One of the objective is to understand the impact of land-use, soil properties (slope, crust, etc) and rainfall (dry and wet seasons) on surface and subsurface flows. We present here modeling results of the runoff plot experiments (1m2 scale) performed from 2002 to 2007. The plots distribution among the catchment and over the years gives a good representativity of the different runoff responses. The role of crust, slope and land-use on runoff is examined. Finally we discuss how this plot scale will be integrated in a sub-catchment model, with a particular attention on the observed paradox: how to explain that runoff coefficients at the catchment scale are much slower than at the plot scale ?

  18. Convective turbulent dust emission (CTDE) observed over Horqin Sandy Land area and validation of a CTDE scheme

    NASA Astrophysics Data System (ADS)

    Li, X. L.; Klose, M.; Shao, Y.; Zhang, H. S.

    2014-08-01

    In this paper, a data set obtained from a sandstorm monitoring station located in Horqin Sandy Land area in northern China from December 2010 to November 2011 is used to investigate the seasonal variations and characteristics of convective turbulent dust emission (CTDE) and to validate a CTDE scheme. The observations show that CTDE events occur during the local daytime, with 85% of them between 08:00 and 15:00 local standard time. While a CTDE event may last for 0.5 to 8 h, the duration of 79% of the events is shorter than 3 h. CTDE occurs most frequently in summer and then in fall, less frequently in spring, and least in winter. The total CTDE flux in the year (=1.63 × 104 µg m-2 s-1) is considerable and important to the background dust concentration and dust cycles from the view of a longer time scale. The CTDE dust flux, Fobs, falls into the range of 0-30 µg m-2 s-1 and is positively correlated with the convective scaling velocity, w*, but not so much with the friction velocity, u*. A CTDE event was observed on 14 October 2011, which lasted for 7 h with a maximum of Fobs = 9.4 µg m-2 s-1. This event is used to validate the CTDE scheme. A linear relationship between the predicted and the observed CTDE dust fluxes is found, and an important model parameter is calibrated for this sandy land.

  19. TRMM Precipitation Radar and Microwave Imager Observations of Convective and Stratiform Rain Over Land and Their Theoretical Implications

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Weinman, J. A.; Lau, William K. M. (Technical Monitor)

    2001-01-01

    Observations of brightness temperature, Tb made over land regions by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometer have been analyzed along with the nearly simultaneous measurements of the vertical profiles of reflectivity factor, Z, made by the Precipitation Radar (PR) onboard the TRMM satellite. This analysis is performed to explore the interrelationship between the TMI and PR data in areas that are covered predominantly by convective or stratiform rain. In particular, we have compared on a scale of 20 km, average vertical profiles of Z with the averages of Tbs in the 19, 37 and 85 GHz channels. Generally, we find from these data that as Z increases, Tbs in the three channels decrease due to extinction. In order to explain physically the relationship between the Tb and Z observations, we have performed radiative transfer simulations utilizing vertical profiles of hydrometeors applicable to convective and stratiform rain regions. These profiles are constructed taking guidance from the Z observations of PR and recent LDR and ZDR measurements made by land-based polarimetric radars.

  20. The impact of land surface temperature on soil moisture anomaly detection from passive microwave observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For several years passive microwave observations have been used to retrieve soil moisture from the Earth’s surface. Low frequency observations have the most sensitivity to soil moisture, therefore the modern Soil Moisture and Ocean Salinity (SMOS) and future Soil Moisture Active and Passive (SMAP) ...

  1. Comparison of plasmaspheric electron content over sea and land using Jason-2 observations

    NASA Astrophysics Data System (ADS)

    Gulyaeva, Tamara; Cherniak, Iurii; Zakharenkova, Irina

    2016-07-01

    The Global Ionospheric Maps of Total Electron Content, GIM-TEC, may suffer from model assumptions, in particular, over the oceans where relatively few measurements are available due to a scarcity of ground-based GPS receivers network only on seashores and islands which involve more assumptions or interpolations imposed on GIM mapping techniques. The GPS-derived TEC represents the total electron content integrated through the ionosphere, iTEC, and the plasmasphere, pTEC. The sea/land differences in the F2 layer peak electron density, NmF2, and the peak height, hmF2, gathered with topside sounding data exhibit tilted ionosphere along the seashores with denser electron population at greater peak heights over the sea. Derivation of a sea/land proportion of total electron content from the new source of the satellite-based measurements would allow improve the mapping GIM-TEC products and their assimilation by the ionosphere-plasmasphere IRI-Plas model. In this context the data of Jason-2 mission provided through the NOAA CLASS Website (http://www.nsof.class.noaa.gov/saa/products/catSearch) present a unique database of pTEC measured through the plasmasphere over the Jason-2 orbit (1335 km) to GPS orbit (20,200 km) which become possible from GPS receivers placed onboard of Jason-2 with a zenith looking antenna that can be used not only for precise orbit determination (POD), but can also provide new data on the plasma density distribution in the plasmasphere. Special interest represents possibility of the potential increase of the data volume in two times due to the successful launch of the Jason-3 mission on 17 January 2016. The present study is focused on a comparison of plasmasphere electron content, pTEC, over the sea and land with a unique data base of the plasmasphere electron content, pTEC, using measurements onboard Jason-2 satellite during the solar minimum (2009) and solar maximum (2014). Slant TEC values were scaled to estimate vertical pTEC using a geometric

  2. Local Scale Radiobrightness Modeling During the Intensive Observing Period-4 of the Cold Land Processes Experiment-1

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco; deRoo, Roger; England, Anthony W.; Gu, Hao-Yu; Pham, Hanh; Boprie, David; Graf, Tobias; Koike, Toshio; Armstrong, Richard

    2005-01-01

    The NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and frozen ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in 2002 and 2003 in Colorado, USA. One of the goals of the experiment was to test the capabilities of microwave emission models at different scales. Initial forward model validation work has concentrated on the Local-Scale Observation Site (LSOS), a 0.8 ha study site consisting of open meadows separated by trees where the most detailed measurements were made of snow depth and temperature, density, and grain size profiles. Results obtained in the case of the 3& Intensive Observing Period (IOP3) period (Feb., 2003, dry snow) suggest that a model based on Dense Medium Radiative Transfer (DMRT) theory is able to model the recorded brightness temperatures using snow parameters derived from field measurements. This paper focuses on the ability of forward DMRT modelling, combined with snowpack measurements, to reproduce the radiobrightness signatures observed by the University of Michigan s Truck-Mounted Radiometer System (TMRS) at 19 and 37 GHz during the 4th IOP (IOP4) in March, 2003. Unlike IOP3, conditions during IOP4 include both wet and dry periods, providing a valuable test of DMRT model performance. In addition, a comparison will be made for the one day of coincident observations by the University of Tokyo's Ground-Based Microwave Radiometer-7 (GBMR-7) and the TMRS. The plot-scale study in this paper establishes a baseline of DMRT performance for later studies at successively larger scales. And these scaling studies will help guide the choice of future snow retrieval algorithms and the design of future Cold Lands observing systems.

  3. Exploitation of multi-temporal Earth Observation imagery for monitoring land cover change in mining sites

    NASA Astrophysics Data System (ADS)

    Petropoulos, G.; Partsinevelos, P.; Mitraka, Z.

    2012-04-01

    Surface mining has been shown to cause intensive environmental degradation in terms of landscape, vegetation and biological communities. Nowadays, the commercial availability of remote sensing imagery at high spatiotemporal scales, has improved dramatically our ability to monitor surface mining activity and evaluate its impact on the environment and society. In this study we investigate the potential use of Landsat TM imagery combined with diverse classification techniques, namely artificial neural networks and support vector machines for delineating mining exploration and assessing its effect on vegetation in various surface mining sites in the Greek island of Milos. Assessment of the mining impact in the study area is validated through the analysis of available QuickBird imagery acquired nearly concurrently to the TM overpasses. Results indicate the capability of the TM sensor combined with the image analysis applied herein as a potential economically viable solution to provide rapidly and at regular time intervals information on mining activity and its impact to the local environment. KEYWORDS: mining environmental impact, remote sensing, image classification, change detection, land reclamation, support vector machines, neural networks

  4. CAROLS: A New Airborne L-Band Radiometer for Ocean Surface and Land Observations

    PubMed Central

    Zribi, Mehrez; Pardé, Mickael; Boutin, Jacquline; Fanise, Pascal; Hauser, Daniele; Dechambre, Monique; Kerr, Yann; Leduc-Leballeur, Marion; Reverdin, Gilles; Skou, Niels; Søbjærg, Sten; Albergel, Clement; Calvet, Jean Christophe; Wigneron, Jean Pierre; Lopez-Baeza, Ernesto; Rius, Antonio; Tenerelli, Joseph

    2011-01-01

    The “Cooperative Airborne Radiometer for Ocean and Land Studies” (CAROLS) L-Band radiometer was designed and built as a copy of the EMIRAD II radiometer constructed by the Technical University of Denmark team. It is a fully polarimetric and direct sampling correlation radiometer. It is installed on board a dedicated French ATR42 research aircraft, in conjunction with other airborne instruments (C-Band scatterometer—STORM, the GOLD-RTR GPS system, the infrared CIMEL radiometer and a visible wavelength camera). Following initial laboratory qualifications, three airborne campaigns involving 21 flights were carried out over South West France, the Valencia site and the Bay of Biscay (Atlantic Ocean) in 2007, 2008 and 2009, in coordination with in situ field campaigns. In order to validate the CAROLS data, various aircraft flight patterns and maneuvers were implemented, including straight horizontal flights, circular flights, wing and nose wags over the ocean. Analysis of the first two campaigns in 2007 and 2008 leads us to improve the CAROLS radiometer regarding isolation between channels and filter bandwidth. After implementation of these improvements, results show that the instrument is conforming to specification and is a useful tool for Soil Moisture and Ocean Salinity (SMOS) satellite validation as well as for specific studies on surface soil moisture or ocean salinity. PMID:22346599

  5. Using Historical Precipitation, Temperature, and Runoff Observations to Evaluate Evaporation Formulations in Land Surface Models

    NASA Technical Reports Server (NTRS)

    Koster, Randal D.; Mahanama, P. P.

    2012-01-01

    Key to translating soil moisture memory into subseasonal precipitation and air temperature forecast skill is a realistic treatment of evaporation in the forecast system used - in particular, a realistic treatment of how evaporation responds to variations in soil moisture. The inherent soil moisture-evaporation relationships used in today's land surface models (LSMs), however, arguably reflect little more than guesswork given the lack of evaporation and soil moisture data at the spatial scales represented by regional and global models. Here we present a new approach for evaluating this critical aspect of LSMs. Seasonally averaged precipitation is used as a proxy for seasonally-averaged soil moisture, and seasonally-averaged air temperature is used as a proxy for seasonally-averaged evaporation (e.g., more evaporative cooling leads to cooler temperatures) the relationship between historical precipitation and temperature measurements accordingly mimics in certain important ways nature's relationship between soil moisture and evaporation. Additional information on the relationship is gleaned from joint analysis of precipitation and streamflow measurements. An experimental framework that utilizes these ideas to guide the development of an improved soil moisture-evaporation relationship is described and demonstrated.

  6. Advanced Land use Classification Considering Intra-annual Cropping patterns and Urbanization processes as a Contribution to Improve Knowledge base for Water Management.

    NASA Astrophysics Data System (ADS)

    Kumar, N.; Tischbein, B.; Beg, M. K.

    2014-12-01

    Land use and its spatial pattern and dynamics strongly influence water resources and water demand. Therefore, integrated water resources management coordinating water supply and demand is using modeling tools in order to assess the impact of land use changes on the water balance and to conceive infrastructural and operational measures to cope with these impacts. As a consequence, the appropriateness of water management measures depends on the reliability of the output gained by the modeling tools which in turn is highly determined by the capability of the models and the quality of model inputs. This research combines the Soil and Water Assessment Tool (SWAT) and an advanced procedure for spatio-temporal detection of land use dynamics and irrigation in the Upper Kharun basin in the Chhattisgarh State in India. An on-screen visual digitization technique using the Landsat satellite images and their derivatives (NDVI and tasseled cap indices) were employed for land use classification. The land use maps prepared at different time steps within a year can be combined to produce a single multi-temporal land use classification. This approach captures and integrates all the major variations within a year in a single map and hence better represents an area with multiple crop rotations and different levels of urbanization. Urbanization and intensification of irrigation by increasing use of groundwater are major land use processes at the global scale as well as in the study region. The study reveals that an increasing pumping rate of groundwater for irrigation is the main reason for decreasing the groundwater contribution to streamflow and subsequently a lowering in discharge and water yield. On the other hand, annual surface runoff is increased significantly by an expansion in built up areas over the decades in the study area. This information (i) enhances the understanding of land use changes and their relevant drivers, and (ii) facilitates the introduction of best water and

  7. Reconstruction of hyperspectral CHRIS/PROBA signal by the Earth Observation Land Data Assimilation System (EO-LDAS)

    NASA Astrophysics Data System (ADS)

    Chernetskiy, Maxim; Gobron, Nadine; Gomez-Dans, Jose; Lewis, Philip

    EO-LDAS is a system that allows one to interpret spectral observations of the land surface to provide an optimal estimate of state of the Earth. It allows a consistent combination of observations from different sensors despite the difference in spatial and spectral resolution and acquisition frequencies. The system is based on a variational data assimilation (DA) scheme, and uses physically-based radiative transfer models (RTM) to map from state to observation. In addition the system takes into account observational uncertainty, prior information and a model of spatial/temporal evolution of the state. Such approach is very useful for the future satellite constellations as well as for reanalysis of historical data. The main purpose of EO-LDAS is the retrieval of biophysical land variables. However, once the state is known after inverting some observations, the system can be used to forward model and predict other observations. The main aim of this contribution is the validation of EO-LDAS by reconstructing CHRIS/PROBA hyperspectral signal on the base of MODIS 500 m, Landsat ETM+ and MISR full resolution data over the Barrax site during the SPARC 2004 campaign. First, multispectral data were inverted by EO-LDAS in order to obtain a set of biophysical parameters which were then used in a forward mode to obtain full spectra over various fields covering Barrax area. The reconstruction was performed using the same view/sun geometry as initial PROBA scene. Single set of spectra from MODIS, ETM+ and MISR were used and a combination of MODIS-ETM+ and MISR-ETM+. In addition uncertainties of output biophysical land parameters were considered for understanding real accuracy and applicability of combinations of different sensors. Finally, spatial and temporal regularisation models were applied to add extra constraints to the inversion. The proposed contribution demonstrates the capabilities of EO-LDAS for the reconstruction of hyperspectral bands on the base of different

  8. Robust comparison of climate models with observations using blended land air and ocean sea surface temperatures

    NASA Astrophysics Data System (ADS)

    Cowtan, Kevin; Hausfather, Zeke; Hawkins, Ed; Jacobs, Peter; Mann, Michael E.; Miller, Sonya K.; Steinman, Byron A.; Stolpe, Martin B.; Way, Robert G.

    2015-08-01

    The level of agreement between climate model simulations and observed surface temperature change is a topic of scientific and policy concern. While the Earth system continues to accumulate energy due to anthropogenic and other radiative forcings, estimates of recent surface temperature evolution fall at the lower end of climate model projections. Global mean temperatures from climate model simulations are typically calculated using surface air temperatures, while the corresponding observations are based on a blend of air and sea surface temperatures. This work quantifies a systematic bias in model-observation comparisons arising from differential warming rates between sea surface temperatures and surface air temperatures over oceans. A further bias arises from the treatment of temperatures in regions where the sea ice boundary has changed. Applying the methodology of the HadCRUT4 record to climate model temperature fields accounts for 38% of the discrepancy in trend between models and observations over the period 1975-2014.

  9. Observed and simulated effect of plant physiology and structure on land surface energy fluxes and soil conditions

    NASA Astrophysics Data System (ADS)

    Lu, Yen-Sen; Rihani, Jehan; Langensiepen, Matthias; Simmer, Clemens

    2016-04-01

    parameterizations are implemented into the CLM3.5 version within TerrSysMP. Simulation results from both parameterizations are compared against the original Ball-Berry-Collatz model in the standard version of CLM3.5. Furthermore results using MODIS LAI are compared against simulations using a simple parameterization of LAI based on ground surface temperature. All simulation results are compared against Eddy Covariance flux and soil moisture network observations performed. A Taylor-diagram and other statistic methods including model performance indices are employed to compare the different parameterizations with the observations. The two way feedback between water table dynamics and energy fluxes is explored to evaluate the effect of vegetation input on energy and hydrologic state of the simulated terrestrial system. Preliminary results show that the Jarvis-Stewart along with parameterized LAI performs well in simulating latent heat and sensible heat for grass and winter wheat type of land cover condition during 2012 except for some time period. While applying PF-CLM3.5 for coupled surface-land surface simulation, water table depth increases with the increase of transpiration. This result indicates stomatal control scheme in CLM3.5 is not sensitive to the reduction of soil wetness if the water table is relatively high. In this study changing stomatal scheme and LAI input can lead to high variability of resulting energy fluxes.

  10. Observation of Energetic Particle Driven Modes Relevant to Advanced Tokamak Regimes

    SciTech Connect

    R. Nazikian; B. Alper; H.L. Berk; D. Borba; C. Boswell; R.V. Budny; K.H. Burrell; C.Z. Cheng; E.J. Doyle; E. Edlund; R.J. Fonck; A. Fukuyama; N.N. Gorelenkov; C.M. Greenfield; D.J. Gupta; M. Ishikawa; R.J. Jayakumar; G.J. Kramer; Y. Kusama; R.J. La Haye; G.R. McKee; W.A. Peebles; S.D. Pinches; M. Porkolab; J. Rapp; T.L. Rhodes; S.E. Sharapov; K. Shinohara; J.A. Snipes; W.M. Solomon; E.J. Strait; M. Takechi; M.A. Van Zeeland; W.P. West; K.L. Wong; S. Wukitch; L. Zeng

    2004-10-21

    Measurements of high-frequency oscillations in JET [Joint European Torus], JT-60U, Alcator C-Mod, DIII-D, and TFTR [Tokamak Fusion Test Reactor] plasmas are contributing to a new understanding of fast ion-driven instabilities relevant to Advanced Tokamak (AT) regimes. A model based on the transition from a cylindrical-like frequency-chirping mode to the Toroidal Alfven Eigenmode (TAE) has successfully encompassed many of the characteristics seen in experiments. In a surprising development, the use of internal density fluctuation diagnostics has revealed many more modes than has been detected on edge magnetic probes. A corollary discovery is the observation of modes excited by fast particles traveling well below the Alfven velocity. These observations open up new opportunities for investigating a ''sea of Alfven Eigenmodes'' in present-scale experiments, and highlight the need for core fluctuation and fast ion measurements in a future burning-plasma experiment.

  11. Estimating observing locations for advancing beyond the winter predictability barrier of Indian Ocean dipole event predictions

    NASA Astrophysics Data System (ADS)

    Feng, Rong; Duan, Wansuo; Mu, Mu

    2016-04-01

    In this paper, we explored potential observing locations (i.e., the sensitive areas) of positive Indian Ocean dipole (IOD) events to advance beyond the winter predictability barrier (WPB) using the geophysical fluid dynamics laboratory climate model version 2p1 (GFDL CM2p1). The sensitivity analysis is conducted through perfect model predictability experiments, in which the model is assumed to be perfect and so any prediction errors are caused by initial errors. The results show that the initial errors with an east-west dipole pattern are more likely to result in a significant WPB than spatially correlated noises; the areas where the large values of the dipole pattern initial errors are located have great effects on prediction uncertainties in winter and provide useful information regarding the sensitive areas. Further, the prediction uncertainties in winter are more sensitive to the initial errors in the subsurface large value areas than to those in the surface large value areas. The results indicate that the subsurface large value areas are sensitive areas for advancing beyond the WPB of IOD predictions and if we carry out intensive observations across these areas, the prediction errors in winter may be largely reduced. This will lead to large improvements in the skill of wintertime IOD event forecasts.

  12. Anticipating land surface change

    PubMed Central

    Streeter, Richard; Dugmore, Andrew J.

    2013-01-01

    The interplay of human actions and natural processes over varied spatial and temporal scales can result in abrupt transitions between contrasting land surface states. Understanding these transitions is a key goal of sustainability science because they can represent abrupt losses of natural capital. This paper recognizes flickering between alternate land surface states in advance of threshold change and critical slowing down in advance of both threshold changes and noncritical transformation. The early warning signals we observe are rises in autocorrelation, variance, and skewness within millimeter-resolution thickness measurements of tephra layers deposited in A.D. 2010 and A.D. 2011. These signals reflect changing patterns of surface vegetation, which are known to provide early warning signals of critical transformations. They were observed toward migrating soil erosion fronts, cryoturbation limits, and expanding deflation zones, thus providing potential early warning signals of land surface change. The record of the spatial patterning of vegetation contained in contemporary tephra layers shows how proximity to land surface change could be assessed in the widespread regions affected by shallow layers of volcanic fallout (those that can be subsumed within the existing vegetation cover). This insight shows how we could use tephra layers in the stratigraphic record to identify “near misses,” close encounters with thresholds that did not lead to tipping points, and thus provide additional tools for archaeology, sustainability science, and contemporary land management. PMID:23530230

  13. Global fields of soil moisture and land surface evapotranspiration derived from observed precipitation and surface air temperature

    NASA Technical Reports Server (NTRS)

    Mintz, Y.; Walker, G. K.

    1993-01-01

    The global fields of normal monthly soil moisture and land surface evapotranspiration are derived with a simple water budget model that has precipitation and potential evapotranspiration as inputs. The precipitation is observed and the potential evapotranspiration is derived from the observed surface air temperature with the empirical regression equation of Thornthwaite (1954). It is shown that at locations where the net surface radiation flux has been measured, the potential evapotranspiration given by the Thornthwaite equation is in good agreement with those obtained with the radiation-based formulations of Priestley and Taylor (1972), Penman (1948), and Budyko (1956-1974), and this provides the justification for the use of the Thornthwaite equation. After deriving the global fields of soil moisture and evapotranspiration, the assumption is made that the potential evapotranspiration given by the Thornthwaite equation and by the Priestley-Taylor equation will everywhere be about the same; the inverse of the Priestley-Taylor equation is used to obtain the normal monthly global fields of net surface radiation flux minus ground heat storage. This and the derived evapotranspiration are then used in the equation for energy conservation at the surface of the earth to obtain the global fields of normal monthly sensible heat flux from the land surface to the atmosphere.

  14. Planar LIF observation of unburned fuel escaping the upper ring-land crevice in an SI engine

    SciTech Connect

    Green, R.M.; Cloutman, L.D.

    1997-01-01

    PLIF has been used to observe the in-cylinder transport of unburned fuel that, while trapped in the ring-land and ring-groove crevices, survives combustion in the propagating flame. Away from the top-ring gap, we detect a wall-jet comprised of unburned charge exiting the top ring-land crevice opening. At the location of the top-ring gap, we observed unburned fuel lying in the cool boundary layer along the cylinder wall during the later stages of the expansion stroke. This layer is scraped into the roll-up vortex during the exhaust stroke. These data lead us to conclude that away from the end gap, unburned, high pressure charge, trapped between the two compression rings escapes as a wall jet after ring-reversal near the bottom center. Conversely, at the ring gap, when the cylinder pressure drops below the pressure between the compression rings, the trapped charge escapes through the gap and forms a thin layer on the cylinder wall.

  15. Robust Comparison of Climate Models with Observations Using Blended Land Air and Ocean Sea Surface Temperatures

    NASA Astrophysics Data System (ADS)

    Hausfather, Z.; Jacobs, P.; Cowtan, K.; Hawkins, E.; Mann, M. E.; Miller, S. K.; Steinman, B. A.; Way, R. G.; Stolpe, M.

    2015-12-01

    Model-observation comparisons provide an important test of climate models' ability to realistically simulate the transient evolution of the system. A great deal of attention has recently focused on the so-called "hiatus" period of the past ~15 years, when estimates of recent surface temperature evolution fall at the lower end of climate model projections. This work quantifies a systematic bias in model-observation comparisons arising from differential warming rates between sea surface temperatures and surface air temperatures over oceans. Global mean temperatures from climate model simulations are typically calculated using surface air temperatures, while the corresponding observations are based on a blend of air and sea surface temperatures. A further bias arises from the treatment of temperatures in regions where the sea ice boundary has changed. We discuss the magnitude of these biases, and their implications for the evaluation of climate model performance over the "hiatus" period and the full instrumental record.

  16. Monitoring arid lands using AVHRR-observed visible reflectance and SMMR37-GHz polarization difference

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.

    1990-01-01

    Visible reflectance along a transect through the Sahel and Sudan zones of Africa has been derived from observations by the AVHRR on the NOAA-7 and NOAA-9 satellites and compared with concurrent observations of the 37-GHz polarization difference by the SMMR on the Nimbus-7 satellite. The study period was January 1982 to December 1986, which included an unprecedented drought during 1984 over the Sahel zone. While spatial and temporal patterns of these two data sets are found to be highly correlated, there are also quantitative differences which need to be understood.

  17. Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection

    PubMed Central

    Álvarez-Romero, Jorge G.; Pressey, Robert L.; Ban, Natalie C.; Brodie, Jon

    2015-01-01

    Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both sets of objectives. Our

  18. Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection.

    PubMed

    Álvarez-Romero, Jorge G; Pressey, Robert L; Ban, Natalie C; Brodie, Jon

    2015-01-01

    Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both sets of objectives. Our

  19. Global Land-surface Evaporation Estimated from Satellite-based Observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper outlines a new methodology to derive evaporation from satellite observations. The approach uses a variety of satellite-sensor products to estimate daily evaporation at a global scale, with a 0.25 degree spatial resolution. Central to this approach is the use of the Priestley and Taylor (P...

  20. Photometric Observations of Soils and Rocks at the Mars Exploration Rover Landing Sites

    NASA Technical Reports Server (NTRS)

    Johnson, J. R.; Arvidson, R. A.; Bell, J. F., III; Farrand, W.; Guinness, E.; Johnson, M.; Herkenhoff, K. E.; Lemmon, M.; Morris, R. V.; Seelos, F., IV

    2005-01-01

    The Panoramic Cameras (Pancam) on the Spirit and Opportunity Mars Exploration Rovers have acquired multispectral reflectance observations of rocks and soils at different incidence, emission, and phase angles that will be used for photometric modeling of surface materials. Phase angle coverage at both sites extends from approx. 0 deg. to approx. 155 deg.

  1. Trends and Variability in Observed Runoff from Land Terminating Glaciers in Greenland

    NASA Astrophysics Data System (ADS)

    Petersen, D.; Ahlstrom, A. P.

    2015-12-01

    The Greenland ice sheet is losing mass at an accelerated rate with both surface melting and iceberg discharge increasing notably over the last decade. The impact of Greenland ice sheet mass loss on the ongoing global sea level rise has raised concern and a better understanding of the reaction of the ice sheet to a future warmer climate is needed. Yet, observational records of surface melting have so far only been in the form of stake readings or short-term discharge measurements. Here we present continuous, long-term observations of discharge from pro-glacial lake Tasersiaq in West Greenland (66.3°N, 50.4°W) whose drainage basin extends over around 8500 km2 of which around 80% is ice covered (by Greenland Ice Sheet and local glaciers). The discharge time series covers the period from 1975 to 2014 and gives insight into the hydrological system's reaction to climatic forcing, e.g. a clear impact from major volcanic eruptions is observed. Over the entire data period a significant positive trend of 0.06 km3/yr in annual discharge is seen, where the median annual discharge is 2.50 km3. In addition to the trend in annual discharge a large and increasing year-to-year variability is observed. We examine both discharge trend and variability in the context of atmospheric circulation patterns and indicators of climate variability.

  2. Observations of fair-weather cumuli over land: Dynamical factors controlling cloud size and cover

    NASA Astrophysics Data System (ADS)

    Lamer, Katia; Kollias, Pavlos

    2015-10-01

    Comprehensive observations of shallow convection at the Atmospheric Radiation Measurement Southern Great Plains site are carefully analyzed to study the macrophysical and dynamical properties of active and forced cumuli separately and investigate their relationship to the subcloud layer turbulent structure. Clearly, active clouds possess stronger dynamics and greater horizontal extent than their forced counterpart. As previously reported, upper level stability and relative humidity do control the predominance of active clouds. While cloud cover remains difficult to associate to mixed-layer parameters (small correlation coefficients), mixed-layer top vertical velocity skewness, and coherent updraft fraction most significantly correlate to cumulus cloud cover and especially the portion attributed to active clouds; both of which are not currently considered in shallow cloudiness parameterizations. This study also points to several factors that continue to limit our ability to adequately sample shallow cumuli and suggests that forward models will be necessary to bridge observations and model outputs.

  3. Quantifying Surface Energy Flux Estimation Uncertainty Using Land Surface Temperature Observations

    NASA Astrophysics Data System (ADS)

    French, A. N.; Hunsaker, D.; Thorp, K.; Bronson, K. F.

