Analysis of the US Air Force Defense Meteorological Satellite Program Imagery for Global Lightning
NASA Technical Reports Server (NTRS)
Scharfen, Gregory R.
1999-01-01
The U. S. Air Force operates the Defense Meteorological Satellite Program (DMSP), a system of near-polar orbiting satellites designed for use in operational weather forecasting and other applications. DMSP satellites carry a suite of sensors that provide images of the earth and profiles of the atmosphere. The National Snow and Ice Data Center (NSIDC) at the University of Colorado has been involved with the archival of DMSP data and its use for several research projects since 1979. This report summarizes the portion of this involvement funded by NASA.
NASA Astrophysics Data System (ADS)
Alken, P.; Olsen, N.; Finlay, C. C.; Chulliat, A.
2017-12-01
In order to investigate the spatial structure and development of rapid (sub-decadal) changes in the geomagnetic core field, including its secular variation and acceleration, global magnetic measurements from space play a crucial role. With the end of the CHAMP mission in September 2010, there has been a gap in high-quality satellite magnetic field measurements until the Swarm mission was launched in November 2013. Geomagnetic main field models during this period have relied on the global ground observatory network which, due to its sparse spatial configuration, has difficulty in resolving secular variation and acceleration at higher spherical harmonic degrees. In this presentation we will show new results in building main field models during this "gap period", based on vector magnetic measurements from four Defense Meteorological Satellite Program (DMSP) satellites. While the fluxgate instruments onboard DMSP were not designed for high-quality core field modeling, we find that the DMSP dataset can provide valuable information on secular variation and acceleration during the gap period.
DMSP Spacecraft Charging in Auroral Environments
NASA Technical Reports Server (NTRS)
Colson, Andrew; Minow, Joseph
2011-01-01
The Defense Meteorological Satellite Program (DMSP) spacecraft are a series of low-earth orbit (LEO) satellites whose mission is to observe the space environment using the precipitating energetic particle spectrometer (SSJ/4-5). DMSP satellites fly in a geosynchronous orbit at approx.840 km altitude which passes through Earth s ionosphere. The ionosphere is a region of partially ionized gas (plasma) formed by the photoionization of neutral atoms and molecules in the upper atmosphere of Earth. For satellites in LEO, such as DMSP, the plasma density is usually high and the main contributors to the currents to the spacecraft are the precipitating auroral electrons and ions from the magnetosphere as well as the cold plasma that constitutes the ionosphere. It is important to understand how the ionosphere and auroral electrons can accumulate surface charges on satellites because spacecraft charging has been the cause of a number of significant anomalies for on-board instrumentation on high altitude spacecraft. These range from limiting the sensitivity of measurements to instrument malfunction depending on the magnitude of the potential difference over the spacecraft surface. Interactive Data Language (IDL) software was developed to process SSJ/4-5 electron and ion data and to create a spectrogram of the particles number and energy fluxes. The purpose of this study is to identify DMSP spacecraft charging events and to present a preliminary statistical analysis. Nomenclature
Geomagnetic main field modeling with DMSP
NASA Astrophysics Data System (ADS)
Alken, P.; Maus, S.; Lühr, H.; Redmon, R. J.; Rich, F.; Bowman, B.; O'Malley, S. M.
2014-05-01
The Defense Meteorological Satellite Program (DMSP) launches and maintains a network of satellites to monitor the meteorological, oceanographic, and solar-terrestrial physics environments. In the past decade, geomagnetic field modelers have focused much attention on magnetic measurements from missions such as CHAMP, Ørsted, and SAC-C. With the completion of the CHAMP mission in 2010, there has been a multiyear gap in satellite-based vector magnetic field measurements available for main field modeling. In this study, we calibrate the special sensor magnetometer instrument on board DMSP to create a data set suitable for main field modeling. These vector field measurements are calibrated to compute instrument timing shifts, scale factors, offsets, and nonorthogonality angles of the fluxgate magnetometer cores. Euler angles are then computed to determine the orientation of the vector magnetometer with respect to a local coordinate system. We fit a degree 15 main field model to the data set and compare with the World Magnetic Model and Ørsted scalar measurements. We call this model DMSP-MAG-1, and its coefficients and software are available for download at http://geomag.org/models/dmsp.html. Our results indicate that the DMSP data set will be a valuable source for main field modeling for the years between CHAMP and the recently launched Swarm mission.
1986-03-20
a thermal plasma analyzer, a fluxgate magnetometer , and a space radiation dosimeter. Together, ’these provide a strong tool for analyzing the high...the SSJ/4 auroral electron and ion detectors (Hardy et al ). the SSIE and SSIES thermal plasma experiments (Smiddy et al2 ), the SSM magnetometer (Rich...1978) The Topside Ionosphere Plasma Monitor (SSIE) for the Block 5D/Flight 2 DMSP Satellite, AFGL-TR-78-007 1, AD A058503. 3. Rich. F.J. (1984) Fluxgate
DMSP observations of high latitude Poynting flux during magnetic storms
NASA Astrophysics Data System (ADS)
Huang, Cheryl Y.; Huang, Yanshi; Su, Yi-Jiun; Hairston, Marc R.; Sotirelis, Thomas
2017-11-01
Previous studies have demonstrated that energy can enter the high-latitude regions of the Ionosphere-Thermosphere (IT) system on open field lines. To assess the extent of high-latitude energy input, we have carried out a study of Poynting flux measured by the Defense Meteorological Satellite Program (DMSP) satellites during magnetic storms. We report sporadic intense Poynting fluxes measured by four DMSP satellites at polar latitudes during two moderate magnetic storms which occurred in August and September 2011. Comparisons with a widely used empirical model for energy input to the IT system show that the model does not adequately capture electromagnetic (EM) energy at very high latitudes during storms. We have extended this study to include more than 30 storm events and find that intense EM energy is frequently detected poleward of 75° magnetic latitude.
Options for Modernizing Military Weather Satellites
2012-09-01
was prepared under the supervision of David E. Mosher and Matthew S. Goldberg of CBO’s National Security Division. It draws on earlier analysis ...DoD pioneered the use of weather satellites to observe cloud patterns so that intelligence analysts would not waste the limited supply of film ...based on CBO analysis of DoD plans. X X X X X 2012 2016 2020 2024 2028 2032 2036 WSF 2 WSF 1 DMSP 20 DMSP 19 DMSP 17 DMSP 18 DMSP 16 JPSS 2 JPSS
The DMSP Space Weather Sensors Data Archive Listing (1982-2013) and File Formats Descriptions
2014-08-01
environment sensors including the auroral particle spectrometer (SSJ), the fluxgate magnetometer (SSM), the topside thermal plasma monitor (SSIES... Fluxgate Magnetometer (SSM) for the Defense Meteorological Satellite Program (DMSP) Block 5D-2, Flight 7, Instrument Papers, AFGL-TR-84-0225; ADA155229...Flux) SSM The fluxgate magnetometer . (Special Sensor, Magnetometer ) SSULI The ultraviolet limb imager SSUSI The ultraviolet spectrographic imager
Survey of DMSP Charging Events During the Period Preceding Cycle 23 Solar Maximum
NASA Technical Reports Server (NTRS)
Parker, Linda Neergaard; Minow, Joseph I.
2013-01-01
It has been well established that POLAR orbiting satellites can see mild to severe charging levels during solar minimum conditions (Frooninckx and Sojka, 1992, Anderson and Koons, 1996, Anderson, 2012). However, spacecraft operations during solar maximum cannot be considered safe from auroral charging. Recently, we have seen examples of high level charging during the recent approach to solar maximum. We present here a survey of charging events seen by the Defense Meteorological Satellite Program (DMSP) satellites (F16, F17) during the solstices of 2011 and 2012. In this survey, we summarize the condition necessary for charging to occur in this environment, we describe how the lower than normal maximum conditions are conducive to the environment conditions necessary for charging in the POLAR orbit, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period. We also show examples of other interesting phenomenological events seen in the DMSP data, but which are not considered surface charging events, and discuss the differences.
Survey of DMSP Charging During the Period Preceding Cycle 24 Solar Maximum
NASA Technical Reports Server (NTRS)
NeergaardParker, L.; Minow, Joseph I.
2013-01-01
It has been well established that polar orbiting satellites can see mild to severe charging levels during solar minimum conditions (Frooninckx and Sojka, 1992, Anderson and Koons, 1996, Anderson, 2012). However, spacecraft operations during solar maximum cannot be considered safe from auroral charging. Recently, we have seen examples of high level charging during the recent approach to solar maximum. We present here a survey of charging events seen by the Defense Meteorological Satellite Program (DMSP) satellites (F16, F17) during the solstices of 2011 and 2012. In this survey, we summarize the condition necessary for charging to occur in this environment, we describe how the lower than normal maximum conditions are conducive to the environment conditions necessary for charging in the polar orbit, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period. We also show examples of other interesting phenomenological events seen in the DMSP data, but which are not considered surface charging events, and discuss the differences.
Arctic sea ice albedo - A comparison of two satellite-derived data sets
NASA Technical Reports Server (NTRS)
Schweiger, Axel J.; Serreze, Mark C.; Key, Jeffrey R.
1993-01-01
Spatial patterns of mean monthly surface albedo for May, June, and July, derived from DMSP Operational Line Scan (OLS) satellite imagery are compared with surface albedos derived from the International Satellite Cloud Climatology Program (ISCCP) monthly data set. Spatial patterns obtained by the two techniques are in general agreement, especially for June and July. Nevertheless, systematic differences in albedo of 0.05 - 0.10 are noted which are most likely related to uncertainties in the simple parameterizations used in the DMSP analyses, problems in the ISCCP cloud-clearing algorithm and other modeling simplifications. However, with respect to the eventual goal of developing a reliable automated retrieval algorithm for compiling a long-term albedo data base, these initial comparisons are very encouraging.
Snow cover of the Upper Colorado River Basin from satellite passive microwave and visual imagery
Josberger, E.G.; Beauvillain, E.
1989-01-01
A comparison of passive microwave images from the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) and visual images from the Defense Meteorological Satellite Program (DMSP) of the Upper Colorado River Basin shows that passive microwave satellite imagery can be used to determine the extent of the snow cover. Eight cloud-free DMSP images throughout the winter of 1985-1986 show the extent of the snowpack, which, when compared to the corresponding SMMR images, determine the threshold microwave characteristics for snow-covered pixels. With these characteristics, the 27 sequential SMMR images give a unique view of the temporal history of the snow cover extent through the first half of the water year. -from Authors
Quantification of Transient Changes of Thermospheric Neutral Density
2014-11-24
Pedersen conductivity at high latitudes. Based on Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites...the model. The seasonal variations of the ratio have been investigated for both hemispheres, and an interhemispheric asymmetry has been identified...Satellite Program (DMSP) F- 15, F-16, F-17 and F-18 satellites and the Iridium satellite constellation is presented, using an inverse procedure for high
Observations and Operational Products from the Special Sensor Ultraviolet Limb Imager (SSULI)
NASA Astrophysics Data System (ADS)
Dandenault, Patrick; Nicholas, Andrew C.; Coker, Clayton; Budzien, Scott A.; Chua, Damien H.; Finne, Ted T.; Metzler, Christopher A.; Dymond, Kenneth F.
The Naval Research Laboratory (NRL) has developed five ultraviolet remote sensing instru-ments for the Air Force Defense Meteorological Satellite Program (DMSP). These instruments known as SSULI (Special Sensor Ultraviolet Limb Imager) are on the DMSP block of 5D3 satellites, which first launched in 2003. The DMSP satellites are launched in a near-polar, sun-synchronous orbit at an altitude of approximately 830 km. SSULI measures vertical profiles of the natural airglow radiation from atoms, molecules and ions in the upper atmosphere and ionosphere by viewing the earth's limb at a tangent altitude of approximately 50 km to 750 km. Limb observations are made from the extreme ultraviolet (EUV) to the far ultraviolet (FUV) over the wavelength range of 80 nm to 170 nm, with 1.8 nm resolution. An extensive operational data processing system, the SSULI Ground Data Analysis Software (GDAS), has been developed to generate environmental data products from SSULI spectral data in near-real time for use at the Air Force Weather Agency (AFWA). The operational software uses advanced science algorithms developed at NRL and was designed to calibrate data from USAF Raw Sensor Data Records (RSDR) and generate Environmental Data Records (EDRs). Data products from SSULI observations include vertical profiles of electron (Ne) densities, N2, O2, O, O+, Temperature and also vertical Total Electron Content (TEC). On October 18, 2009, the third SSULI sensor launched from Vandenberg Air Force Base, aboard the DMSP F18 spacecraft. An overview of the SSULI operational program and the status of the F18 sensor will be discussed.
Energetics of the April 2000 magnetic superstorm observed by DMSP
NASA Astrophysics Data System (ADS)
Burke, William J.; Huang, Cheryl Y.; Rich, Frederick J.
2006-01-01
During the late main phase of the April 6, 2000 storm with Dst approaching -300 nT, four Defense Meteorological Satellite Program (DMSP) satellites encountered repeated episodes of intense field-aligned currents whose magnetic perturbations exceeded 1300 nT, corresponding to |J∥| > 1 A/m. They had relatively fast rise times (˜5 min) and lasted for ˜20 min. The large magnetic perturbations occurred within the expanded auroral oval at magnetic latitudes below 60°. From Poynting-flux calculations we estimate that during each event several hundred tera-Joules of energy that dissipates in the mid-latitude ionosphere and thermosphere. Ground magnetometers at auroral and middle latitudes detected weak fluctuations that were incommensurate with magnetic perturbations observations at DMSP altitudes. Observed discrepancies between ground and satellite magnetometer measurements suggest that under storm conditions operational models systematically underestimate the level of electromagnetic energy available to the ionosphere thermosphere. We demonstrate a transmission-line model for M-I coupling that allows calculations of this electromagnetic energy input with no a priori knowledge of ionospheric conductances.
High-resolution satellite imagery for mesoscale meteorological studies
NASA Technical Reports Server (NTRS)
Johnson, David B.; Flament, Pierre; Bernstein, Robert L.
1994-01-01
In this article high-resolution satellite imagery from a variety of meteorological and environmental satellites is compared. Digital datasets from Geostationary Operational Environmental Satellite (GOES), National Oceanic and Atmospheric Administration (NOAA), Defense Meteorological Satellite Program (DMSP), Landsat, and Satellite Pour l'Observation de la Terre (SPOT) satellites were archived as part of the 1990 Hawaiian Rainband Project (HaRP) and form the basis of the comparisons. During HaRP, GOES geostationary satellite coverage was marginal, so the main emphasis is on the polar-orbiting satellites.
A temperature and vegetation adjusted NTL urban index for urban area mapping and analysis
NASA Astrophysics Data System (ADS)
Zhang, Xiya; Li, Peijun
2018-01-01
Accurate and timely information regarding the extent and spatial distribution of urban areas on regional and global scales is crucially important for both scientific and policy-making communities. Stable nighttime light (NTL) data from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) provides a unique proxy of human settlement and activity, which has been used in the mapping and analysis of urban areas and urbanization dynamics. However, blooming and saturation effects of DMSP/OLS NTL data are two unresolved problems in regional urban area mapping and analysis. This study proposed a new urban index termed the Temperature and Vegetation Adjusted NTL Urban Index (TVANUI). It is intended to reduce blooming and saturation effects and to enhance urban features by combining DMSP/OLS NTL data with Normalized Difference Vegetation Index (NDVI) and land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer onboard the Terra satellite. The proposed index was evaluated in two study areas by comparison with established urban indices. The results demonstrated the proposed TVANUI was effective in enhancing the variation of DMSP/OLS light in urban areas and in reducing blooming and saturation effects, showing better performance than three established urban indices. The TVANUI also significantly outperformed the established urban indices in urban area mapping using both the global-fixed threshold and the local-optimal threshold methods. Thus, the proposed TVANUI provides a useful variable for urban area mapping and analysis on regional scale, as well as for urbanization dynamics using time-series DMSP/OLS and related satellite data.
The extent of burning in African savanna
NASA Technical Reports Server (NTRS)
Cahoon, D. R. JR.; Levine, J. S.; Cofer, W. R. Iii; Stocks, B. J.
1994-01-01
The temporal and spatial distribution of African savanna grassland fires has been examined, and the areal extent of these fires has been estimated for the subequatorial African continent. African savanna fires have been investigated using remote sensing techniques and imagery collected by low-light sensors on Defense Meteorological Satellite Program (DMSP) satellites and by the Advanced Very High Resolution Radiometer (AVHRR) which is aboard polar orbiting National Oceanic and Atmospheric Administration (NOAA) satellites. DMSP imagery has been used to map the evolution of savanna burning over all of the African continent and the analysis of AVHRR imagery has been used to estimate the areal extent of the burning in the southern hemispheric African savannas. The work presented primarily reflects the analysiscompleted for the year 1987. However, comparisons have been made with other years and the representativeness of the 1987 analysis is discussed.
NASA Technical Reports Server (NTRS)
Epperson, David L.; Davis, Jerry M.; Bloomfield, Peter; Karl, Thomas R.; Mcnab, Alan L.; Gallo, Kevin P.
1995-01-01
A methodology is presented for estimating the urban bias of surface shelter temperatures due to the effect of the urban heat island. Multiple regression techniques were used to predict surface shelter temperatures based on the time period 1986-89 using upper-air data from the European Centre for Medium-Range Weather Forecasts (ECMWF) to represent the background climate, site-specific data to represent the local landscape, and satellite-derived data -- the normalized difference vegetation index (NDVI) and the Defense Meteorological Satellite Program (DMSP) nighttime brightness data -- to represent the urban and rural landscape. Local NDVI and DMSP values were calculated for each station using the mean NDVI and DMSP values from a 3 km x 3 km area centered over the given station. Regional NDVI and DMSP values were calculated to represent a typical rural value for each station using the mean NDVI and DMSP values from a 1 deg x 1 deg latitude-longitude area in which the given station was located. Models for the United States were then developed for monthly maximum, mean, and minimum temperatures using data from over 1000 stations in the U.S. Cooperative (COOP) Network and for monthly mean temperatures with data from over 1150 stations in the Global Historical Climate Network (GHCN). Local biases, or the differences between the model predictions using the observed NDVI and DMSP values, and the predictions using the background regional values were calculated and compared with the results of other research. The local or urban bias of U.S. temperatures, as derived from all U.S. stations (urban and rural) used in the models, averaged near 0.40 C for monthly minimum temperatures, near 0.25 C for monthly mean temperatures, and near 0.10 C for monthly maximum temperatures. The biases of monthly minimum temperatures for individual stations ranged from near -1.1 C for rural stations to 2.4 C for stations from the largest urban areas. The results of this study indicate minimal problems for global application once global NDVI and DMSP data become available.
Poverty assessment using DMSP/OLS night-time light satellite imagery at a provincial scale in China
NASA Astrophysics Data System (ADS)
Wang, Wen; Cheng, Hui; Zhang, Li
2012-04-01
All countries around the world and many international bodies, including the United Nations Development Program (UNDP), United Nations Food and Agricultural Organization (FAO), the International Fund for Agricultural Development (IFAD) and the International Labor Organization (ILO), have to eliminate rural poverty. Estimation of regional poverty level is a key issue for making strategies to eradicate poverty. Most of previous studies on regional poverty evaluations are based on statistics collected typically in administrative units. This paper has discussed the deficiencies of traditional studies, and attempted to research regional poverty evaluation issues using 3-year DMSP/OLS night-time light satellite imagery. In this study, we adopted 17 socio-economic indexes to establish an integrated poverty index (IPI) using principal component analysis (PCA), which was proven to provide a good descriptor of poverty levels in 31 regions at a provincial scale in China. We also explored the relationship between DMSP/OLS night-time average light index and the poverty index using regression analysis in SPSS and a good positive linear correlation was modelled, with R2 equal to 0.854. We then looked at provincial poverty problems in China based on this correlation. The research results indicated that the DMSP/OLS night-time light data can assist analysing provincial poverty evaluation issues.
High-level spacecraft charging in the low-altitude polar auroral environment
NASA Astrophysics Data System (ADS)
Gussenhoven, M. S.; Hardy, D. A.; Rich, F.; Burke, W. J.; Yeh, H.-C.
1985-11-01
Regions of intense keV electron precipitation, such as inverted-V structures, at times colocate with ionospheric plasma depletion regions in the high-latitude polar ionosphere. When Defense Meteorological Satellite Program (DMSP) F6 and F7 satellites, at 840 km, enter these regions in darkness, ion signatures of high spacecraft-to-ambient plasma potential differences (several hundred volts negative) are observed with the new SSJ/4 ion detectors. A systematic survey of charging events and the environment in which they occur was made using the DMSP F6 and F7 precipitating ion and electron detectors, the SSIE thermal plasma probes, and the SSM (F7 only) vector magnetometer. The charging events of November 26, 1983, are analyzed in detail since they occurred on both satellites. Critical levels of number flux and average energy for the precipitating electrons, and the threshold density of the thermal ionospheric ions are defined for different levels of spacecraft charging.
On Using the Weimer Statistical Model for Real-Time Ionospheric Specifications and Forecasts
NASA Astrophysics Data System (ADS)
Bekerat, H. A.; Schunk, R. W.; Scherliess, L.
2002-12-01
The Weimer statistical model (Weimer, 2001) for the high-latitude convection pattern was tested with regard to its ability to produce real-time convection patterns. This work is being conducted under the polar section of GAIM (Global Assimilation of Ionospheric Measurements). The method adopted involves the comparison of the cross-track ion drift velocities measured by DMSP satellites with those calculated from the Weimer model. Starting with a Weimer pattern obtained using real-time IMF and solar wind data at the time of a DMSP satellite pass in the high-latitude ionosphere, the cross-track ion drift velocities along the DMSP track were calculated from the Weimer convection model and compared to those measured by the DMSP satellite. Then, in order to improve the agreement between the measurement and the model, two of the input parameters to the model, the IMF clock-angle and the solar wind speed, were varied to get the pattern that gives the best agreement with the DMSP satellite measurements. Four months of data (March, July, September, and December 1998) were used to test the Weimer model. The result shows that the agreement between the measurement and the Weimer model is improved by using this procedure. The Weimer model is good in a statistical sense, it was able to produce the large-scale structure in most cases. However, it is not good enough to be used for real-time ionospheric specifications and forecasts because it failed to produce a lot of the mesoscale structure measured along most DMSP satellite passes. Reference Weimer, D. R., J. Geophys. Res., 106, 407,2001
NASA Astrophysics Data System (ADS)
Huang, Y.; Su, Y. J.; Huang, C. Y.; Hairston, M. R.; Sutton, E. K.
2015-12-01
We will present various observations regarding the geomagnetic energy input and the response of Ionosphere-Thermosphere (IT) system during the March 17, 2015 storm, the largest one in solar cycle 24. The Poynting fluxes measured by Defense Meteorological Satellite Program (DMSP) satellites (F16, F17 and F18) show significant enhancements in the auroral oval and at high latitudes poleward of the auroral oval. Moreover, the ion temperatures observed by DMSP satellites (F16, F17 and F19) at magnetic latitudes greater than 80° are higher than those in the auroral oval, and the their averaged increases are 316K in the northern hemisphere and 248 K in the southern hemisphere, respectively. In addition, the neutral density residuals measured by the Gravity Recovery and Climate Experiment (GRACE) satellite indicate the largest values at the highest orbital latitudes. The wave-like perturbations originating at high latitudes move equatorward with decreasing amplitudes along GRACE orbits, implying a source region for Traveling Atmospheric Disturbances (TADs) at polar latitudes.
The TOPEX satellite option study
NASA Technical Reports Server (NTRS)
1982-01-01
The applicability of an existing spacecraft bus and subsystems to the requirements of ocean circulation measurements are assessed. The operational meteorological satellite family TIROS and DMSP are recommended. These programs utilize a common bus to satisfy their Earth observation missions. Note that although the instrument complements were different, the pointing accuracies were different, and, initially, the boosters were different, a high degree of commonality was achieved.
NASA Astrophysics Data System (ADS)
Mishin, E. V.; Burke, W. J.
2005-07-01
We compare plasma and field disturbances observed in the ring current/plasmasphere overlap region and in the conjugate ionosphere during the magnetic storm of 5 June 1991. Data come from the Combined Release and Radiation Effects Satellite (CRRES) flying in a geostationary transfer orbit and three satellites of the Defense Meteorological Satellite Program (DMSP) series in Sun-synchronous polar orbits. In the region between ring current nose structures and the electron plasma sheet, CRRES detected wave-like features in local electric and magnetic fields, embedded in structured cold plasmas. Mapped to the ionosphere, these fields should reflect structuring within subauroral plasma streams (SAPS). Indeed, during the period of interest, DMSP F8, F9, and F10 satellites observed highly structured SAPS in the evening ionosphere at topside altitudes. They were collocated with precipitating ring current ions, enhanced fluxes of suprathermal electrons and ions, elevated electron temperatures, and irregular plasma density troughs. Overall, these events are similar to electromagnetic structures observed by DMSP satellites within SAPS during recent geomagnetic storms (Mishin et al., 2003, 2004). Their features can be explained in terms of Alfvén and fast magnetosonic perturbations. We developed a scenario for the formation of elevated electron temperatures at the equatorward side of the SAPS. It includes a lower-hybrid drift instability driven by diamagnetic currents, consistent with strong lower- and upper-hybrid plasma wave activity and intense fluxes of the low-energy electrons and ions near the ring current's inner edge.
Radiometry with nighttime DMSP images in digital form. [satellite earth observations
NASA Technical Reports Server (NTRS)
Croft, T. A.
1981-01-01
The USAF Defense Meteorological Satellite Program (DMSP) spacecraft sends images to earth in the form of numbers. It has been common practice to erase the only digital records, the magnetic tapes, for reuse, after films (resembling photographs) have been created from the numbers. While the DMSP images have been widely used, their application in research has been hindered by both the lack of digital data and the lack of an authoritative source of related technical information. The character of the digital form is considered. Each image is essentially a three-dimensional list (X,Y,Z) in which X and Y represent the position coordinates of a pixel and Z is its associated radiance. Only the value of Z is given and the X-Y position must be deduced from adjunct information. Each original scan composed of 1464 pixels represents an area on the earth's surface about 3 km wide and 3000 km long. Strengths and weaknesses of the system with respect to research applications are considered, and concepts for the design of a nocturnal imager are discussed.
Processing of DMSP magnetic data: Handbook of programs, tapes, and datasets
NASA Technical Reports Server (NTRS)
Langel, R. A.; Sabaka, T. J.; Ridgway, J. R.
1990-01-01
The DMSP F-7 satellite was an operational Air Force meteorological satellite which carried a magnetometer for geophysical measurements. The magnetometer was located within the body of the spacecraft in the presence of large spacecraft fields. In addition to stray magnetic fields, the data have inherent position and time inaccuracies. Algorithms were developed to identify and remove time varying magnetic field noise from the data. These algorithms are embodied in an automated procedure which fits a smooth curve through the data and then identifies outliers and which filters the predominant Fourier component of noise from the data. Techniques developed for Magsat were then modified and used to attempt determination of the spacecraft fields, of any rotation between the magnetometer axes and the spacecraft axes, and of any scale changes within the magnetometer itself. Software setup and usage are documented and program listings are included in the Appendix. The initial and resulting data are archived on magnetic cartridge and the formats are documented.
NASA Technical Reports Server (NTRS)
Newell, Patrick T.; Meng, CHING-I.; Huffman, Robert E.
1992-01-01
The Polar Beacon Experiment and Auroral Research (Polar BEAR) satellite included the capability for imaging the dayside auroral oval in full sunlight at several wavelengths. Particle observations from the DMSP F7 satellite during dayside auroral oval crossings are compared with approximately simultaneous Polar BEAR 1356-A images to determine the magnetospheric source region of the dayside auroral oval. The source region is determined from the DMSP particle data, according to recent work concerning the classification and identification of precipitation source regions. The close DMSP/Polar BEAR coincidences all occur when the former satellite is located between 0945 and 1000 MLT. Instances of auroral arcs mapping to each of several different regions, including the boundary plasma sheet, the low-latitude boundary layer, and the plasma mantle were found. It was determined that about half the time the most prominent auroral arcs are located at the interfaces between distinct plasma regions, at least at the local time studied here.