    2015-12-01

    Remote sensing with thermal infrared is widely recognized as good way to estimate surface heat fluxes, map crop water use, and detect water-stressed vegetation. When combined with net radiation and soil heat flux data, observations of sensible heat fluxes derived from surface temperatures (LST) are indicative of instantaneous evapotranspiration (ET). There are, however, substantial reasons LST data may not provide the best way to estimate of ET. For example, it is well known that observations and models of LST, air temperature, or estimates of transport resistances may be so inaccurate that physically based model nevertheless yield non-meaningful results. Furthermore, using visible and near infrared remote sensing observations collected at the same time as LST often yield physically plausible results because they are constrained by less dynamic surface conditions such as green fractional cover. Although sensitivity studies exist that help identify likely sources of error and uncertainty, ET studies typically do not provide a way to assess the relative importance of modeling ET with and without LST inputs. To better quantify model benefits and degradations due to LST observational inaccuracies, a Bayesian uncertainty study was undertaken using data collected in remote sensing experiments at Maricopa, Arizona. Visible, near infrared and thermal infrared data were obtained from an airborne platform. The prior probability distribution of ET estimates were modeled using fractional cover, local weather data and a Penman-Monteith mode, while the likelihood of LST data was modeled from a two-source energy balance model. Thus the posterior probabilities of ET represented the value added by using LST data. Results from an ET study over cotton grown in 2014 and 2015 showed significantly reduced ET confidence intervals when LST data were incorporated.

  4. Earth Observing System (EOS)/ Advanced Microwave Sounding Unit-A (AMSU-A): Special Test Equipment. Software Requirements

    NASA Technical Reports Server (NTRS)

    Schwantje, Robert

    1995-01-01

    This document defines the functional, performance, and interface requirements for the Earth Observing System/Advanced Microwave Sounding Unit-A (EOS/AMSU-A) Special Test Equipment (STE) software used in the test and integration of the instruments.

  5. Observing gravitational waves from core-collapse supernovae in the advanced detector era

    NASA Astrophysics Data System (ADS)

    Gossan, S. E.; Sutton, P.; Stuver, A.; Zanolin, M.; Gill, K.; Ott, C. D.

    2016-02-01

    The next galactic core-collapse supernova (CCSN) has already exploded, and its electromagnetic (EM) waves, neutrinos, and gravitational waves (GWs) may arrive at any moment. We present an extensive study on the potential sensitivity of prospective detection scenarios for GWs from CCSNe within 5 Mpc, using realistic noise at the predicted sensitivity of the Advanced LIGO and Advanced Virgo detectors for 2015, 2017, and 2019. We quantify the detectability of GWs from CCSNe within the Milky Way and Large Magellanic Cloud, for which there will be an observed neutrino burst. We also consider extreme GW emission scenarios for more distant CCSNe with an associated EM signature. We find that a three-detector network at design sensitivity will be able to detect neutrino-driven CCSN explosions out to ˜5.5 kpc , while rapidly rotating core collapse will be detectable out to the Large Magellanic Cloud at 50 kpc. Of the phenomenological models for extreme GW emission scenarios considered in this study, such as long-lived bar-mode instabilities and disk fragmentation instabilities, all models considered will be detectable out to M31 at 0.77 Mpc, while the most extreme models will be detectable out to M82 at 3.52 Mpc and beyond.

  6. Observing Gravitational Waves from Core-Collapse Supernovae in the Advanced Detector Era

    NASA Astrophysics Data System (ADS)

    Gossan, Sarah; Sutton, Patrick; Stuver, Amber L.; Zanolin, Michele; Gill, Kiranjyot; Ott, Christian D.

    2016-01-01

    The next galactic core-collapse supernova (CCSN) has already exploded, and its electromagnetic (EM) waves, neutrinos, and gravitational waves (GWs) may arrive at any moment. We present an extensive study on the potential sensitivity of prospective detection scenarios for GWs from CCSNe within 5Mpc, using realistic noise at the predicted sensitivity of the Advanced LIGO and Advanced Virgo detectors for 2015, 2017, and 2019. We quantify the detectability of GWs from CCSNe within the Milky Way and Large Magellanic Cloud, for which there will be an observed neutrino burst. We also consider extreme GW emission scenarios for more distant CCSNe with an associated EM signature. We find that a three detector network at design sensitivity will be able to detect neutrino-driven CCSN explosions out to ~5.5 kpc, while rapidly rotating core collapse will be detectable out to the Large Magellanic Cloud at 50kpc. Of the phenomenological models for extreme GW emission scenarios considered in this study, such as long-lived bar-mode instabilities and disk fragmentation instabilities, all models considered will be detectable out to M31 at 0.77 Mpc, while the most extreme models will be detectable out to M82 at 3.52 Mpc and beyond.

  7. Retrieval of Surface and Atmospheric Geophysical Variables over Snow-Covered Land from Combined Microwave and Infrared Satellite Observations.

    NASA Astrophysics Data System (ADS)

    Prigent, C.; Aires, F.; Rossow, W. B.

    2003-03-01

    Surface temperature and emissivities, as well as atmospheric water vapor and cloud liquid water, have been calculated from Special Sensor Microwave Imager observations for snow-covered land areas using a neural network inversion scheme that includes first-guess information. A learning database to train the neural network is derived from a global collection of coincident surface and atmospheric parameters, extracted from the National Centers for Environmental Prediction reanalysis, from the International Satellite Cloud Climatology Project data, and from microwave emissivity atlases previously calculated. Despite the large space and time variability of the snow microwave response, the surface and atmospheric parameters are retrieved. Water vapor is estimated with a theoretical rms error of approximately 30%, verified against radiosonde measurements, that is almost the same as over snow-free land. The theoretical rms error of the surface skin temperature retrieval is 1.5 and 1.9 K, respectively, for clear and cloudy scenes. The surface skin temperatures are compared with the surface air temperatures measured at meteorological stations to verify that the expected differences are found. The space and time variations of the retrieved surface emissivities are evaluated by comparison with surface parameter variations such as surface air temperature, snow depth, and vegetation cover.

  8. Assessing the Mechanical and Electrical Properties of Comet Churyumov Gerasimenko from Radar Observations and Philae Landing Dynamic

    NASA Astrophysics Data System (ADS)

    Heggy, Essam; Ahmed, Elshafie; Wlodek, Kofman; Nicolas, Thomas; Sierks, Holger; Jorda, Laurent; Hviid, Stubbe

    2015-08-01

    Constraining the ambiguities associated with the surface compressive strength of comets and icy satellites is crucial for understanding landing characteristics, proper anchoring, optimizing drilling and penetration in the upper layer of the surface regolith of these planetary bodies. Using the compressive strength and dielectric measurements conducted on dry-snow as a plausible first order approximation of a cometary analog at low temperature and variable densities, we propose an empirical model that correlates the surface compressive strength to the dielectric properties. This model is being validated using the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) and Bi-Static Radar (BSR) observations onboard the Rosetta mission. Our results suggest that the average surface compressive strength at 67P surface range from 2 kPa to 1 MPa, for a mean surface temperature of -70° C. We also analyzed the OSIRIS images of the Philae lander first impact footprints which are suggested to be ~15 cm deep into the upper regoligth and hence suggesting a low surface compressive strength close to 2 kPa. We will discuss the implications of these results for future landing and sampling experiments for small bodies.

  9. The observed evapotranspiration combining the energy and water balance for different land use under semiarid Mediterranean catchment

    NASA Astrophysics Data System (ADS)

    Zitouna Chebbi, Rim; Mekki, Insaf; Jacob, Frédéric; Masmoudi, Moncef; Prévot, Laurent; Ben Mechlia, Netij; Voltz, Marc; Albergel, Jean

    2014-05-01

    The Mediterranean semiarid cultivated catchments are affected by global and climate change and are characterized by very complex hydrological systems. The improvement of their management requires a best understanding of the hydrological processes and developing reliable means for characterizing the temporal dynamics of soil water balance in a spatially distributed manner. The main objective of this study is: i) to analyze the observed evapotranspiration in relation to natural drivers (i.e. rainfall and soil properties) and anthropogenic forcing (i.e. land use and crop successions), and ) ii to assess the differences in both energy and water balances. We focus on a hilly semiarid Mediterranean catchment devoted to rainfed agriculture, so-called the Kamech catchment, which is located in the Cap Bon Peninsula, north-eastern Tunisia. The site belongs to the OMERE observatory for environmental research and it is monitored for the different hydrological cycle components under influence of anthropogenic forcing. The analysis is based on in-situ data measured under the common cereals/legumes/pasture cropping systems within the Kamech catchment. Energy and water balance components and vegetation parameters were collected in different fields and during various crop growth cycles. The results showed the highly variable response of energy and water balances depending on soil types, land use, and climatic conditions. The annual rainfall is mainly converted into evapotranspiration during the growing cycle for different land uses. The runoff amounts, for most of the sites, correspond to less than 10% of the rainfall amount. The evapotransipration ratios differed significantly across site and season in relation to soil properties and cumulated rainfall. We observe large differences in soil water dynamics among the legumes (fababean and chickpea) and cereals (wheat, oat, and triticale). Soil water is larger for legume crops, despite substantial plant growth during winter

  10. Tropical cyclone rainbands over land in South Florida: Multiwavelength radar observations and their educational applications

    NASA Astrophysics Data System (ADS)

    Donaher, Shaunna

    This dissertation investigates the wind structure observed in outer rainbands of three tropical cyclones in August and September 2008 in South Florida. Average wind profiles during fourteen stratiform periods are evaluated using a velocity-azimuth display (VAD) technique applied to Level-2 Miami (KAMX) WSR-88D data to study wind structure in high vertical resolution from a height of 65 meters to 6550 meters above ground level. The maximum horizontal wind speed in the rainbands is typically observed between 1000-1500 meters in height, with occasional evidence of a secondary horizontal wind maximum near 3500-5000 meters. This secondary maximum is found to be stronger than the low-level maximum in four cases of stronger storms observed at further distances (425-450 km) from storm center. Storm-relative wind components are calculated, and radial wind profiles show a mean switch from radial inflow at low levels to radial outflow around 2500-3000 meters AGL. The radial inflow maximum is around 500 meters, while maximum outflow is much more variable. Temporal variability within one four hour period is examined, and an ascending and strengthening low-level wind maximum is seen, along with a decrease in the low-level radial inflow over time. Low-level winds are studied in great detail using the high resolution VAD data. All rainbands show a logarithmic wind speed decrease below 500 meters; friction velocity and aerodynamic roughness length are calculated in this log-wind regime for each band. Although the roughness length is found to be higher and much more variable than previous observations, using the calculated components for a fit between 65-120 meters AGL allows for an estimate of wind speeds up to 500 meters above ground level with good accuracy. Variability within the four longest stratiform periods is examined in high temporal and vertical resolution using X-band radar and wind profiler data. Vertical features extending from the near-surface up to the height of the

  11. Earth Observing System (EOS)/Advanced Microwave Sounding Unit-A (AMSU-A)

    NASA Technical Reports Server (NTRS)

    Mullooly, William

    1995-01-01

    This is the thirty-first monthly report for the Earth Observing System (EOS)/Advanced Microwave Sounding Unit- A (AMSU-A), Contract NAS5-32314, and covers the period from 1 July 1995 through 31 July 1995. This period is the nineteenth month of the Implementation Phase which provides for the design, fabrication, assembly, and test of the first EOS/AMSU-A, the Protoflight Model. Included in this report is the Master Program Schedule (Section 2), a report from the Product Team Leaders on the status of all major program elements (Section 3), Drawing status (Section 4), Weight and Power Budgets (CDRL) 503 (Section 5), Performance Assurance (CDRL 204) (Section 6), Configuration Management Status Report (CDRL 203) (Section 7), Documentation/Data Management Status Report (Section 8), and Contract Status (Section 9).

  12. VIRTIS-Rosetta Observations of 67P/Churyumov-Gerasimenko Nucleus and Coma During the Mission Pre-Landing Phase.

    NASA Astrophysics Data System (ADS)

    Capaccioni, F.; Filacchione, G.; Erard, S.; Arnold, G.; Capria, M. T.; De Sanctis, M. C.; Tosi, F.; Ciarniello, M.; Bockelée-Morvan, D.; Leyrat, C.; Palomba, E.; Piccioni, G.; Raponi, A.; Longobardo, A.; Migliorini, A.; Ammannito, E.; Combi, M. R.; Fink, U.; McCord, T. B.; Carlson, R. W.; Jaumann, R.; Drossart, P.; Formisano, M.; Schmitt, B.; Frigeri, A.; Flamini, E.

    2014-12-01

    The paper will describe the major results obtained during the pre-landing phase, running from July throughout November 2014, of the Rosetta Mission by the instrument VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer), the dual channel spectrometer onboard Rosetta. The nucleus observations were performed in a wide range of conditions with spatial resolution varying from the initial 500m down to 12.5m and have allowed to generate compositional maps of the illuminated areas. Special emphasis was placed on mapping those surface regions considered reachable areas for the Philae Lander descent, and to those area in the "neck" of the nucleus which from the very early Osiris observations did show hints of surface outgassing activity. The surface temperature has been determined since the first distant observations of the nucleus. Already on the mid of july from a distance of 15000km, when the nucleus was filling one VIRTIS-M pixel, the mean surface temperature has been measured as 205+-5K. This pointed to a surface structure largely covered by a porous crust, mainly devoid of water ice. The major results obtained at higher spatial resolution shall be described and discussed. Finally, an extensive campaign of observations at limb to measure abundances of major volatile compounds (H2O, CO2 and CO) as well as dust scattering properties were carried out. Authors acknowledge the support from national funding agencies.

  13. MAPSAR: a small L-band SAR mission for land observation

    NASA Astrophysics Data System (ADS)

    Schröder, Reinhard; Puls, Jürgen; Hajnsek, Irena; Jochim, Fritz; Neff, Thomas; Kono, Janio; Renato Paradella, Waldir; Marcos Quintino da Silva, Mario; de Morisson Valeriano, Dalton; Pereira Farias Costa, Maycira

    2005-01-01

    This paper introduces Multi-Application Purpose SAR (MAPSAR). A new Synthetic Aperture Radar (SAR) mission for earth observation. MAPSAR is the result of a joint pre-phase A study conducted by INPE and DLR targeting a mission for assessment, management and monitoring of natural resources. The applicability of the sensor system was investigated for cartography, forestry, geology, geomorphology, hydrology, agriculture, disaster management, oceanography, urban studies and security. An L-band SAR, based on INPE's multi-mission platform (MMP), has been chosen as payload of the satellite. The key component of the SAR instrument is the SAR antenna, which is designed as an elliptical parabolic reflector antenna. L-band (high spatial resolution, quad-pol) has been selected for the SAR sensor as optimum frequency accounting for the majority of Brazilian and German user requirements. At the moment, the pre-phase A has been concluded and the phase A is planned to start in early 2003.

  14. Sangamon field experiments: observations of the diurnal evolution of the planetary boundary layer over land

    SciTech Connect

    Hicks, B.B.; Hess, G.D.; Wesely, M.L.; Yamada, T.; Frenzen, P.; Hart, R.L.; Sisterson, D.L.; Hess, P.E.; Kulhanek, F.C.; Lipschutz, R.C.; Zerbe, G.A.

    1981-09-01

    Two complementary experimental studies of the evolving structure of the lower 2 km of the atmosphere, conducted over farmlands in central Illinois during essentially the same mid-summer weeks of two successive years, are described. The first experiment (21 July - 13 August 1975) investigated the early morning break up of the nocturnal stable layer and the rapid growth of the mixed layer before noon; the second (16 to 30 July 1976) examined the decline of the mixed layer through the late afternoon and evening, and the formation and intensification of the ground-based inversion before midnight. Methods of observation and data reduction are summarized in some detail, and the data obtained in the form of hourly wind and temperature profiles, plus sufficient surface flux information to characterize the lower boundary conditions, are tabulated in a series of appendices. These results constitute complete data sets which may be used to test models of the diurnal evolution of the lower atmosphere.

  15. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estellés, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Rosenberg, P.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Woolley, A.

    2015-01-01

    The Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under

  16. Advances in Understanding Top-of-Atmosphere Radiation Variability from Satellite Observations

    NASA Astrophysics Data System (ADS)

    Loeb, Norman G.; Kato, Seiji; Su, Wenying; Wong, Takmeng; Rose, Fred G.; Doelling, David R.; Norris, Joel R.; Huang, Xianglei

    2012-07-01

    This paper highlights how the emerging record of satellite observations from the Earth Observation System (EOS) and A-Train constellation are advancing our ability to more completely document and understand the underlying processes associated with variations in the Earth's top-of-atmosphere (TOA) radiation budget. Large-scale TOA radiation changes during the past decade are observed to be within 0.5 Wm-2 per decade based upon comparisons between Clouds and the Earth's Radiant Energy System (CERES) instruments aboard Terra and Aqua and other instruments. Tropical variations in emitted outgoing longwave (LW) radiation are found to closely track changes in the El Niño-Southern Oscillation (ENSO). During positive ENSO phase (El Niño), outgoing LW radiation increases, and decreases during the negative ENSO phase (La Niña). The coldest year during the last decade occurred in 2008, during which strong La Nina conditions persisted throughout most of the year. Atmospheric Infrared Sounder (AIRS) observations show that the lower temperatures extended throughout much of the troposphere for several months, resulting in a reduction in outgoing LW radiation and an increase in net incoming radiation. At the global scale, outgoing LW flux anomalies are partially compensated for by decreases in midlatitude cloud fraction and cloud height, as observed by Moderate Resolution Imaging Spectrometer and Multi-angle Imaging SpectroRadiometer, respectively. CERES data show that clouds have a net radiative warming influence during La Niña conditions and a net cooling influence during El Niño, but the magnitude of the anomalies varies greatly from one ENSO event to another. Regional cloud-radiation variations among several Terra and A-Train instruments show consistent patterns and exhibit marked fluctuations at monthly timescales in response to tropical atmosphere-ocean dynamical processes associated with ENSO and Madden-Julian Oscillation.

  17. Diagnosing Land Water Storage Variations in Major Indian River Basins using GRACE observations

    NASA Astrophysics Data System (ADS)

    Soni, Aarti; Syed, Tajdarul H.

    2015-10-01

    Scarcity of freshwater is one of the most critical resource issue the world is facing today. Due to its finite nature, renewable freshwater reserves are under relentless pressure due to population growth, economic development and rapid industrialization. Assessment of Terrestrial Water Storage (TWS), as an unified measure of freshwater reserve, is vital to understand hydrologic and climatic processes controlling its availability. In this study, TWS variations from Gravity Recovery and Climate Experiment (GRACE) satellites are analyzed in conjuction with multi-platform hydrologic observations for the period of 2003-2012. Here, the primary objective is to quantify and attribute the observed short-term variability of TWS and groundwater storage in the largest river basins of India (Ganga, Godavari, Krishna and Mahanadi). Alongside commendable agreement between TWS variations obtained from GRACE and water balance computation, results highlight some of the important deficiencies between the two. While monthly changes in TWS are highly correlated with precipitation, monthly TWS anomalies reveal a 1-2 month lag in their concurrence. Analysis of groundwater storage estimates demonstrate significant decline in the Ganga basin (- 1.28 ± 0.20 mm/month) but practically no change in the Mahanadi basin. On the contrary, groundwater storage in Godavari and Krishna basins reveal notable increase at the rate of 0.74 ± 0.21 mm/month and 0.97 ± 0.21 mm/month respectively. Subsequently, in order to assess the influence of quasi-periodic, planetary scale, variations in the Earth's climate system, groundwater storage anomalies are evaluated with reference to ENSO variability. Results manifest that in all the basins, with the exception of Ganga, groundwater storage is dominantly influenced by ENSO, with large decrease (increase) during El Niño (La Niña) events. In the Ganga basin, groundwater storage variations refer to possible amalgamation of human intervention and natural climate

  18. Size distributions of mineral aerosols and dust emission flux observed over Horqin Sandy Land area in northern China

    NASA Astrophysics Data System (ADS)

    Li, X.; Zhang, H. S.

    2013-01-01

    Size distribution of mineral aerosols is of primary importance in determining their residence time in atmosphere, transport patterns, removal mechanisms as well as their effects on climate and human health. This study aims to obtain dust particle size distribution and size-resolved dust emission flux under different weather conditions over a sandy land area in northern China (Horqin Sandy Land, Inner Mongolia), using the observational data from Horqin sandstorm monitoring station in the spring of 2010 and 2012. Dust (PM20) mass concentration was measured by a 10-stage quartz crystal microbalance (QCM) cascade impactor. The statistical results indicate that finer dust particles (r ≤ 1.0 μm) take a large proportion of all PM20 concentration under clear-day conditions, while coarser dust particles (r ≥ 2.5 μm) concentration increased under dust-day conditions, with the peak occurring between 4-7 μm. The dust particle size distributions during the pre-dust-emission and dust-emission periods of a dust event on 7 April 2012 have similar features to the statistical results. During the dust event, the magnitude of dust emission flux of all sizes increased about one or two orders (0.1-10 μg m-2 s-1) as u* increase from 0.54 to 1.29 m s-1. The maximum total F value was about 43.0 μg m-2 s-1 and the maximum size-resolved F(Ddi) is 12.3 μg m-2 s-1 in 0.3-0.45 μm size bin when u* is 1.29 m s-1. Dust advection has effects on airborne dust size distribution, making the proportion of dust particles of different sizes more uniform, as observed in a non-local dust event on 19 April 2012.

  19. All-weather estimates of the land surface skin temperatures from combined analyses of microwave and infrared satellite observations

    NASA Astrophysics Data System (ADS)

    Jimenez, C.; Aires, F.; Prigent, C.; Catherinot, J.; Rossow, W. B.

    2011-12-01

    The surface skin temperature (Ts) is a key parameter at the land-atmosphere interface. Global datasets of Ts are traditionally estimated from satellite infrared radiance observations, under clear sky conditions. First, the inter-comparison of different IR land surface temperature satellite datasets (ISCCP, MODIS, and AIRS) is presented, along with an evaluation with in situ measurements at selected stations archived during CEOP (Coordinated Enhanced Observing Period). The objective is to assess the accuracy of the Ts estimates, and to evidence the major error sources in the retrieval. Results show that the major sources of differences between the different satellite products come from instrument calibration differences, especially for high Ts, followed by the impact of the water vapor treatment in the algorithm, and the differences in surface emissivities. The main limitation of satellite infrared measurements of Ts is their inability to penetrate clouds, limiting them to clear conditions. Microwave wavelengths, being much less affected by clouds than the infrared, are an attractive alternative in cloudy regions as they can be used to derive an all-sky skin Ts product. A neural network inversion scheme has been developed to retrieve surface Ts along with atmospheric water vapor, cloud liquid water, and surface emissivities over land from a combined analysis of Special Sensor Microwave /Imager (SSM/I) and International Satellite Cloud Climatology Project (ISCCP) data. In the absence of routine in situ Ts measurements, retrieved all-weather Ts values are first evaluated globally by comparison to the surface air temperature (Tair) measured by the meteorological station network. The Ts-Tair difference from the global comparisons showed all the expected variations with solar flux, soil characteristics, and cloudiness. This evaluation has been recently extended locally at a few sites by using the Ts in-situ measurements from several CEOP stations representing different

  20. Observations of Dynamic Changes at an Advancing Tidewater Glacier: Hubbard Glacier, Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Elliott, J.; Stearns, L. A.; Pritchard, M. E.; Bartholomaus, T.

    2015-12-01

    Hubbard Glacier, located in southeast Alaska, is the largest non-polar tidewater glacier in the world and one of a small number of glaciers that is steadily advancing. These attributes make it an intriguing target for observations of variations in ice dynamics over time. We use synthetic aperture radar data (ALOS and TerraSAR-X) and high-resolution optical imagery (WorldView and Quickbird) with a pixel tracking technique to map surface velocities from 2008 to the present, lengthening and broadening the time series of ice velocities presented in previous studies. A key result from our analysis is that Hubbard displays peak speeds of up to 12 m/day during the winter months (December - February) and minimum speeds during late summer (August - September). The times of peak and minimum speeds is quite different from those found in previous studies of Hubbard surface velocities derived from Landsat imagery, GPS, and photogrammetric methods. Those studies found peak speeds during late spring (May - June) and minimum speeds in fall (October-November), a pattern observed generally at tidewater glaciers. A second major feature we observe in our time series is the dramatic seasonal variation in surface speeds. The minimum speeds we find along the terminal lobe of the glacier are much lower than those found in previous studies, with values decreasing to near zero. Such a dramatic slow down of a tidewater glacier has not been widely observed. This result, along with the recent pattern of seasonal velocity peaks and minimas, suggests that Hubbard has undergone a change in ice dynamics.

  1. The Unmanned Research Airplane Facility at the Cyprus Institute: Advanced Atmospheric Observations

    NASA Astrophysics Data System (ADS)

    Lange, Manfred A.; Argyrides, Marios; Ioannou, Stelios; Keleshis, Christos

    2014-05-01

    Unmanned Aerial Systems (UASs) have been established as versatile tools for different applications, providing data and observations for atmospheric and Earth-Systems research. They provide an urgently needed link between in-situ ground based measurements and satellite remote sensing observations and are distinguished by significant versatility, flexibility and moderate operational costs. Building on an earlier project (Autonomous Flying Platforms for Atmospheric and Earth Surface Observations project; APAESO) of the Energy, Environment and Water Research Center (EEWRC) at the Cyprus Institute (APAESO is co-financed by the European Development Fund and the Republic of Cyprus through the Cyprus Research Promotion Foundation), we have built up an Unmanned Research Aircraft Facility at The Cyprus Institute (CyI-URAF). The basic components of this facility comprise four CRUISERS airplanes (ET-Air, Slovakia) as UAS platforms, a substantial range of scientific instruments to be flown on these platforms, a mobile Ground Control Station and a well-equipped workshop and calibration laboratory. The APAESO platforms are suitable to carrying out atmospheric and earth-surface observations in the (Eastern) Mediterranean (and elsewhere). They enable 3D measurements for determining physical, chemical and radiative atmospheric properties, aerosol and dust concentrations and atmospheric dynamics as well as 2D investigations into land management practices, vegetation and agricultural mapping, contaminant detection and the monitoring and assessment of hydrological parameters and processes of a given region at high spatial resolution. We will report on some of the essential modifications of the platforms and some of the instrumentation that were instrumental in preparing the research airplanes for a variety of collaborative research projects with. The first scientific mission involved the employment of a DOAS-system (Differential Optical Absorption Spectroscopy) in cooperation with

  2. Combined hydrogen and lithium beam emission spectroscopy observation system for Korea Superconducting Tokamak Advanced Research.

    PubMed

    Lampert, M; Anda, G; Czopf, A; Erdei, G; Guszejnov, D; Kovácsik, Á; Pokol, G I; Réfy, D; Nam, Y U; Zoletnik, S

    2015-07-01

    A novel beam emission spectroscopy observation system was designed, built, and installed onto the Korea Superconducting Tokamak Advanced Research tokamak. The system is designed in a way to be capable of measuring beam emission either from a heating deuterium or from a diagnostic lithium beam. The two beams have somewhat complementary capabilities: edge density profile and turbulence measurement with the lithium beam and two dimensional turbulence measurement with the heating beam. Two detectors can be used in parallel: a CMOS camera provides overview of the scene and lithium beam light intensity distribution at maximum few hundred Hz frame rate, while a 4 × 16 pixel avalanche photo-diode (APD) camera gives 500 kHz bandwidth data from a 4 cm × 16 cm region. The optics use direct imaging through lenses and mirrors from the observation window to the detectors, thus avoid the use of costly and inflexible fiber guides. Remotely controlled mechanisms allow adjustment of the APD camera's measurement location on a shot-to-shot basis, while temperature stabilized filter holders provide selection of either the Doppler shifted deuterium alpha or lithium resonance line. The capabilities of the system are illustrated by measurements of basic plasma turbulence properties. PMID:26233377

  3. Combined hydrogen and lithium beam emission spectroscopy observation system for Korea Superconducting Tokamak Advanced Research

    SciTech Connect

    Lampert, M.; Anda, G.; Réfy, D.; Zoletnik, S.; Czopf, A.; Erdei, G.; Guszejnov, D.; Kovácsik, Á.; Pokol, G. I.; Nam, Y. U.

    2015-07-15

    A novel beam emission spectroscopy observation system was designed, built, and installed onto the Korea Superconducting Tokamak Advanced Research tokamak. The system is designed in a way to be capable of measuring beam emission either from a heating deuterium or from a diagnostic lithium beam. The two beams have somewhat complementary capabilities: edge density profile and turbulence measurement with the lithium beam and two dimensional turbulence measurement with the heating beam. Two detectors can be used in parallel: a CMOS camera provides overview of the scene and lithium beam light intensity distribution at maximum few hundred Hz frame rate, while a 4 × 16 pixel avalanche photo-diode (APD) camera gives 500 kHz bandwidth data from a 4 cm × 16 cm region. The optics use direct imaging through lenses and mirrors from the observation window to the detectors, thus avoid the use of costly and inflexible fiber guides. Remotely controlled mechanisms allow adjustment of the APD camera’s measurement location on a shot-to-shot basis, while temperature stabilized filter holders provide selection of either the Doppler shifted deuterium alpha or lithium resonance line. The capabilities of the system are illustrated by measurements of basic plasma turbulence properties.

  4. Temporal Stability of Soil Moisture and Radar Backscatter Observed by the Advanced Synthetic Aperture Radar (ASAR)

    PubMed Central

    Wagner, Wolfgang; Pathe, Carsten; Doubkova, Marcela; Sabel, Daniel; Bartsch, Annett; Hasenauer, Stefan; Blöschl, Günter; Scipal, Klaus; Martínez-Fernández, José; Löw, Alexander

    2008-01-01

    The high spatio-temporal variability of soil moisture is the result of atmospheric forcing and redistribution processes related to terrain, soil, and vegetation characteristics. Despite this high variability, many field studies have shown that in the temporal domain soil moisture measured at specific locations is correlated to the mean soil moisture content over an area. Since the measurements taken by Synthetic Aperture Radar (SAR) instruments are very sensitive to soil moisture it is hypothesized that the temporally stable soil moisture patterns are reflected in the radar backscatter measurements. To verify this hypothesis 73 Wide Swath (WS) images have been acquired by the ENVISAT Advanced Synthetic Aperture Radar (ASAR) over the REMEDHUS soil moisture network located in the Duero basin, Spain. It is found that a time-invariant linear relationship is well suited for relating local scale (pixel) and regional scale (50 km) backscatter. The observed linear model coefficients can be estimated by considering the scattering properties of the terrain and vegetation and the soil moisture scaling properties. For both linear model coefficients, the relative error between observed and modelled values is less than 5 % and the coefficient of determination (R2) is 86 %. The results are of relevance for interpreting and downscaling coarse resolution soil moisture data retrieved from active (METOP ASCAT) and passive (SMOS, AMSR-E) instruments.

  5. Terrigenous fluxes of pollen, insect scale and land plant palynodebris observed by sediment traps deployed in the subarctic Pacific

    NASA Astrophysics Data System (ADS)

    Tsutsui, H.; Takahashi, K.; Fowell, S. J.; Matsuoka, K.; Jordan, R. W.; Yamamoto, S.

    2014-12-01

    From 1990 to 2009, sediment traps in the subarctic Pacific (SA; 49°N, 174°W) were deployed and recovered during each summer, allowing the long-term observation of particle fluxes. As the Pacific Decadal Oscillation index changed in 1999 as air-temp cooled, this study focused on pollen, land plant debris and insect scale fluxes at SA during 1998 to 2006. The max pollen and fern spores flux was a mean of 74 grains m2 d-1, and the following details: 65% of the total pollen counts represented by wind-pollinated trees (e.g., alder, birch and pine), 24% by the herbaceous plants (as herbs), and 11% by fern spores. Spore, herbaceous and wind-pollinated tree pollen (as wind-pollen) fluxes peaked in May and Sep-Oct, but flux peaks of the latter also occurred in April and Jun. The annual flux peaks of insect scales (of unknown origin) and land-plant debris were in May and Sep, but over the entire study period the max insect scale flux of 161 was in Aug 2002, with a mean of 16 scales m2d-1, while the max (in Aug 2004) and mean land-plant debris fluxes were 107 and 10 plant fragments m2d-1, respectively. The sediment traps are situated both side of the Aleutian Is., where snow and ice occurs from Oct to May. The ice-snow season accounts for 25% of the total annual particle flux in SA trap, with 75% throughout the rest of the year. The correlation coefficient among pollen, insect scales and land plant debris are: 1) 0.58 (p<1%) between wind-pollen and insect scales, 2) 0.75 (p<5%) between herb-pollen and land plant debris, 3) but only 0.14 between insect scales and herbaceous pollen. Thus, the production location, residence time, route and mode of transport of the particles are important factors. Normally, the wind-pollinated tree flowering season in the northern part of Alaska and Japan where are an upper stream to the stations is from Apr to Jun, with the pollen usually transported across the ocean by winds. Assuming that the pollen takes several months to arrive SA, the

  6. Joint IAMAS/IAHS Symposium J1 on Global Monitoring and Advanced Observing Techniques in the Atmosphere and Hydrosphere

    NASA Technical Reports Server (NTRS)

    Ohring, G.; Aoki, T.; Halpern D.; Henderson-Sellers, A.; Charlock, T.; Joseph, J.; Labitzke, K.; Raschke, E.; Smith, W.

    1994-01-01

    Seventy papers were presented at the two-and-a-half-day Symposium on Global Monitoring and Advanced Observing Techniques in the Atmosphere and Hydrosphere. The symposium was jointly organized by the International Association of Meteorology and Atmospheric Sciences (IAMAS) and the International Association of Hydrological Sciences (IAHS). Global observing systems are receiving increased attention in connection with such problems as monitoring global climate change. The symposium included papers on observational requirements; measurement methodologies; descriptions of available datasets; results of analysis of observational data; plans for future observing systems, including the Global Climate Observing System (GCOS) and the Global Ocean Observing System (GOOS); and the programs and plans of the space agencies.

  7. Pulsed Plasma Thruster (PPT) Technology: Earth Observing-1 PPT Operational and Advanced Components Being Developed

    NASA Technical Reports Server (NTRS)

    Pencil, Eric J.; Benson, Scott W.; Arrington, Lynn A.; Frus, John; Hoskins, W. Andrew; Burton, Rodney

    2003-01-01

    In 2002 the pulsed plasma thruster (PPT) mounted on the Earth Observing-1 spacecraft was operated successfully in orbit. The two-axis thruster system is fully incorporated in the attitude determination and control system and is being used to automatically counteract disturbances in the pitch axis of the spacecraft. The first tests conducted in space demonstrated the full range of PPT operation, followed by calibration of control torques from the PPT in the attitude control system. Then the spacecraft was placed in PPT control mode. To date, it has operated for about 30 hr. The PPT successfully controlled pitch momentum during wheel de-spin, solar array acceleration and deceleration during array rewind, and environmental torques in nominal operating conditions. Images collected with the Advanced Landsat Imager during PPT operation have demonstrated that there was no degradation in comparison to full momentum wheel control. In addition, other experiments have been performed to interrogate the effects of PPT operation on communication packages and light reflection from spacecraft surfaces. Future experiments will investigate the possibility of orbit-raising maneuvers, spacecraft roll, and concurrent operation with the Hyperion imager. Future applications envisioned for pulsed plasma thrusters include longer life, higher precision, multiaxis thruster configurations for three-axis attitude control systems or high-precision, formationflying systems. Advanced components, such as a "dry" mica-foil capacitor, a wear-resistant spark plug, and a multichannel power processing unit have been developed under contract with Unison Industries, General Dynamics, and C.U. Aerospace. Over the last year, evaluation tests have been conducted to determine power processing unit efficiency, atmospheric functionality, vacuum functionality, thruster performance evaluation, thermal performance, and component life.

  8. A Novel Concept for Observing Land-Surface-Atmosphere Feedback Based on a Synergy of Scanning Lidar Systems

    NASA Astrophysics Data System (ADS)

    Wulfmeyer, V.; Turner, D. D.; Mauder, M.; Behrendt, A.; Ingwersen, J.; Streck, T.

    2015-12-01

    Improved simulations of land-surface-atmosphere interaction are fundamental for improving weather forecast and climate models. This requires observations of 2D fields of surface fluxes and the 3D structure of the atmospheric boundary layer simultaneously. A novel strategy is introduced for studying land-surface exchange and entrainment processes in the convective boundary layer (CBL) over complex terrain by means of a new generation of remote sensing systems. The sensor synergy consists of scanning Doppler lidar (DL), water-vapor differential absorption lidar (WVDIAL), and temperature rotational Raman lidar (TRRL) systems supported by surface in-situ measurements. The 2D measurements of surface fluxes are realized by the operation of a DL, a WVDIAL, and a TRRL along the same line-of-sight (LOS) in a range-height-indicator (RHI) mode whereas the other DL is performing a series of cross track RHI scans along this LOS. This new setup enables us to determine the friction velocity as well as surface sensible and latent heat fluxes by closing the complete set of Monin-Obukhov similarity relationships under a variety of surface layer stability conditions and different land cover and soil properties. As this closure is performed at all DL crossing points along the LOS, this is a strategy towards a 2D mapping of surface fluxes entirely based on remote sensing systems. Further details are presented at the conference. The second configuration is the simultaneous vertical profiling of vertical wind, humidity and temperature by DL, WVDIAL and TRRL so that latent heat and sensible heat flux profiles as well as a variety of different turbulent moments can be measured in the CBL. Consequently, by alternating of RHI scanning and vertical pointing modes, entrainment fluxes and surface fluxes can be measured almost simultaneously. This novel strategy has been realized for the first time during the Surface Atmospheric Boundary Layer Exchange (SABLE) campaign in the Kraichgau region

  9. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Rosenberg, P. D.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estelles, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Trembath, J.; Woolley, A.

    2015-07-01

    The Fennec climate programme aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE (Service des Avions Français Instrumentés pour la Recherche en Environnement) Falcon 20 is described, with specific focus on instrumentation specially developed for and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include (1) the first airborne measurement of dust particles sizes of up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI (Spinning Enhanced Visible Infra-Red Imager) satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in situ observations of processes in SABL clouds showing dust acting as cloud condensation nuclei (CCN) and ice nuclei (IN) at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold pool (haboob) issued from deep convection over the Atlas Mountains, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area

  10. Surface-Wind Anomalies in North-Atlantic and North Pacific from SSM/I Observations: Influence on Temperature of Adjoining Land Regions

    NASA Technical Reports Server (NTRS)

    Otterman, Joseph; Atlas, R.; Ingraham, J.; Ardizzone, J.; Starr, D.; Terry, J.

    1998-01-01

    Surface winds over the oceans are derived from Special Sensor Microwave Imager (SSM/I) measurements, assigning direction by Variational Analysis Method (VAM). Validations by comparison with other measurements indicate highly-satisfactory data quality. Providing global coverage from 1988, the dataset is a convenient source for surface-wind climatology. In this study, the interannual variability of zonal winds is analyzed concentrating on the westerlies in North Atlantic and North Pacific, above 30 N. Interannual differences in the westerlies exceeding 10 m sec (exp -1) are observed over large regions, often accompanied by changes of the same magnitude in the easterlies below 30 N. We concentrate on February/March, since elevated temperatures, by advancing snow-melt, can produce early spring. The extremely strong westerlies in 1997 observed in these months over North Atlantic (and also North Pacific) apparently contributed to large surface-temperature anomalies in western Europe, on the order of +3 C above the climatic monthly average for England and France. At these latitudes strong positive anomalies extended in a ring around the globe. We formulated an Index of South westerlies for the North Atlantic, which can serve as an indicator for day-by-day advection effects into Europe. In comparing 1997 and 1998 with the previous years, we establish significant correlations with the temperature anomalies (one to five days later, depending on the region, and on the season). This variability of the ocean-surface winds and of the temperature anomalies on land may be related to the El Nino/La Nina oscillations. Such large temperature fluctuations over large areas, whatever the cause, can be regarded as noise in attempts to assess long-term trends in global temperature.

  11. Crop Production for Advanced Life Support Systems - Observations From the Kennedy Space Center Breadboard Project

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Sager, J. C.; Prince, R. P.; Knott, W. M.; Mackowiak, C. L.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Peterson, B. V.; Goins, G. D.

    2003-01-01

    The use of plants for bioregenerative life support for space missions was first studied by the US Air Force in the 1950s and 1960s. Extensive testing was also conducted from the 1960s through the 1980s by Russian researchers located at the Institute of Biophysics in Krasnoyarsk, Siberia, and the Institute for Biomedical Problems in Moscow. NASA initiated bioregenerative research in the 1960s (e.g., Hydrogenomonas) but this research did not include testing with plants until about 1980, with the start of the Controlled Ecological Life Support System (CELSS) Program. The NASA CELSS research was carried out at universities, private corporations, and NASA field centers, including Kennedy Space Center (KSC). The project at KSC began in 1985 and was called the CELSS Breadboard Project to indicate the capability for plugging in and testing various life support technologies; this name has since been dropped but bioregenerative testing at KSC has continued to the present under the NASA s Advanced Life Support (ALS) Program. A primary objective of the KSC testing was to conduct pre-integration tests with plants (crops) in a large, atmospherically closed test chamber called the Biomass Production Chamber (BPC). Test protocols for the BPC were based on observations and growing procedures developed by university investigators, as well as procedures developed in plant growth chamber studies at KSC. Growth chamber studies to support BPC testing focused on plant responses to different carbon dioxide (CO2) concentrations, different spectral qualities from various electric lamps, and nutrient film hydroponic culture techniques.

  12. Science Data Processing for the Advanced Microwave Scanning Radiometer: Earth Observing System

    NASA Technical Reports Server (NTRS)

    Goodman, H. Michael; Regner, Kathryn; Conover, Helen; Ashcroft, Peter; Wentz, Frank; Conway, Dawn; Lobl, Elena; Beaumont, Bruce; Hawkins, Lamar; Jones, Steve

    2004-01-01

    The National Aeronautics and Space Administration established the framework for the Science Investigator-led Processing Systems (SIPS) to enable the Earth science data products to be produced by personnel directly associated with the instrument science team and knowledgeable of the science algorithms. One of the first instantiations implemented for NASA was the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) SIPS. The AMSR-E SIPS is a decentralized, geographically distributed ground data processing system composed of two primary components located in California and Alabama. Initial science data processing is conducted at Remote Sensing Systems (RSS) in Santa Rosa, California. RSS ingests antenna temperature orbit data sets from JAXA and converts them to calibrated, resampled, geolocated brightness temperatures. The brightness temperatures are sent to the Global Hydrology and Climate Center in Huntsville, Alabama, which generates the geophysical science data products (e.g., water vapor, sea surface temperature, sea ice extent, etc.) suitable for climate research and applications usage. These science products are subsequently sent to the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado for archival and dissemination to the at-large science community. This paper describes the organization, coordination, and production techniques employed by the AMSR-E SIPS in implementing, automating and operating the distributed data processing system.

  13. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants

    PubMed Central

    Judd, Lesley A.; Jackson, Brian E.; Fonteno, William C.

    2015-01-01

    The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics) has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain. PMID:27135334

  14. Observations Regarding Use of Advanced CFD Analysis, Sensitivity Analysis, and Design Codes in MDO

    NASA Technical Reports Server (NTRS)

    Newman, Perry A.; Hou, Gene J. W.; Taylor, Arthur C., III

    1996-01-01

    Observations regarding the use of advanced computational fluid dynamics (CFD) analysis, sensitivity analysis (SA), and design codes in gradient-based multidisciplinary design optimization (MDO) reflect our perception of the interactions required of CFD and our experience in recent aerodynamic design optimization studies using CFD. Sample results from these latter studies are summarized for conventional optimization (analysis - SA codes) and simultaneous analysis and design optimization (design code) using both Euler and Navier-Stokes flow approximations. The amount of computational resources required for aerodynamic design using CFD via analysis - SA codes is greater than that required for design codes. Thus, an MDO formulation that utilizes the more efficient design codes where possible is desired. However, in the aerovehicle MDO problem, the various disciplines that are involved have different design points in the flight envelope; therefore, CFD analysis - SA codes are required at the aerodynamic 'off design' points. The suggested MDO formulation is a hybrid multilevel optimization procedure that consists of both multipoint CFD analysis - SA codes and multipoint CFD design codes that perform suboptimizations.

  15. Earth Observing System (EOS)/Advanced Microwave Sounding Unit-A (AMSU-A)

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is the twentieth monthly report for the Earth Observing System/Advanced Microwave Sounding Unit-A (EOS/AMSU-A), Contract NAS5-32314, and covers the period from 1 August 1994 through 31 August 1994. This period is the eighth month of the Implementation Phase which provides for the design, fabrication, assembly, and test of the first EOS/AMSU-A, the Protoflight Model. During this period the number one priority for the program continued to be the issuance of Requests for Quotations (RFQ) to suppliers and the procurement of the long-lead receiver components. Significant effort was also dedicated to preparation and conduct of internal design reviews and preparation for the PDR scheduled in September. An overview of the program status, including key events, action items, and documentation submittals, is provided in Section 2 of this report. The Program Manager's 'Priority Issues' are defined in Section 3. Section 4 through 7 provide detailed progress reports for the system engineering effort, each subsystem, performance assurance, and configuration/data management. Contractual matters are discussed in Section 8.

  16. Spectra: the last advance of T-FLaP technology for in continuous oceanographic observations

    NASA Astrophysics Data System (ADS)

    Marcelli, Marco; Piermattei, Viviana; Madonia, Alice; Mainardi, Umberto

    2015-04-01

    Ocean models have become increasingly useful as computing capabilities and in situ measurement systems have been improved. An operational observing and forecasting system of the ocean properties needs effective data collection programs for model data assimilation and satellite calibration. However, the development of observational networks is strongly limited by the advances of reliable, user-friendly and low cost technologies. These requirements cannot be achieved with current marine measurement technologies, which are too expensive for extensive utilization. For all these reasons in the last decades the use of low cost instrumentations from ships of opportunity (promoted within VOS and SOOP international research programmes), is gaining more and more attention. In order to reduce operative costs and to enhance spatial resolution of data, stand-alone systems provide continuous real-time information about the physical and biological states of the surface waters by moving ships. Following this philosophy, T-FLaP evolution leds to the development of a new low-cost mini ferrybox system, called Spectra, suitable for continuous in situ measures of temperature, conductivity (salinity and density), chlorophyll a and chromophoric dissolved organic matter (CDOM) fluorescence. The philosophy that inspired this instrument is therefore that of Ferrybox, but with miniaturization of components and a considerable reduction in costs. Spectra is composed by an electronic unit, dedicated to the data acquisition, transmission and storage, equipped with a GPS and a hydraulic unit where the measures occur. The measuring cell is a flow-through tubular cell where the water flows. The measuring cell has a modular structure. The design of the measuring cell has been studied in order to ensure that the sensors are in direct contact with the volume of water passing through the probe. In this work a detailed description of Spectra system is given. Moreover, the results of the application of

  17. Coherence-based land cover classification in forested areas of Chattisgarh, Central India, using environmental satellite--advanced synthetic aperture radar data

    NASA Astrophysics Data System (ADS)

    Nizalapur, Vyjayanthi; Madugundu, Rangaswamy; Jha, Chandra Shekhar

    2011-01-01

    In the present work, the potential of synthetic aperture radar (SAR) interferometric coherence in land cover classification is studied over forested areas of Bilaspur, Chattisgarh, India using Environmental Satellite--Advanced Synthetic Aperture Radar (ENVISAT-ASAR) C-band data. Single look complex (SLC) interferometric pair ASAR data of 24th September 2006 (SLC-1) and 29th October 2006 (SLC-2) covering the study area were acquired and processed to generate backscatter and interferometric coherence images. A false colored composite of coherence, backscatter difference, and mean backscatter was generated and subjected to maximum likelihood classification to delineate major land cover classes of the study area viz., water, barren, agriculture, moist deciduous forest, and sal mixed forests. Accuracy assessment of the classified map is carried out using kappa statistics. Results of the study suggested potential use of ENVISAT-ASAR C-band data in land cover classification of the study area with an overall classification accuracy of 82.5%, average producer's accuracy of 83.69%, and average user's accuracy of 81%. The present study gives a unique scope of SAR data application in land cover classification over the tropical deciduous forest systems of India, which is still waiting for its indigenous SAR system.

  18. Diagnosing the Local Land-Atmosphere Coupling (LoCo) in Models and Observations: A Study of Dry/Wet Extremes in the U. S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Santanello, J. A.; Peters-Lidard, C. D.; Kumar, S.; Dong, X.; Kennedy, A. D.

    2010-12-01

    Land-atmosphere interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed due to the complex interactions and feedbacks present across a range of scales. Further, uncoupled systems or experiments (e.g., the Project for Intercomparison of Land Parameterization Schemes, PILPS) may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land-atmosphere coupling (LoCo) is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during the summers of 2006/7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet extremes of this region, along with the sensitivity of PBL-LSM coupling to perturbations in soil moisture. As such, this methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which is serving as a testbed for LoCo experiments to evaluate coupling diagnostics within the community.

  19. Alaskan glaciers: Recent observations in respect to the earthquake-advance theory

    USGS Publications Warehouse

    Post, A.S.

    1965-01-01

    Preliminary aerial photographic studies indicate that the Alaskan earthquake produced some rockfalls but no significant snow and ice avalanches on glaciers. No rapid, short-lived glacier advances (surges) are conclusively associated with this earthquake. Recent evidence fails to support the earthquake-advance theory of Tarr and Martin.

  20. Application of Observed Precipitation in NCEP Global and Regional Data Assimilation Systems, Including Reanalysis and Land Data Assimilation

    NASA Astrophysics Data System (ADS)

    Mitchell, K. E.

    2006-12-01

    precipitation analyses by other institutions. Other global precipitation analyses produced by other methodologies are also used by EMC in certain applications, such as CPC's well-known satellite-IR based technique known as "GPI", and satellite-microwave based estimates from NESDIS or NASA. Finally, the presentation will cover the three assimilation methods used by EMC to assimilate precipitation data, including 1) 3D-VAR variational assimilation in NCEP's Global Data Assimilation System (GDAS), 2) direct insertion of precipitation-inferred vertical latent heating profiles in NCEP's N. American Data Assimilation System (NDAS) and its N. American Regional Reanalysis (NARR) counterpart, and 3) direct use of observed precipitation to drive the Noah land model component of NCEP's Global and N. American Land Data Assimilation Systems (GLDAS and NLDAS). In the applications of precipitation analyses in data assimilation at NCEP, the analyses are temporally disaggregated to hourly or less using time-weights calculated from A) either radar-based estimates or an analysis of hourly gauge-observations for the CONUS-domain daily precipitation analyses, or B) global model forecasts of 6-hourly precipitation (followed by linear interpolation to hourly or less) for the global CMAP precipitation analysis.

  1. Land usage attributed to corn ethanol production in the United States: sensitivity to technological advances in corn grain yield, ethanol conversion, and co-product utilization

    PubMed Central

    2014-01-01

    Background Although the system for producing yellow corn grain is well established in the US, its role among other biofeedstock alternatives to petroleum-based energy sources has to be balanced with its predominant purpose for food and feed as well as economics, land use, and environmental stewardship. We model land usage attributed to corn ethanol production in the US to evaluate the effects of anticipated technological change in corn grain production, ethanol processing, and livestock feeding through a multi-disciplinary approach. Seven scenarios are evaluated: four considering the impact of technological advances on corn grain production, two focused on improved efficiencies in ethanol processing, and one reflecting greater use of ethanol co-products (that is, distillers dried grains with solubles) in diets for dairy cattle, pigs, and poultry. For each scenario, land area attributed to corn ethanol production is estimated for three time horizons: 2011 (current), the time period at which the 15 billion gallon cap for corn ethanol as per the Renewable Fuel Standard is achieved, and 2026 (15 years out). Results Although 40.5% of corn grain was channeled to ethanol processing in 2011, only 25% of US corn acreage was attributable to ethanol when accounting for feed co-product utilization. By 2026, land area attributed to corn ethanol production is reduced to 11% to 19% depending on the corn grain yield level associated with the four corn production scenarios, considering oil replacement associated with the soybean meal substituted in livestock diets with distillers dried grains with solubles. Efficiencies in ethanol processing, although producing more ethanol per bushel of processed corn, result in less co-products and therefore less offset of corn acreage. Shifting the use of distillers dried grains with solubles in feed to dairy cattle, pigs, and poultry substantially reduces land area attributed to corn ethanol production. However, because distillers dried grains

  2. All-weather land surface skin temperatures from a combined analysis of microwave and infrared satellite observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The surface skin temperature (Ts) is a key parameter at the land-atmosphere interface. Upwelling longwave radiation directly epends upon Ts. Energy exchanges at the land-surface boundary are largely controlled by the difference between Ts and the surface air temperature, the air and the surface reac...

  3. Effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge: A Field observation and analysis

    USGS Publications Warehouse

    Zhang, Y.-K.; Schilling, K.E.

    2006-01-01

    The effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge were studied with water level measurements collected from two monitoring wells over a period of 122 days. The two wells were installed under similar conditions except that one was drilled on the east side of a creek which was covered with grass, and the other on the west side of the creek which was burned into a bare ground. Substantial differences in water level fluctuations were observed at these two wells. The water level in the east grass (EG) well was generally lower and had much less response to rainfall events than the west no-grass (WNG) well. Grass cover lowered the water table, reduced soil moisture through ET losses, and thus reduced groundwater recharge. The amount of ET by the grass estimated with a water table recession model decreased exponentially from 7.6 mm/day to zero as the water table declined from near the ground surface to 1.42 m below the ground surface in 33 days. More groundwater recharge was received on the WNG side than on the EG side following large rainfall events and by significant slow internal downward drainage which may last many days after rainfall. Because of the decreased ET and increased R, significantly more baseflow and chemical loads may be generated from a bare ground watershed compared to a vegetated watershed. ?? 2005 Elsevier Ltd All rights reserved.

  4. Land degradation in a semi-urban catchment in Burkina Faso: monitoring land use change and soil erosion with earth observations and field surveys

    NASA Astrophysics Data System (ADS)

    Angeluccetti, Irene; Coviello, Velio; Vezza, Paolo; Grimaldi, Stefania; Steffenino, Sara; Magloire Koussoubé, Alain

    2015-04-01

    Soil erosion is currently menacing the availability of arable land in various countries worldwide. In particular the countries located in the Sahel area of Sub-Saharan Africa are extremely prone to this type of environmental degradation. The same countries rely traditionally upon subsistence farming, which makes the population more vulnerable to environmental changes. The study here presented exploits remote sensed data for identifying the main degradation processes occurring in a small catchment of central Burkina Faso (i.e., Boulbi watershed). This catchment, approximately 100 square km large, is characterized by the presence of a 30 years old dam, whose reservoir feeds 80 ha of rice-fields. This produce contributes up to 13% of the regional rice production. Nonetheless other crops, along with rain-fed rice, are grown all across the Boulbi catchment during the rainy season. Both the increasing gully erosion and the urbanization of the capital city pushing from the North are significantly threatening the farming activities. By using aerial frames acquired with a 16 years' time interval (i.e., 1996, 2012), free satellite imagery, and field surveys, the base cartography of the investigated area was updated and the most active gullies were identified. Moreover a change detection analysis was performed on both artifacts and land use features. More than 200.000 square m of erosion areas and an increase of nearly 90% in built-up areas were detected. In addition, the importance of producing up-to-date base data was proven by the exploitation of the outcomes for the production of a catchment land and water management plan.

  5. The COSMOS Survey: Hubble Space Telescope Advanced Camera for Surveys Observations and Data Processing

    NASA Astrophysics Data System (ADS)

    Koekemoer, A. M.; Aussel, H.; Calzetti, D.; Capak, P.; Giavalisco, M.; Kneib, J.-P.; Leauthaud, A.; Le Fèvre, O.; McCracken, H. J.; Massey, R.; Mobasher, B.; Rhodes, J.; Scoville, N.; Shopbell, P. L.

    2007-09-01

    We describe the details of the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) observations of the COSMOS field, including the data calibration and processing procedures. We obtained a total of 583 orbits of HST ACS/WFC imaging in the F814W filter, covering a field that is 1.64 deg2 in area, the largest contiguous field ever imaged with HST. The median exposure depth across the field is 2028 s (one HST orbit), achieving a limiting point-source depth AB(F814W)=27.2 (5 σ). We also present details of the astrometric image registration and distortion removal and image combination using MultiDrizzle, motivating the choice of our final pixel scale (30 mas pixel-1), based on the requirements for weak-lensing science. The final set of images are publicly available through the archive sites at IPAC and STScI, along with further documentation on how they were produced. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 5-26555 also based on data collected at: the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan; the XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA; the European Southern Observatory under Large Program 175.A-0839, Chile; Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and the National Optical Astronomy Observatory, which are operated by AURA under cooperative agreement with the National Science Foundation; the National Radio Astronomy Observatory which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc; and the Canada-France-Hawaii Telescope (CFHT) with MegaPrime/MegaCam operated as a joint project by the CFHT Corporation, CEA/DAPNIA, the National

  6. Retrieval of the land surface-air temperature difference from high spatial resolution satellite observations over complex surfaces in the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Gao, Shiyang; Chen, Haishan; Yu, Jiahui; Tang, Qun

    2015-08-01

    The temperature difference between the surface and the air (dTsa) directly indicates the intensity and heat fluxes of land-atmosphere interaction. Considering the effects of surface characteristics and air condition on the surface temperature, using 1 km data from the MOD02 thermal infrared bands of the EOS/moderate-resolution imaging spectroradiometer (MODIS) on satellite Aqua, other MODIS products and temperatures observed from weather stations at 14:00 China standard time (CST), the study analyzes the relationships between dTsa and brightness temperature in the infrared atmospheric window band (Bt31 and Bt32), the water vapor band (Bt28), the atmospheric temperature band (Bt25), and the CO2 band (Bt34). A model estimating dTsa is built. The model coefficients are estimated for 96 stations representing 96 sets of surface and atmospheric conditions, and 71 sets of coefficients among them passing 90% confidence levels of estimating dTsa are selected as references. Combined with the probabilistic neural network (PNN) method and nine parameters reflecting surface characteristics in one season and month, the Tibetan Plateau surface is classified as 71 types with 71 sets of coefficients. PNN is certified an efficient classification method for multiple parameters and mass data. Based on PNN and estimated model, estimated dTsa shows 1.36°C root-mean-square error and a standard deviation of 0.74°C, and dTsa distribution exhibits all centers with peak value and valley value of European Centre for Medium-Range Weather Forecasts, MYD07, and simple regression model results, showing its superiority. The model is worthy of further exploration and application in an effort to advance the retrieval of surface energy fluxes from remote sensing.