High-latitude spacecraft charging in low-Earth polar orbit
NASA Astrophysics Data System (ADS)
Frooninckx, Thomas B.
Spacecraft charging within the upper ionosphere is commonly thought to be insignificant and thus has received little attention. Recent experimental evidence has shown that electric potential differences as severe as 680 volts can develop between Defense Meteorological Satellite Program (DMSP) polar-orbiting (840 kilometers) spacecraft and their high-latitude environment. To explore space vehicle charging in this region more fully, an analysis was performed using DMSP F6, F7, F8, and F9 satellite precipitating particle and ambient plasma measurements taken during the winters of 1986-87 (solar minimum) and 1989-90 (solar maximum). An extreme solar cycle dependence was discovered as charging occurred more frequently and with greater severity during the period of solar minimum. One hundred seventy charging events ranging from -46 to 1,430 volts were identified, and satellite measurements and Time Dependent Ionospheric Model (TDIM) output were used to characterize the environments which generated and inhibited these potentials. All current sources were considered to determine the cause of the solar cycle dependence.
Data Impact of the DMSP F18 SSULI UV Data on the Operational GAIM Model
NASA Astrophysics Data System (ADS)
Dandenault, P. B.; Metzler, C. A.; Nicholas, A. C.; Coker, C.; Budzien, S. A.; Chua, D. H.; Finne, T. T.; Dymond, K.; Walker, P. W.; Schunk, R. W.; Scherliess, L.; Gardner, L. C.
2011-12-01
The Naval Research Laboratory (NRL) has developed five ultraviolet remote sensing instruments for the United States Air Force (USAF) Defense Meteorological Satellite Program (DMSP). The DMSP satellites are launched in a near-polar, sun-synchronous orbit at an altitude of approximately 830 km. Each Special Sensor Ultraviolet Limb Imager (SSULI) instrument measures vertical profiles of the natural airglow radiation from atoms, molecules and ions in the upper atmosphere and ionosphere by viewing the earth's limb within a tangent altitude range of approximately 50 km to 750 km. Limb observations are made from the extreme ultraviolet (EUV) to the far ultraviolet (FUV) over the wavelength range of 80 nm to 170 nm, with 1.8 nm resolution. Data products from SSULI observations include nightglow and dayglow Sensor Data Records (SDRs), as well as Environmental Data Records (EDRs) which contain vertical profiles of electron (Ne) densities, N2, O2, O, O+, and Temperature, hmF2, NmF2 and vertical Total Electron Content (TEC). On October 18, 2009, the third SSULI sensor launched from Vandenberg Air Force Base aboard the DMSP F18 spacecraft. The Calibration and Validation of the F18 instrument has completed and the SSULI program is scheduled to go operational at the Air Force Weather Agency (AFWA) in Fall 2011. The SSULI F18 data are ingested by the Global Assimilation of Ionospheric Measurements (GAIM) space weather model, which was developed by Utah State University and has been used operationally at AFWA since February 2006. A brief overview of the SSULI F18 SDR data assimilation process with GAIM is provided and the impact of the SSULI 1356 Å emission on the GAIM model is examined for spring and summer 2011 nightside data in the low-latitude region.
NASA Astrophysics Data System (ADS)
Landry, R. G.; Anderson, P. C.
2017-12-01
Subauroral ion drifts (SAID) are a phenomenon sometimes observed in the subauroral ionosphere in dusk to post-midnight magnetic local time sectors during magnetically active periods characterized by strong poleward electric fields that drive westward ion drifts greater than 1 km/s. SAIDs typically will span 1-2 degrees magnetic latitude and several hours in magnetic local time. SAIDs are often observed colocated with the midlatitude trough. The strong electric field can act to reduce the ionospheric conductivity further through enhanced recombination and vertical transport. The theory that SAIDs are generated by ionospheric Pedersen currents fed by ring current driven field-aligned currents (FAC) requires the decreased conductance associated with the midlatitude trough to produce the latitudinally narrow, large amplitude SAID electric field. Using Dynamics Explorer 2 (DE 2) plasma measurements of SAIDs from altitudes of 200 to 1000 km, we investigate the statistical variation of the ionospheric composition, temperature, and vertical ion drifts as a function of altitude. Using Defense Meteorological Satellite Program (DMSP) measurements from 1987-2012, we extend the empirical study at the DMSP altitude of 830 km to investigate how season, longitude, and any ionospheric preconditioning before SAID formation affect the likelihood of SAID occurrence and coincidence with FACs and ion density troughs.
New DMSP database of precipitating auroral electrons and ions
NASA Astrophysics Data System (ADS)
Redmon, Robert J.; Denig, William F.; Kilcommons, Liam M.; Knipp, Delores J.
2017-08-01
Since the mid-1970s, the Defense Meteorological Satellite Program (DMSP) spacecraft have operated instruments for monitoring the space environment from low Earth orbit. As the program evolved, so have the measurement capabilities such that modern DMSP spacecraft include a comprehensive suite of instruments providing estimates of precipitating electron and ion fluxes, cold/bulk plasma composition and moments, the geomagnetic field, and optical emissions in the far and extreme ultraviolet. We describe the creation of a new public database of precipitating electrons and ions from the Special Sensor J (SSJ) instrument, complete with original counts, calibrated differential fluxes adjusted for penetrating radiation, estimates of the total kinetic energy flux and characteristic energy, uncertainty estimates, and accurate ephemerides. These are provided in a common and self-describing format that covers 30+ years of DMSP spacecraft from F06 (launched in 1982) to F18 (launched in 2009). This new database is accessible at the National Centers for Environmental Information and the Coordinated Data Analysis Web. We describe how the new database is being applied to high-latitude studies of the colocation of kinetic and electromagnetic energy inputs, ionospheric conductivity variability, field-aligned currents, and auroral boundary identification. We anticipate that this new database will support a broad range of space science endeavors from single observatory studies to coordinated system science investigations.
Ou, Jinpei; Liu, Xiaoping; Li, Xia; Li, Meifang; Li, Wenkai
2015-01-01
Recently, the stable light products and radiance calibrated products from Defense Meteorological Satellite Program's (DMSP) Operational Linescan System (OLS) have been useful for mapping global fossil fuel carbon dioxide (CO2) emissions at fine spatial resolution. However, few studies on this subject were conducted with the new-generation nighttime light data from the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the Suomi National Polar-orbiting Partnership (NPP) Satellite, which has a higher spatial resolution and a wider radiometric detection range than the traditional DMSP-OLS nighttime light data. Therefore, this study performed the first evaluation of the potential of NPP-VIIRS data in estimating the spatial distributions of global CO2 emissions (excluding power plant emissions). Through a disaggregating model, three global emission maps were then derived from population counts and three different types of nighttime lights data (NPP-VIIRS, the stable light data and radiance calibrated data of DMSP-OLS) for a comparative analysis. The results compared with the reference data of land cover in Beijing, Shanghai and Guangzhou show that the emission areas of map from NPP-VIIRS data have higher spatial consistency of the artificial surfaces and exhibit a more reasonable distribution of CO2 emission than those of other two maps from DMSP-OLS data. Besides, in contrast to two maps from DMSP-OLS data, the emission map from NPP-VIIRS data is closer to the Vulcan inventory and exhibits a better agreement with the actual statistical data of CO2 emissions at the level of sub-administrative units of the United States. This study demonstrates that the NPP-VIIRS data can be a powerful tool for studying the spatial distributions of CO2 emissions, as well as the socioeconomic indicators at multiple scales.
NASA Sea Ice and Snow Validation Program for the DMSP SSM/I: NASA DC-8 flight report
NASA Technical Reports Server (NTRS)
Cavalieri, D. J.
1988-01-01
In June 1987 a new microwave sensor called the Special Sensor Microwave Imager (SSM/I) was launched as part of the Defense Meteorological Satellite Program (DMSP). In recognition of the importance of this sensor to the polar research community, NASA developed a program to acquire the data, to convert the data into sea ice parameters, and finally to validate and archive both the SSM/I radiances and the derived sea ice parameters. Central to NASA's sea ice validation program was a series of SSM/I aircraft underflights with the NASA DC-8 airborne Laboratory. The mission (the Arctic '88 Sea Ice Mission) was completed in March 1988. This report summarizes the mission and includes a summary of aircraft instrumentation, coordination with participating Navy aircraft, flight objectives, flight plans, data collected, SSM/I orbits for each day during the mission, and lists several piggyback experiments supported during this mission.
NASA Astrophysics Data System (ADS)
Cao, Yang; Zhang, Jing; Yang, Mingxiang; Lei, Xiaohui
2017-07-01
At present, most of Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS) night-time light data are applied to large-scale regional development assessment, while there are little for the study of earthquake and other disasters. This study has extracted night-time light information before and after earthquake within Wenchuan county with adoption of DMSP/OLS night-time light data. The analysis results show that the night-time light index and average intensity of Wenchuan county were decreased by about 76% and 50% respectively from the year of 2007 to 2008. From the year of 2008 to 2011, the two indicators were increased by about 200% and 556% respectively. These research results show that the night-time light data can be used to extract the information of earthquake and evaluate the occurrence of earthquakes and other disasters.
Maintaining US Space Weather Capabilities after DMSP: Research to Operations
NASA Astrophysics Data System (ADS)
Machuzak, J. S.; Gentile, L. C.; Burke, W. J.; Holeman, E. G.; Ober, D. M.; Wilson, G. R.
2012-12-01
The first Defense Meteorological Satellite Program (DMSP) spacecraft was launched in 1972; the last is scheduled to fly in 2020. Presently, there is no replacement for the space-weather monitoring sensors that now fly on DMSP. The present suite has provided comprehensive, long-term records that constitute a critical component of the US space weather corporate memory. Evolving operational needs and research accomplishments justify continued collection of space environmental data. Examples include measurements to: (1) Monitor the Dst index in real time as a driver of next-generation satellite drag models; (2) Quantify electromagnetic energy fluxes from deep space to the ionosphere/ thermosphere that heat neutrals, drive disturbance-dynamo winds and degrade precise orbit determinations; (3) Determine strengths of stormtime electric fields at high and low latitudes that lead to severe blackouts and spacecraft anomalies; (4) Specify variability of plasma density irregularities, equatorial plasma bubbles, and the Appleton anomaly to improve reliability of communication, navigation and surveillance links; (5) Characterize energetic particle fluxes responsible for auroral clutter and radar degradation; (6) Map regions of L-Band scintillation for robust GPS applications; and (7) Update the World Magnetic Field Model needed to maintain guidance system superiority. These examples illustrate the utility of continued space environment awareness. Comprehensive assessments of both operational requirements and research advances are needed to make informed selections of sensors and spacecraft that support future capabilities. A proposed sensor set and satellite constellation to provide the needed measurement capabilities will be presented.
New DMSP Database of Precipitating Auroral Electrons and Ions.
Redmon, Robert J; Denig, William F; Kilcommons, Liam M; Knipp, Delores J
2017-08-01
Since the mid 1970's, the Defense Meteorological Satellite Program (DMSP) spacecraft have operated instruments for monitoring the space environment from low earth orbit. As the program evolved, so to have the measurement capabilities such that modern DMSP spacecraft include a comprehensive suite of instruments providing estimates of precipitating electron and ion fluxes, cold/bulk plasma composition and moments, the geomagnetic field, and optical emissions in the far and extreme ultraviolet. We describe the creation of a new public database of precipitating electrons and ions from the Special Sensor J (SSJ) instrument, complete with original counts, calibrated differential fluxes adjusted for penetrating radiation, estimates of the total kinetic energy flux and characteristic energy, uncertainty estimates, and accurate ephemerides. These are provided in a common and self-describing format that covers 30+ years of DMSP spacecraft from F06 (launched in 1982) through F18 (launched in 2009). This new database is accessible at the National Centers for Environmental Information (NCEI) and the Coordinated Data Analysis Web (CDAWeb). We describe how the new database is being applied to high latitude studies of: the co-location of kinetic and electromagnetic energy inputs, ionospheric conductivity variability, field aligned currents and auroral boundary identification. We anticipate that this new database will support a broad range of space science endeavors from single observatory studies to coordinated system science investigations.
1985-10-01
grid points on 1 /20 lat /long meshI 4 c. SST global scale analysis ( 1 or 100 km lat /long grid) .. d. SST climatic scale analysis (50 or 500 km lat ...long grid) e. SST monthly means (2 1 /20 or 250 km lat /long grid) 3. Analog Sea Surface Temperature Product Set ’-%". V" " a. GOSSTCOMP charts - weekly...Mercator contour charts, each a ., 500 by 500 lat /long segment, 1 °C contour interval b. Regional charts - set of three charts covering the U.S
Solar Array and Auroral Charging Studies of DMSP Spacecraft
NASA Technical Reports Server (NTRS)
Matias, Kelwin
2013-01-01
The SSJ electrostatic analyzers and the SSIES plasma instruments on the DMSP spacecraft in low Earth polar orbit can be used to conduct case studies of auroral and solar array charging. We will use a program written in the Interactive Data Language (IDL) to evaluate questionable charging events in the SSJ records by comparing charging signatures in SSJ and SSIES data. In addition, we will assemble a number of case studies of solar array charging showing the signatures from the SSJ data and compare to the SSIES charging signatures. In addition we will use Satellite Tool Kit (STK) to propagate orbits, obtain solar intensity, and use to verify onset of charging with sunrise.