  7. Assimilation of Satellite Remote Sensing Retrievals into Land Surface Models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For at least two decades, remote sensing observations have been used to define static model parameters and/or forcing inputs for a range of land surface models. However, recent advances in remote sensing theory have also enabled the satellite-based retrieval of dynamic land model states (e.g. leaf ...

  8. Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A): Instrumentation interface control document

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This Interface Control Document (ICD) defines the specific details of the complete accomodation information between the Earth Observing System (EOS) PM Spacecraft and the Advanced Microwave Sounding Unit (AMSU-A)Instrument. This is the first submittal of the ICN: it will be updated periodically throughout the life of the program. The next update is planned prior to Critical Design Review (CDR).

  9. Earth Observing System (EOS) Advanced Microwave Sounding Unit: A (EOS/AMSU-A) Firmware Version Description Document

    NASA Technical Reports Server (NTRS)

    Cisneros, A.

    1998-01-01

    This is the final submittal of the Earth Observing System/Advanced Microwave Sounding Unit-A Firmware Version Description Document. Its purpose is to provide a precise description of the particular version of the firmware being released. This description also defines the version of the requirements and design applicable to this version.

  10. Earth Observing System/Advanced Microwave SoundingUnit-A (EOS/AMSU-A): Acquisition activities plan

    NASA Technical Reports Server (NTRS)

    Schwantje, Robert

    1994-01-01

    This is the acquisition activities plan for the software to be used in the Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) system. This document is submitted in response to Contract NAS5-323 14 as CDRL 508. The procurement activities required to acquire software for the EOS/AMSU-A program are defined.

  11. Earth Observing System (EOS)/Advanced Microwave Sounding Unit-A (AMSU-A): Instrument logic diagrams

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This report contains all of the block diagrams and internal logic diagrams for the Earth Observation System Advanced Microwave Sounding Unit-A (AMSU-A). These diagrams show the signal inputs, outputs, and internal signal flow for the AMSU-A.

  12. Land Subsidence Detection in Agricultural Areas of Konya Closed Basin by PS-InSAR and GNSS Observations

    NASA Astrophysics Data System (ADS)

    Canaslan Comut, Fatma; Lazecky, Milan; Ustun, Aydin; Yalvack, Sefa

    2015-05-01

    The aim of this study is to determine and to monitor the areas affected by land subsidence caused by the decrease of groundwater, by using geodetic methods in Konya Closed Basin, Turkey. The GPS and InSAR techniques which complement each other perfectly will be used to deduce spatial deformations caused by the land subsidence. The land subsidence activity in the area of Küçükköy situated at the Konya Closed Basin (KCB) of the Central Anatolia Region in Turkey has been studied using the Stanford Method for Persistent Scatterers (StaMPS) InSAR technique. Significant movements of land subsidence ranging from mm to cm per year were detected with ENVISAT ASAR data between 2003 and 2010 above the city center. Results are also compared with GNSS measurements. Estimated deformation rate of KCKY GPS station is approximately - 2 cm/yr.

  13. Detecting ecosystem performance anomalies for land management in the upper colorado river basin using satellite observations, climate data, and ecosystem models

    USGS Publications Warehouse

    Gu, Y.; Wylie, B.K.

    2010-01-01

    This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005-2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using "percentage of bare soil" ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005-2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions. ?? 2010 by the authors.

  14. Detecting Ecosystem Performance Anomalies for Land Management in the Upper Colorado River Basin Using Satellite Observations, Climate Data, and Ecosystem Models

    USGS Publications Warehouse

    Gu, Yingxin; Wylie, Bruce K.

    2010-01-01

    This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005–2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using “percentage of bare soil” ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005–2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions.

  15. The contributions of precipitation and soil moisture observations to the skill of soil moisture estimates in a land data assimilation system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contributions of precipitation and soil moisture observations to soil moisture skill in a land data assimilation system are assessed. Relative to baseline estimates from the Modern Era Retrospective-analysis for Research and Applications (MERRA), the study investigates soil moisture skill derive...

  16. Evaluation of the ground heat flux simulated by a multi-layer land surface scheme using high-quality observations at grass land and bare soil

    NASA Astrophysics Data System (ADS)

    Schulz, Jan-Peter; Vogel, Gerd; Becker, Claudia; Kothe, Steffen; Ahrens, Bodo

    2015-04-01

    Two parameterisations for the dependence of the soil thermal conductivity on the soil water content are compared, using the multi-layer land surface scheme TERRA of the Consortium for Small-scale Modeling (COSMO) atmospheric model. The simulations were carried out in offline mode with identical atmospheric forcing data from the Meteorological Observatory Lindenberg of the German Meteorological Service (Deutscher Wetterdienst). The results show that the ground heat flux computed by the reference version of TERRA is systematically overestimated under dry conditions. In this version, the thermal conductivity does not depend on the simulated water content of the soil. Since the ground heat flux is part of the surface energy balance it affects the other components such as turbulent heat fluxes and surface temperature. An overestimation of the ground heat flux during daytime leads to an underestimation of the other surface fluxes and to a reduced surface warming, during afternoon and night this behaviour is reversed. The two formulations for soil thermal conductivity, presented by O. Johansen on the one hand and M. C. McCumber and R. A. Pielke on the other hand, both reduce the ground heat flux in TERRA under dry conditions, the former yielding good results while the latter is even leading to underestimations. In addition to this, the former is also applied in coupled mode in the climate version of the COSMO model, the COSMO-CLM, for Africa, resulting in improved diurnal cycles of near-surface temperature in dry regions. Furthermore, it is shown with the Lindenberg measurements that the soil temperature and hence the ground heat flux are particularly influenced by the effects of shading of the incoming solar radiation due to the vegetation cover, leading to a significantly reduced solar radiation at the sub-canopy land surface, even under a layer of grass. For future improvements of TERRA these effects should be represented.

  17. Joint IAMAS/IAHS symposium J1 on global monitoring and advanced observing techniques in the atmosphere and hydrosphere

    SciTech Connect

    Ohring, G. ); Aoki, T. ); Halpern, D. ); Henderson-Sellers, A. ); Charlock, T. ); Joseph, J. ); Labitzke, K. ); Raschke, E. ); Smith, W. )

    1994-04-01

    Seventy papers were presented at the two-and-a-half-day Symposium on Global Monitoring and Advanced Observing Techniques in the Atmosphere and Hydrosphere. The symposium was jointly organized by the International Association of Meteorology and Atmospheric Sciences (IAMAS) and the International Association of Hydrological Sciences (IAHS) and took place in Yokohama, Japan, 13-15 July 1993, as part of the IAMAS/IAHS Join Assembly. Global observing systems are receiving increased attention in connection with such problems as monitoring global climate change. The symposium included papers on observational requirements; measurement methodologies; descriptions of available datasets; results of analysis of observational data; plans for future observing systems, including the Global Climate Observing System (GCOS) and the Global Ocean Observing System (GOOS); and the programs and plans of the space agencies.

  18. Inter-annual and Intra-annual Variability in River Flow and Inundation in African River Systems: Results from a new pan-African Land-surface Model Validated against Earth Observations

    NASA Astrophysics Data System (ADS)

    Dadson, S. J.

    2014-12-01

    The role of surface-water flooding in controlling fluxes of water and carbon between the land and the atmosphere is increasingly recognized in studies of the Earth system. Simultaneous advances in remote earth observation and large-scale land-surface and hydrological modeling promise improvements in our ability to understand these linkages, and suggest that improvements in prediction of river flow and inundation extents may result. Here we present an analysis of newly-available observational estimates of surface water inundation obtained through satellite Earth observation with results from simulations produced by using the Joint UK Land Environment Simulator (JULES) land-surface model operating at 0.5 degree resolution over the African continent. The model was forced with meteorological input from the WATCH Forcing Data for the period 1981-2001 and sensitivity to various model configurations and parameter settings were tested. Both the PDM and TOPMODEL sub-grid scale runoff generation schemes were tested for parameter sensitivities, with the evaluation focussing on simulated river discharge in sub-catchments of the Congo, Nile, Niger, Orange, Okavango and Zambezi rivers. It was found that whilst the water balance in each of the catchments can be simulated with acceptable accuracy, the individual responses of each river vary between model configurations so that there is no single runoff parameterization scheme or parameter values that yields optimal results across all catchments. We trace these differences to the model's representation of sub-surface flow and make some suggestions to improve the performance of large-scale land-surface models for use in similar applications. Our findings also demonstrate links between episodes of extensive surface water flooding and large-scale climatic indices, although the pattern of correlations contains a level of spatial and temporal detail that warrants careful attention to the climatology of individual situations. These

  19. [Multi-Scale Convergence of Cold-Land Process Representation in Land-Surface Models, Microwave Remote Sensing, and Field Observations

    NASA Technical Reports Server (NTRS)

    Shi, Jiancheng

    2005-01-01

    The cryosphere is a major component of the hydrosphere and interacts significantly with the global climate system, the geosphere, and the biosphere. Measurement of the amount of water stored in the snow pack and forecasting the rate of melt are thus essential for managing water supply and flood control systems. Snow hydrologists are confronted with the dual problems of estimating both the quantity of water held by seasonal snow packs and time of snow melt. Monitoring these snow parameters is essential for one of the objectives of the Earth Science Enterprise-understanding of the global hydrologic cycle. Measuring spatially distributed snow properties, such as snow water equivalence (SWE) and wetness, from space is a key component for improvement of our understanding of coupled atmosphere-surface processes. Through the GWEC project, we have significantly advanced our understandings and improved modeling capabilities of the microwave signatures in response to snow and underground properties.

  20. Cold and dry processes in the Martian Arctic: Geomorphic observations at the Phoenix landing site and comparisons with terrestrial cold desert landforms

    NASA Astrophysics Data System (ADS)

    Levy, Joseph S.; Head, James W.; Marchant, David R.

    2009-11-01

    We analyze Surface Stereo Imager observations of rocks, sediments, and permafrost-related landforms in the vicinity of the Phoenix lander, comparing the imaged features to analogous examples of physical weathering and periglacial processes observed in the Antarctic Dry Valleys. Observations at the Phoenix landing site of pitted rocks, “puzzle rocks” undergoing in-situ breakdown, perched clasts, and thermal contraction crack polygon morphologies strikingly similar to terrestrial sublimation polygons, all strongly suggest that stable (non-churning) permafrost processes dominate the Phoenix landing site. Morphological evidence suggests that cold-desert processes, in the absence of wet active-layer cryoturbation, and largely driven by sublimation of buried ice (either pore ice, excess ice, or both) are shaping the landscape.

  1. Goals Set in the Land of the Living/Dying: A Longitudinal Study of Patients Living with Advanced Cancer

    ERIC Educational Resources Information Center

    Nissim, Rinat; Rennie, David; Fleming, Stephen; Hales, Sarah; Gagliese, Lucia; Rodin, Gary

    2012-01-01

    A longitudinal qualitative research study was undertaken to provide an understanding of a prolonged experience of advanced cancer, as seen through the eyes of dying individuals. Using a variant of the grounded theory method, the authors theoretically sampled, from outpatient clinics in a large comprehensive cancer treatment center, 27 patients…

  2. SimER: An advanced three-dimensional environmental risk assessment code for contaminated land and radioactive waste disposal applications

    SciTech Connect

    Kwong, S.; Small, J.; Tahar, B.

    2007-07-01

    SimER (Simulations of Environmental Risks) is a powerful performance assessment code developed to undertake assessments of both contaminated land and radioactive waste disposal. The code can undertake both deterministic and probabilistic calculations, and is fully compatible with all available best practice guidance and regulatory requirements. SimER represents the first time-dependent performance assessment code capable of providing a detailed representation of system evolution that is designed specifically to address issues found across UK nuclear sites. The code adopts flexible input language with build-in unit checking to model the whole system (i.e. near-field, geosphere and biosphere) in a single code thus avoiding the need for any time consuming data transfer and the often laborious interface between the different codes. This greatly speeds up the assessment process and has major quality assurance advantages. SimER thus provides a cost-effective tool for undertaking projects involving risk assessment from contaminated land assessments through to full post-closure safety cases and other work supporting key site endpoint decisions. A Windows version (v1.0) of the code was first released in June 2004. The code has subsequently been subject to further testing and development. In particular, Viewers have been developed to provide users with visual information to assist the development of SimER models, and output can now be produced in a format that can be used by the FieldView software to view the results and produce animation from the SimER calculations. More recently a Linux version of the code has been produced to extend coverage to the commonly used platform bases and offer an improved operating environment for probabilistic assessments. Results from the verification of the SimER code for a sample of test cases for both contaminated land and waste disposal applications are presented. (authors)

  3. Time series analysis of discolored seawater reflectance observed by Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) at Fukutoku-Okonaba submarine volcano, Japan

    NASA Astrophysics Data System (ADS)

    Urai, Minoru

    2014-01-01

    Monitoring submarine volcanoes is not an easy task compared to land volcanoes because they are covered by seawater and located in remote areas. Satellite remote sensing is a powerful tool for monitoring underwater volcanic activities such as discolored seawater, floating material and volcanic plumes. Discolored seawater is a good indicator of submarine volcanic activities. Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) made extensive observations from 2006 to 2011 of the Fukutoku-Okanoba submarine volcano, which is located 1300 km south of Tokyo, and is one of the most active submarine volcanoes in Japan. The high discolored seawater brightness coincides with relatively high activity of Fukutoku-Okanoba. No discolored seawater was observed for 6 months before the 2010 Fukutoku-Okanoba submarine eruption, meaning that Fukutoku-Okanoba was quiescent before the eruption. Both high brightness and apparent color change of discolored seawater derived from AVNIR-2 mean emergence of large amount of hot spring water, implying that the submarine volcano is highly active. This study demonstrates that satellite remote sensing is an effective tool for monitoring activities of inaccessible submarine volcanoes.

  4. Utilizing CLASIC observations and multiscale models to study the impact of improved Land surface representation on modeling cloud- convection

    SciTech Connect

    Niyogi, Devdutta S.

    2013-06-07

    The CLASIC experiment was conducted over the US southern great plains (SGP) in June 2007 with an objective to lead an enhanced understanding of the cumulus convection particularly as it relates to land surface conditions. This project was design to help assist with understanding the overall improvement of land atmosphere convection initiation representation of which is important for global and regional models. The study helped address one of the critical documented deficiency in the models central to the ARM objectives for cumulus convection initiation and particularly under summer time conditions. This project was guided by the scientific question building on the CLASIC theme questions: What is the effect of improved land surface representation on the ability of coupled models to simulate cumulus and convection initiation? The focus was on the US Southern Great Plains region. Since the CLASIC period was anomalously wet the strategy has been to use other periods and domains to develop the comparative assessment for the CLASIC data period, and to understand the mechanisms of the anomalous wet conditions on the tropical systems and convection over land. The data periods include the IHOP 2002 field experiment that was over roughly same domain as the CLASIC in the SGP, and some of the DOE funded Ameriflux datasets.

  5. Investigation of environmental change pattern in Japan. Observation of present state of agricultural land-use by analysing LANDSAT data

    NASA Technical Reports Server (NTRS)

    Maruyasu, T. (Principal Investigator); Hayashi, S.

    1977-01-01

    The author has identified the following significant results. Species and ages of grasses in pastures were identified, and soils were classified into several types using LANDSAT data. This data could be used in a wide area of cultivation, reclamation, or management planning on agricultural land.

  6. Observations on computational methodologies for use in large-scale, gradient-based, multidisciplinary design incorporating advanced CFD codes

    NASA Technical Reports Server (NTRS)

    Newman, P. A.; Hou, G. J.-W.; Jones, H. E.; Taylor, A. C., III; Korivi, V. M.

    1992-01-01

    How a combination of various computational methodologies could reduce the enormous computational costs envisioned in using advanced CFD codes in gradient based optimized multidisciplinary design (MdD) procedures is briefly outlined. Implications of these MdD requirements upon advanced CFD codes are somewhat different than those imposed by a single discipline design. A means for satisfying these MdD requirements for gradient information is presented which appear to permit: (1) some leeway in the CFD solution algorithms which can be used; (2) an extension to 3-D problems; and (3) straightforward use of other computational methodologies. Many of these observations have previously been discussed as possibilities for doing parts of the problem more efficiently; the contribution here is observing how they fit together in a mutually beneficial way.

  7. Pulse advancement and delay in an integrated-optical two-port ring-resonator circuit: direct experimental observations.

    PubMed

    Uranus, H P; Zhuang, L; Roeloffzen, C G H; Hoekstra, H J W M

    2007-09-01

    We report experimental observations of the negative-group-velocity (v(g)) phenomenon in an integrated-optical two-port ring-resonator circuit. We demonstrate that when the v(g) is negative, the (main) peak of output pulse appears earlier than the peak of a reference pulse, while for a positive v(g), the situation is the other way around. We observed that a pulse splitting phenomenon occurs in the neighborhood of the critical-coupling point. This pulse splitting limits the maximum achievable delay and advancement of a single device as well as facilitating a smooth transition from highly advanced to highly delayed pulse, and vice versa, across the critical-coupling point. PMID:17767325

  8. Use of advanced earth observation tools for the analyses of recent surface changes in Kalahari pans and Namibian coastal lagoons

    NASA Astrophysics Data System (ADS)

    Behling, Robert; Milewski, Robert; Chabrillat, Sabine; Völkel, Jörg

    2016-04-01

    The remote sensing analyses in the BMBF-SPACES collaborative project Geoarchives - Signals of Climate and Landscape Change preserved in Southern African Geoarchives - focuses on the use of recent and upcoming Earth Observation Tools for the study of climate and land use changes and its impact on the ecosystem. It aims at demonstrating the potential of recently available advanced optical remote sensing imagery with its extended spectral coverage and temporal resolution for the identification and mapping of sediment features associated with paleo-environmental archives as well as their recent dynamic. In this study we focus on the analyses of two ecosystems of major interest, the Kalahari salt pans as well as the lagoons at Namibia's west coast, that present high dynamic caused by combined hydrological and surface processes linked to climatic events. Multitemporal remote sensing techniques allow us to derive the recent surface dynamic of the salt pans and also provide opportunities to get a detailed understanding of the spatiotemporal development of the coastal lagoons. Furthermore spaceborne hyperspectral analysis can give insight to the current surface mineralogy of the salt pans on a physical basis and provide the intra pan distribution of evaporites. The soils and sediments of the Kalahari salt pans such as the Omongwa pan are a potentially significant storage of global carbon and also function as an important terrestrial climate archive. Thus far the surface distribution of evaporites have been only assessed mono-temporally and on a coarse regional scale, but the dynamic of the salt pans, especially the formation of evaporites, is still uncertain and poorly understood. For the salt pan analyses a change detection is applied using the Iterative-reweighted Multivariate Alteration Detection (IR-MAD) method to identify and investigate surface changes based on a Landsat time-series covering the period 1984-2015. Furthermore the current spatial distribution of

  9. The impacts of precipitating hydrometeors radiative effects on land surface temperature in contemporary GCMs using satellite observations

    NASA Astrophysics Data System (ADS)

    Li, J.-L. F.; Lee, Wei-Liang; Yu, Jia-Yuh; Hulley, Glynn; Fetzer, Eric; Chen, Yi-Chun; Wang, Yi-Hui

    2016-01-01

    An accurate representation of the land surface temperature (LST) climatology of the coupled land-atmosphere system has strong implications for the reliability of projected land surface processes and their variability inferred by the global climate models (GCMs) contributed to the Intergovernmental Panel on Climate Change CMIP5. We have identified a substantial underestimation of the total ice water path and biases of surface radiation budget commonly seen in the CMIP models which are highly correlated to the biases of LST over land. One of the potential causes of the CMIP model biases is the missing representation of large frozen precipitating hydrometeors and their radiative effects (i.e., snow) in all CMIP3 and most CMIP5 models. We examine the impacts of snow on the radiation, all-sky and clear-sky LST, and air-land heat fluxes to explore the implications to the common biases in CMIP models by performing sensitivity experiments with and without snow radiation effects using the National Center for Atmospheric Research Community Earth System Model version 1. It is found that an exclusion of the snow radiative effects the CESM1 generates the LST biases (up to 2-3 K) in the midlatitude and high latitude, in particular, in December, January, and February (DJF). All-sky and clear-sky LST in model simulations are found to be too cold and are mainly due to underestimated downward surface (longwave) LW radiation in DJF, which is consistent with those in CMIP models. The correlation between the changes of the LST and downward surface LW radiation is very high both in summer and winter seasons.

  10. Runoff production in a small agricultural catchment in Lao PDR: influence of slope, land-use and observation scale

    NASA Astrophysics Data System (ADS)

    Patin, J.; Ribolzi, O.; Mugler, C.; Valentin, C.; Mouche, E.

    2010-12-01

    After years of traditional slash and burn cultures, the Houay Pano catchment is now under high land pressures due to population resettling and environmental preservation policies. This evolution leads to rapid land-use changes in the uplands, such as fallow time reductions and growing of cash crops as teaks or banana. The catchment is located in the Luang Prabang province, in the north of Lao PDR and was selected in late 1998 as a benchmark site for the Managing Soil Erosion Consortium (MSEC). It is a small (60ha) agricultural catchment representative of the rural mountainous South East Asia : it exhibits steep cultivated slopes (from 2% to more than 110%) under a wet-dry monsoon climate. To understand the partition between runoff and infiltration, data from runoff on 20 plot experiments (1m2) under natural rainfall and with representative slopes and land uses is collected from 2003 to 2009. A simulated rainfall experiment was conducted in 2002 on bare soil plots (1m2) with different antecedent cultures. We investigate the role of crust, slope and land-use on runoff production at different scales. A model accounting for small scale variability is applied to compute the time and space variations of soil infiltrability at the plot scale (1m2) and sub-catchment scale (0.6ha). From the hypothesis of exponentially distributed infiltrabilities at the centimeter scale, we found that infiltration is log-normaly distributed over time for a given land use. The median infiltrability vary from 10mm/h under teak cultures to 150mm/h on plots with fallow. Variations along a year are tribute to many meteorological and human factors.

  11. Earth Observing System (EOS)/Advanced Microwave Sounding Unit-A (AMSU-A): Calibration management plan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is the Calibration Management Plan for the Earth Observing System/Advanced Microwave Sounding Unit-A (AMSU-A). The plan defines calibration requirements, calibration equipment, and calibration methods for the AMSU-A, a 15 channel passive microwave radiometer that will be used for measuring global atmospheric temperature profiles from the EOS polar orbiting observatory. The AMSU-A system will also provide data to verify and augment that of the Atmospheric Infrared Sounder.

  12. Land use/cover classification of small areas by conventional digital camcorder imagery: A comparative performance of traditional and advanced methods

    NASA Astrophysics Data System (ADS)

    Sim, C. K.; Lim, H. S.; Mat Jafri, M. Z.; Abdullah, K.

    2013-05-01

    This study aims to investigate the performance of digital camcorder datasets for land cover classification. The chosen study area was the Universiti Sains Malaysia campus in Penang, Peninsular Malaysia. We encountered difficulties in obtaining cloud-free scenes because Malaysia is an equatorial region. This problem can be overcome by using airborne images. Digital images were taken from a low-altitude light aircraft (Cessna 172Q) at an average altitude of 2.44 km above sea level. The color image was separated into three bands (i.e., red, green, and blue) for multispectral analysis. We compared the performance of traditional methods (i.e., minimum distance and maximum likelihood) and advanced methods (i.e., frequency-based contextual and neural network (NN) techniques). The classified land cover map was geometrically corrected to provide a geocode map. This study presents preliminary findings vis-à-vis the potential application of an ordinary digital camcorder in local urban studies. The NN classifier produced the best result among the tested methods. A high degree of accuracy was achieved by the NN technique.

  13. Comparison of Satellite-Derived TOA Shortwave Clear-Sky Fluxes to Estimates from GCM Simulations Constrained by Satellite Observations of Land Surface Characteristics

    NASA Technical Reports Server (NTRS)

    Anantharaj, Valentine G.; Nair, Udaysankar S.; Lawrence, Peter; Chase, Thomas N.; Christopher, Sundar; Jones, Thomas

    2010-01-01

    Clear-sky, upwelling shortwave flux at the top of the atmosphere (S(sub TOA raised arrow)), simulated using the atmospheric and land model components of the Community Climate System Model 3 (CCSM3), is compared to corresponding observational estimates from the Clouds and Earth's Radiant Energy System (CERES) sensor. Improvements resulting from the use of land surface albedo derived from Moderate Resolution Imaging Spectroradiometer (MODIS) to constrain the simulations are also examined. Compared to CERES observations, CCSM3 overestimates global, annual averaged S(sub TOA raised arrow) over both land and oceans. However, regionally, CCSM3 overestimates S(sub TOA raised arrow) over some land and ocean areas while underestimating it over other sites. CCSM3 underestimates S(sub TOA raised arrow) over the Saharan and Arabian Deserts and substantial differences exist between CERES observations and CCSM3 over agricultural areas. Over selected sites, after using groundbased observations to remove systematic biases that exist in CCSM computation of S(sub TOA raised arrow), it is found that use of MODIS albedo improves the simulation of S(sub TOA raised arrow). Inability of coarse resolution CCSM3 simulation to resolve spatial heterogeneity of snowfall over high altitude sites such as the Tibetan Plateau causes overestimation of S(sub TOA raised arrow) in these areas. Discrepancies also exist in the simulation of S(sub TOA raised arrow) over ocean areas as CCSM3 does not account for the effect of wind speed on ocean surface albedo. This study shows that the radiative energy budget at the TOA is improved through the use of MODIS albedo in Global Climate Models.

  14. Preliminary design of land displacement-optical fiber sensor and analysis of observation during laboratory and field test

    NASA Astrophysics Data System (ADS)

    Bayuwati, Dwi; Waluyo, Tomi B.; Widiyatmoko, Bambang

    2015-01-01

    An optical fiber optic sensor for detecting land displacement is discussed in this paper. The sensor system consists of a laser at wavelength 1.3 um, optical fiber coupler, optical fiber as sensor and light transmitting media, PIN photodiodedetector system, data logger and personal computer. Sensor was made from a curved optical fiber with diameter 35 mm, which will be changed into a heart-shape fiber if it is pulled. The heart-shape fiber sensor is the modification of the earlier displacement fiber sensor model which was in an ellipse form. Light to and from the optical fiber sensor was transmitted into a length of a multi core, single mode optical fiber cable. The scheme of the optical displacement sensor system has been described here. Characterization in the laboratory has been done by applying a series of pulling mechanism, on the heart-shape fiber sensor; which represents the land displacement process. Characterization in the field was carried out by mounting the sensor system on a scaled-down model of a land slope and artificially reproducing the landslide process using a steady-flow of artificial rainfall as the trigger. The voltage sensor output was recorded during the artificial landslide process. The displacement occurence can be indicated from the declining of the sensor signal received by the detector while the reference signal is steady. Characterization in the laboratory resulted in the performance of the optical fiber land displacement, namely, sensitivity 0.027(mV/mV)/mm, resolution 0.37 mm and measurement range 30 mm; compared with earlier optical fiber sensor performance with similar sensitivity and resolution which works only in 8 mm displacement range. Based on the experiment of landslides simulation in the field, we can define a critical condition in the real situation before landslides occurence to take any measures to prevent more casualties and losses.

  15. Contemporary changes of water resources, water and land use in Central Asia based on observations and modeling.

    NASA Astrophysics Data System (ADS)

    Shiklomanov, A. I.; Prousevitch, A.; Sokolik, I. N.; Lammers, R. B.

    2015-12-01

    Water is a key agent in Central Asia ultimately determining human well-being, food security, and economic development. There are complex interplays among the natural and anthropogenic drivers effecting the regional hydrological processes and water availability. Analysis of the data combined from regional censuses and remote sensing shows a decline in areas of arable and irrigated lands and a significant decrease in availability of arable and irrigated lands per capita across all Central Asian countries since the middle of 1990thas the result of post-Soviet transformation processes. This change could lead to considerable deterioration in food security and human system sustainability. The change of political situation in the region has also resulted in the escalated problems of water demand between countries in international river basins. We applied the University of New Hampshire - Water Balance Model - Transport from Anthropogenic and Natural Systems (WBM-TrANS) to understand the consequences of changes in climate, water and land use on regional hydrological processes and water availability. The model accounts for sub-pixel land cover types, glacier and snow-pack accumulation/melt across sub-pixel elevation bands, anthropogenic water use (e.g. domestic and industrial consumption, and irrigation for most of existing crop types), hydro-infrastructure for inter-basin water transfer and reservoir/dam regulations. A suite of historical climate re-analysis and temporal extrapolation of MIRCA-2000 crop structure datasets has been used in WBM-TrANS for this project. A preliminary analysis of the model simulations over the last 30 years has shown significant spatial and temporal changes in hydrology and water availability for crops and human across the region due to climatic and anthropogenic causes. We found that regional water availability is mostly impacted by changes in extents and efficiency of crop filed irrigation, especially in highly arid areas of Central Asia

  16. Evaluating runoff simulations from the Community Land Model 4.0 using observations from flux towers and a mountainous watershed

    SciTech Connect

    Li, Hongyi; Huang, Maoyi; Wigmosta, Mark S.; Ke, Yinghai; Coleman, Andre M.; Leung, Lai-Yung R.; Wang, Aihui; Ricciuto, Daniel M.

    2011-12-24

    Previous studies using the Community Land Model (CLM) focused on simulating landatmosphere interactions and water balance at continental to global scales, with limited attention paid to its capability for hydrologic simulations at watershed or regional scales. This study evaluates the performance of CLM 4.0 (CLM4) for hydrologic simulations, and explores possible directions of improvement. Specifically, it is found that CLM4 tends to produce unrealistically large temporal variation of runoff for applications at a mountainous catchment in the Northwest United States where subsurface runoff is dominant, as well as at a few flux tower sites. We show that runoff simulations from CLM4 can be improved by: (1) increasing spatial resolution of the land surface representations; (2) calibrating parameter values; (3) replacing the subsurface formulation with a more general nonlinear function; (4) implementing the runoff generation schemes from the Variability Infiltration Capacity (VIC) model. This study also highlights the importance of evaluating both the energy and water fluxes application of land surface models across multiple scales.

  17. Assimilation of satellite observed brightness temperature and terrestrial water storage into the Catchment land surface model for improved soil moisture estimation

    NASA Astrophysics Data System (ADS)

    Girotto, M.; De Lannoy, G. J. M.; Reichle, R. H.; Rodell, M.

    2014-12-01

    Root zone soil moisture (0-1m) is an important variable for hydrological and weather forecast models. Its prediction accuracy depends on a good initialization of soil moisture because it regulates the energy and mass balance exchange between land surface and atmosphere. Observations from recent (or near future) soil moisture missions (e.g. SMOS/SMAP) have been (or will be) used in innovative studies to provide high spatial (i.e. 40 km) and temporal resolution (i.e. 3-days) soil moisture estimates from brightness temperature observations. However, these missions are only sensitive to near-surface soil moisture (0-5 cm). In contrast with other routinely available global remote sensing measurements, the Gravity Recovery and Climate Experiment (GRACE) mission provides accurate measurements of the entire vertically integrated terrestrial water storage (TWS) column. GRACE is characterized by low spatial (i.e. 400 km) and temporal (i.e. monthly) resolutions, therefore it requires disaggregation to higher spatial and temporal scales. In this work we have investigated the potential for using TWS and brightness temperature observations to improve root zone soil moisture. We have assimilated GRACE and SMOS observations into the Catchment land surface model, using the NASA Goddard Earth Observing System, version 5 (GEOS-5) land surface data assimilation system. The ensemble-based assimilation scheme is used to disaggregate the GRACE observations in space and time (from observation to model resolution scales), and also to vertically decompose the observations into individual land surface moisture components (i.e.: groundwater, surface and root zone soil moisture). Model estimates with and without observations assimilation are compared against independent measurements of groundwater and soil moisture over the Continental U.S. Results suggest that the joint assimilation of GRACE and SMOS data has the potential to improve soil moisture estimates. However, the performance of the

  18. Recent Advances on INSAR Temporal Decorrelation: Theory and Observations Using UAVSAR

    NASA Technical Reports Server (NTRS)

    Lavalle, M.; Hensley, S.; Simard, M.

    2011-01-01

    We review our recent advances in understanding the role of temporal decorrelation in SAR interferometry and polarimetric SAR interferometry. We developed a physical model of temporal decorrelation based on Gaussian-statistic motion that varies along the vertical direction in forest canopies. Temporal decorrelation depends on structural parameters such as forest height, is sensitive to polarization and affects coherence amplitude and phase. A model of temporal-volume decorrelation valid for arbitrary spatial baseline is discussed. We tested the inversion of this model to estimate forest height from model simulations supported by JPL/UAVSAR data and lidar LVIS data. We found a general good agreement between forest height estimated from radar data and forest height estimated from lidar data.

  19. Preliminary validation of Albedo, FAPAR and LAI Essential Climate Variables products derived from PROBA-V observations in the Copernicus Global Land Service

    NASA Astrophysics Data System (ADS)

    Camacho, Fernando; Sanchez, Jorge; Lacaze, Roselyne; Smets, Bruno

    2015-04-01

    From 1st January 2013, the Copernicus Global Land Service is operational, providing in near real time a set of biophysical variables over the globe, including Surface Albedo (SA), Leaf Area Index (LAI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) Essential Climate Variables among other variables such as the Fraction of Vegetation Cover (FCover) are delivered at 1 km resolution and 10-days frequency. These ECVs are also key inputs for land surface applications such as agriculture monitoring, yield estimate, food security, environmental monitoring (e.g. desertification, drought). The first version of these Copernicus Global Land products were based on SPOT/VGT observations (1999-2004). The continuity of the production is currently based on PROBA-V 1 km observations, and the evolution of the services will provide enhanced spatial resolution (333m). This study presents the preliminary validation results of PROBA-V Albedo, FAPAR, LAI and FCover 1 km products, focused on the consistency with SPOT/VGT GEOV1 products during the overlap period (November 2013 - May 2014) and including intercomparison with MODIS C5 equivalent products. The procedure follows as much as possible guidelines and metrics defined by the Land Product Validation (LPV) group of the Committee on Earth Observation Satellite (CEOS) for the validation of satellite-derived land products and propose additional metrics to quantify spatial and temporal consistency among the several products. Several criteria of performance were evaluated including product completeness, spatial consistency, temporal consistency, inter-annual precision and accuracy. Inter-comparison with reference satellite products (SPOT/VGT GEOV1 and MODIS C5) are presented over a network of sites (BELMANIP-2). The accuracy of PROBA-V LAI and FAPAR products was evaluated against a number of agricultural sites using the ImagineS database, whereas for Albedo few homogeneous sites with available ground data were

  20. Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

    2012-01-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters

  1. Recent Observational Advances in our Understanding of Magnetic Reconnection in Earth's Magnetosphere

    NASA Astrophysics Data System (ADS)

    Angelopoulos, V.

    2014-12-01

    The availability of multi-point observations through the ion diffusion region has provided a wealth of information on the workings of magnetic reconnection at the dayside magnetopause and at the nightside plasma sheet. Ion inertia and finite gyroradius result in clear Hall effects on ion inertial length scales that have been observed by single and multi-point spacecraft resulting in a fairly detailed understanding of that physics. The role of Hall dynamics on establishing the reconnection rate, and the outflow conditions is well understood. Electron violation of the frozen-in condition is much more subtle and rarely observed at the X-point; indirect evidence has been more frequently observed in parallel electric fields. The waves responsible for this violation and for resultant energy conversion are at the forefront of observational studies. The contraction of islands centered at multiple O-points could provide for rapid energy conversion. However, observations of in vivo FTEs at the dayside and classical plasmoids at the nightside, are rare even near the expected most probable location of reconnection. Rather, asymmetric proto-plasmoids and dipolarization (a.k.a reconnection) fronts at the nightside signify distinctly different evolution of the reconnection geometry from that of X and O points. Operating within meso-scale (1-3Re) flows the inherently kinetic (at electron inertial scales embeded in ion inertial scale current systems) processes at such fronts play a significant role in the dynamics and drive global magnetospheric energy conversion and flux transport. Recent studies suggest that the entire magnetosphere is, in fact, connected front-to-back by reconnection pulses resulting in meso-scale flows. The upcoming Heliophysics System Observatory, motivated by the launch of MMS and the coordinated observations of THEMIS, ARTEMIS, Van Allen probes and other space and ground assets will answer key questions on this subject locally, regionally and globally.

  2. Advancing in situ modeling of ICMEs: New techniques for new observations

    NASA Astrophysics Data System (ADS)

    Mulligan, T.; Reinard, Alysha A.; Lynch, Benjamin J.

    2013-04-01

    It is generally known that multispacecraft observations of interplanetary coronal mass ejections (ICMEs) are more likely to reveal their three-dimensional structure than single-spacecraft observations. The launch of STEREO in October 2006 has greatly increased the number of multipoint ICME studies, but the field is still in its infancy. To date, many studies still use flux rope models that rely on single track observations through a vast, multifaceted structure, which oversimplifies the problem and hinders interpretation of the large-scale geometry. This oversimplification is especially problematic for multispacecraft ICME observations in which only one spacecraft observes a flux rope structure. To tackle these complex problems, we describe two new techniques and combine them to analyze two ICMEs observed at the twin STEREO spacecraft on 22-23 May 2007, when the spacecraft were separated by ˜ 9∘. We find a combination of non-force-free flux rope multispacecraft modeling, together with a new non-flux rope ICME plasma flow deflection model, better constrains the large-scale structure of these ICMEs. We also introduce a new spatial mapping technique that allows us to put multispacecraft observations and the new ICME model results in context with the convecting solar wind. What is distinctly different about this analysis is that it reveals aspects of ICME geometry and dynamics in a far more visually intuitive way than previously accomplished. In the case of the 22-23 May ICMEs, the analysis facilitates a more physical understanding of ICME large-scale structure, the location and geometry of flux rope substructures within these ICMEs, and their dynamic interaction with the ambient solar wind.

  3. Review: advances in in situ and satellite phenological observations in Japan.

    PubMed

    Nagai, Shin; Nasahara, Kenlo Nishida; Inoue, Tomoharu; Saitoh, Taku M; Suzuki, Rikie

    2016-04-01

    To accurately evaluate the responses of spatial and temporal variation of ecosystem functioning (evapotranspiration and photosynthesis) and services (regulating and cultural services) to the rapid changes caused by global warming, we depend on long-term, continuous, near-surface, and satellite remote sensing of phenology over wide areas. Here, we review such phenological studies in Japan and discuss our current knowledge, problems, and future developments. In contrast with North America and Europe, Japan has been able to evaluate plant phenology along vertical and horizontal gradients within a narrow area because of the country's high topographic relief. Phenological observation networks that support scientific studies and outreach activities have used near-surface tools such as digital cameras and spectral radiometers. Differences in phenology among ecosystems and tree species have been detected by analyzing the seasonal variation of red, green, and blue digital numbers (RGB values) extracted from phenological images, as well as spectral reflectance and vegetation indices. The relationships between seasonal variations in RGB-derived indices or spectral characteristics and the ecological and CO2 flux measurement data have been well validated. In contrast, insufficient satellite remote-sensing observations have been conducted because of the coarse spatial resolution of previous datasets, which could not detect the heterogeneous plant phenology that results from Japan's complex topography and vegetation. To improve Japanese phenological observations, multidisciplinary analysis and evaluation will be needed to link traditional phenological observations with "index trees," near-surface and satellite remote-sensing observations, "citizen science" (observations by citizens), and results published on the Internet. PMID:26307639

  4. Review: advances in in situ and satellite phenological observations in Japan

    NASA Astrophysics Data System (ADS)

    Nagai, Shin; Nasahara, Kenlo Nishida; Inoue, Tomoharu; Saitoh, Taku M.; Suzuki, Rikie

    2016-04-01

    To accurately evaluate the responses of spatial and temporal variation of ecosystem functioning (evapotranspiration and photosynthesis) and services (regulating and cultural services) to the rapid changes caused by global warming, we depend on long-term, continuous, near-surface, and satellite remote sensing of phenology over wide areas. Here, we review such phenological studies in Japan and discuss our current knowledge, problems, and future developments. In contrast with North America and Europe, Japan has been able to evaluate plant phenology along vertical and horizontal gradients within a narrow area because of the country's high topographic relief. Phenological observation networks that support scientific studies and outreach activities have used near-surface tools such as digital cameras and spectral radiometers. Differences in phenology among ecosystems and tree species have been detected by analyzing the seasonal variation of red, green, and blue digital numbers (RGB values) extracted from phenological images, as well as spectral reflectance and vegetation indices. The relationships between seasonal variations in RGB-derived indices or spectral characteristics and the ecological and CO2 flux measurement data have been well validated. In contrast, insufficient satellite remote-sensing observations have been conducted because of the coarse spatial resolution of previous datasets, which could not detect the heterogeneous plant phenology that results from Japan's complex topography and vegetation. To improve Japanese phenological observations, multidisciplinary analysis and evaluation will be needed to link traditional phenological observations with "index trees," near-surface and satellite remote-sensing observations, "citizen science" (observations by citizens), and results published on the Internet.

  5. Using novel Earth observation products to characterise wetland extend and methand dynamics in the Jules Land surface model: the ESA ALANIS-Methane Project

    NASA Astrophysics Data System (ADS)

    Hayman, G.; Clark, D.; Blyth, E.; Bartsch, A.; Paulik, C.; Schlaffer, S.; Reschke, J.; Prigent, C.; Aires, F.; Buchwitz, M.; Schneising, O.; Burrows, J.; O'Connor, F.; Gedney, N.

    2012-04-01

    The role of wetlands in the global methane cycle continues to be the subject of much current interest [1-3]. Wetlands are generally accepted as being the largest, but least well quantified, single source of methane (CH4), with emission estimates ranging from 105-278 Tg yr-1 [4]. Although the emissions of methane from the wetlands and lakes of the boreal region are smaller than those from tropical wetlands, the size and remoteness of the boreal region pose a significant challenge to the quantification of both terrestrial ecosystem processes and their feedbacks to regional and global climate. Earth Observation (EO) data have become an important tool for characterizing the main processes and estimating key variables governing the land-atmosphere interface. To that end, the European Space Agency (ESA) initiated the Atmosphere-LANd Interactions Study (ALANIS), in collaboration with the Integrated Land Ecosystem-Atmosphere Processes Study (iLEAPS). One of the three ALANIS themes is investigating wetland dynamics and methane emissions (denoted ALANIS methane, www.alanis-methane.info). The ALANIS methane project has a focus on the boreal Eurasia region. There are two main goals: to produce a suite of relevant datasets derived from Earth Observation (EO): a regional wetland extent dynamics product characterizing spatial changes of inundated areas over time at low spatial resolution; a local wetland extent dynamics product characterizing spatial changes of lake and wetland surface over time at high/medium spatial resolution; a snowmelt onset/duration/end product suitable for determining when methane emissions from wetlands restart after the winter season; a freeze onset product suitable for determining when lake/wetland methane emissions stop after the summer season; and, atmospheric column CH4 concentrations. to use these (and other) EO products to evaluate and improve the Joint UK Land Environment Simulator (JULES, http://www.jchmr.org/jules), a state-of-the-art land

  6. Earth observing data and methods for advancing water harvesting technologies in the semi-arid rain-fed environments of India

    USGS Publications Warehouse

    Sharma, C.; Thenkabail, P.; Sharma, R. R.

    2011-01-01

    The paper develops approaches and methods of modeling and mapping land and water productivity of rain-fed crops in semi-arid environments of India using hyperspectral, hyperspatial, and advanced multispectral remote sensing data and linking the same to field-plot data and climate station data. The overarching goal is to provide information to advance water harvesting technologies in the agricultural croplands of the semi-arid environments of India by conducting research in a representative pilot site in Jodhpur, Rajasthan, India. ?? 2011 IEEE.

  7. Advancing Variable Star Astronomy: The Centennial History of the American Association of Variable Star Observers

    NASA Astrophysics Data System (ADS)

    Williams, Thomas R.; Saladyga, Michael

    2011-05-01

    Preface; Part I. Pioneers in Variable Star Astronomy Prior to 1909: 1. The emergence of variable star astronomy - a need for observations; 2. A need for observers; Part II. The Founding of the AAVSO - The William Tyler Olcott Era: 3. The amateur's amateur; 4. Amateurs in the service of science; Part III. The Leon Campbell Era: 5. Leon Campbell to the rescue; 6. Formalizing relationships; 7. The Pickering Memorial Endowment; 8. Fading of the Old Guard; 9. Growing pains and distractions; Part IV. The Service Bureau - The Margaret Mayall Era: 10. Learning about independence; 11. Eviction from Harvard College Observatory; 12. Actions and reactions; 13. In search of a home; 14. Survival on Brattle Street; 15. AAVSO achievements; 16. Breathing room on Concord Avenue; Part V. Analysis and Science: The Janet Mattei Era: 17. The growth of a director; 18. Learning the ropes the hard way; 19. Managing with renewed confidence; 20. Expanding the scientific charter; Part VI. Accelerating Observational Science - The Arne Henden Era: 21. Bridging the gap; 22. Accelerating the science - the Henden era begins; Epilogue; Appendices; Index.

  8. Geotectonic modeling of lithosphere dynamics and deformation: advances and challenges (inspired by geological observations)

    NASA Astrophysics Data System (ADS)

    Burov, Evgueni

    2014-05-01

    Thermo-mechanical numerical modeling becomes a universal tool for studying short- and long-term lithosphere processes, validating and verifying geodynamic and geological concepts and putting stronger constraints on the observational data. State-of-the-art models are focused on most complete integration of geoscientific methods and geological observations and account for complex thermo-rheological and mineralogical structure of the lithosphere, implement high resolution calculations allowing for direct match of their outputs with the geological and geophysical observations. Challenges of these models are vast including understanding of the behavior of complex geological systems and processes, parameterization of rheological parameters and other rock properties for geological conditions, not forgetting a large number of future methodological breakthroughs such as the development of ultra-high resolution 3D models coupled with thermodynamic processes, fluid circulation and surface processes. We here discuss both geological and geodynamic applications of the models, their principals, and major results of regional modeling studies focused on rifting, convergent and transform plate boundaries and mantle-lithosphere interactions.

  9. Advanced dynamical models for very well observed asteroids : perturbations from small bodies, relativity, non - gravitational effects.

    NASA Astrophysics Data System (ADS)

    Bernardi, Fabrizio; Farnocchia, Davide; Milani, Andrea

    2012-08-01

    The availability of radar data and high precision optical observations has increased the number of objects with a very well constrained orbit, especially for those objects with a long observed arc. In these cases, the uncertainty of orbital predictions is often dominated by the inaccuracy of the dynamical model. However, the motion of small solar system bodies poses a serious challenge in modeling their dynamics. In particular, for those objects with a chaotic motion small differences in the model are amplified with propagation. Thus, we need to take into account small perturbations too, especially for long - term prediction. An improved dynamical model is relevant in several applications such as assessing the risk of an impact between an asteroid and the Earth. The N - body model describing the motion of a small solar system body includes the Newtonian attraction of the planets. The contribution o f other perturbing bodies has to be taken into account. We propose to include the Moon, two dwarf planets (Ceres and Pluto) and fifteen asteroids (Pallas, Vesta, Juno, Metis, Hygiea, Eunomia, Psyche, Amphitrite, Euphrosyne, Europa, Cybele, Sylvia, Davida, Herculina, Interamnia). The next step is the introduction of the relativity terms due to both the Sun and the planets . Despite their small magnitude, planetary relativistic terms turn out to be relevant for objects experiencing close approaches with a planet. Finally, we discuss non - gravitational effects such as solar radiation pressure and the Yarkovsky effect. In particular, the latter acts as a tiny but secular semimajor axis drift that may decisively drive long - term predictions. These non - gravitational effects are difficult to model as they depend on object ’ s physical properties that are typically unknown. However, a very well observed object can have an orbit precise enough to allow the determination of the parameters defining a non - gravitational perturbation and thus the modeling of the corresponding

  10. Recent advances in satellite observations of solar variability and global atmospheric ozone

    NASA Technical Reports Server (NTRS)

    Heath, D. F.

    1974-01-01

    The launch of Nimbus 4 in April 1974 has made possible simultaneous measurements of the ultraviolet solar irradiance and the global distribution of atmospheric ozone by the monitor of ultraviolet solar energy (MUSE) and backscatter ultraviolet (BUV) experiments respectively. Two long lived ultraviolet active solar regions which are about 180 deg apart in solar longitude were observed to be associated with central meridian passages of solar magnetic sector boundaries. The boundaries may be significant in the evaluation of correlations between solar magnetic sector structure and atmospheric circulation.

  11. Advanced SuperDARN meteor wind observations based on raw time series analysis technique

    NASA Astrophysics Data System (ADS)

    Tsutsumi, M.; Yukimatu, A. S.; Holdsworth, D. A.; Lester, M.

    2009-04-01

    The meteor observation technique based on SuperDARN raw time series analysis has been upgraded. This technique extracts meteor information as biproducts and does not degrade the quality of normal SuperDARN operations. In the upgrade the radar operating system (RADOPS) has been modified so that it can oversample every 15 km during the normal operations, which have a range resolution of 45 km. As an alternative method for better range determination a frequency domain interferometry (FDI) capability was also coded in RADOPS, where the operating radio frequency can be changed every pulse sequence. Test observations were conducted using the CUTLASS Iceland East and Finland radars, where oversampling and FDI operation (two frequencies separated by 3 kHz) were simultaneously carried out. Meteor ranges obtained in both ranging techniques agreed very well. The ranges were then combined with the interferometer data to estimate meteor echo reflection heights. Although there were still some ambiguities in the arrival angles of echoes because of the rather long antenna spacing of the interferometers, the heights and arrival angles of most of meteor echoes were more accurately determined than previously. Wind velocities were successfully estimated over the height range of 84 to 110 km. The FDI technique developed here can be further applied to the common SuperDARN operation, and study of fine horizontal structures of F region plasma irregularities is expected in the future.

  12. Advances in a study of sky quality for astronomical observations in Colombia

    NASA Astrophysics Data System (ADS)

    González-Díaz, D.; Pinzón, G.

    2015-10-01

    The aim of this study is to determine the sky quality in Colombia for astronomical observations in the optic. About 10,000 images in infrared (6.7 mu m and 10.7 mu m) were analyzed from the GOES meteorological satellites in three night times taken during a period of five years (2008 to 2014). A novel methodology was followed to determine how clear or covered was the sky in a given image. Meteorological data also were used from the weather stations network of the national meteorological institute, IDEAM. A correlation between threshold temperature and altitude was found for a historical data series of about 30 years. The results of the average percentage of nights with clear skies per year or clear sky fraction (CSF) were validated with the reports on the number of hours of astronomical observation from the logbooks of Llano del Hato Observatory in Merida-Venezuela, obtaining a cumulative percentage difference during the five years less than 10%. Annual cloud covering was computed over the whole country and it was classified the nights as clear or usable based on the definition of a quality factor.

  13. Advances in Assimilation of Satellite-Based Passive Microwave Observations for Soil-Moisture Estimation

    NASA Technical Reports Server (NTRS)

    De Lannoy, Gabrielle J. M.; Pauwels, Valentijn; Reichle, Rolf H.; Draper, Clara; Koster, Randy; Liu, Qing

    2012-01-01

    Satellite-based microwave measurements have long shown potential to provide global information about soil moisture. The European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS, [1]) mission as well as the future National Aeronautics and Space Administration (NASA) Soil Moisture Active and Passive (SMAP, [2]) mission measure passive microwave emission at L-band frequencies, at a relatively coarse (40 km) spatial resolution. In addition, SMAP will measure active microwave signals at a higher spatial resolution (3 km). These new L-band missions have a greater sensing depth (of -5cm) compared with past and present C- and X-band microwave sensors. ESA currently also disseminates retrievals of SMOS surface soil moisture that are derived from SMOS brightness temperature observations and ancillary data. In this research, we address two major challenges with the assimilation of recent/future satellite-based microwave measurements: (i) assimilation of soil moisture retrievals versus brightness temperatures for surface and root-zone soil moisture estimation and (ii) scale-mismatches between satellite observations, models and in situ validation data.

  14. Continuous and event-based time series analysis of observed floodplain groundwater flow under contrasting land-use types.

    PubMed

    Kellner, Elliott; Hubbart, Jason A

    2016-10-01

    There is an ongoing need to improve quantitative understanding of land-use impacts on floodplain groundwater flow regimes. A study was implemented in Hinkson Creek Watershed, Missouri, USA, including equidistant grids of nine piezometers, equipped with pressure transducers, which were installed at two floodplain study sites: a remnant bottomland hardwood forest (BHF) and a historical agricultural field (Ag). Data were logged at thirty minute intervals for the duration of the 2011, 2012, 2013, and 2014 water years (October 1, 2010-September 30, 2014). Results show significant (p<0.001) differences between Darcy-estimated groundwater flow at the two study sites. Although median flow values at the two sites were similar (0.009 and 0.010mday(-1) for the Ag and BHF sites, respectively), the BHF displayed a more dynamic flow regime compared to the Ag site. Maximum flow values were 0.020 and 0.049mday(-1) for the Ag and BHF sites, respectively. Minimum flow values were -0.018 and -0.029mday(-1) for the Ag and BHF sites, respectively. The BHF showed greater magnitude, longer duration, and more frequent negative flows, relative to the Ag site. Event-based analyses indicated a more seasonally responsive flow regime at the BHF, with higher flows than the Ag site during the wet season and lower flows than the Ag site during the dry season. Notably, the seasonal pattern of relative site flow differences was consistent across a wide range of precipitation event magnitudes (i.e. 8-45mm). Results are by majority attributable to greater rates of plant water use by woody vegetation and preferential subsurface flow at the BHF site. Collectively, results suggest greater flood attenuation capacity and streamwater buffering potential by the BHF floodplain, relative to the Ag, and highlight the value of floodplain forests as a land and water resource management tool. PMID:27232970

  15. Observations of compound sawteeth in ion cyclotron resonant heating plasma using ECE imaging on experimental advanced superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Hussain, Azam; Zhao, Zhenling; Xie, Jinlin; Zhu, Ping; Liu, Wandong; Ti, Ang

    2016-04-01

    The spatial and temporal evolutions of compound sawteeth were directly observed using 2D electron cyclotron emission imaging on experimental advanced superconducting tokamak. The compound sawtooth consists of partial and full collapses. After partial collapse, the hot core survives as only a small amount of heat disperses outwards, whereas in the following full collapse a large amount of heat is released and the hot core dissipates. The presence of two q = 1 surfaces was not observed. Instead, the compound sawtooth occurs mainly at the beginning of an ion cyclotron resonant frequency heating pulse and during the L-H transition phase, which may be related to heat transport suppression caused by a decrease in electron heat diffusivity.

  16. Observation of pedestal turbulence in edge localized mode-free H-mode on experimental advanced superconducting tokamak

    SciTech Connect

    Han, X. Zhang, T.; Zhang, S. B.; Wang, Y. M.; Shi, T. H.; Liu, Z. X.; Kong, D. F.; Qu, H.; Gao, X.

    2014-10-15

    Two different pedestal turbulence structures have been observed in edge localized mode-free phase of H-mode heated by lower hybrid wave and RF wave in ion cyclotron range of frequencies (ICRF) on experimental advanced superconducting tokamak. When the fraction of ICRF power P{sub ICRF}/P{sub total} exceeds 0.7, coherent mode is observed. The mode is identified as an electromagnetic mode, rotating in electron diamagnetic direction with a frequency around 50 kHz and toroidal mode number n = −3. Whereas when P{sub ICRF}/P{sub total} is less than 0.7, harmonic mode with frequency f = 40–300 kHz appears instead. The characteristics of these two modes are demonstrated preliminarily. The threshold value of heating power and also the plasma parameters are distinct.

  17. Utilizing NASA Earth Observations to Assess Estuary Health and Enhance Management of Water Resources in Coastal Texas through Land Cover and Precipitation Mapping

    NASA Astrophysics Data System (ADS)

    Crepps, G.; Gonsoroski, E.; Lynn, T.; Schick, R.; Pereira da Silva, R.

    2015-12-01

    This project partnered with the National Park Service (NPS) to help analyze the correlation between mesquite trees and the salinity of the Laguna Madre of Padre Island National Seashore. The lagoon is a hypersaline estuary; however, there is historical evidence that this was not always the case. It is hypothesized that the increase in the number of honey mesquite trees (Prosopis grandulosa var. glandulosa) in the area has contributed to the Laguna Madre's increased salinity by decreasing the groundwater inflow to the lagoon. These mesquite trees have long taproots capable of extracting significant amounts of groundwater. This project utilized Earth observation data in ERDAS IMAGINE and ArcGIS software to create map time series and analyze the data. Landsat 5, 7, and 8 data were used to create land use/land cover (LULC) maps in order to analyze the change in the occurrence of mesquite trees over time. Thermal maps of the lagoon were generated using Landsat 5, 7, and 8 data to understand changes in groundwater inflow. In addition, TRMM and GRACE derived changes in root zone soil moisture content data were compared over the study period. By investigating the suspected positive correlation between the mesquite trees and the salinity of the Laguna Madre, the NPS can improve future land management practices.

  18. Advancing the Vision of the Global Earth Observation System of Systems: a European Perspective

    NASA Astrophysics Data System (ADS)

    Edwards, A. W.; Craglia, M.; Nativi, S.