Tripathy, Bismay Ranjan; Sajjad, Haroon; Elvidge, Christopher D; Ting, Yu; Pandey, Prem Chandra; Rani, Meenu; Kumar, Pavan
2018-04-01
Changes in the pattern of electric power consumption in India have influenced energy utilization processes and socio-economic development to greater extent during the last few decades. Assessment of spatial distribution of electricity consumption is, thus, essential for projecting availability of energy resource and planning its infrastructure. This paper makes an attempt to model the future electricity demand for sustainable energy and its management in India. The nighttime light database provides a good approximation of availability of energy. We utilized defense meteorological satellite program-operational line-scan system (DMSP-OLS) nighttime satellite data, electricity consumption (1993-2013), gross domestic product (GDP) and population growth to construct the model. We also attempted to examine the sensitiveness of electricity consumption to GDP and population growth. The results revealed that the calibrated DMSP and model has provided realistic information on the electric demand with respect to GDP and population, with a better accuracy of r 2 = 0.91. The electric demand was found to be more sensitive to GDP (r = 0.96) than population growth (r = 0.76) as envisaged through correlation analysis. Hence, the model proved to be useful tool in predicting electric demand for its sustainable use and management.
NASA Astrophysics Data System (ADS)
Tripathy, Bismay Ranjan; Sajjad, Haroon; Elvidge, Christopher D.; Ting, Yu; Pandey, Prem Chandra; Rani, Meenu; Kumar, Pavan
2018-04-01
Changes in the pattern of electric power consumption in India have influenced energy utilization processes and socio-economic development to greater extent during the last few decades. Assessment of spatial distribution of electricity consumption is, thus, essential for projecting availability of energy resource and planning its infrastructure. This paper makes an attempt to model the future electricity demand for sustainable energy and its management in India. The nighttime light database provides a good approximation of availability of energy. We utilized defense meteorological satellite program-operational line-scan system (DMSP-OLS) nighttime satellite data, electricity consumption (1993-2013), gross domestic product (GDP) and population growth to construct the model. We also attempted to examine the sensitiveness of electricity consumption to GDP and population growth. The results revealed that the calibrated DMSP and model has provided realistic information on the electric demand with respect to GDP and population, with a better accuracy of r 2 = 0.91. The electric demand was found to be more sensitive to GDP ( r = 0.96) than population growth ( r = 0.76) as envisaged through correlation analysis. Hence, the model proved to be useful tool in predicting electric demand for its sustainable use and management.
The melting sea ice of Arctic polar cap in the summer solstice month and the role of ocean
NASA Astrophysics Data System (ADS)
Lee, S.; Yi, Y.
2014-12-01
The Arctic sea ice is becoming smaller and thinner than climatological standard normal and more fragmented in the early summer. We investigated the widely changing Arctic sea ice using the daily sea ice concentration data. Sea ice data is generated from brightness temperature data derived from the sensors: Defense Meteorological Satellite Program (DMSP)-F13 Special Sensor Microwave/Imagers (SSM/Is), the DMSP-F17 Special Sensor Microwave Imager/Sounder (SSMIS) and the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument on the NASA Earth Observing System (EOS) Aqua satellite. We tried to figure out appearance of arctic sea ice melting region of polar cap from the data of passive microwave sensors. It is hard to explain polar sea ice melting only by atmosphere effects like surface air temperature or wind. Thus, our hypothesis explaining this phenomenon is that the heat from deep undersea in Arctic Ocean ridges and the hydrothermal vents might be contributing to the melting of Arctic sea ice.
HF radar signatures of the cusp and low-latitude boundary layer
NASA Technical Reports Server (NTRS)
Baker, K. B.; Dudeney, J. R.; Greenwald, R. A.; Pinnock, M.; Newell, P. T.; Rodger, A. S.; Mattin, N.; Meng, C.-I.
1995-01-01
Continuous ground-based observations of ionospheric and magnetospheric regions are critical to the Geospace Environmental Modeling (GEM) program. It is therefore important to establish clear intercalibrations between different ground-based instruments and satellites in order to clearly place the ground-based observations in context with the corresponding in situ satellite measurements. HF-radars operating at high latitudes are capable of observing very large spatial regions of the ionosphere on a nearly continuous basis. In this paper we report on an intercalibration study made using the Polar Anglo-American Conjugate Radar Experiment radars located at Goose Bay, Labrador, and Halley Station, Antarctica, and the Defense Meteorological Satellite Program (DMSP) satellites. The DMSP satellite data are used to provide clear identifications of the ionospheric cusp and the low-latitude boundary layer (LLBL). The radar data for eight cusp events and eight LLBL events have been examined in order to determine a radar signature of these ionospheric regions. This intercalibraion indicates that the cusp is always characterized by wide, complex Doppler power spectra, whereas the LLBL is usually found to have spectra dominated by a single component. The distribution of spectral widths in the cusp is of a generally Gaussian form with a peak at about 220 m/s. The distribution of spectral widths in the LLBL is more like an exponential distribution, with the peak of the distribution occurring at about 50 m/s. There are a few cases in the LLBL where the Doppler power spectra are strikingly similar to those observed in the cusp.
Salvaging of the Final SSMIS Flight Unit for a Future Flight-of-Opportunity
NASA Astrophysics Data System (ADS)
Tratt, D. M.; Boucher, D. J., Jr.; Park, E. S.; Swadley, S. D.; Poe, G.
2017-12-01
The final Special Sensor Microwave Imager/Sounder (SSMIS) that was originally manifested aboard the DMSP F-20 platform became available when that mission was deactivated. The U.S. Naval Research Laboratory and The Aerospace Corporation have secured the de-manifested SSMIS for potential flight on a future mission-of-opportunity. A number of mission options are under consideration, including installation aboard the International Space Station. The intent is for any such deployment to provide a measure of continuity between SSMIS units currently operating aboard DMSP F-16, F-17, and F-18 and whatever equivalent sensor may be selected for the next-generation DoD Weather Satellite Follow-on program. We will describe the current status of SSMIS preparations for flight.
Using DMSP/OLS nighttime imagery to estimate carbon dioxide emission
NASA Astrophysics Data System (ADS)
Desheng, B.; Letu, H.; Bao, Y.; Naizhuo, Z.; Hara, M.; Nishio, F.
2012-12-01
This study highlighted a method for estimating CO2 emission from electric power plants using the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS) stable light image product for 1999. CO2 emissions from power plants account for a high percentage of CO2 emissions from fossil fuel consumptions. Thermal power plants generate the electricity by burning fossil fuels, so they emit CO2 directly. In many Asian countries such as China, Japan, India, and South Korea, the amounts of electric power generated by thermal power accounts over 58% in the total amount of electric power in 1999. So far, figures of the CO2 emission were obtained mainly by traditional statistical methods. Moreover, the statistical data were summarized as administrative regions, so it is difficult to examine the spatial distribution of non-administrative division. In some countries the reliability of such CO2 emission data is relatively low. However, satellite remote sensing can observe the earth surface without limitation of administrative regions. Thus, it is important to estimate CO2 using satellite remote sensing. In this study, we estimated the CO2 emission by fossil fuel consumption from electric power plant using stable light image of the DMSP/OLS satellite data for 1999 after correction for saturation effect in Japan. Digital number (DN) values of the stable light images in center areas of cities are saturated due to the large nighttime light intensities and characteristics of the OLS satellite sensors. To more accurately estimate the CO2 emission using the stable light images, a saturation correction method was developed by using the DMSP radiance calibration image, which does not include any saturation pixels. A regression equation was developed by the relationship between DN values of non-saturated pixels in the stable light image and those in the radiance calibration image. And, regression equation was used to adjust the DNs of the radiance calibration image. Then, saturated DNs of the stable light image was corrected using adjusted radiance calibration image. After that, regression analysis was performed with cumulative DNs of the corrected stable light image, electric power consumption, electric power generation and CO2 emission by fossil fuel consumption from electric power plant each other. Results indicated that there are good relationships (R2>90%) between DNs of the corrected stable light image and other parameters. Based on the above results, we estimated the CO2 emission from electric power plant using corrected stable light image. Keywords: DMSP/OLS, stable light, saturation light correction method, regression analysis Acknowledgment: The research was financially supported by the Sasakawa Scientific Research Grant from the Japan Science Society.
NASA Astrophysics Data System (ADS)
Jiao, S.; Yu, J.; Wang, Y.; Zhu, L.; Zhou, Q.
2018-04-01
In recent decades, urbanization has resulted a massive increase in the amount of infrastructure especially large buildings in large cities worldwide. There has been a noticeable expansion of entire cities both horizontally and vertically. One of the common consequences of urban expansion is the increase of ground loads, which may trigger land subsidence and can be a potential threat of public safety. Monitoring trends of urban expansion and land subsidence using remote sensing technology is needed to ensure safety along with urban planning and development. The Defense Meteorological Satellite Program Operational Line scan System (DMSP/OLS) Night-Time Light (NTL) images have been used to study urbanization at a regional scale, proving the capability of recognizing urban expansion patterns. In the current study, a normalized illuminated urban area dome volume (IUADV) based on inter-calibrated DMSP/OLS NTL images is shown as a practical approach for estimating urban expansion of Beijing at a single period in time and over subsequent years. To estimate the impact of urban expansion on land subsidence, IUADV was correlated with land subsidence rates obtained using the Stanford Method for Persistent Scatterers (StaMPS) approach within the Persistent Scatterers InSAR (PSInSAR) methodology. Moderate correlations are observed between the urban expansion based on the DMSP/OLS NTL images and land subsidence. The correlation coefficients between the urban expansion of each year and land subsidence tends to gradually decrease over time (Coefficient of determination R = 0.80 - 0.64 from year 2005 to year 2010), while the urban expansion of two sequential years exhibit an opposite trend (R = 0.29 - 0.57 from year 2005 to year 2010) except for the two sequential years between 2007 and 2008 (R = 0.14).
DMSP Auroral Charging at Solar Cycle 24 Maximum
NASA Technical Reports Server (NTRS)
Chandler, M.; Parker, L. Neergaard; Minow, J. I.
2013-01-01
It has been well established that polar orbiting satellites can experience mild to severe auroral charging levels (on the order of a few hundred volts to few kilovolts negative frame potentials) during solar minimum conditions. These same studies have shown a strong reduction in charging during the rising and declining phases of the past few solar cycles with a nearly complete suppression of auroral charging at solar maximum. Recently, we have observed examples of high level charging during the recent approach to Solar Cycle 24 solar maximum conditions not unlike those reported by Frooninckx and Sojka. These observations demonstrate that spacecraft operations during solar maximum cannot be considered safe from auroral charging when solar activity is low. We present a survey of auroral charging events experienced by the Defense Meteorological Satellite Program (DMSP) F16 satellite during Solar Cycle 24 maximum conditions. We summarize the auroral energetic particle environment and the conditions necessary for charging to occur in this environment, we describe how the lower than normal solar activity levels for Solar Cycle 24 maximum conditions are conducive to charging in polar orbits, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period.
NASA Astrophysics Data System (ADS)
Scott, D. J.; Brandt, M.; Savoie, M. H.; Stewart, J. S.
2016-12-01
The National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) has been producing and distributing passive microwave snow and ice data sets from the Special Sensor Microwave Imager (SSM/I) and Special Sensor Microwave Imager/Sounder (SSMIS) for over two decades. Aboard the Defense Meteorological Satellite Program (DMSP) platforms, SSM/I and SSMIS have been operating across eight different orbiting DMSP satellites since 1987, providing an invaluable 30 year record for snow and ice climate data studies. Each sensor has performed within or beyond its expected life cycle, ultimately resulting in a transition across platforms to continue the data record. On occasion the satellites have failed unexpectedly, requiring an unplanned need for science and data management to come together and adjust production code and services to get the data back online in a timely fashion. In recent years, this has become a greater importance as climate blogging sites have increased the visibility of near-real-time passive microwave products to communicate the current changes in the Polar Regions. This presentation summarizes the history and most recent activities surrounding satellite transitions, including the scientific assessment and development required in maintaining a streamlined data record across multiple sensors. In addition, we examine challenges in long-term provenance as well as the considerations and decisions made based on value added products utilizing these data, as well as cryospheric research and general public needs.
1993-02-01
Aeronautics and Space Administration; DMSP: Defense Meteorological Satellit= innovative helicopter survey for ambient Program; AVHRR: Advanced Very High...a" aA z’•Lae Na g 419" .aso ." -I Nas"o Te a ’ b 0 York A4CJ ’ crk A19. YCrk t•nrtid 0 .436 b = -. 49cr9k Trott *._-. 3 - -. Now A19. No~v, AtC. Nowv
The Auroral Field-aligned Acceleration - Cluster Results
NASA Astrophysics Data System (ADS)
Vaivads, A.; Cluster Auroral Team
The four Cluster satellites cross the auroral field lines at altitudes well above most of acceleration region. Thus, the orbit is appropriate for studies of the generator side of this region. We consider the energy transport towards the acceleration region and different mechanisms for generating the potential drop. Using data from Cluster we can also for the first time study the dynamics of the generator on a minute scale. We present data from a few auroral field crossings where Cluster are in conjunction with DMSP satellites. We use electric and magnetic field data to estimate electrostatic po- tential along the satellite orbit, Poynting flux as well as the presence of plasma waves. These we can compare with data from particle and wave instruments on Cluster and on low latitude satellites to try to make a consistent picture of the acceleration region formation in these cases. Preliminary results show close agreement both between in- tegrated potential values at Cluster and electron peak energies at DMSP as well as close agreement between the integrated Poynting flux values at Cluster and the elec- tron energy flux at DMSP. At the end we draw a parallels between auroral electron acceleration and electron acceleration at the magnetopause.
Arctic coastal polynya observations with ERS-1 SAR and DMSP SSM/I
NASA Technical Reports Server (NTRS)
Cavalieri, D. J.; Onstott, R. G.
1993-01-01
Work to improve the characterization of the distribution of new and young sea ice types and open water amount within Arctic coastal polynyas through the combined use of ERS-1 SAR (Synthetic Aperture Radar) and DMSP SSM/I (Defense Meteorological Satellite Program Special Sensor Microwave/Imager) data is described. Two St. Lawrence Island polynya events are studied using low resolution, geocoded SAR images and coincident SSM/I data. The SAR images are analyzed in terms of polarization and spectral gradient ratios. Results of the combined analysis show that the SAR ice type classification is consistent with that from SSM/I and that the combined use of SAR and SSM/I can improve the characterization of thin ice better than either data set can do alone.