    2012-12-01

    The purpose of the Global Earth Observation System of Systems (GEOSS), a network of Earth observation and information systems, contributed on a voluntary basis by Members and Participating Organisations of the intergovernmental Group on Earth Observations (GEO), is to achieve comprehensive, coordinated and sustained observations of the Earth system, in order to improve monitoring of the state of the Earth, increase understanding of Earth processes, and enhance prediction of the behaviour of the Earth system. Such a global research effort requires an integrated multi-disciplinary effort that is underpinned by a cyber-infrastructure which is able to discover and access vast quantities of data across heterogeneous information systems and many disciplines. As GEO develops and the implementation of the GEOSS gathers pace, it is becoming common practice for groups to be organised at national, regional and international level to address critical issues. In many cases these groups evolve to become "communities", organising themselves to carry out tasks of interest to that community. In most cases, communities develop their own "community portal" to provide a focal point on the web for their activities. The data and information held by the members of a specific community can normally be discovered via their particular "community portal". There is now a clear recognition that the many thematic community initiatives, each with their own information system and portal, need to be fully connected into the overall GEOSS architecture. With the introduction of a brokering capability this becomes possible. The value of the brokering approach has been demonstrated within the European Union funded EuroGEOSS research project. The EuroGEOSS brokering capability has now been incorporated into the GEOSS information system, (known as the GEOSS Common Infrastructure, or GCI) and renamed the GEOSS Discovery and Access Broker. In a matter of a few months the GEOSS DAB has enabled the GEOSS to

  19. Advanced fire observation by the Intelligent Infrared Sensor prototype FOCUS on the International Space Station

    NASA Astrophysics Data System (ADS)

    Oertel, D.; Haschberger, P.; Tank, V.; Lanzl, F.; Zhukov, B.; Jahn, H.; Briess, K.; Lorenz, E.; Roeser, H.-P.; Ginati, A.; Tobehn, C.; Schulte in den Bäumen, J.; Christmann, U.

    1999-01-01

    Current and planned operational space-borne Earth observation systems provide spatially, radiometrically or temporally crude data for the detection and monitoring of high temperature phenomena on the surface of our planet. High Temperature Events (HTE) very often cause environmental disasters. Such HTE are forest and savannah fires, fires of open coal mines, volcanic activities and others (e.g. fires of oil wells, pipelines etc.). A simultaneous co-registration of a combination of infrared (IR) and visible (VIS) channels is the key for a reliable autonomous on-board detection of High Temperature Events (HTE) on Earth surface, such as vegetation fires and volcano eruptions. This is the main feature of the FOCUS experiment. Furthermore there are ecology-oriented objectives of the FOCUS experiment mainly related to spectrometric/imaging remote inspection and parameter extraction of selected HTEs, and to the assessment of some ecological consequences of HTEs, such as aerosol and gas emission. Based on own experimental work and supported by Co-Investigators from Italy, Greece, France, Spain, Russia and Germany, DLR proposed in 1997 to use the International Space Station (ISS) in its early utilization phase as a platform and test-bed for an Intelligent Infrared Sensor prototype FOCUS of a future Environmental Disaster Recognition Satellite System. FOCUS is considered by ESA as an important mission combining a number of proven technologies and observation techniques to provide the scientific and operational user community with key data for the classification and monitoring of forest fires. FOCUS was selected as one of five European ``Groupings'' to be flown as an externally mounted payload during the early utilisation phase of the ISS. The FOCUS Phase A Study will be performed by OHB-System, DLR and Zeiss from September 1998 until May 1999.

  20. Combined Observational and Modeling Efforts to Better Understand Aerosol-Cloud-Precipitation Interactions Over Land: Preliminary Results from 7-SEAS/BASELInE 2013

    NASA Technical Reports Server (NTRS)

    Loftus, Adrian M.; Tsay, Si-Chee

    2015-01-01

    This talk presents some of the detailed observations of low-level stratocumulus over northern Vietnam during 7-SEASBASELInE 2013 by SMARTLabs' ACHIEVE W-band cloud radar and other remote sensing instruments. These observations are the first of their kind for this region and will aid in ongoing studies of biomass-burning aerosol impacts on local and regional weather and climate. Preliminary results from simulations using the Goddard Cumulus Ensemble (GCE) with recently implemented triple-moment bulk microphysics to examine the sensitivity of low-level stratocumulus over land to aerosols are also presented. Recommendations for future observational activities in the 7-SEAS northern region in collaboration with international partners will also be discussed.

  1. Influence of Dust and Black Carbon on the Snow Albedo in the NASA Goddard Earth Observing System Version 5 Land Surface Model

    NASA Technical Reports Server (NTRS)

    Yasunari, Teppei J.; Koster, Randal D.; Lau, K. M.; Aoki, Teruo; Sud, Yogesh C.; Yamazaki, Takeshi; Motoyoshi, Hiroki; Kodama, Yuji

    2011-01-01

    Present-day land surface models rarely account for the influence of both black carbon and dust in the snow on the snow albedo. Snow impurities increase the absorption of incoming shortwave radiation (particularly in the visible bands), whereby they have major consequences for the evolution of snowmelt and life cycles of snowpack. A new parameterization of these snow impurities was included in the catchment-based land surface model used in the National Aeronautics and Space Administration Goddard Earth Observing System version 5. Validation tests against in situ observed data were performed for the winter of 2003.2004 in Sapporo, Japan, for both the new snow albedo parameterization (which explicitly accounts for snow impurities) and the preexisting baseline albedo parameterization (which does not). Validation tests reveal that daily variations of snow depth and snow surface albedo are more realistically simulated with the new parameterization. Reasonable perturbations in the assigned snow impurity concentrations, as inferred from the observational data, produce significant changes in snowpack depth and radiative flux interactions. These findings illustrate the importance of parameterizing the influence of snow impurities on the snow surface albedo for proper simulation of the life cycle of snow cover.

  2. Advances and Limitations of Atmospheric Boundary Layer Observations with GPS Occultation over Southeast Pacific Ocean

    NASA Technical Reports Server (NTRS)

    Xie, F.; Wu, D. L.; Ao, C. O.; Mannucci, A. J.; Kursinski, E. R.

    2012-01-01

    The typical atmospheric boundary layer (ABL) over the southeast (SE) Pacific Ocean is featured with a strong temperature inversion and a sharp moisture gradient across the ABL top. The strong moisture and temperature gradients result in a sharp refractivity gradient that can be precisely detected by the Global Positioning System (GPS) radio occultation (RO) measurements. In this paper, the Constellation Observing System for Meteorology, Ionosphere & Climate (COSMIC) GPS RO soundings, radiosondes and the high-resolution ECMWF analysis over the SE Pacific are analyzed. COSMIC RO is able to detect a wide range of ABL height variations (1-2 kilometer) as observed from the radiosondes. However, the ECMWF analysis systematically underestimates the ABL heights. The sharp refractivity gradient at the ABL top frequently exceeds the critical refraction (e.g., -157 N-unit per kilometer) and becomes the so-called ducting condition, which results in a systematic RO refractivity bias (or called N-bias) inside the ABL. Simulation study based on radiosonde profiles reveals the magnitudes of the N-biases are vertical resolution dependent. The N-bias is also the primary cause of the systematically smaller refractivity gradient (rarely exceeding -110 N-unit per kilometer) at the ABL top from RO measurement. However, the N-bias seems not affect the ABL height detection. Instead, the very large RO bending angle and the sharp refractivity gradient due to ducting allow reliable detection of the ABL height from GPS RO. The seasonal mean climatology of ABL heights derived from a nine-month composite of COSMIC RO soundings over the SE Pacific reveals significant differences from the ECMWF analysis. Both show an increase of ABL height from the shallow stratocumulus near the coast to a much higher trade wind inversion further off the coast. However, COSMIC RO shows an overall deeper ABL and reveals different locations of the minimum and maximum ABL heights as compared to the ECMWF analysis

  3. The observation of atmospheric structure with TOMS and some potential advancements. [Total Ozone Mapping Spectrometer

    NASA Technical Reports Server (NTRS)

    Krueger, A. J.

    1985-01-01

    An overview is given of the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) which was designed to observe the spatial characteristics of total ozone that were not resolved by the nadir-viewing Nimbus BUV and SBUV instruments. At the wavelengths suitable for total ozone measurements, the radiance is large enough that the entire daytime atmosphere could be surveyed with about 50-km resolution from a polar orbiting satellite. The resulting high spatial resolution TOMS ozone images are found to reflect the internal dynamic structure of the lower atmosphere. Features which can be identified and tracked include: planetary wave scale troughs and ridges, mesoscale cutoff lows and rapidly moving troughs, jet stream confluence and difluence areas, hurricanes, and polar night lows. These features control the ozone above any given location and account for nearly all the variance in the total ozone. The instrument has been used to track the volcanic eruption clouds from El Chichon, Mount St. Helens, Alaid, and smaller eruptions such as Galunggung. It would be feasible to use a similar instrument on a geostationary platform to obtain half-hourly maps. Determination of the vertical ozone distribution in the lower stratosphere using Radon transform principles would be of importance in measuring jet stream folds and the related troposphere-stratosphere exchange.

  4. Biomass burning observations for near-real-time applications: advances in satellite data processing

    NASA Astrophysics Data System (ADS)

    Hyer, E. J.; Reid, J. S.; Prins, E. M.; Hoffman, J.; Schmidt, C. C.; Giglio, L.; Peterson, D. A.

    2011-12-01

    Satellites have been used to provide information on fire activity for wildfire response and air quality applications for many years. While important refinements have been made to algorithmic processing of single satellite scenes for fire detection, most near-real-time (NRT) applications still use fire products in their simplest form-a list of locations and times of fires detected from space. This information can be thought of as the numerator in a fire activity term: it captures relative variations in fire activity, and can be transformed into absolute fire activity only by assuming that the sensitivity of the sensor (the denominator) is consistent and unchanging. This standard for satellite fire products arose from computational necessity, and persists because of simplicity. Using only this limited information restricts development of NRT fire applications in two key ways: first, it does not permit applications to account for variations in detection efficiency by a single sensor, and second, it provides no pathway for quantitative integration of multiple sensors, especially if those sensors have different fire detection properties. We will demonstrate techniques, using current satellite fire products, to improve the fidelity of the description of fire activity from satellite by accounting for variation in detection efficiency, and demonstrate how an absolute metric of fire sensitivity can be used to integrate fire detections from diverse sources, such as polar and geostationary satellite observations, in order to improve NRT description of spatial and temporal patterns of fire activity.

  5. One-dimensional soil temperature simulation with Common Land Model by assimilating in situ observations and MODIS LST with the ensemble particle filter

    NASA Astrophysics Data System (ADS)

    Yu, Zhongbo; Fu, Xiaolei; Luo, Lifeng; Lü, Haishen; Ju, Qin; Liu, Di; Kalin, Dresden A.; Huang, Dui; Yang, Chuanguo; Zhao, Lili

    2014-08-01

    Soil temperature plays an important role in hydrology, agriculture, and meteorology. In order to improve the accuracy of soil temperature simulation, a soil temperature data assimilation system was developed based on the Ensemble Particle Filter (EnPF) and the Common Land Model (CLM), and then applied in the Walnut Gulch Experimental Watershed (WGEW) in Arizona, United States. Surface soil temperature in situ observations and Moderate Resolution Imaging Spectroradiometer Land Surface Temperature (MODIS LST) data were assimilated into the system. In this study, four different assimilation experiments were conducted: (1) assimilating in situ observations of instantaneous surface soil temperature each hour, (2) assimilating in situ observations of instantaneous surface soil temperature once per day, (3) assimilating verified MODIS LST once per day, and (4) assimilating original MODIS LST once per day. These four experiments reflect a transition from high-quality and more frequent in situ observations to lower quality and less frequent remote sensing data in the data assimilation system. The results from these four experiments show that the assimilated results are better than the simulated results without assimilation at all layers except the bottom layer, while the superiority gradually diminishes as the quality and frequency of the observations decrease. This demonstrates that remote sensing data can be assimilated using the ensemble particle filter in poorly gauged catchments to obtain highly accurate soil variables (e.g., soil moisture, soil temperature). Meanwhile, the results also demonstrate that the ensemble particle filter is effective in assimilating soil temperature observations to improve simulations, but the performance of the data assimilation method is affected by the frequency of assimilation and the quality of the input data.

  6. Advanced interpretation of land subsidence by validating multi-interferometric SAR data: the case study of the Anthemountas basin (northern Greece)

    NASA Astrophysics Data System (ADS)

    Raspini, F.; Loupasakis, C.; Rozos, D.; Moretti, S.

    2013-04-01

    The potential of repeat-pass space borne SAR (Synthetic Aperture Radar) interferometry has been exploited to investigate spatial patterns of land subsidence in the Anthemountas basin, in the northern part of Greece. The PSI (Persistent Scatterer Interferometry) approach, based on the processing of long series of SAR acquisitions, has been applied to forty-two images acquired in 1995-2001 by ERS1/2 satellites. Interferometric results have been analyzed at a basin scale as support for land motion mapping and at local scale for the characterization of ground motion events affecting the village of Perea in the Thermaikos municipality and the "Macedonia" international airport. PSI results revealed a moderate subsidence phenomenon along the wider coastal zone of Anthemountas basin corresponding to intense groundwater extraction. Highest values, exceeding 20 mm yr-1, were measured in the airport area where the thickest sequence of compressible Quaternary sediments occurs. Intense subsidence has been detected also in the Perea village (maximum deformation up to 10-15 mm yr-1), where a series of fractures, causing damages to both buildings and infrastructure, occurred in 2005-2006. Furthermore, a linear pattern of deformation, elongated parallel to the major normal Thermi fault, has been observed, indicating movements with a probable tectonic component.

  7. [Observations on pe-eclampsia-eclampsia and the advances in the evolution of some laboratory tests].

    PubMed

    Noguera Sánchez, M F; Ayala Barahona, T; Arredondo Soberón, F; Morgan, M A

    1997-07-01

    The preeclampsia-eclampsia syndrome is a vasospastic disorder and probably has a placental origin. Once the hypertensive syndrome is established the uteroplacental blood flow is reduced as well as the intervillous blood flow. Since 18-24 weeks of gestation and before the symptoms of preeclampsia become overt, changes in placental flow velocity can be detected with Doppler technics. The placental theories for the etiology of preeclampsia are focused on the hypoxic effect in the trophoblastic tissue of second trimester. The placental ischemic changes are evident and seen in the uteroplacental bed. They are interrelated with the stages of trophoblastic invasion of the spiral arteries during the 14 and 20 weeks. When the trophoblastic invasion is over, the spiral arteries become a high resistance system. The defect observed in preeclampsia is the lack of invasion of the trophoblast to the maternal arteries. The diminished placental perfusion probably creates endothelial damage. This damage has several effects: decreased prostaglandin production, activated coagulation cascade, stimulated fibrin aggregation, and increased vascular permeability. The ideal laboratory test for preeclampsia shall predict the onset of this entity. Recent findings seem promising. The fibronectin concentration increases 2-3 wks. prior to the clinical manifestation of preeclampsia. Severe hypertension shows an abnormal decrease in fibronectin levels. Hypocalciuria has been described as an early predictor in the development of preeclampsia. Other agents undergoing extensive evaluation as predictors are: uric acid, b-thromboglobin, prolactin and atrial natriuretic peptide. Recently high levels of b-HCG (human corionic gonadotrophin) have been linked to a lack of trophoblastic invasion during the second trimester, therefore this is a potential marker for those patients that will eventually develop preeclampsia. PMID:9312519

  8. First Observation of Charge Reduction and Desorption Kinetics of Multiply Protonated Peptides Soft Landed onto Self-Assembled Monolayer Surfaces

    SciTech Connect

    Hadjar, Omar; Futrell, Jean H.; Laskin, Julia

    2007-12-13

    The kinetics of charge reduction and desorption of different species produced by soft-landing of mass-selected ions was studied using in situ secondary ion mass spectrometry (SIMS) in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). The improved SIMS capability described in this work utilizes an in-line 8 keV Cs+ ion gun and allows us to interrogate the surface both during the ion deposition and after the deposition is terminated. As a model system doubly protonated ions of Gramicidin S were deposited onto a fluorinated self-assembled monolayer (FSAM) surface. Our results demonstrate for the first time that various peptide-related peaks in FT-ICR SIMS spectra follow very different kinetics. We obtained unique kinetics signatures for doubly protonated, singly protonated and neutral peptides retained on the surface and followed their evolution as a function of time. The experimental results are in excellent agreement with a kinetic model that takes into account charge reduction and thermal desorption of different species from the surface.

  9. Estimating the human contribution to groundwater depletion in the Middle East, from GRACE data, land surface models, and well observations

    NASA Astrophysics Data System (ADS)

    Joodaki, Gholamreza; Wahr, John; Swenson, Sean

    2014-03-01

    Data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission are used to estimate monthly changes in total water storage across the Middle East during February 2003 to December 2012. The results show a large negative trend in total water storage centered over western Iran and eastern Iraq. Subtracting contributions from the Caspian Sea and two large lakes, Tharthar and Urmiah, and using output from a version of the CLM4.5 land surface model to remove contributions from soil moisture, snow, canopy storage, and river storage, we conclude that most of the long-term water loss is due to a decline in groundwater storage. By dividing the region into seven mascons outlined along national boundaries and fitting them to the data, we find that the largest groundwater depletion is occurring in Iran, with a mass loss rate of 25 ± 3 Gt/yr during the study period. The conclusion of significant Iranian groundwater loss is further supported by in situ well data from across the country. Anthropogenic contributions to the groundwater loss are estimated by removing the natural variations in groundwater predicted by CLM4.5. These results indicate that over half of the groundwater loss in Iran (14 ± 3 Gt/yr) may be attributed to human withdrawals.

  10. Observations of Past Lunar Landing Sites by the D-CIXS X-Ray Spectrometer on SMART-1

    NASA Astrophysics Data System (ADS)

    Grande, M.; Kellett, B. J.; Howe, C.; Perry, C. H.; Swinyard, B.; Dunkin, S.; Huovelin, J.; Alha, L.; D'Uston, L. C.; Maurice, S.; Gasnault, O.; Barabash, S.; Joy, K. H.; Crawford, I. A.; Lawrence, D.; Fernandes, V.; Casanova, I.; Wieczorek, M.; Thomas, N.

    2007-03-01

    D-CIXS initial observations show a first unambiguous remote sensing of calcium in the lunar regolith. Data obtained are broadly consistent with current understanding of mare and highland composition. Ground truth is provided by the returned Apollo and Lun

  11. Earth Observation in Support of Science and Applications Development in the Field "land and Environment": Synthesis Results from the Esa-Most Dragon Cooperation Programme

    NASA Astrophysics Data System (ADS)

    Cartalis, C.; Asimakopoulos, D. N.; Ban, Y.; Bao, Y.; Bi, Y.; Defourny, P.; Del Barrio, G.; Fan, J.; Gao, Z.; Gong, H.; Gong, J.; Gong, P.; Li, C.; Pignatti, S.; Sarris, A.; Yang, G.

    2015-04-01

    Dragon is a cooperation Programme between the European Space Agency (ESA) and the Ministry of Science and Technology (MOST) of the P.R. China. The Programme, initiated in 2004, focuses on the exploitation of ESA, Third Party Missions (TPM) and Chinese Earth Observation (EO) data for geo-science and applications development in land, ocean and atmospheric applications. In particular, the Programme brings together joint Sino- European teams to investigate 50 thematic projects. In this paper, the results of the research projects1 in the thematic field "Land and Environment" will be briefly presented, whereas emphasis will be given in the assessment of the usefulness of the results for an integrated assessment of the state of the environment in the respective study areas. Furthermore new knowledge gained in such fields as desertification assessment, drought and epidemics' monitoring, forest modeling, cropwatch monitoring, climate change vulnerability (including climate change adaptation and mitigation plans), urbanization monitoring and land use/cover change assessment and monitoring, will be presented. Such knowledge will be also linked to the capacities of Earth Observation systems (and of the respective EO data) to support the temporal, spatial and spectral requirements of the research studies. The potential of DRAGON to support such targets as "technology and knowledge transfer at the bilateral level", "common EO database for exploitation" and "data sharing and open access data policy" will be also presented. Finally special consideration will be given in highlighting the replication potential of the techniques as developed in the course of the projects, as well as on the importance of the scientific results for environmental policy drafting and decision making.

  12. Land Surface Temperature product validation using NOAA's surface climate observation networks - Scaling methodology for the Visible Infrared Imager Radiometer Suite (VIIRS)

    NASA Astrophysics Data System (ADS)

    Guillevic, P. C.; Privette, J. L.; Coudert, B.; Davis, E.; Meyers, T. P.; Palecki, M. A.; Augustine, J. A.; Ottle, C.

    2011-12-01

    The Land Surface Temperature (LST) product from the Visible Infrared Imager Radiometer Suite (VIIRS) will provide key information for estimating Earth surface energy and water fluxes, improving weather forecasting at high spatial and temporal resolutions, and monitoring climate change. The main challenges in estimating LST from VIIRS and similar sensors (e.g., AVHRR, MODIS, AATSR) are the need to correct for surface emissivity and atmospheric water vapor attenuation, and the difficulty in quantifying LST product accuracy due to the lack of comparable in situ measurements. This work presents a new methodology that combines in situ observations with fine-scale surface modeling to allow routine quantitative assessment of VIIRS LST products and a physically-based framework for testing and improving the retrieval algorithm. The validation scheme uses NOAA's surface observations (surface and meteorological) collected by the US Climate Reference Network (CRN) and the Surface Radiation Budget Network (SURFRAD). The scaling methodology consists of the merging of information collected at different spatial resolutions and the SEtHyS land surface model to fully characterize the satellite products, i.e. measurements from ground stations to satellites platforms at high and moderate resolutions. Based on ground stations deployed over the continental United States, it has the capability to explore scaling issues over terrestrial surfaces spanning a large range of climate regimes and land cover types, including forests and mixed vegetated areas. The approach can be applied to ground stations worldwide. The project was initiated under NPOESS/JPSS program, and it is tested and proven here with NASA/MODIS data. The primary goal is to establish, in near real time, the accuracy of the LST product derived from VIIRS over a selection of field validation sites for the VIIRS algorithm working group and the science-user community.

  13. Observations performed by the SESAME/Permittivity Probe during the descent and after the landing of Philae upon the nucleus of Comet Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Schmidt, Walter; Le Gall, Alice; Hamelin, Michel; Caujolle-Bert, Sylvain; Lethuillier, Anthony; Ciarletti, Valerie; Grard, Réjean

    2015-04-01

    The Permittivity Probe (PP), a component of the SESAME instrument on board Rosetta's Lander Philae, was operated prior to the separation of Philae from Rosetta, during the descent and at the location of the final landing site. The working principle of PP consists in measuring, with a receiving dipole, the voltage induced in the medium by a current of known phase and amplitude injected by a transmitting antenna. The primary objective of PP is to analyse the electrical properties of the comet surface material down to a depth of about 2 m, and to record their variations with temperature, solar illumination and heliocentric distance. These observations are particularly sensitive to the concentration of water ice at the landing site. The second objective of the instrument is to monitor the spectrum of the electromagnetic and electrostatic waves generated by the interaction between the comet and the solar wind at frequencies of up to 20 kHz. The measurements performed during the descent were mainly devoted to the calibration of the instrument in its nominal configuration, with deployed landing gear and away from the Rosetta spacecraft influence, in an environment of known permittivity, either a vacuum or a plasma whose density and temperature would have been derived from the LAP and MIP data. This approach is unfortunately invalidated owing to the fact the PP receiver was most of the time saturated by the operation of the CONSERT radar during the descent, an interference which seemed to have been minimized during in-flight interference tests, but which was significantly stronger after separation of Philae from Rosetta. Nevertheless, it was possible to recover some information about the instrument's transmitter and receiver performances then used during the analysis of the data measured on the cometary surface. Undisturbed measurements were fortunately performed at the landing site, under various solar illuminations, using the three feet of Philae as transmitting and

  14. ALOS-PALSAR multi-temporal observation for describing land use and forest cover changes in Malaysia

    NASA Astrophysics Data System (ADS)

    Avtar, R.; Suzuki, R.; Ishii, R.; Kobayashi, H.; Nagai, S.; Fadaei, H.; Hirata, R.; Suhaili, A. B.

    2012-12-01

    The establishment of plantations in carbon rich peatland of Southeast Asia has shown an increase in the past decade. The need to support development in countries such as Malaysia has been reflected by having a higher rate of conversion of its forested areas to agricultural land use in particular oilpalm plantation. Use of optical data to monitor changes in peatland forests is difficult because of the high cloudiness in tropical region. Synthetic Aperture Radar (SAR) based remote sensing can potentially be used to monitor changes in such forested landscapes. In this study, we have demonstrated the capability of multi-temporal Fine-Beam Dual (FBD) data of Phased Array L-band Synthetic Aperture Radar (PALSAR) to detect forest cover changes in peatland to other landuse such as oilpalm plantation. Here, the backscattering properties of radar were evaluated to estimate changes in the forest cover. Temporal analysis of PALSAR FBD data shows that conversion of peatland forest to oilpalm can be detected by analyzing changes in the value of σoHH and σoHV. This is characterized by a high value of σoHH (-7.89 dB) and σoHV (-12.13 dB) for areas under peat forests. The value of σoHV decreased about 2-4 dB due to the conversion of peatland to a plantation area. There is also an increase in the value of σoHH/σoHV. Changes in σoHV is more prominent to identify the peatland conversion than in the σoHH. The results indicate the potential of PALSAR to estimate peatland forest conversion based on thresholding of σoHV or σoHH/σoHV for monitoring changes in peatland forest. This would improve our understanding of the temporal change and its effect on the peatland forest ecosystem.

  15. Sensing land pollution.

    NASA Technical Reports Server (NTRS)

    Bowden, L. W.

    1971-01-01

    Land pollution is described in numerous ways by various societies. Pollutants of land are material by-products of human activity and range from environmentally ineffective to positively toxic. The pollution of land by man is centuries old and correlates directly with economy, technology and population. In order to remotely sense land pollution, standards or thresholds must be established. Examples of the potential for sensing land pollution and quality are presented. The technological capabilities for remotely sensed land quality is far advanced over the judgment on how to use the sensed data. Until authoritative and directive decisions on land pollution policy are made, sensing of pollutants will be a random, local and academic affair.

  16. ESTIMATION OF LAND SURFACE BROADBAND ALBEDOS AND LEAF AREA INDEX FROM EO-1 DATA AND VALIDATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Advanced Land Imager (ALI) is a multispectral sensor onboard NASA Earth Observer-1 (EO-1). It has similar spatial resolution to the Landsat-7 Enhanced Thematic Mapper Plus (ETM+), with three additional spectral bands. We developed new algorithms for estimating both land surface broadband albedo...

  17. Advanced MicroObserver UGS integration with and cueing of the BattleHawk squad level loitering munition and UAV

    NASA Astrophysics Data System (ADS)

    Steadman, Bob; Finklea, John; Kershaw, James; Loughman, Cathy; Shaffner, Patti; Frost, Dean; Deller, Sean

    2014-06-01

    Textron's Advanced MicroObserver(R) is a next generation remote unattended ground sensor system (UGS) for border security, infrastructure protection, and small combat unit security. The original MicroObserver(R) is a sophisticated seismic sensor system with multi-node fusion that supports target tracking. This system has been deployed in combat theaters. The system's seismic sensor nodes are uniquely able to be completely buried (including antennas) for optimal covertness. The advanced version adds a wireless day/night Electro-Optic Infrared (EOIR) system, cued by seismic tracking, with sophisticated target discrimination and automatic frame capture features. Also new is a field deployable Gateway configurable with a variety of radio systems and flexible networking, an important upgrade that enabled the research described herein. BattleHawkTM is a small tube launched Unmanned Air Vehicle (UAV) with a warhead. Using transmitted video from its EOIR subsystem an operator can search for and acquire a target day or night, select a target for attack, and execute terminal dive to destroy the target. It is designed as a lightweight squad level asset carried by an individual infantryman. Although BattleHawk has the best loiter time in its class, it's still relatively short compared to large UAVs. Also it's a one-shot asset in its munition configuration. Therefore Textron Defense Systems conducted research, funded internally, to determine if there was military utility in having the highly persistent MicroObserver(R) system cue BattleHawk's launch and vector it to beyond visual range targets for engagement. This paper describes that research; the system configuration implemented, and the results of field testing that was performed on a government range early in 2013. On the integrated system that was implemented, MicroObserver(R) seismic detections activated that system's camera which then automatically captured images of the target. The geo-referenced and time-tagged MicroObserver

  18. The Texas Water Observatory: Utilizing Advanced Observing System Design for Understanding Water Resources Sustainability Across Climatic and Geologic Gradients of Texas

    NASA Astrophysics Data System (ADS)

    Mohanty, B.; Moore, G. W.; Miller, G. R.; Quiring, S. M.; Everett, M. E.; Morgan, C.