Improving the Cost Estimation of Space Systems. Past Lessons and Future Recommendations
2008-01-01
a reasonable gauge for the relative propor- tions of cost growth attributable to errors, decisions, and other causes in any MDAP. Analysis of the...program. The program offices visited were the Defense Metrological Satellite Pro- gram (DMSP), Evolved Expendable Launch Vehicle (EELV), Advanced...3 years 1.8 0.9 3–8 years 1.8 0.9 8+ years 3.7 1.8 Staffing Requirement 7.4 3.7 areas represent earned value and budget drills ; the tan area on top
Compendium of meteorological space programs, satellites, and experiments
NASA Technical Reports Server (NTRS)
Dubach, Leland L.; Ng, Carolyn
1988-01-01
This compendium includes plans and events known to the authors through January 1987. Compilation of the information began in 1967. This document is intended: (1) as a historical record of all satellites and instrumentation that has been useful for meteorological research or operational uses; and (2) as a working document to be used to assist meteorologists in identifying meteorological satellites, locating data from these satellites, and understanding experiment operation which is related to satellite data that may be of interest to them. A summary of all known launched satellites for all countries and their experiments, which were concerned with meteorological operations or research, are included. Programs covered include AEM, Apollo, ATS, Bhaskara, Cosmos, Discoverer, DMSP, DOD, DODGE, EOLE, ERBE, ESSA, Explorer, Gemini, GMS, GOES/SMS, INSAT, IRS, LANDSAT, Mercury, Meteor 1 and 2, Meteosat, Molniya, MOS, Nimbus, NOAA (1-5)/ITOS, NOAA (6,7,D)/TIROS-N, NOAA (8-10, H-J)/ATN, Salyut, Seasat, Shuttle 1, Shuttle 2: Spacelab, Skylab, Soyuz, TIROS, TOPEX, Vanguard, Voskhod, Vostok, and Zond.
Analyzing the Velocity of Urban Dynamic Over Northeastern China Using Dmsp-Ols Night-Time Lights
NASA Astrophysics Data System (ADS)
Zhou, Y.
2017-09-01
Stable night-time lights (NTL) data from the Defense Meteorological Satellite Program Operational Line-scan System (DMSPOLS) can serve as a good proxy for anthropogenic development. Here DMSP-OLS NTL data was used to detect the urban development status in northeastern China. The spatial and temporal gradients are combined to depict the velocity of urban expanding process. This velocity index represents the instantaneous local velocity along the Earth's surface needed to maintain constant NTL condition, and has a mean of 0.36 km/yr for northeastern China. The velocity change of NTL is lower in the urban center and its near regions, and the suburbs show a relatively high value. The connecting zones between satellite cities and metropolis have also a rapid rate of NTL evolution. The dynamic process of urbanization over the study area is mainly in a manner of spreading from urban cores to edges. The rank size of the velocity for the prefectures is analyzed and a long tail distribution is found. The velocity index can provide insights for the future pattern of urban sprawl.
High latitude currents in the 0600 to 0900 MLT sector - Observations from Viking and DMSP-F7
NASA Technical Reports Server (NTRS)
Bythrow, P. F.; Potemra, T. A.; Zanetti, L. J.; Erlandson, R. A.; Hardy, D. A.; Rich, F. J.; Acuna, M. H.
1987-01-01
High-resolution magnetic field and charged-particle data acquired on March 25, 1986 by the Viking and DMSP-F7 satellites, as they traversed the dawn sector auroral zone on nearly antiparallel trajectories within 40 min of each oher, are analyzed. Magnetic field measurements by Viking at 0850 MLT and by DMSP at 0630 MLT indicate the presence of a large-scale earthward-directed region 1 Birkeland current and an upward-flowing region 2 current. Both satellites also observed a third Birkeland current adjacent to and poleward of the region 1 system with opposite flow. This poleward system is about 0.5 deg invariant latitude wide and has a current density comparable to the region 1 and 2 systems. The highest-latitude current is identified as region 0. Its charged-particle signatures were used to infer field line mapping to the equatorial plane.
SSUSI-lite: next generation far-ultraviolet sensor for characterizing geospace
NASA Astrophysics Data System (ADS)
Paxton, Larry J.; Hicks, John E.; Grey, Matthew P.; Parker, Charles W.; Hourani, Ramsay S.; Marcotte, Kathryn M.; Carlsson, Uno P.; Kerem, Samuel; Osterman, Steven N.; Maas, Bryan J.; Ogorzalek, Bernard S.
2016-10-01
SSUSI-Lite is an update of an existing sensor, SSUSI. The current generation of Defense Meteorological Satellite Program (DMSP) satellites (Block 5D3) includes a hyperspectral, cross-tracking imaging spectrograph known as the Special Sensor Ultraviolet Spectrographic Imager (SSUSI). SSUSI has been part of the DMSP program since 1990. SSUSI is designed to provide space weather information such as: auroral imagery, ionospheric electron density profiles, and neutral density composition changes. The sensors that are flying today (see http://ssusi.jhuapl.edu) were designed in 1990 - 1992. There have been some significant improvements in flight hardware since then. The SSUSI-Lite instrument is more capable than SSUSI yet consumes ½ the power and is ½ the mass. The total package count (and as a consequence, integration cost and difficulty) was reduced from 7 to 2. The scan mechanism was redesigned and tested and is a factor of 10 better. SSUSI-Lite can be flown as a hosted payload or a rideshare - it only needs about 10 watts and weighs under 10 kg. We will show results from tests of an interesting intensified position sensitive anode pulse counting detector system. We use this approach because the SSUSI sensor operates in the far ultraviolet - from about 110 to 180 nm or 0.11 to 0.18 microns.
DMSP Auroral Charging at Solar Cycle 24 Maximum
NASA Technical Reports Server (NTRS)
Chandler, Michael; Parker, Linda Neergaard; Minow, Joseph I.
2013-01-01
It has been well established that polar orbiting satellites can experience mild to severe auroral charging levels (on the order of a few hundred volts to few kilovolts negative frame potentials) during solar minimum conditions (Frooninckx and Sojka, 1992; Anderson and Koons, 1996; Anderson, 2012). These same studies have shown a strong reduction in charging during the rising and declining phases of the past few solar cycles with a nearly complete suppression of auroral charging at solar maximum. Recently, we have observed examples of high level charging during the recent approach to Solar Cycle 24 solar maximum conditions not unlike those reported by Frooninckx and Sojka (1992). These observations demonstrate that spacecraft operations during solar maximum cannot be considered safe from auroral charging when solar activity is low. We present a survey of auroral charging events experienced by the Defense Meteorological Satellite Program (DMSP) F16 satellite during Solar Cycle 24 maximum conditions. We summarize the auroral energetic particle environment and the conditions necessary for charging to occur in this environment, we describe how the lower than normal solar activity levels for Solar Cycle 24 maximum conditions are conducive to charging in polar orbits, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period.
NASA Technical Reports Server (NTRS)
Swift, C. T.; Goodberlet, M. A.; Wilkerson, J. C.
1990-01-01
The Defence Meteorological Space Program's (DMSP) Special Sensor Microwave/Imager (SSM/I), an operational wind speed algorithm was developed. The algorithm is based on the D-matrix approach which seeks a linear relationship between measured SSM/I brightness temperatures and environmental parameters. D-matrix performance was validated by comparing algorithm derived wind speeds with near-simultaneous and co-located measurements made by off-shore ocean buoys. Other topics include error budget modeling, alternate wind speed algorithms, and D-matrix performance with one or more inoperative SSM/I channels.
NASA Astrophysics Data System (ADS)
Jing, X.; Shao, X.; Cao, C.; Fu, X.
2013-12-01
Night-time light imagery offers a unique view of the Earth's surface. In the past, the nighttime light data collected by the DMSP-OLS sensors have been used as efficient means to correlate with the global socio-economic activities. With the launch of Suomi National Polar-orbiting Partnership (S-NPP) satellite in October 2011, the Day Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard S-NPP represents a major advancement in night time imaging capabilities because it surpassed its predecessor DMSP-OLS in radiometric accuracy, spatial resolution, and geometric quality. In this paper, we compared the performance of DNB image and DMSP image in correlating regional socio-economic activities and analyzed the leading causes for the differences. The correlation coefficients between the socio-economic variables such as population, regional GDP etc. and the characteristic variables derived from the night time light images of DNB and DMSP at provincial level in China were computed as performance metrics for comparison. In general, the correlation between DNB data and socio-economic data is better than that of DMSP data. To explain the difference in the correlation, we further analyzed the effects of several factors such as radiometric saturation and quantization of DMSP data, low spatial resolution, different data acquisition times between DNB and DMSP images, and difference in the transformation used in converting digital number (DN) value to radiance.
Generating Accurate Urban Area Maps from Nighttime Satellite (DMSP/OLS) Data
NASA Technical Reports Server (NTRS)
Imhoff, Marc; Lawrence, William; Elvidge, Christopher
2000-01-01
There has been an increasing interest by the international research community to use the nighttime acquired "city-lights" data sets collected by the US Defense Meteorological Satellite Program's Operational Linescan system to study issues relative to urbanization. Many researchers are interested in using these data to estimate human demographic parameters over large areas and then characterize the interactions between urban development , natural ecosystems, and other aspects of the human enterprise. Many of these attempts rely on an ability to accurately identify urbanized area. However, beyond the simple determination of the loci of human activity, using these data to generate accurate estimates of urbanized area can be problematic. Sensor blooming and registration error can cause large overestimates of urban land based on a simple measure of lit area from the raw data. We discuss these issues, show results of an attempt to do a historical urban growth model in Egypt, and then describe a few basic processing techniques that use geo-spatial analysis to threshold the DMSP data to accurately estimate urbanized areas. Algorithm results are shown for the United States and an application to use the data to estimate the impact of urban sprawl on sustainable agriculture in the US and China is described.
NASA Technical Reports Server (NTRS)
Katsaros, Kristina B.; Bhatti, Iftekhar; Mcmurdie, Lynn A.; Patty, Grant W.
1989-01-01
This paper describes some basic research techniques and algorithms developed to diagnose fronts in cyclonic storms over the ocean with data from satellite-borne microwave radiometers. Methods are developed for flagging strong gradients in integrated atmospheric water vapor and the presence of rain by using data from the SSMR on board the polar orbiting Seasat and Nimbus-7 satellites. Examination of 65 frontal systems showed that the water vapor gradient flag correctly identified 86 percent of the fronts, while the precipitation flagged 91 percent. The two types of flags emphasize different portions of the cyclone and are therefore complementary. Ultimately, these techniques are intended for operational use with data from the Special Sensor Microwave Imager which was launched in June 1987 on a satellite in the Defense Meteorological Satellite Program (DMSP).
SAPS effects on thermospheric winds during the 17 March 2013 storm
NASA Astrophysics Data System (ADS)
Sheng, C.; Lu, G.; Wang, W.; Doornbos, E.; Talaat, E. R.
2017-12-01
Strong subauroral polarization streams (SAPS) were observed by DMSP satellites during the main phase of the 17 March 2013 geomagnetic storm. Both DMSP F18 and GOCE satellites sampled at 19 MLT during this period, providing near-simultaneous measurements of ion drifts and neutral winds near dusk. The fortuitous satellite conjunction allows us to directly examine the SAPS effects on thermospheric winds. In addition, two sets of model runs were carried out for this event: (1) the standard TIEGCM run with high-latitude forcing; (2) the SAPS-TIEGCM run by incoporating an empirical model of SAPS in the subauroral zone. The difference between these two runs represents the influence of SAPS forcing. In particular, we examine ion-neutral coupling at subauroral latitudes through detailed forcing term analysis to determine how the SAPS-related strong westward ion drifts alter thermospheric winds.
Weather Satellite Enterprise Information Chain
NASA Astrophysics Data System (ADS)
Jamilkowski, M. L.; Grant, K. D.; Miller, S. W.; Cochran, S.
2015-12-01
NOAA & NASA are acquiring the next-generation civilian operational weather satellite: Joint Polar Satellite System (JPSS). Contributing the afternoon orbit & ground system (GS) to replace current NOAA POES Satellites, its sensors will collect meteorological, oceanographic & climatological data. The JPSS Common Ground System (CGS), consisting of C3 and IDP segments, is developed by Raytheon. It now flies the Suomi National Polar-orbiting Partnership (S-NPP) satellite, transferring data between ground facilities, processing them into environmental products for NOAA weather centers, and expanding to support JPSS-1 in 2017. As a multi-mission system, CGS provides combinations of C3, data processing, and product delivery for numerous NASA, NOAA, DoD and international missions.The CGS provides a wide range of support to a number of missions: Command and control and mission management for the S-NPP mission today, expanding this support to the JPSS-1 satellite mission in 2017 Data acquisition for S-NPP, the JAXA's Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the DoD Data routing over a global fiber network for S-NPP, JPSS-1, GCOM-W1, POES, DMSP, Coriolis/WindSat, NASA EOS missions, MetOp for EUMETSAT and the National Science Foundation Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 The CGS plays a key role in facilitating the movement and value-added enhancement of data all the way from satellite-based sensor data to delivery to the consumers who generate forecasts and produce watches and warnings. This presentation will discuss the information flow from sensors, through data routing and processing, and finally to product delivery. It will highlight how advances in architecture developed through lessons learned from S-NPP and implemented for JPSS-1 will increase data availability and reduce latency for end user applications.
Ou, Jinpei; Liu, Xiaoping; Li, Xia; Li, Meifang; Li, Wenkai
2015-01-01
Recently, the stable light products and radiance calibrated products from Defense Meteorological Satellite Program’s (DMSP) Operational Linescan System (OLS) have been useful for mapping global fossil fuel carbon dioxide (CO2) emissions at fine spatial resolution. However, few studies on this subject were conducted with the new-generation nighttime light data from the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the Suomi National Polar-orbiting Partnership (NPP) Satellite, which has a higher spatial resolution and a wider radiometric detection range than the traditional DMSP-OLS nighttime light data. Therefore, this study performed the first evaluation of the potential of NPP-VIIRS data in estimating the spatial distributions of global CO2 emissions (excluding power plant emissions). Through a disaggregating model, three global emission maps were then derived from population counts and three different types of nighttime lights data (NPP-VIIRS, the stable light data and radiance calibrated data of DMSP-OLS) for a comparative analysis. The results compared with the reference data of land cover in Beijing, Shanghai and Guangzhou show that the emission areas of map from NPP-VIIRS data have higher spatial consistency of the artificial surfaces and exhibit a more reasonable distribution of CO2 emission than those of other two maps from DMSP-OLS data. Besides, in contrast to two maps from DMSP-OLS data, the emission map from NPP-VIIRS data is closer to the Vulcan inventory and exhibits a better agreement with the actual statistical data of CO2 emissions at the level of sub-administrative units of the United States. This study demonstrates that the NPP-VIIRS data can be a powerful tool for studying the spatial distributions of CO2 emissions, as well as the socioeconomic indicators at multiple scales. PMID:26390037
Characteristics, of TIROS, GOES, DMSP and LANDSAT Systems
NASA Technical Reports Server (NTRS)
Gray, T. I., Jr.; Mccrary, D. G.; Armstrong, T. A. (Principal Investigator)
1981-01-01
The characteristics of the TIROS, GOES, DMSP and LANDSAT systems of satellites are described. The data listed for each system are altitude of orbit, inclination/position, orbit type, orbits per day, expected operational lifetime and the sensor systems. The sensor systems are described as to wavelength of each channel, resolution, field of view and other pertinent information. Data information such as availability rate, collection method, primary use/application and how to obtain additional information is also given.
Cloud Particle Size and Water/Ice Ratio Estimation using the DMSP SSMIS Sounder
NASA Astrophysics Data System (ADS)
Peng, G. S.; Fote, A. A.; Wu, D. L.; Boucher, D. J.; Thomas, B. H.; Kishi, A. M.
2008-12-01
The Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager/Sounder (SSMIS) is a next-generation passive conically scanning microwave radiometer. It combines both imaging and sounding capabilities of current operational instruments, SSM/I, SSM/T-1 and SSM/T-2. It also improves the capability of temperature sounding by providing profiles from the surface up to 70 km altitude with higher spatial resolutions (~37.5 for lower air and ~75 km for upper air). DMSP Flight 17 launched on 4 November 2006 from Vandenberg Air Force Base carrying the second SSMIS sounder. During the SSMIS Cal/Val period, cold patches were observed in the 50-55 GHz temperature sounding channels at low latitudes. Cold patches were also more apparent in the horizontal polarization (H- pol) than the Vertical polarization (V-pol) channels. A difference in sensitivity of the H-pol and V-pol channels gives the ratio of water to ice in the clouds. Subsequent investigation showed that these patches appeared in the 91.6 GHz channels but not the 37 GHz channels. This information, together with the theoretical scattering efficiency for spherical particles of various sizes, gives an upper bound of < 2 mm diameter for water and ice particles that may not be detected by SSMIS operational 'cloud clearing' algorithms.
Processing of DMSP magnetic data and its use in geomagnetic field modeling
NASA Technical Reports Server (NTRS)
Ridgway, J. R.; Sabaka, T. J.; Chinn, D.; Langel, R. A.
1989-01-01
The DMSP F-7 satellite is an operational Air Force meteorological satellite which carried a magnetometer for geophysical measurements. The magnetometer was located within the body of the spacecraft in the presence of large spacecraft fields. In addition to stray magnetic fields, the data have inherent position and time inaccuracies. Algorithms were developed to identify and remove time varying magnetic field noise from the data. Techniques developed for Magsat were then modified and used to attempt determination of the spacecraft fields, of any rotation between the magnetometer axes and the spacecraft axes, and of any scale changes within the magnetometer itself. The corrected data were then used to attempt to model the geomagnetic field. This was done in combination with data from Magsat, from the standard magnetic observatories, from aeromagnetic and other survey data, and from DE-2 spacecraft field data. Future DMSP missions can be upgraded in terms of geomagnetic measurements by upgrading the time and position information furnished with the data, placing the magnetometer at the end of the boom, upgrading the attitude determination at the magnetometer, and increasing the accuracy of the magnetometer.
NASA Technical Reports Server (NTRS)
Chen, L.; Gray, W. M.
1985-01-01
The characteristics of the upper tropospheric outflow patterns which occur with tropical cyclone intensification and weakening over all of the global tropical cyclone basins during the year long period of the First GARP Global Experiment (FGGE) are discussed. By intensification is meant the change in the tropical cyclone's maximum wind or central pressure, not the change of the cyclone's outer 1 to 3 deg radius mean wind which we classify as cyclone strength. All the 80 tropical cyclones which existed during the FGGE year are studied. Two-hundred mb wind fields are derived from the analysis of the European Center for Medium Range Weather Forecasting (ECMWF) which makes extensive use of upper tropospheric satellite and aircraft winds. Corresponding satellite cloud pictures from the polar orbiting U.S. Defense Meteorological Satellite Program (DMSP) and other supplementary polar and geostationary satellite data are also used.
Magnetic Field Experiment Data Analysis System
NASA Technical Reports Server (NTRS)
Holland, D. B.; Zanetti, L. J.; Suther, L. L.; Potemra, T. A.; Anderson, B. J.
1995-01-01
The Johns Hopkins University Applied Physics Laboratory (JHU/APL) Magnetic Field Experiment Data Analysis System (MFEDAS) has been developed to process and analyze satellite magnetic field experiment data from the TRIAD, MAGSAT, AMPTE/CCE, Viking, Polar BEAR, DMSP, HILAT, UARS, and Freja satellites. The MFEDAS provides extensive data management and analysis capabilities. The system is based on standard data structures and a standard user interface. The MFEDAS has two major elements: (1) a set of satellite unique telemetry processing programs for uniform and rapid conversion of the raw data to a standard format and (2) the program Magplot which has file handling, data analysis, and data display sections. This system is an example of software reuse, allowing new data sets and software extensions to be added in a cost effective and timely manner. Future additions to the system will include the addition of standard format file import routines, modification of the display routines to use a commercial graphics package based on X-Window protocols, and a generic utility for telemetry data access and conversion.
NASA Technical Reports Server (NTRS)
Cavalieri, Donald J.; Parkinson, Claire L.; Gloersen, Per; Zwally, H. Jay
1997-01-01
Satellite multichannel passive-microwave sensors have provided global radiance measurements with which to map, monitor, and study the Arctic and Antarctic polar sea ice covers. The data span over 18 years (as of April 1997), starting with the launch of the Scanning Multichannel Microwave Radiometer (SMMR) on NASA's SeaSat A and Nimbus 7 in 1978 and continuing with the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSMI) series beginning in 1987. It is anticipated that the DMSP SSMI series will continue into the 21st century. The SSMI series will be augmented by new, improved sensors to be flown on Japanese and U.S. space platforms. This User's Guide provides a description of a new sea ice concentration data set generated from observations made by three of these multichannel sensors. The data set includes gridded daily ice concentrations (every-other-day for the SMMR data) for both the north and south polar regions from October 26, 1978 through September 30, 1995, with the one exception of a 6-week data gap from December 3, 1987 through January 12, 1988. The data have been placed on two CD-ROMs that include a ReadMeCD file giving the technical details on the file format, file headers, north and south polar grids, ancillary data sets, and directory structure of the CD-ROM. The CD-ROMS will be distributed by the National Snow and Ice Data Center in Boulder, CO.
Multispacecraft Observations and Modeling of the 22/23 June 2015 Geomagnetic Storm
NASA Technical Reports Server (NTRS)
Reiff, P. H.; Daou, A. G.; Sazykin, S. Y.; Nakamura, R.; Hairston, M. R.; Coffey, V.; Chandler, M. O.; Anderson, B. J.; Russell, C. T.; Welling, D.;
2016-01-01
The magnetic storm of 22-23 June 2015 was one of the largest in the current solar cycle. We present in situ observations from the Magnetospheric Multiscale Mission (MMS) and the Van Allen Probes (VAP) in the magnetotail, field-aligned currents from AMPERE (Active Magnetosphere and Planetary Electrodynamics Response), and ionospheric flow data from Defense Meteorological Satellite Program (DMSP). Our real-time space weather alert system sent out a "red alert," correctly predicting Kp indices greater than 8. We show strong outflow of ionospheric oxygen, dipolarizations in the MMS magnetometer data, and dropouts in the particle fluxes seen by the MMS Fast Plasma Instrument suite. At ionospheric altitudes, the AMPERE data show highly variable currents exceeding 20 MA. We present numerical simulations with the Block Adaptive Tree-Solarwind - Roe - Upwind Scheme (BATS-R-US) global magnetohydrodynamic model linked with the Rice Convection Model. The model predicted the magnitude of the dipolarizations, and varying polar cap convection patterns, which were confirmed by DMSP measurements.
NASA Astrophysics Data System (ADS)
Kilcommons, Liam M.; Redmon, Robert J.; Knipp, Delores J.
2017-08-01
We have developed a method for reprocessing the multidecadal, multispacecraft Defense Meteorological Satellite Program Special Sensor Magnetometer (DMSP SSM) data set and have applied it to 15 spacecraft years of data (DMSP Flight 16-18, 2010-2014). This Level-2 data set improves on other available SSM data sets with recalculated spacecraft locations and magnetic perturbations, artifact signal removal, representations of the observations in geomagnetic coordinates, and in situ auroral boundaries. Spacecraft locations have been recalculated using ground-tracking information. Magnetic perturbations (measured field minus modeled main field) are recomputed. The updated locations ensure the appropriate model field is used. We characterize and remove a slow-varying signal in the magnetic field measurements. This signal is a combination of ring current and measurement artifacts. A final artifact remains after processing: step discontinuities in the baseline caused by activation/deactivation of spacecraft electronics. Using coincident data from the DMSP precipitating electrons and ions instrument (SSJ4/5), we detect the in situ auroral boundaries with an improvement to the Redmon et al. (2010) algorithm. We embed the location of the aurora and an accompanying figure of merit in the Level-2 SSM data product. Finally, we demonstrate the potential of this new data set by estimating field-aligned current (FAC) density using the Minimum Variance Analysis technique. The FAC estimates are then expressed in dynamic auroral boundary coordinates using the SSJ-derived boundaries, demonstrating a dawn-dusk asymmetry in average FAC location relative to the equatorward edge of the aurora. The new SSM data set is now available in several public repositories.
Data processing for the DMSP microwave radiometer system
NASA Technical Reports Server (NTRS)
Rigone, J. L.; Stogryn, A. P.
1977-01-01
A software program was developed and tested to process microwave radiometry data to be acquired by the microwave sensor (SSM/T) on the Defense Meteorological Satellite Program spacecraft. The SSM/T 7-channel microwave radiometer and systems data will be data-linked to Air Force Global Weather Central (AFGWC) where they will be merged with ephemeris data prior to product processing for use in the AFGWC upper air data base (UADB). The overall system utilizes an integrated design to provide atmospheric temperature soundings for global applications. The fully automated processing at AFGWC was accomplished by four related computer processor programs to produce compatible UADB soundings, evaluate system performance, and update the a priori developed inversion matrices. Tests with simulated data produced results significantly better than climatology.
2017-12-08
NASA image acquired November 11-12, 2012. On November 12, 2012, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured the top nighttime image of city, village, and highway lights near Delhi, India. For comparison, the lower image shows the same area one night earlier, as observed by the Operational Line Scan (OLS) system on a Defense Meteorological Satellite Program (DMSP) spacecraft. Since the 1960s, the U.S. Air Force has operated DMSP in order to observe clouds and other weather variables in key wavelengths of infrared and visible light. Since 1972, the DMSP satellites have included the Operational Linescan System (OLS), which gives weather forecasters some ability to see in the dark. It has been a highly successful sensor, but it is dependent on older technology with lower resolution than most scientists would like. And for many years, DMSP data were classified. Through improved optics and “smart” sensing technology, the VIIRS “day-night band,” is ten to fifteen times better than the OLS system at resolving the relatively dim lights of human settlements and reflected moonlight. Each VIIRS pixel shows roughly 740 meters (0.46 miles) across, compared to the 3-kilometer footprint (1.86 miles) of DMSP. Beyond the resolution, the new sensor can detect dimmer light sources. And since the VIIRS measurements are fully calibrated (unlike DMSP), scientists now have the precision required to make quantitative measurements of clouds and other features. “In contrast to the Operational Line Scan system, the imagery from the new day-night band is almost like a nearsighted person putting on glasses for the first time and looking at the Earth anew,” says Steve Miller, an atmospheric scientist at Colorado State University. “VIIRS has allowed us to bring this coarse, blurry view of night lights into clearer focus. Now we can see things in such great detail and at such high precision that we’re really talking about a new kind of measurement.” Unlike a film camera that captures a photograph in one exposure, VIIRS produces an image by repeatedly scanning a scene and resolving it as millions of individual picture elements, or pixels. The day-night band goes a step further, determining on-the-fly whether to use its low, medium, or high-gain mode. If a pixel is very bright, a low-gain mode on the sensor prevents the pixel from over-saturating. If the pixel is dark, the signal will be amplified. “On a hand-held camera, there’s a nighttime setting where the shutter will stay open much longer than it would under daylight imaging conditions,” says Chris Elvidge, who leads the Earth Observation Group at NOAA’s National Geophysical Data Center. “The day-night band is similar. It increases the exposure time—the amount of time that it’s collecting photons for pixels.” NASA Earth Observatory image by Jesse Allen and Robert Simmon, using Suomi NPP VIIRS and DMSP OLS data provided courtesy of Chris Elvidge (NOAA National Geophysical Data Center). Suomi NPP is the result of a partnership between NASA, NOAA, and the Department of Defense. Caption by Mike Carlowicz. Instrument: Suomi NPP - VIIRS Credit: NASA Earth Observatory Click here to view all of the Earth at Night 2012 images Click here to read more about this image NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific
Energy coupling during the August 2011 magnetic storm
NASA Astrophysics Data System (ADS)
Huang, C. Y.; Su, Y.; Sutton, E. K.; Weimer, D. R.; Davidson, R.