    2015-12-01

    The Texas Water Observatory (TWO) is a new distributed network of field observatories for better understanding of the hydrologic flow in the critical zone (encompassing groundwater, soil water, surface water, and atmospheric water) at various space and time scales. Core sites in the network will begin in Brazos River corridor and expand from there westward. Using many advanced observational platforms and real-time / near-real time sensors, this observatory will monitor high frequency data of water stores and fluxes, critical for understanding and modeling the in the state of Texas and Southern USA. Once implemented, TWO will be positioned to support high-impact water science that is highly relevant to societal needs and serve as a regional resource for better understanding and/or managing agriculture, water resources, ecosystems, biodiversity, disasters, health, energy, and weather/climate. TWO infrastructure will span land uses (cultivation agriculture, range/pasture, forest), landforms (low-relief erosional uplands to depositional lowlands), and across climatic and geologic gradients of Texas to investigate the sensitivity and resilience of fertile soils and the ecosystems they support. Besides developing a network of field water observatory infrastructure/capacity for accounting water flow and storage, TWO will facilitate developing a new generation interdisciplinary water professionals (from various TAMU Colleges) with better understanding and skills for attending to future water challenges of the region. This holistic growth will have great impact on TAMU research enterprise related to water resources, leading to higher federal and state level competitiveness for funding and establishing a center of excellence in the region

  19. An Update on Oceanic Precipitation Rate and its Zonal Distribution in Light of Advanced Observations from Space

    NASA Technical Reports Server (NTRS)

    Behrangi, Ali; Stephens, Graeme; Adler, Robert F.; Huffman, George J.; Lambrigsten, Bjorn; Lebstock, Matthew

    2014-01-01

    This study contributes to the estimation of the global mean and zonal distribution of oceanic precipitation rate using complementary information from advanced precipitation measuring sensors and provides an independent reference to assess current precipitation products. Precipitation estimates from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and CloudSat cloud profiling radar (CPR) were merged, as the two complementary sensors yield an unprecedented range of sensitivity to quantify rainfall from drizzle through the most intense rates. At higher latitudes, where TRMM PR does not exist, precipitation estimates from Aqua's Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) complemented CloudSat CPR to capture intense precipitation rates. The high sensitivity of CPR allows estimation of snow rate, an important type of precipitation at high latitudes, not directly observed in current merged precipitation products. Using the merged precipitation estimate from the CloudSat, TRMM, and Aqua platforms (this estimate is abbreviated to MCTA), the authors' estimate for 3-yr (2007-09) nearglobal (80degS-80degN) oceanic mean precipitation rate is approx. 2.94mm/day. This new estimate of mean global ocean precipitation is about 9% higher than that of the corresponding Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) value (2.68mm/day) and about 4% higher than that of the Global Precipitation Climatology Project (GPCP; 2.82mm/day). Furthermore, MCTA suggests distinct differences in the zonal distribution of precipitation rate from that depicted in GPCPand CMAP, especially in the Southern Hemisphere.

  20. Earth-based and Galileo SSI multispectral observations of eastern mare serenitatis and the Apollo 17 landing site

    NASA Technical Reports Server (NTRS)

    Hiesinger, H.; Jaumann, R.; Neukum, G.

    1993-01-01

    Both the Apollo 17 and the Mare Serenitatis region were observed by Galileo during its fly-by in December 1992. We used earth-based multispectral data to define mare units which then can be compared with the results of the Galileo SSI data evaluation.

  1. A new neural network approach including first guess for retrieval of atmospheric water vapor, cloud liquid water path, surface temperature, and emissivities over land from satellite microwave observations

    NASA Astrophysics Data System (ADS)

    Aires, F.; Prigent, C.; Rossow, W. B.; Rothstein, M.

    2001-07-01

    The analysis of microwave observations over land to determine atmospheric and surface parameters is still limited due to the complexity of the inverse problem. Neural network techniques have already proved successful as the basis of efficient retrieval methods for nonlinear cases; however, first guess estimates, which are used in variational assimilation methods to avoid problems of solution nonuniqueness or other forms of solution irregularity, have up to now not been used with neural network methods. In this study, a neural network approach is developed that uses a first guess. Conceptual bridges are established between the neural network and variational assimilation methods. The new neural method retrieves the surface skin temperature, the integrated water vapor content, the cloud liquid water path and the microwave surface emissivities between 19 and 85 GHz over land from Special Sensor Microwave Imager observations. The retrieval, in parallel, of all these quantities improves the results for consistancy reasons. A database to train the neural network is calculated with a radiative transfer model and a global collection of coincident surface and atmospheric parameters extracted from the National Center for Environmental Prediction reanalysis, from the International Satellite Cloud Climatology Project data, and from microwave emissivity atlases previously calculated. The results of the neural network inversion are very encouraging. The theoretical RMS error of the surface temperature retrieval over the globe is 1.3 K in clear-sky conditions and 1.6 K in cloudy scenes. Water vapor is retrieved with a theoretical RMS error of 3.8 kg m-2 in clear conditions and 4.9 kg m-2 in cloudy situations. The theoretical RMS error in cloud liquid water path is 0.08 kg m-2. The surface emissivities are retrieved with an accuracy of better than 0.008 in clear conditions and 0.010 in cloudy conditions. Microwave land surface temperature retrieval presents a very attractive

  2. Use of EO-1 Advanced Land Imager (ALI) multispectral image data and real-time field sampling for water quality mapping in the Hirfanlı Dam Lake, Turkey.

    PubMed

    Kavurmacı, Murat; Ekercin, Semih; Altaş, Levent; Kurmaç, Yakup

    2013-08-01

    This paper focuses on the evaluation of water quality variations in Hirfanlı Water Reservoir, which is one of the most important water resources in Turkey, through EO-1 (Earth Observing-1) Advanced Land Imager (ALI) multispectral data and real-time field sampling. The study was materialized in 20 different sampling points during the overpass of the EO-1 ALI sensor over the study area. A multi-linear regression technique was used to explore the relationships between radiometrically corrected EO-1 ALI image data and water quality parameters: chlorophyll a, turbidity, and suspended solids. The retrieved and verified results show that the measured and estimated values of water quality parameters are in good agreement (R (2) >0.93). The resulting thematic maps derived from EO-1 multispectral data for chlorophyll a, turbidity, and suspended solids show the spatial distribution of the water quality parameters. The results indicate that the reservoir has average nutrient values. Furthermore, chlorophyll a, turbidity, and suspended solids values increased at the upstream reservoir and shallow coast of the Hirfanlı Water Reservoir. PMID:23423869

  3. Use of Land Surface Temperature Observations in a Two-Source Energy Balance Model Towards Improved Monitoring of Evapotranspiration and Drought

    NASA Astrophysics Data System (ADS)

    Hain, C.; Anderson, M. C.; Otkin, J.; Semmens, K. A.; Zhan, X.; Fang, L.; Li, Z.

    2014-12-01

    As the world's water resources come under increasing tension due to the dual stressors of climate change and population growth, accurate knowledge of water consumption through evapotranspiration (ET) over a range in spatial scales will be critical in developing adaptation strategies. However, direct validation of ET models is challenging due to lack of available observations that are sufficiently representative at the model grid scale (10-100 km). Prognostic land-surface models require accurate information about observed precipitation, soil moisture storage, groundwater, and artificial controls on water supply (e.g., irrigation, dams, etc.) to reliably link rainfall to evaporative fluxes. In contrast, diagnostic estimates of ET can be generated, with no prior knowledge of the surface moisture state, by energy balance models using thermal-infrared remote sensing of land-surface temperature (LST) as a boundary condition. One such method, the Atmosphere Land Exchange Inverse (ALEXI) model provides estimates of surface energy fluxes through the use of mid-morning change in LST and radiation inputs. The LST inputs carry valuable proxy information regarding soil moisture and its effect on soil evaporation and canopy transpiration. Additionally, the Evaporative Stress Index (ESI) representing anomalies in the ratio of actual-to-potential ET has shown to be a reliable indicator of drought. ESI maps over the continental US show good correspondence with standard drought metrics and with patterns of precipitation, but can be generated at significantly higher spatial resolution due to a limited reliance on ground observations. Furthermore, ESI is a measure of actual stress rather than potential for stress, and has physical relevance to projected crop development. Because precipitation is not used in construction of the ESI, it provides an independent assessment of drought conditions and has particular utility for real-time monitoring in regions with sparse rainfall data or

  4. Land Boundary Conditions for the Goddard Earth Observing System Model Version 5 (GEOS-5) Climate Modeling System: Recent Updates and Data File Descriptions

    NASA Technical Reports Server (NTRS)

    Mahanama, Sarith P.; Koster, Randal D.; Walker, Gregory K.; Takacs, Lawrence L.; Reichle, Rolf H.; De Lannoy, Gabrielle; Liu, Qing; Zhao, Bin; Suarez, Max J.

    2015-01-01

    The Earths land surface boundary conditions in the Goddard Earth Observing System version 5 (GEOS-5) modeling system were updated using recent high spatial and temporal resolution global data products. The updates include: (i) construction of a global 10-arcsec land-ocean lakes-ice mask; (ii) incorporation of a 10-arcsec Globcover 2009 land cover dataset; (iii) implementation of Level 12 Pfafstetter hydrologic catchments; (iv) use of hybridized SRTM global topography data; (v) construction of the HWSDv1.21-STATSGO2 merged global 30 arc second soil mineral and carbon data in conjunction with a highly-refined soil classification system; (vi) production of diffuse visible and near-infrared 8-day MODIS albedo climatologies at 30-arcsec from the period 2001-2011; and (vii) production of the GEOLAND2 and MODIS merged 8-day LAI climatology at 30-arcsec for GEOS-5. The global data sets were preprocessed and used to construct global raster data files for the software (mkCatchParam) that computes parameters on catchment-tiles for various atmospheric grids. The updates also include a few bug fixes in mkCatchParam, as well as changes (improvements in algorithms, etc.) to mkCatchParam that allow it to produce tile-space parameters efficiently for high resolution AGCM grids. The update process also includes the construction of data files describing the vegetation type fractions, soil background albedo, nitrogen deposition and mean annual 2m air temperature to be used with the future Catchment CN model and the global stream channel network to be used with the future global runoff routing model. This report provides detailed descriptions of the data production process and data file format of each updated data set.

  5. Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations

    NASA Astrophysics Data System (ADS)

    Martin, J.; Reichstein, M.

    2012-12-01

    We upscaled FLUXNET observations of carbon dioxide, water and energy fluxes to the global scale using the machine learning technique, Model Tree Ensembles (MTE). We trained MTE to predict site-level gross primary productivity (GPP), terrestrial ecosystem respiration (TER), net ecosystem exchange (NEE), latent energy (LE), and sensible heat (H) based on remote sensing indices, climate and meteorological data, and information on land use. We applied the trained MTEs to generate global flux fields at a 0.5° x 0.5o spatial resolution and a monthly temporal resolution from 1982-2008. Cross-validation analyses revealed good performance of MTE in predicting among-site flux variability with modeling efficiencies (MEf) between 0.64 and 0.84, except for NEE (MEf = 0.32). Performance was also good for predicting seasonal patterns (MEf between 0.84 and 0.89, except for NEE (0.64)). By comparison, predictions of monthly anomalies were weak. Our products are increasingly used to evaluate global land surface models. However, depending on the flux of interest (e.g. gross primary production, terrestrial ecosystem respiration, net ecosystem exchange, evapotranspiration) and the pattern of interest (mean annual map, seasonal cycles, interannual variability, trends) the robustness and uncertainty of these products varies considerably. To avoid pitfalls, this talk also aims at providing an overview of uncertainties associated with these products, and to provide recommendations on the usage for land surface model evaluations. Finally, we present FLUXCOM - an ongoing activity that aims at generating an ensemble of data-driven FLUXNET based products based on diverse approaches.

  6. Temporal and spatial variability of daytime land surface temperature in Houston: Comparing DISCOVER-AQ aircraft observations with the WRF model and satellites

    NASA Astrophysics Data System (ADS)

    Huang, Min; Lee, Pius; McNider, Richard; Crawford, James; Buzay, Eric; Barrick, John; Liu, Yuling; Krishnan, Praveena

    2016-01-01

    Based on a semiempirical diurnal temperature cycle model and aircraft observations taken at different times of the day, daytime land surface temperature (LST) is derived at six locations in the Greater Houston area on the least cloudy day during NASA's DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaign in September 2013. The aircraft-derived daytime LSTs show ranges (max-min) of 11-25°K varying by location, with the daily maxima occurring near 1300-1400 local time. Two Weather Research and Forecasting model simulations that were configured differently are compared with these aircraft-derived LST, indicating location- and time-dependent performance. The NOAA GOES geostationary satellite observed similar LST spatial patterns in Houston to those in finer resolution from two polar-orbiting satellite instruments (Moderate Resolution Imaging Spectroradiometer and Visible Infrared Imaging Radiometer Suite), and it provided useful information of the LST temporal variability missing from the polar-orbiting satellite products. However, spatial- and time-varying discrepancies are found among LSTs from these various platforms, which are worth further evaluation in order to benefit model evaluation and improvement. The aircraft and satellite LSTs are overall anticorrelated with satellite vegetation indexes. This emphasizes the importance of vegetation cover in urban planning due to its cooling effect and further impact on biogenic emissions and regional air quality. The approaches shown in this study are also suitable for applications under cloudless conditions at other locations and times, such as during the remaining DISCOVER-AQ deployments conducted in three other populated regions with diverse land uses.

  7. Time-Series analysis of MODIS NDVI data along with ancillary data for Land use/Land cover mapping of Uttarakhand

    NASA Astrophysics Data System (ADS)

    Patakamuri, S. K.; Agrawal, S.; Krishnaveni, M.

    2014-12-01

    Land use and land cover plays an important role in biogeochemical cycles, global climate and seasonal changes. Mapping land use and land cover at various spatial and temporal scales is thus required. Reliable and up to date land use/land cover data is of prime importance for Uttarakhand, which houses twelve national parks and wildlife sanctuaries and also has a vast potential in tourism sector. The research is aimed at mapping the land use/land cover for Uttarakhand state of India using Moderate Resolution Imaging Spectroradiometer (MODIS) data for the year 2010. The study also incorporated smoothening of time-series plots using filtering techniques, which helped in identifying phenological characteristics of various land cover types. Multi temporal Normalized Difference Vegetation Index (NDVI) data for the year 2010 was used for mapping the Land use/land cover at 250m coarse resolution. A total of 23 images covering a single year were layer stacked and 150 clusters were generated using unsupervised classification (ISODATA) on the yearly composite. To identify different types of land cover classes, the temporal pattern (or) phenological information observed from the MODIS (MOD13Q1) NDVI, elevation data from Shuttle Radar Topography Mission (SRTM), MODIS water mask (MOD44W), Nighttime Lights Time Series data from Defense Meteorological Satellite Program (DMSP) and Indian Remote Sensing (IRS) Advanced Wide Field Sensor (AWiFS) data were used. Final map product is generated by adopting hybrid classification approach, which resulted in detailed and accurate land use and land cover map.

  8. Seasonal variations in dust concentration and dust emission observed over Horqin Sandy Land area in China from December 2010 to November 2011

    NASA Astrophysics Data System (ADS)

    Li, Xiaolan; Zhang, Hongsheng

    2012-12-01

    Hourly mean dust concentration observations and meteorological measurements obtained from a sandstorm monitoring station in Horqin Sandy Land area in China from December 2010 to November 2011 were used to investigate the seasonal variations in dust concentration and dust emission flux as well as their relationship with meteorological parameters and soil condition. Based on 14 local dust emission events in spring 2011, the friction velocity (u*) and free convective velocity (w*) were calculated, and their correlation with dust emission flux was used to evaluate the dynamic and thermal impact on dust emission by turbulence. Results indicated that dust events occur in every season with peak dust activity in spring. The maximum dust concentration is 1654.1 μg m-3 and dust emission flux is 98.4 μg m-2 s-1. Freezing of soil in winter effectively decreases soil erodibility and suppresses dust emission. However, soil moisture does not show a significant impact on dust emission in this semi-arid Horqin Sandy Land area. Both friction velocity and free convective velocity could reflect the trend in dust emission flux, but both with obvious underestimation. The thermal impact on dust emission by turbulence is found to be far less than its dynamic impact.

  9. Development of high-speed and wide-angle visible observation diagnostics on Experimental Advanced Superconducting Tokamak using catadioptric optics.

    PubMed

    Yang, J H; Yang, X F; Hu, L Q; Zang, Q; Han, X F; Shao, C Q; Sun, T F; Chen, H; Wang, T F; Li, F J; Hu, A L

    2013-08-01

    A new wide-angle endoscope for visible light observation on the Experimental Advanced Superconducting Tokamak (EAST) has been recently developed. The head section of the optical system is based on a mirror reflection design that is similar to the International Thermonuclear Experimental Reactor-like wide-angle observation diagnostic on the Joint European Torus. However, the optical system design has been simplified and improved. As a result, the global transmittance of the system is as high as 79.6% in the wavelength range from 380 to 780 nm, and the spatial resolution is <5 mm for the full depth of field (4000 mm). The optical system also has a large relative aperture (1:2.4) and can be applied in high-speed camera diagnostics. As an important diagnostic tool, the optical system has been installed on the HT-7 (Hefei Tokamak-7) for its final experimental campaign, and the experiments confirmed that it can be applied to the investigation of transient processes in plasma, such as ELMy eruptions in H-mode, on EAST. PMID:24007102

  10. Development of high-speed and wide-angle visible observation diagnostics on Experimental Advanced Superconducting Tokamak using catadioptric optics

    SciTech Connect

    Yang, J. H.; Hu, L. Q.; Zang, Q.; Han, X. F.; Shao, C. Q.; Sun, T. F.; Chen, H.; Wang, T. F.; Li, F. J.; Hu, A. L.; Yang, X. F.

    2013-08-15

    A new wide-angle endoscope for visible light observation on the Experimental Advanced Superconducting Tokamak (EAST) has been recently developed. The head section of the optical system is based on a mirror reflection design that is similar to the International Thermonuclear Experimental Reactor-like wide-angle observation diagnostic on the Joint European Torus. However, the optical system design has been simplified and improved. As a result, the global transmittance of the system is as high as 79.6% in the wavelength range from 380 to 780 nm, and the spatial resolution is <5 mm for the full depth of field (4000 mm). The optical system also has a large relative aperture (1:2.4) and can be applied in high-speed camera diagnostics. As an important diagnostic tool, the optical system has been installed on the HT-7 (Hefei Tokamak-7) for its final experimental campaign, and the experiments confirmed that it can be applied to the investigation of transient processes in plasma, such as ELMy eruptions in H-mode, on EAST.

  11. Recent Advances in Quantifying Hydrological Processes Linking Water, Carbon, and Energy Exports into Coastal Margins Along the Arctic Land-Sea Boundary

    NASA Astrophysics Data System (ADS)

    Rawlins, M. A.

    2014-12-01

    The high northern latitudes have experienced rapid warming in recent decades with projections of larger increases likely by the end of this century. Warming permafrost and an acceleration of the arctic freshwater cycle are among the myriad interconnected changes taking place that have the potential to impact ecosystems throughout the pan-Arctic. The Arctic Ocean receives a disproportionately large amount of global freshwater runoff and as such near-shore coastal margins along the arctic land-sea boundary are strongly influenced by riverine freshwater discharge. Alterations in hydrological flows driven by a changing climate and other perturbations, therefore, are likely to impact the biology and biogeochemistry of arctic coastal margins. Advances have been made in the quantification of water, carbon, and materials transports with recent studies documenting significant changes in exports of quantities such as dissolved organic carbon from large rivers, linked in turn to changes in landscape characteristics and hydrological flow rates. Here key measured data sets, derived empirical relationships, and the resulting pan-Arctic estimates for several constituents are described for the major arctic rivers and full pan-Arctic basin. Complementary estimates from a process-based model are presented, illustrating the potential for leveraging measured data to derive more accurate flows at basin and continental scales. A series of retrospective model simulations point to an increasing influence of river-borne heat transport on ice melt in coastal margins. Case studies of large freshwater anomalies provide a framework for understanding connections between river discharge and the biology and biogeochemistry of arctic coastal margins.

  12. Advances in Web-Based, Near Real-Time Climate Data Ingest For NOAA's Cooperative Volunteer Observation Network

    NASA Astrophysics Data System (ADS)

    Owen, T.; Brewer, M.; Redmond, K.; McCurdy, G.; Kelly, G.; Bonack, B.; Somrek, B.; Doesken, N.; Bollinger, J.

    2006-12-01

    NOAA is charged with collection, preservation and accessibility of a quality digital record of Cooperative Network data and metadata. This record has historically been derived through the imaging and keying of so- called "B-91' forms that are sent by observers and the National Weather Service to the National Climatic Data Center (NCDC). The processing time, including quality assurance checks and serial publication, typically is 45-60 days beyond the data month. Technological and communication advances, coupled with integrated climate and weather and water reporting needs have reached a threshold where near real-time (i.e., daily) reporting of observations is desirable. While ASOS data have long been directly reported to NCDC in this time horizon, National Weather Service Cooperative Network (COOP) data has continued to be recorded on forms. Timely data reporting is fundamental to the success of the U.S. effort in Global Earth Observations, especially for monitoring drought as part of the National Integrated Drought Information System (NIDIS). Coupled with implementation planning for transition of Legacy COOP under NOAA's Environmental Real-Time Observing Network (NERON), work toward such a system is timely. NOAA is working closely with Regional Climate Centers, State Climatologists and other partners to develop a web-based interface based on existing systems (e.g., WxCoder, CoCoRAHS and COOLTAP) to provide for the electronic submission of daily COOP data to NCDC and the climate community. To this end, the following guiding principles have been identified: 1) Provide efficient, easy-to-use data entry system for participating COOP observers, 2) Ensure timely availability of COOP data for all customers, 3) Improve data quality through automated near-real-time data QA/QC, 4) Achieve a paperless electronic data collection, transmission, and archiving system. 5) Allow system flexibility to meet demands of integrating data from future observing systems This presentation

  13. Correction to "Influence of Dust and Black Carbon on the Snow Albedo in the NASA Goddard Earth Observing System Version 5 Land Surface Model"

    NASA Technical Reports Server (NTRS)

    Yasunari, Teppei J.; Koster, Randal D.; Kau, K. M.; Aoki, Teruo; Sud, Yogesh C.; Yamazaki, Takeshi; Motoyoshi, Hiroki; Kokdama, Yuji

    2012-01-01

    The website information describing the forcing meteorological data used for the land surface model (LSM) simulation, which were observed at an Automated Meteorological Station CAWS) at the Sapporo District Meteorological Observatory maintained by the Japan Meteorological Agency (JMA), was missing from the text. The 1-hourly data were obtained from the website of Kisyoutoukeijouhou (Information for available JMA-observed meteorological data in the past) on the website of JMA (in Japanese) (available at: http://www.jma.go.jpijmaimenulreport.html). The measurement height information of 59.5 m for the anemometer at the Sapporo Observatory was also obtained from the website of JMA (in Japanese) (available at: http://www.jma.go.jp/jma/menu/report.html). In addition, the converted 10-m wind speed, based on the AWS/JMA data, was further converted to a 2-m wind speed prior to its use with the land model as a usual treatment of off-line Catchment simulation. Please ignore the ice absorption data on the website mentioned in paragraph [15] which was not used for our calculations (but the data on the website was mostly the same as the estimated ice absorption coefficients by the following method because they partially used the same data by Warren [1984]). We calculated the ice absorption coefficients with the method mentioned in the same paragraph, for which some of the refractive index data by Warren [1984] were used and then interpolated between wavelengths, and also mentioned in paragraph [20] for the visible (VIS) and near-infrared (NIR) ranges. The optical data we used were interpolated between wavelengths as necessary.

  14. Langley Aircraft Landing Dynamics Facility

    NASA Technical Reports Server (NTRS)

    Davis, Pamela A.; Stubbs, Sandy M.; Tanner, John A.

    1987-01-01

    The Langley Research Center has recently upgraded the Landing Loads Track (LLT) to improve the capability of low-cost testing of conventional and advanced landing gear systems. The unique feature of the Langley Aircraft Landing Dynamics Facility (ALDF) is the ability to test aircraft landing gear systems on actual runway surfaces at operational ground speeds and loading conditions. A historical overview of the original LLT is given, followed by a detailed description of the new ALDF systems and operational capabilities.

  15. Gamma-ray observations of supernova SN1987A by the balloonborne gamma-ray advanced detector

    SciTech Connect

    Coldwell, R.L.; Rester, A.C. ); Eichhorn, G. ); Starr, R.; Trombka, J.I. ); Lasche, G.P. )

    1988-01-01

    On 8 January 1988, gamma-ray advanced detector (GRAD) supernova observer was launched on a 3.3 x 10{sup 5} cubic meter helium balloon from Williams Field. The instrument maintained a float altitude of 36 kilometers as it drifted eastward along the 78{degrees}S parallel until it was brought down 320 kilometers east of Vostak Station on 10 January and recovered on 13 January. High-energy resolution gamma-ray spectra of the supernova SN1987A were taken; it is hoped that these spectra will provide evidence of explosive nucleosynthesis of the heavy elements in the supernova. Results. The earliest results of the analysis, showed evidence of gamma rays from the radioactive decay of the isotope cobalt-56, the longer-lived daughter of short-lived nickel-56, which was expected to be produced in great abundance in the supernova explosion, but the cobalt-56 line appearing most clearly in the supernova spectrum-the 1,238-kiloelectronvolt gamma-ray--was apparently split into two doppler-shifted and broadened components. This astonishing result appeared to suggest that the mantle of the supernova had expanded asymmetrically with a velocity in excess of 3,000 kilometers per second.

  16. Correlation of Quantitative Motor State Assessment Using a Kinetograph and Patient Diaries in Advanced PD: Data from an Observational Study

    PubMed Central

    Ossig, Christiana; Gandor, Florin; Fauser, Mareike; Bosredon, Cecile; Churilov, Leonid; Reichmann, Heinz; Horne, Malcolm K.; Ebersbach, Georg; Storch, Alexander

    2016-01-01

    Introduction Effective management and development of new treatment strategies for response fluctuations in advanced Parkinson’s disease (PD) largely depends on clinical rating instruments such as the PD home diary. The Parkinson’s kinetigraph (PKG) measures movement accelerations and analyzes the spectral power of the low frequencies of the accelerometer data. New algorithms convert each hour of continuous PKG data into one of the three motor categories used in the PD home diary, namely motor Off state and On state with and without dyskinesia. Objective To compare quantitative motor state assessment in fluctuating PD patients using the PKG with motor state ratings from PD home diaries. Methods Observational cohort study on 24 in-patients with documented motor fluctuations who completed diaries by rating motor Off, On without dyskinesia, On with dyskinesia, and asleep for every hour for 5 consecutive days. Simultaneously collected PKG data (recorded between 6 am and 10 pm) were analyzed and calibrated to the patient’s individual thresholds for Off and dyskinetic state by novel algorithms classifying the continuous accelerometer data into these motor states for every hour between 6 am and 10 pm. Results From a total of 2,040 hours, 1,752 hours (87.4%) were available for analyses from calibrated PKG data (7.5% sleeping time and 5.1% unclassified motor state time were excluded from analyses). Distributions of total motor state hours per day measured by PKG showed moderate-to-strong correlation to those assessed by diaries for the different motor states (Pearson’s correlations coefficients: 0.404–0.658), but inter-rating method agreements on the single-hour-level were only low-to-moderate (Cohen’s κ: 0.215–0.324). Conclusion The PKG has been shown to capture motor fluctuations in patients with advanced PD. The limited correlation of hour-to-hour diary and PKG recordings should be addressed in further studies. PMID:27556806

  17. Incorporating JULES into NASA's Land Information System (LIS) and Investigations of Land-Atmosphere Coupling

    NASA Technical Reports Server (NTRS)

    Santanello, Joseph

    2011-01-01

    NASA's Land Information System (LIS; lis.gsfc.nasa.gov) is a flexible land surface modeling and data assimilation framework developed over the past decade with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. LIS features a high performance and flexible design, and operates on an ensemble of land surface models for extension over user-specified regional or global domains. The extensible interfaces of LIS allow the incorporation of new domains, land surface models (LSMs), land surface parameters, meteorological inputs, data assimilation and optimization algorithms. In addition, LIS has also been demonstrated for parameter estimation and uncertainty estimation, and has been coupled to the Weather Research and Forecasting (WRF) mesoscale model. A visiting fellowship is currently underway to implement JULES into LIS and to undertake some fundamental science on the feedbacks between the land surface and the atmosphere. An overview of the LIS system, features, and sample results will be presented in an effort to engage the community in the potential advantages of LIS-JULES for a range of applications. Ongoing efforts to develop a framework for diagnosing land-atmosphere coupling will also be presented using the suite of LSM and PBL schemes available in LIS and WRF along with observations from the U. S .. Southern Great Plains. This methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate coupling diagnostics within the community.

  18. Vertical and horizontal NO2 transport in urban area associated with land-sea breeze as observed by ground-based MAX-DOAS

    NASA Astrophysics Data System (ADS)

    Takashima, H.; Kanaya, Y.

    2013-12-01

    Since July 2012, continuous NO2 profile observations have been performed by using ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) at Fukuoka (33.55N, 130.36E), an urban site in Japan. MAX-DOAS is a passive remote sensing technique using scatted visible and ultraviolet solar radiation at several elevation angles, and it can allow us to retrieve vertical information on several trace gasses. In this study, the vertical resolution of the profiles is roughly 1 km below 2 km height. We investigate inhomogeneity of NO2 over Fukuoka by observing at two azimuth angles, Tenjin (downtown area) direction and Itoshima (out of downtown area) direction. Understanding of the spatial inhomogeneity of NO2 in urban area is important for measuring a priori profiles for satellite and for validating chemical transport model. Diurnal variation with maximum in the morning is clearly observed in both directions throughout the year for 0-1 km. Diurnal variation with maximum around noon is sometimes observed in Itoshima direction, which is delayed by 1-2 hours from maxima in Tenjin direction. The NO2 maximum for upper level (1-2 km) is also delayed from the maximum in Tenjin direction. From the analysis of surface wind field, these variations seems to be strongly related to vertical/horizontal transport of high concentration of NO2 from the downtown area (and development of the boundary layer) and horizontal transport of low concentration from ocean associated with land-sea breeze. We also present a comparison of NO2 data measured with the Ozone Monitoring Instrument (OMI) satellite sensor.