2013-12-01
We present results from an analysis of high-latitude ionosphere-thermosphere (IT) coupling to the solar wind during a moderate magnetic storm which occurred on 5-6 August 2011. During the storm, a multi-point set of observations of the ionosphere and thermosphere was available. We make use of ionospheric measurements of electromagnetic and particle energy made by the Defense Meteorological Satellite Program (DMSP), and neutral densities measured by the Gravity Recovery and Climate Experiment (GRACE) satellite to infer: (1) the energy budget and (2) timing of the energy transfer process during the storm. We conclude that the primary location for energy input to the IT system is the extremely high latitude region. We suggest that the total energy available to the IT system is not completely captured either by observation or empirical models.
NASA Astrophysics Data System (ADS)
Dymond, K.; Nicholas, A. C.; Budzien, S. A.; Stephan, A. W.; Coker, C.; Hei, M. A.; Groves, K. M.
2015-12-01
The Special Sensor Ultraviolet Limb Imager (SSULI) instruments are ultraviolet limb scanning sensors flying on the Defense Meteorological Satellite Program (DMSP) satellites. The SSULIs observe the 80-170 nanometer wavelength range covering emissions at 91 and 136 nm, which are produced by radiative recombination of the ionosphere. We invert these emissions tomographically using newly developed algorithms that include optical depth effects due to pure absorption and resonant scattering. We present the details of our approach including how the optimal altitude and along-track sampling were determined and the newly developed approach we are using for regularizing the SSULI tomographic inversions. Finally, we conclude with validations of the SSULI inversions against ALTAIR incoherent scatter radar measurements and demonstrate excellent agreement between the measurements.
Tests of Spectral Cloud Classification Using DMSP Fine Mode Satellite Data.
1980-06-02
processing techniques of potential value. Fourier spectral analysis was identified as the most promising technique to upgrade automated processing of...these measurements on the Earth’s surface is 0. 3 n mi. 3. Pickett, R.M., and Blackman, E.S. (1976) Automated Processing of Satellite Imagery Data at Air...and Pickett. R. Al. (1977) Automated Processing of Satellite Imagery Data at the Air Force Global Weather Central: Demonstrations of Spectral Analysis
Developing NOAA's Climate Data Records From AVHRR and Other Data
NASA Astrophysics Data System (ADS)
Privette, J. L.; Bates, J. J.; Kearns, E. J.
2010-12-01
As part of the provisional NOAA Climate Service, NOAA is providing leadership in the development of authoritative, measurement-based information on climate change and variability. NOAA’s National Climatic Data Center (NCDC) recently initiated a satellite Climate Data Record Program (CDRP) to provide sustained and objective climate information derived from meteorological satellite data that NOAA has collected over the past 30+ years - particularly from its Polar Orbiting Environmental Satellites (POES) program. These are the longest sustained global measurement records in the world and represent billions of dollars of investment. NOAA is now applying advanced analysis methods -- which have improved remarkably over the last decade -- to the POES AVHRR and other instrument data. Data from other satellite programs, including NASA and international research programs and the Defense Meteorological Satellite Program (DMSP), are also being used. This process will unravel the underlying climate trend and variability information and return new value from the records. In parallel, NCDC will extend these records by applying the same methods to present-day and future satellite measurements, including the Joint Polar Satellite System (JPSS) and Jason-3. In this presentation, we will describe the AVHRR-related algorithm development activities that CDRP recently selected and funded through open competitions. We will particularly discuss some of the technical challenges related to adapting and using AVHRR algorithms with the VIIRS data that should become available with the launch of the NPOESS Preparatory Project (NPP) satellite in early 2012. We will also describe IT system development activities that will provide data processing and reprocessing, storage and management. We will also outline the maturing Program framework, including the strategies for coding and development standards, community reviews, independent program oversight, and research-to-operations algorithm migration and execution. Timeline of NOAA's polar orbiters that carried AVHRR. NOAA's approach to flying the same or similar instruments sequentially is well-suited to CDR development.
High-resolution mapping of anthropogenic heat in China from 1992 to 2010.
Yang, Wangming; Chen, Bing; Cui, Xuefeng
2014-04-14
Anthropogenic heat generated by human activity contributes to urban and regional climate warming. Due to the resolution and accuracy of existing anthropogenic heat data, it is difficult to analyze and simulate the corresponding effects. This study exploited a new method to estimate high spatial and temporal resolutions of anthropogenic heat based on long-term data of energy consumption and the US Air Force Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) data from 1992 to 2010 across China. Our results showed that, throughout the entire study period, there are apparent increasing trends in anthropogenic heat in three major metropoli, i.e., the Beijing-Tianjin region, the Yangzi River delta and the Pearl River delta. The annual mean anthropogenic heat fluxes for Beijing, Shanghai and Guangzhou in 2010 were 17 Wm⁻², 19 and 7.8 Wm⁻², respectively. Comparisons with previous studies indicate that DMSP-OLS data could provide a better spatial proxy for estimating anthropogenic heat than population density and our analysis shows better performance at large scales for estimation of anthropogenic heat.
NASA Astrophysics Data System (ADS)
Chen, K.; Jia, T.
2017-09-01
The Defense Meteorological Satellite Programs Operational Linescan System (DMSP-OLS) nighttime lights imagery has been widely used to monitor economic activities and regional development in recent decades. In this paper, we firstly processed the nighttime light imageries of the Mainland China from 1992 to 2013 due to the radiation or geometric errors. Secondly, by dividing the Mainland China into seven regions, we found high correlation between the sum light values and GDP of each region. Thirdly, we extracted the economic centers of each region based on their nighttime light images. Through the analysis, we found the distribution of these economic centers was relatively concentrated and the migration of these economic centers showed certain directional trend or circuitous changes, which suggested the imbalanced socio-economic development of each region. Then, we calculated the Regional Development Gini of each region using the nighttime light data, which indicated that social-economic development in South China presents great imbalance while it is relatively balanced in Southwest China. This study would benefit the macroeconomic control to regional economic development and the introduction of appropriate economic policies from the national level.
The Mesoscale Ionospheric Simulation Testbed (MIST) Regional Data Assimilation Model (Invited)
NASA Astrophysics Data System (ADS)
Comberiate, J.; Kelly, M. A.; Miller, E.; Paxton, L.
2013-12-01
The Mesoscale Ionospheric Simulation Testbed (MIST) provides a regional nowcast and forecast of electron density values and has sufficient resolution to include equatorial plasma bubbles. The SSUSI instrument on the DMSP F18 satellite has high-resolution nightly observations of plasma bubbles at 8 PM local time throughout the current solar maximum. MIST can assimilate SSUSI UV observations, GPS TEC measurements, and SCINDA S4 readings simultaneously into a single scintillation map over a region of interest. MIST also models ionospheric physics to provide a short-term UHF scintillation forecast based on assimilated data. We will present examples of electron density and scintillation maps from MIST. We will also discuss the potential to predict scintillation occurrence up to 6 hours in advance using observations of the equatorial arcs from SSUSI observations at 5:30 PM local time on the DMSP F17 satellite.
Remote Determination of Auroral Energy Characteristics During Substorm Activity
NASA Technical Reports Server (NTRS)
Germany, G. A.; Parks, G. K.; Brittnacher, M. J.; Cumnock, J.; Lummerzheim, D.; Spann, J. F., Jr.
1997-01-01
Ultraviolet auroral images from the Ultraviolet Imager onboard the POLAR satellite can be used as quantitative remote diagnostics of the auroral regions, yielding estimates of incident energy characteristics, compositional changes, and other higher order data products. In particular, images of long and short wavelength N2 Lyman-Birge-Hopfield (LBH) emissions can be modeled to obtain functions of energy flux and average energy that are basically insensitive to changes in seasonal and solar activity changes. This technique is used in this study to estimate incident electron energy flux and average energy during substorm activity occurring on May 19, 1996. This event was simultaneously observed by WIND, GEOTAIL, INTERBALL, DMSP and NOAA spacecraft as well as by POLAR. Here incident energy estimates derived from Ultraviolet Imager (UVI) are compared with in situ measurements of the same parameters from an overflight by the DMSP F12 satellite coincident with the UVI image times.
NASA Astrophysics Data System (ADS)
Hairston, M. R.; Coley, W. R.; Ruohoniemi, J. M.
2016-12-01
July through September 2015 was a relatively quiet period punctuated by nine small to moderate geomagnetic storms (Dst minima ranging from -25 to -98 nT). We are conducting a study of the subauroral midlatitude ionospheric zonal flows in the predawn morning sector (magnetic local times ranging from 2.2 to 5.6 hours) using satellite data from DMSP F15 and F16 along with the midlatitude SuperDARN radars. We will present an empirical model of the background quiettime flows based on these data and then compare those flows to the observed stormtimes flows. The stormtime data will be used to explore the extent of the penetration electric field in this predawn region. Additional satellite flow data from other local times (evening and dayside) will also be presented to check for any local time variation in the extent of the penetration electric field.
Earth remote sensing with NPOESS: instruments and environmental data products
NASA Astrophysics Data System (ADS)
Glackin, David L.; Cunningham, John D.; Nelson, Craig S.
2004-02-01
The NPOESS (National Polar-orbiting Operational Environmental Satellite System) program represents the merger of the NOAA POES (Polar-orbiting Environmental Satellite) program and the DoD DMSP (Defense Meteorological Satellite Program) satellites. Established by presidential directive in 1994, a tri-agency Integrated Program Office (IPO) in Silver Spring, Maryland, has been managing NPOESS development, and is staffed by representatives of NOAA, DoD, and NASA. NPOESS is being designed to provide 55 atmospheric, oceanographic, terrestrial, and solar-geophysical data products, and will disseminate them to civilian and military users worldwide. The first NPOESS satellite is scheduled to be launched late in this decade, with the other two satellites of the three-satellite constellation due to be launched over the ensuing four years. NPOESS will remain operational for at least ten years. The 55 Environmental Data Records (EDRs) will be provided by a number of instruments, many of which will be briefly described in this paper. The instruments will be hosted in various combinations on three NPOESS platforms in three distinct polar sun-synchronous orbits. The instrument complement represents the combined requirements of the weather, climate, and environmental remote sensing communities. The three critical instruments are VIIRS (Visible/Infrared Imager-Radiometer Suite), CMIS (Conical Microwave Imager/Sounder), and CrIS (Cross-track Infrared Sounder). The other IPO-developed instruments are OMPS (Ozone Mapper/Profiler Suite), GPSOS (Global Positioning System Occultation Sensor), the APS (Aerosol Polarimeter Sensor), and the SESS (Space Environment Sensor Suite). NPOESS will also carry various "leveraged" instruments, i.e., ones that do not require development by the IPO. These include the ATMS (Advanced Technology Microwave Sounder), the TSIS (Total Solar Irradiance Sensor), the ERBS (Earth Radiation Budget Sensor), and the ALT (Radar Altimeter).
NASA Astrophysics Data System (ADS)
Yuan, Zhigang; Qiao, Zheng; Li, Haimeng; Huang, Shiyong; Wang, Dedong; Yu, Xiongdong; Yu, Tao
2017-04-01
Subauroral polarization stream (SAPS) electric field can play an important role in the coupling between the inner magnetosphere and ionosphere; however, the production mechanism of SAPS has not been yet solved. During an energetic ion injection event on 26 March 2004, at latitudes lower than the equatorward boundaries of precipitating plasma sheet electrons and ions, the Defense Meteorological Satellite Program (DMSP) F13 satellite simultaneously observed a strong SAPS with the peak velocity of 1294 m/s and downward flowing field-aligned currents (FACs). Conjugate observations of DMSP F13 and NOAA 15 satellites have shown that FACs flowing into the ionosphere just lie in the outer boundary of the ring current (RC). The downward flowing FACs were observed in a region of positive latitudinal gradients of the ion energy density, implying that the downward flowing FACs are more likely linked to the azimuthal gradient than the radial gradient of the RC ion pressure. Our result demonstrates that RC ion pressure gradients on the outer boundary of the RC in the evening sector during energetic ion injection events can lead to downward flowing FACs so as to cause strong SAPS in condition of low ionospheric conductivities.
Cloud-to-Ground Lightning Estimates Derived from SSMI Microwave Remote Sensing and NLDN
NASA Technical Reports Server (NTRS)
Winesett, Thomas; Magi, Brian; Cecil, Daniel
2015-01-01
Lightning observations are collected using ground-based and satellite-based sensors. The National Lightning Detection Network (NLDN) in the United States uses multiple ground sensors to triangulate the electromagnetic signals created when lightning strikes the Earth's surface. Satellite-based lightning observations have been made from 1998 to present using the Lightning Imaging Sensor (LIS) on the NASA Tropical Rainfall Measuring Mission (TRMM) satellite, and from 1995 to 2000 using the Optical Transient Detector (OTD) on the Microlab-1 satellite. Both LIS and OTD are staring imagers that detect lightning as momentary changes in an optical scene. Passive microwave remote sensing (85 and 37 GHz brightness temperatures) from the TRMM Microwave Imager (TMI) has also been used to quantify characteristics of thunderstorms related to lightning. Each lightning detection system has fundamental limitations. TRMM satellite coverage is limited to the tropics and subtropics between 38 deg N and 38 deg S, so lightning at the higher latitudes of the northern and southern hemispheres is not observed. The detection efficiency of NLDN sensors exceeds 95%, but the sensors are only located in the USA. Even if data from other ground-based lightning sensors (World Wide Lightning Location Network, the European Cooperation for Lightning Detection, and Canadian Lightning Detection Network) were combined with TRMM and NLDN, there would be enormous spatial gaps in present-day coverage of lightning. In addition, a globally-complete time history of observed lightning activity is currently not available either, with network coverage and detection efficiencies varying through the years. Previous research using the TRMM LIS and Microwave Imager (TMI) showed that there is a statistically significant correlation between lightning flash rates and passive microwave brightness temperatures. The physical basis for this correlation emerges because lightning in a thunderstorm occurs where ice is first present in the cloud and electric charge separation occurs. These ice particles efficiently scatter the microwave radiation at the 85 and 37 GHz frequencies, thus leading to large brightness temperature depressions. Lightning flash rate is related to the total amount of ice passing through the convective updraft regions of thunderstorms. Confirmation of this relationship using TRMM LIS and TMI data, however, remains constrained to TRMM observational limits of the tropics and subtropics. Satellites from the Defense Meteorology Satellite Program (DMSP) have global coverage and are equipped with passive microwave imagers that, like TMI, observe brightness temperatures at 85 and 37 GHz. Unlike the TRMM satellite, however, DMSP satellites do not have a lightning sensor, and the DMSP microwave data has never been used to derive global lightning. In this presentation, a relationship between DMSP Special Sensor Microwave Imager (SSMI) data and ground-based cloud-to-ground (CG) lightning data from NLDN is investigated to derive a spatially complete time history of CG lightning for the USA study area. This relationship is analogous to the established using TRMM LIS and TMI data. NLDN has the most spatially and temporally complete CG lightning data for the USA, and therefore provides the best opportunity to find geospatially coincident observations with SSMI sensors. The strongest thunderstorms generally have minimum 85 GHz Polarized Corrected brightness Temperatures (PCT) less than 150 K. Archived radar data was used to resolve the spatial extent of the individual storms. NLDN data for that storm spatial extent defined by radar data was used to calculate the CG flash rate for the storm. Similar to results using TRMM sensors, a linear model best explained the relationship between storm-specific CG flash rates and minimum 85 GHz PCT. However, the results in this study apply only to CG lightning. To extend the results to weaker storms, the probability of CG lightning (instead of the flash rate) was calculated for storms having 85 GHz PCT greater than 150 K. NLDN data was used to determine if a CG strike occurred for a storm. This probability of CG lightning was plotted as a function of minimum 85 GHz PCT and minimum 37 GHz PCT. These probabilities were used in conjunction with the linear model to estimate the CG flash rate for weaker storms with minimum 85 GHz PCTs greater than 150 K. Results from the investigation of CG lightning and passive microwave radiation signals agree with the previous research investigating total lightning and brightness temperature. Future work will take the established relationships and apply them to the decades of available DMSP data for the USA to derive a map of CG lightning flash rates. Validation of this method and uncertainty analysis will be done by comparing the derived maps of CG lightning flash rates against existing NLDN maps of CG lightning flash rates.