  19. Trends in Mapping, Measuring, and Monitoring Land Cover Change

    NASA Astrophysics Data System (ADS)

    Loveland, T. R.; Hansen, M.

    2007-12-01

    The necessity for improved maps and statistics documenting the rates and characteristics of land cover change from local to global scales has been driven by the acceptance that land change has pervasive and substantial environmental consequences. The expanding need for accurate land cover change characteristics data over long time periods and large geographic areas has stimulated both methodological and mission advances. Two important methodological advances include the use of the continuous fields approach for quantifying key landscape characteristics including vegetation cover and surface imperviousness, and the increased emphasis on using probability sampling to precisely estimate land cover change rates. We are using Landsat-based sampling within ecoregions to assess 1972-2000 land change in the United States. An additional methodological trend is the use of multi-source remotely sensed data for land cover change assessments. An example that blends these three elements is our use of MODIS and Landsat to map and measure 2000-2005 global deforestation. MODIS forest fraction maps provide an annual source of forest change locations that provides an efficient means to stratify probable change. Automated classification of randomly sampled Landsat scenes provide a means for detecting forest change within forest biomes and generating precise estimates of period deforestation. Studies such as this are enabled by the NASA Earth Observing System program and the NASA-USGS Landsat Data Continuity Mission. Together, these missions extend the global Earth observation record to unprecedented levels and enable new generations of detailed land change assessments.

  20. An Exploration, for the Upper Indus Basin, of Elevation Dependency in the Relationships Between Locally Observed Near Surface Air Temperature (SAT) and Remotely-Sensed Land Surface Temperature (LST)

    NASA Astrophysics Data System (ADS)

    Forsythe, N. D.; Fowler, H. J.; Blenkinsop, S.; Kilsby, C. G.; Archer, D. R.; Hardy, A. J.; Holderness, T. D. C.

    2014-12-01

    The distribution of ground-based observations of near-surface air temperature (SAT) is extremely skewed toward low elevation areas. Land surface temperature (LST) remote sensing data products -- from thermal and infrared wavelength satellite imagery -- provide spatial coverage independent of elevation, although they only provide values for "clear sky" conditions, the prevalence of which may be influenced by elevation-dependent factors. It is thus imperative for researchers studying EDW to characterise the relationship between observations of "all-sky" SAT and "clear-sky" thermal/infrared (TIR) LST in order to overcome the extreme sparseness of SAT observations at high elevations. Drawing on local SAT observation data from both manned meteorological stations and AWS units covering an elevation range from 1500 to 4700m asl in the Upper Indus Basin, coupled with cloud climatologies from MODIS and global reanalyses, this study develops "clear-sky" and "all-sky" comparative, site-based climatologies of: [a] ground-observed SAT [b] reanalysis SAT and LST (skin surface temperature) Relationships between these climatologies and corresponding clear-sky/TIR satellite-retrieved LST are quantitatively assessed in the context of elevation-dependency and cloud cover prevalence. The implications of these relationships are discussed in the context of efforts to develop a multi-decadal TIR LST data product. While multi-decadal and even centennial trends are calculated from station-based observations of SAT, the relatively short record lengths of satellite-borne instruments used to produce currently available TIR LST data products better lend themselves to characterisation of interannual variability than trend calculation. Thus progress is detailed on EDW-driven efforts to validate such an LST product for the Himalayan region using historical imagery from the second and third generation of the Advanced Very High Resolution Radiometer (AVHRR/2, AVHRR/3) instrument flown on NOAA

  1. Recent Advances In Cryogenic Monolithic Millimeter-wave Integrated Circuit (MMIC) Low Noise Amplifiers For Astrophysical Observations

    NASA Astrophysics Data System (ADS)

    Samoska, Lorene; Church, S.; Cleary, K.; Gaier, T.; Gawande, R.; Kangaslahti, P.; Lawrence, C.; Readhead, A.; Reeves, R.; Seiffert, M.; Sieth, M.; Varonen, M.; Voll, P.

    2012-05-01

    In this work, we discuss advances in high electron mobility transistor (HEMT) low noise amplifier (LNA) monolithic millimeter-wave integrated circuits (MMICs) for use as front end amplifiers in ultra-low noise receivers. Applications include focal plane arrays for studying the polarization of the cosmic microwave background radiation and foreground separation, receiver arrays for molecular spectroscopy, and high redshift CO surveys for probing the epoch of reionization. Recent results and a summary of best indium phosphide (InP) low noise amplifier data will be presented. Cryogenic MMIC LNAs using state-of-the-art InP technology have achieved record performance, and have advantages over other detectors in the 30-300 GHz range. InP MMIC LNAs operate at room temperature and may achieve near-optimum performance at 20K, a temperature readily achieved with modern cryo-coolers. In addition, wide-bandwidth LNAs are suitable for heterodyne applications as well as direct detector applications. Recent results include Ka-band MMICs with 15K noise temperature performance, and Q-Band MMICs with on-wafer measured cryogenic noise of 12K at 38 GHz. In addition, W-Band amplifiers with 25K noise temperature at 95 GHz will be presented, as well as wide-band LNAs with noise temperature below 45K up to 116 GHz. At higher frequencies, we will discuss progress on MMIC LNAs and receiver modules in G-Band (140-220 GHz), where our group has achieved less than 60K receiver noise temperature at 166 GHz. We will address extending the high performance of these MMIC LNAs to even higher frequencies for spectroscopic surveys, and make projections on future performance given current trends. These MMIC amplifiers can play a key role in future ground-based and space-based instruments for astrophysical observations.

  2. Near-Field Tsunami Models with Rapid Earthquake Source Inversions from Land and Ocean-Based Observations: The Potential for Forecast and Warning

    NASA Astrophysics Data System (ADS)

    Melgar, D.; Bock, Y.; Crowell, B. W.; Haase, J. S.

    2013-12-01

    Computation of predicted tsunami wave heights and runup in the regions adjacent to large earthquakes immediately after rupture initiation remains a challenging problem. Limitations of traditional seismological instrumentation in the near field which cannot be objectively employed for real-time inversions and the non-unique source inversion results are a major concern for tsunami modelers. Employing near-field seismic, GPS and wave gauge data from the Mw 9.0 2011 Tohoku-oki earthquake, we test the capacity of static finite fault slip models obtained from newly developed algorithms to produce reliable tsunami forecasts. First we demonstrate the ability of seismogeodetic source models determined from combined land-based GPS and strong motion seismometers to forecast near-source tsunamis in ~3 minutes after earthquake origin time (OT). We show that these models, based on land-borne sensors only tend to underestimate the tsunami but are good enough to provide a realistic first warning. We then demonstrate that rapid ingestion of offshore shallow water (100 - 1000 m) wave gauge data significantly improves the model forecasts and possible warnings. We ingest data from 2 near-source ocean-bottom pressure sensors and 6 GPS buoys into the earthquake source inversion process. Tsunami Green functions (tGFs) are generated using the GeoClaw package, a benchmarked finite volume code with adaptive mesh refinement. These tGFs are used for a joint inversion with the land-based data and substantially improve the earthquake source and tsunami forecast. Model skill is assessed by detailed comparisons of the simulation output to 2000+ tsunami runup survey measurements collected after the event. We update the source model and tsunami forecast and warning at 10 min intervals. We show that by 20 min after OT the tsunami is well-predicted with a high variance reduction to the survey data and by ~30 minutes a model that can be considered final, since little changed is observed afterwards, is

  3. Enhanced Methane Concentrations over the East-Siberian Arctic Shelf: Explanation Hypothesis Based on the Analysis of Data from Land, Marine, and Satellite Observations.

    NASA Astrophysics Data System (ADS)

    Anisimov, O. A.; Kokorev, V.

    2014-12-01

    There is a lack of consensus with regard to the observed enhanced concentrations of methane at East Siberian Arctic Shelf (ESAS), as well as on the long-running effect it may have on the global climate. One group of scientists suggest that it is attributed to venting from the deep layers, and may dramatically increase in the coming decades due to thawing and increased perforation of permafrost, ultimately leading to amplification of the global warming. The other group refutes this hypothesis and supports the standpoint that the observed enhanced fluxes, up to 6-8 ppm whereas the latitude-mean is 185 ppm, are not related to recent permafrost changes but are rather attributed to the geological structure of the shelf. We analyzed data from land, marine and satellite observations and developed the conceptual model that consistently explains the atmospheric methane field in the Arctic in the context of the past, present, and future environmental changes. We explore the hypothesis, according to which enhanced concentrations of methane are associated with the geological history of ESAS. We hypothesized that observed enhanced methane venting is bound to unfrozen bottom sediments surrounding fault zones and paleo river beds, where permafrost never existed in the bottom sediments, while elsewhere on the inner shelf of ESAS sediments remain frozen and impermeable for gases since the last glacial maximum. We tested this hypothesis through analysis of the geological and paleo data, constructing the digital high resolution map of the fault zones and paleo river beds, comparing it with locations of the hydrographic stations where enhanced methane fluxes have been observed (Fig. 1), and performing spatial statistical analysis. We demonstrated that (1) the current rate of methane concentration rise over the ESAS does not exceed that in the rest of the Arctic and in the Northern hemisphere, and (2) the probability of methane concentrations being above the average decreases with the

  4. The LandCarbon Web Application: Advanced Geospatial Data Delivery and Visualization Tools for Communication about Ecosystem Carbon Sequestration and Greenhouse Gas Fluxes

    NASA Astrophysics Data System (ADS)

    Thomas, N.; Galey, B.; Zhu, Z.; Sleeter, B. M.; Lehmer, E.

    2015-12-01

    The LandCarbon web application (http://landcarbon.org) is a collaboration between the U.S. Geological Survey and U.C. Berkeley's Geospatial Innovation Facility (GIF). The LandCarbon project is a national assessment focused on improved understanding of carbon sequestration and greenhouse gas fluxes in and out of ecosystems related to land use, using scientific capabilities from USGS and other organizations. The national assessment is conducted at a regional scale, covers all 50 states, and incorporates data from remote sensing, land change studies, aquatic and wetland data, hydrological and biogeochemical modeling, and wildfire mapping to estimate baseline and future potential carbon storage and greenhouse gas fluxes. The LandCarbon web application is a geospatial portal that allows for a sophisticated data delivery system as well as a suite of engaging tools that showcase the LandCarbon data using interactive web based maps and charts. The web application was designed to be flexible and accessible to meet the needs of a variety of users. Casual users can explore the input data and results of the assessment for a particular area of interest in an intuitive and interactive map, without the need for specialized software. Users can view and interact with maps, charts, and statistics that summarize the baseline and future potential carbon storage and fluxes for U.S. Level 2 Ecoregions for 3 IPCC emissions scenarios. The application allows users to access the primary data sources and assessment results for viewing and download, and also to learn more about the assessment's objectives, methods, and uncertainties through published reports and documentation. The LandCarbon web application is built on free and open source libraries including Django and D3. The GIF has developed the Django-Spillway package, which facilitates interactive visualization and serialization of complex geospatial raster data. The underlying LandCarbon data is available through an open application

  5. Digital Elevation Models of the Earth derived from space-based observations: Advances and potential for geomorphological studies

    NASA Astrophysics Data System (ADS)

    Mouratidis, Antonios

    2013-04-01

    Digital Elevation Models (DEMs) are an inherently interdisciplinary topic, both due to their production and validation methods, as well as their significance for numerous disciplines. The most utilized contemporary topographic datasets worldwide are those of global DEMs. Several space-based sources have been used for the production of (almost) global DEMs, namely satellite Synthetic Aperture Radar (SAR) Interferometry/InSAR, stereoscopy of multispectral satellite images and altimetry, producing several versions of autonomous or mixed products (i.e. SRTM, ACE, ASTER-GDEM). Complementary space-based observations, such as those of Global Navigation Satellite Systems (GNSS), are also used, mainly for validation purposes. The apparent positive impact of these elevation datasets so far has been consolidated by the plethora of related scientific, civil and military applications. Topography is a prominent element for almost all Earth sciences, but in Geomorphology it is even more fundamental. In geomorphological studies, elevation data and thus DEMs can be extensively used for the extraction of both qualitative and quantitative information, such as relief classification, determination of slope and slope orientation, delineation of drainage basins, extraction of drainage networks and much more. Global DEMs are constantly becoming finer, i.e. of higher spatial resolution and more "sensitive" to elevation changes, i.e. of higher vertical accuracy and these progresses are undoubtedly considered as a major breakthrough, each time a new improved global DEM is released. Nevertheless, for Geomorphology in particular, if not already there, we are close to the point in time, where the need for discrimination between DSM (Digital Surface Model) and DTM (Digital Terrain Model) is becoming critical; if the distinction between vegetation and man-made structures on one side (DSM), and actual terrain elevation on the other side (DTM) cannot be made, then, in many cases, any further

  6. Next generation of global land cover characterization, mapping, and monitoring

    NASA Astrophysics Data System (ADS)

    Giri, C.; Pengra, B.; Long, J.; Loveland, T. R.

    2013-12-01

    Land cover change is increasingly affecting the biophysics, biogeochemistry, and biogeography of the Earth's surface and the atmosphere, with far-reaching consequences to human well-being. However, our scientific understanding of the distribution and dynamics of land cover and land cover change (LCLCC) is limited. Previous global land cover assessments performed using coarse spatial resolution (300 m-1 km) satellite data did not provide enough thematic detail or change information for global change studies and for resource management. High resolution (˜30 m) land cover characterization and monitoring is needed that permits detection of land change at the scale of most human activity and offers the increased flexibility of environmental model parameterization needed for global change studies. However, there are a number of challenges to overcome before producing such data sets including unavailability of consistent global coverage of satellite data, sheer volume of data, unavailability of timely and accurate training and validation data, difficulties in preparing image mosaics, and high performance computing requirements. Integration of remote sensing and information technology is needed for process automation and high-performance computing needs. Recent developments in these areas have created an opportunity for operational high resolution land cover mapping, and monitoring of the world. Here, we report and discuss these advancements and opportunities in producing the next generations of global land cover characterization, mapping, and monitoring at 30-m spatial resolution primarily in the context of United States, Group on Earth Observations Global 30 m land cover initiative (UGLC).

  7. The emergence of land change science for global environmental change and sustainability

    PubMed Central

    Turner, B. L.; Lambin, Eric F.; Reenberg, Anette

    2007-01-01

    Land change science has emerged as a fundamental component of global environmental change and sustainability research. This interdisciplinary field seeks to understand the dynamics of land cover and land use as a coupled human–environment system to address theory, concepts, models, and applications relevant to environmental and societal problems, including the intersection of the two. The major components and advances in land change are addressed: observation and monitoring; understanding the coupled system—causes, impacts, and consequences; modeling; and synthesis issues. The six articles of the special feature are introduced and situated within these components of study. PMID:18093934

  8. Interferometric synthetic aperture radar observation of vertical land displacement in the vicinity of the All-American Canal at the United States and Mexico border

    NASA Astrophysics Data System (ADS)

    Han, Joo-Yup

    Interferometric Synthetic Aperture Radar (InSAR) provided a synoptic view of the status of groundwater levels in the vicinity of the All-American Canal (AAC) by measuring vertical land displacements. The European Remote Sensing satellite SAR images were used to produce surface deformation maps. The full time period (1992-2000) was divided to two shorter periods (early and late) (1992-97 and 1996-2000). For low coherence areas such as agricultural fields in the Mexicali Valley, Persistent Scatterers InSAR (PSInSAR) was used to detect any deformation signals. The surface deformation maps from InSAR indicated that there were insignificant vertical land displacements in the vicinity of the AAC. However, the surrounding areas of the East Mesa Geothermal Field (EMGF) were subsiding over the full observation period (-38 mm/year). The maximum subsidence rate at the EMGF was reduced by 21% between the early (-43 mm/year) and late (-34 mm/year) periods. The AAC was within the edges of the spatial extent of the EMGF subsidence, especially during the early period, which was associated with a high averaged net geothermal production. The maximum subsidence on the East Highline Canal was -9.5 +/- 0.5 cm and -2.4 +/- 0.8 cm for the early and late periods, respectively. Results from PSInSAR in Mexicali City and the Mexicali Valley showed insignificant displacements. This lack of deformation indicated that there was no measurable surface deformation in the areas, but validation data were not available. The most interesting phenomenon is the high density of persistent scatterers in the areas between the Andrade Mesa and the Mexicali Valley, and the Sand Hills dunes. Forward modeling was conducted to characterize the reservoir zone of the EMGF based on the InSAR displacement over the full time period. Inputs to the model were the maximum subsidence (-3.8 cm) and depth of the reservoir, the radius of the reservoir and Poisson's ratio. An interactive approach was conducted to find the

  9. Assimilation of land surface temperature into the land surface model JULES with an ensemble Kalman filter

    NASA Astrophysics Data System (ADS)

    Ghent, D.; Kaduk, J.; Remedios, J.; Ardö, J.; Balzter, H.

    2010-10-01

    Land surface models have uncertainties due to their approximation of physical processes and the heterogeneity of the land surface. These can be compounded when key variables are inadequately represented. Land surface temperature (LST) is critical as it forms an integral component in the surface energy budget, water stress evaluation, fuel moisture derivation, and soil moisture-climate feedbacks. A reduction in the uncertainty of surface energy fluxes, and moisture quantification, is assumed to be achievable by constraining simulations of LST with observation data. This technique is known as data assimilation and involves the adjustment of the model state at observation times with measurements of a predictable uncertainty. In this paper, the validity of LST simulations in a regionalized parameterization of the land surface model Joint UK Land Environment Simulator (JULES) for Africa is assessed by way of a multitemporal intercomparison study with the Moderate Resolution Imaging Spectroradiometer (MODIS), the Advanced Along Track Scanning Radiometer (AATSR), and the Spinning Enhanced Visible and Infrared Imager (SEVIRI) thermal products, with a two-thirds reduction in model bias found when soil properties are reparameterized. A data assimilation experiment of SEVIRI LST into the JULES model via an ensemble Kalman filter shows an improvement in the modeled LST, soil moisture, and latent and sensible heat fluxes. This paper presents the first investigation into reducing the uncertainty in modeling energy and water fluxes with the United Kingdom's most important land surface model, JULES, by means of data assimilation of LST.

  10. Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Stress Analysis Report

    NASA Technical Reports Server (NTRS)

    Heffner, Robert

    1996-01-01

    Stress analysis of the primary structure of the Meteorological Satellites Project (METSAT) Advanced Microwave Sounding Units-A, A1 Module using static loads is presented. The structural margins of safety and natural frequency predictions for the METSAT design are reported.

  11. Advancing the discussion about systematic classroom behavioral observation, a product review of Tenny, J. (2010). eCOVE observation software. Pacific City, OR: eCOVE Software, LLC.

    PubMed

    Froiland, John Mark; Smith, Liana

    2014-05-01

    Applied child psychologists and behavioral consultants often use systematic behavioral observations to inform the psychological assessment and intervention development process for children referred for attention and hyperactivity problems. This article provides a review of the 2010 version of the eCOVE classroom observation software in terms of its utility in tracking the progress of children with attention and hyperactive behaviors and its use in evaluating teacher behaviors that may impede or promote children's attention and positive behavior. The eCOVE shows promise as an efficient tool for psychologists and behavioral consultants who want to evaluate the effects of interventions for children with symptoms of ADHD, ODD, mood disorders and learning disorders; however, some research-based improvements for future models are suggested. The reviewers also share their firsthand experience in using eCOVE to evaluate teacher and student behavior exhibited on a television show about teaching urban high school students and during a movie about an eccentric new kindergarten teacher. Rich examples are provided of using strategic behavioral observations to reveal how to improve the classroom environment so as to facilitate attention, motivation and positive behavior among youth. Broader implications for enhancing the use of systematic behavioral observations in the assessment of children and adolescents with attention disorders and related behavioral problems are discussed. Key issues are examined such as the use of behavioral observations during psychological consultation to prevent the previously found gender bias in referrals for ADHD. Using behavioral observations to enhance differential diagnosis is also discussed. PMID:22408136

  12. Detection of Rain-on-Snow (ROS) Events Using the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and Weather Station Observations

    NASA Astrophysics Data System (ADS)

    Ryan, E. M.; Brucker, L.; Forman, B. A.

    2015-12-01

    During the winter months, the occurrence of rain-on-snow (ROS) events can impact snow stratigraphy via generation of large scale ice crusts, e.g., on or within the snowpack. The formation of such layers significantly alters the electromagnetic response of the snowpack, which can be witnessed using space-based microwave radiometers. In addition, ROS layers can hinder the ability of wildlife to burrow in the snow for vegetation, which limits their foraging capability. A prime example occurred on 23 October 2003 in Banks Island, Canada, where an ROS event is believed to have caused the deaths of over 20,000 musk oxen. Through the use of passive microwave remote sensing, ROS events can be detected by utilizing observed brightness temperatures (Tb) from AMSR-E. Tb observed at different microwave frequencies and polarizations depends on snow properties. A wet snowpack formed from an ROS event yields a larger Tb than a typical dry snowpack would. This phenomenon makes observed Tb useful when detecting ROS events. With the use of data retrieved from AMSR-E, in conjunction with observations from ground-based weather station networks, a database of estimated ROS events over the past twelve years was generated. Using this database, changes in measured Tb following the ROS events was also observed. This study adds to the growing knowledge of ROS events and has the potential to help inform passive microwave snow water equivalent (SWE) retrievals or snow cover properties in polar regions.

  13. Surface Runoff Variability on two Slope Positions and Land Use in Koupendri Catchment, Benin, West Africa: Observation and Modeling using SCS_CN Approach

    NASA Astrophysics Data System (ADS)

    Azuka, C. V.; Diekkrüger, B.; Igué, A. M.; Bossa, A. Y.

    2015-12-01

    Surface runoff contributes significantly to soil erosion by water which is a serious worldwide problem causing decline in water resources quality, agricultural and forest land productivity, alongside environmental and ecological degradations. A field experiment was carried out on two hillslope (2-7 %) positions (downslope (2.3%), upslope (5.8%)) and two land use types; maize-beans intercrop (MB); fallow shrub-grassland (SG) in Koupendri catchment in north-western part of Benin, West Africa using microplots. The objective was to evaluate the influence of slope positions and land use on surface runoff and their variability, and the ability of Soil Conservation Service Curve Number (SCS-CN) approach to simulate the measured runoff on both slope positions and land use types in Koupendri catchment. Six microplots (1m x 1m) were installed at 0.5m spacing, and on the same soil type in each slope positions and land use giving a total of 24 microplots. Surface runoff was measured after each rain event from September - October, 2014 and major runoff producing rain events were selected for analysis. The data obtained was subjected to analysis of variance (ANOVA) in RCBD. The results showed a very low variability (CV= 9%) for measured surface runoff on both slope positions and land use respectively. The surface runoff measured was significantly (p < 0.05) influenced by the land use with a total surface runoff of 340.1 mm in MB as against 250.3 mm in SG. However, the higher surface runoff depth obtained at the downslope (299.9 mm) compared to the upslope (290.5 mm) was due to shallow soil depth and saturation of the soil downslope but not slope position. Thus, land use must be given greater priority in future surface runoff and soil erosion related studies in the catchment or region. A good simulation (R2= 0.92 - 0.97) of the measured runoff depth was obtained using the SCS-CN approach on both slopes and land use types. A better simulation was obtained under the cultivated plot

  14. The Use of CASES-97 Observations to Assess and Parameterize the Impact of Land-Surface Heterogeneity on Area-Average Surface Heat Fluxes for Large-Scale Coupled Atmosphere-Hydrology Models

    NASA Technical Reports Server (NTRS)

    Chen, Fei; Yates, David; LeMone, Margaret

    2001-01-01

    To understand the effects of land-surface heterogeneity and the interactions between the land-surface and the planetary boundary layer at different scales, we develop a multiscale data set. This data set, based on the Cooperative Atmosphere-Surface Exchange Study (CASES97) observations, includes atmospheric, surface, and sub-surface observations obtained from a dense observation network covering a large region on the order of 100 km. We use this data set to drive three land-surface models (LSMs) to generate multi-scale (with three resolutions of 1, 5, and 10 kilometers) gridded surface heat flux maps for the CASES area. Upon validating these flux maps with measurements from surface station and aircraft, we utilize them to investigate several approaches for estimating the area-integrated surface heat flux for the CASES97 domain of 71x74 square kilometers, which is crucial for land surface model development/validation and area water and energy budget studies. This research is aimed at understanding the relative contribution of random turbulence versus organized mesoscale circulations to the area-integrated surface flux at the scale of 100 kilometers, and identifying the most important effective parameters for characterizing the subgrid-scale variability for large-scale atmosphere-hydrology models.

  15. Satellite land remote sensing advancements for the eighties; Proceedings of the Eighth Pecora Symposium, Sioux Falls, SD, October 4-7, 1983

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Among the topics discussed are NASA's land remote sensing plans for the 1980s, the evolution of Landsat 4 and the performance of its sensors, the Landsat 4 thematic mapper image processing system radiometric and geometric characteristics, data quality, image data radiometric analysis and spectral/stratigraphic analysis, and thematic mapper agricultural, forest resource and geological applications. Also covered are geologic applications of side-looking airborne radar, digital image processing, the large format camera, the RADARSAT program, the SPOT 1 system's program status, distribution plans, and simulation program, Space Shuttle multispectral linear array studies of the optical and biological properties of terrestrial land cover, orbital surveys of solar-stimulated luminescence, the Space Shuttle imaging radar research facility, and Space Shuttle-based polar ice sounding altimetry.

  16. Current Land Subsidence and Sea Level Rise along the North American Coastal Region: Observations from 10-Year (2005-2014) Closely-Spaced GPS and Tide Gauge Stations

    NASA Astrophysics Data System (ADS)

    Yang, L.; Yu, J.; Kearns, T.; Wang, G.

    2014-12-01

    Strong evidence has proved that the global sea-level is now rising at an increased rate and it is projected to continue to rise. However the rise of the sea-level is not uniform around the world. The local or relative sea-level rise will be of great concern to the coastal regions. The combination of the land subsidence and global sea-level rise causes the relative sea-level to rise. Relative sea-level rise increases the risk of flooding and wetland loss problems in near coastal areas, which in turn have important economic, environmental, and human health consequences for the heavily populated and ecologically important coastal region. However the role played by the coastal land subsidence is commonly absent during the discussion of sea-level rise problems. The sea-level can be measured in two ways: satellite altimetry and tide gauges. The sea-level measured by satellite is called the geocentric sea-level that is relative to earth center and the one measured by tide gauges is called local sea-level that is relative to the land. The tide gauge measurements of the local sea-level do not distinguish between whether the water is rising or the land is subsiding. In some coastal areas, land subsidence is occurring at a higher rate than the geocentric sea-level is rising. This can have a great local effect. GPS technology has proven to be efficient and accurate for measuring and tracking absolute land elevation change. There are about 300 publically available Continuously Operating Reference GPS Stations (CORS) within 15 km from the coastal line along North America. In this study, we use publicly available long-history (> 5 years) CORS data to derive current (2005-2014) coastal subsidence in North America. Absolute coastal sea-level rise will be determined by combing the land subsidence and relative sea-level measurements. This study shows that the relative sea-level of the Alaska area appears to be falling because the land is uplifting; this study also shows that the

  17. [Pulmonary tuberculosis after 11 years of observation in a patient suffering from advanced squamous lung cancer cured by radical radiotherapy--a case report].

    PubMed

    Mysiorski, Grzegorz; Marciniak, Marek; Rogowska, Danuta; Sedlaczek, Andrzej; Witkiewicz, Iwona; Tarnowska-Matusiak, Marzenna; Pankowski, Juliusz

    2003-01-01

    Advanced lung cancer is a neoplasm of a poor prognosis. The treatment may improve it to a certain degree but not satisfactory. A case of squamous- cell lung cancer, in a stage III B of TNM classification, which was by cured completely radiotherapy is described. The 11 years post-treatment observation was performed without any symptoms of recurrence. Actually patient is hospitalised due to active tuberculosis. No evidence for lung cancer was found until now. PMID:14587431

  18. Assessing the Impact of Advanced Satellite Observations in the NASA GEOS-5 Forecast System Using the Adjoint Method

    NASA Technical Reports Server (NTRS)

    Gelaro, Ron; Liu, Emily; Sienkiewicz, Meta

    2011-01-01

    The adjoint of a data assimilation system provides a flexible and efficient tool for estimating observation impacts on short-range weather forecasts. The impacts of any or all observations can be estimated simultaneously based on a single execution of the adjoint system. The results can be easily aggregated according to data type, location, channel, etc., making this technique especially attractive for examining the impacts of new hyper-spectral satellite instruments and for conducting regular, even near-real time, monitoring of the entire observing system. In this talk, we present results from the adjoint-based observation impact monitoring tool in NASA's GEOS-5 global atmospheric data assimilation and forecast system. The tool has been running in various off-line configurations for some time, and is scheduled to run as a regular part of the