An improved land mask for the SSM/I grid
NASA Technical Reports Server (NTRS)
Martino, Michael G.; Cavalieri, Donald J.; Gloersen, Per; Zwally, H. Jay; Acker, James G. (Editor)
1995-01-01
This paper discusses the development of a new land/ocean/coastline mask for use with Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) data, and other types of data which are mapped to the polar stereographic SSM/I grid. Pre-existing land masks were found to disagree, to lack certain land features, and to disagree with land boundaries that are visible in high resolution sensor imagery, such as imagery from the Synthetic Aperture Radar (SAR) on the Earth Resources Satellite (ERS-1). The Digital Chart of the World (DCW) database was initially selected as a source of shoreline data for this effort. Techniques for developing a land mask from these shoreline data are discussed. The resulting land mask, although not perfect, is seen to exhibit significant improvement over previous land mask products.
NASA Technical Reports Server (NTRS)
Halpern, D.; Knauss, W.; Brown, O.; Wentz, F.
1993-01-01
The following monthly mean global distributions for 1990 are proposed with a common color scale and geographical map: 10-m height wind speed estimated from the Special Sensor Microwave Imager (SSMI) on a United States (US) Air Force Defense Meteorological Satellite Program (DMSP) spacecraft; sea surface temperature estimated from the advanced very high resolution radiometer (AVHRR/2) on a U.S. National Oceanic and Atmospheric Administration (NOAA) spacecraft; Cartesian components of free drifting buoys which are tracked by the ARGOS navigation system on NOAA satellites; and Cartesian components on the 10-m height wind vector computed by the European Center for Medium-Range Weather Forecasting (ECMWF). Charts of monthly mean value, sampling distribution, and standard deviation values are displayed. Annual mean distributions are displayed.
NASA Technical Reports Server (NTRS)
Halpern, D.; Knauss, W.; Brown, O.; Wentz, F.
1993-01-01
The following monthly mean global distributions for 1991 are presented with a common color scale and geographical map: 10-m height wind speed estimated from the Special Sensor Microwave Imager (SSMI) on a United States Air Force Defense Meteorological Satellite Program (DMSP) spacecraft; sea surface temperature estimated from the advanced very high resolution radiometer (AVHRR/2) on a U.S. National Oceanic and Atmospheric Administration (NOAA) spacecraft; Cartesian components of free-drifting buoys which are tracked by the ARGOS navigation system on NOAA satellites; and Cartesian components of the 10-m height wind vector computed by the European Center for Medium-Range Weather Forecasting (ECMWF). Charts of monthly mean value, sampling distribution, and standard deviation value are displayed. Annual mean distributions are displayed.
2016-03-10
2015, DOD also inquired with NOAA about the possibility of using one of NOAA’s geostationary weather satellites to preserve coverage over the Indian...life of DMSP-20.” It further states, “This means there will always be geostationary coverage” of several regions, including the Indian Ocean, “by U.S...weather prediction. • Geostationary satellites maintain a fixed position relative to the earth, collecting data on a specific geographic region and
NASA Technical Reports Server (NTRS)
Halpern, D.; Fu, L.; Knauss, W.; Pihos, G.; Brown, O.; Freilich, M.; Wentz, F.
1995-01-01
The following monthly mean global distributions for 1993 are presented with a common color scale and geographical map: 10-m height wind speed estimated from the Special Sensor Microwave Imager (SSMI) on a United States (U.S.) Air Force Defense Meteorological Satellite Program (DMSP) spacecraft; sea surface temperature estimated from the Advanced Very High Resolution Radiometer (AVHRR/2) on a U.S. National Oceanic and Atmospheric Administration (NOAA) satellite; 10-m height wind speed and direction estimated from the Active Microwave Instrument (AMI) on the European Space Agency (ESA) European Remote Sensing (ERS-1) satellite; sea surface height estimated from the joint U.S.-France Topography Experiment (TOPEX)/POSEIDON spacecraft; and 10-m height wind speed and direction produced by the European Center for Medium-Range Weather Forecasting (ECMWF). Charts of annual mean, monthly mean, and sampling distributions are displayed.
Seasonal Snow Extent and Snow Volume in South America Using SSM/I Passive Microwave Data
NASA Technical Reports Server (NTRS)
Foster, James L.; Chang, A. T. C.; Hall, D. K.; Kelly, R.; Houser, Paul (Technical Monitor)
2001-01-01
Seasonal snow cover in South America was examined in this study using passive microwave satellite data from the Special Sensor Microwave Imagers (SSM/I) on board Defense Meteorological Satellite Program (DMSP) satellites. For the period from 1992-1998, both snow cover extent and snow depth (snow mass) were investigated during the winter months (May-August) in the Patagonia region of Argentina. Since above normal temperatures in this region are typically above freezing, the coldest winter month was found to be not only the month having the most extensive snow cover but also the month having the deepest snows. For the seven-year period of this study, the average snow cover extent (May-August) was about 0.46 million sq km and the average monthly snow mass was about 1.18 x 10(exp 13) kg. July 1992 was the month having the greatest snow extent (nearly 0.8 million sq km) and snow mass (approximately 2.6 x 10(exp 13) kg).
NASA Technical Reports Server (NTRS)
Galantowicz, J. F.; England, A. W.
1992-01-01
A ground-based simulator of the defense meterological satellite program special sensor microwave/imager (DMSP SSM/I) is described, and its integration with micrometeorological instrumentation for an investigation of microwave emission from moist and frozen soils is discussed. The simulator consists of three single polarization radiometers which are capable of both Dicke radiometer and total power radiometer modes of operation. The radiometers are designed for untended operation through a local computer and a daily telephone link to a laboratory. The functional characteristics of the radiometers are described, together with their field deployment configuration and an example of performance parameters.
NASA Astrophysics Data System (ADS)
Secan, James A.; Reinleitner, Lee A.; Bussey, Robert M.
1990-03-01
Modern military communication, navigation, and surveillance systems depend on reliable, noise-free transionospheric radio frequency channels. They can be severely impacted by small scale electron-density irregularities in the ionosphere, which cause both phase and amplitude scintillation. Basic tools used in planning and mitigation schemes are climatological in nature and thus may greatly over- and under-estimate the effects of scintillation in a given scenario. The results are summarized of a 3 year investigation into the feasibility of using in-situ observations of the ionosphere from the USAF DMSP satellite to calculate estimates of irregularity parameters that could be used to update scintillation models in near real time. Estimates for the level of intensity and phase scintillation on a transionospheric UHF radio link in the early evening auroral zone were calculated from DMSP Scintillation Meter (SM) data and compared to the levels actually observed. The intensity scintillation levels predicted and observed compared quite well, but the comparison with the phase scintillation data was complicated by low-frequency phase noise on the UHF radio link. Results are presented from analysis of DMSP SSIES data collected near Kwajalein Island in conjunction with a propagation-effects experiment. Preliminary conclusions to the assessment study are: (1) the DMSP SM data can be used to make quantitative estimates of the level of scintillation at auroral latitudes, and (2) it may be possible to use the data as a qualitative indicator of scintillation activity levels at equatorial latitudes.
NASA Astrophysics Data System (ADS)
Mackler, David A.
Plasmasheet particles transported Earthward during times of active magnetospheric convection can interact with thermospheric neutrals through charge exchange. The resulting Energetic Neutral Atoms (ENAs) are free to leave the influence of the magnetosphere and can be remotely detected. ENAs associated with low altitude (300--800 km) ion precipitation in the high latitude atmosphere/ionosphere are termed Low Altitude Emissions (LAEs). Remotely observed LAEs are highly non-isotropic in velocity space such that the pitch angle distribution at the time of charge exchange is near 90 degrees. The Geomagnetic Emission Cone (GEC) of LAEs can be mapped spatially, showing where proton energy is deposited during times of varying geomagnetic activity. In this study we present a statistical look at the correlation between LAE flux (intensity and location) and geomagnetic activity as well as comparisons of LAE signatures with in situ ion precipitation. The LAE data is from the MENA imager on the IMAGE satellite over the declining phase of solar cycle 23 (2000--2005). The SYM-H, AE, and Kp indices are used to describe geomagnetic activity. The in situ data is from the Defense Meteorological Satellite Program (DMSP). The goal of the study is to evaluate properties of LAEs in ENA images and determine if those images can be used to infer properties of ion precipitation. Results indicate a general positive correlation to LAE flux for all three indices, with the SYM-H showing the greatest non-linearity. The MLT distribution of LAEs are centered about midnight and spread with increasing activity. The Invariant Latitude for all indices has a slightly negative correlation. The combined results indicate that both LAE and DMSP data behave similarly to geomagnetic activity. LAEs are more spread out in latitude, possibly due to multiple charge exchange interactions, while the in situ data changes to lower latitudes dramatically with increasing flux. The bulk of the data indicates that the LAE latitude region is lower than that of the precipitating ions. The local time coverage of the DMSP constellation during the time of MENA is too limited to infer much information. The ratio of the fluxes (DMSP/LAE) is roughly constant over storm time parameters (LOG[-SYM-H]/Slope/Phase), with the possible exception of favoring Low Altitude Emissions at higher flux and lower latitudes. This may indicate that the change in flux intensity may respond equally between the two.
NASA Astrophysics Data System (ADS)
Hinnant, F.
2009-12-01
The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD and will provide continuity for the NASA Earth Observation System with the launch of the NPOESS Preparatory Project. This poster will provide a top level status update of the program, as well as an overview of the NPOESS system architecture, which includes four segments. The space segment includes satellites in two orbits that carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The NPOESS system design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users through a Command, Control, and Communication Segment (C3S). The data processing for NPOESS is accomplished through an Interface Data Processing Segment (IDPS)/Field Terminal Segment (FTS) that processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government as well as remote terminal users. The Launch Support Segment completes the four segments that make up the NPOESS system that will enhance the connectivity between research and operations and provide critical operational and scientific environmental measurements to military, civil, and scientific users until 2026.
The asteroid rendezvous spacecraft. An adaptation study of TIROS/DMSP technology
NASA Technical Reports Server (NTRS)
1982-01-01
The feasibility of using the TIROS/DMSP Earth orbiting meteorological satellite in application to a near Earth asteroid rendezvous mission. System and subsystems analysis was carried out to develop a configuration of the spacecraft suitable for this mission. Mission analysis studies were also done and maneuver/rendezvous scenarios developed for baseline missions to both Anteros and Eros. The fact that the Asteroid mission is the most complex of the Pioneer class missions currently under consideration notwithstanding, the basic conclusion very strongly supports the suitability of the basic TIROS bus for this mission in all systems and subsystems areas, including science accommodation. Further, the modifications which are required due to the unique mission are very low risk and can be accomplished readily. The key issue is that in virtually every key subsystem, the demands of the Asteroid mission are a subset of the basic meteorological satellite mission. This allows a relatively simple reconfiguration to be accomplished without a major system redesign.
Observations of the diurnal dependence of the high-latitude F region ion density by DMSP satellites
NASA Technical Reports Server (NTRS)
Sojka, J. J.; Raitt, W. J.; Schunk, R. W.; Rich, F. J.; Sagalyn, R. C.
1982-01-01
Data from the DMSP F2 and F4 satellites for the period December 5-10, 1979, have been used to study the diurnal dependence of the high-latitude ion density at 800-km altitude. A 24-hour periodicity in the minimum orbital density (MOD) during a crossing of the high-latitude region is observed in both the winter and summer hemispheres. The phase of the variation in MOD is such that it has a minimum during the 24-hour period between 0700 and 0900 UT. Both the long-term variation of the high-latitude ion density on a time scale of days, and the orbit-by-orbit variations at the same geomagnetic location in the northern (winter) hemisphere for the magnetically quiet time period chosen, show good qualitative agreement with the diurnal dependence predicted by a theoretical model of the ionospheric density at high latitudes under conditions of low convection speeds (Sojka et al., 1981).
Surface Charging in the Auroral Zone on the DMSP Spacecraft in LEO
NASA Astrophysics Data System (ADS)
Anderson, Phillip C.
1998-11-01
A recent anomaly on the DMSP F13 spacecraft was attributed to an electrical malfunction caused by an electrostatic discharge on the vehicle associated with surface charging. It occurred during an intense energetic electron precipitation event (an auroral arc) within a region of very low plasma density in the auroral zone. A study of 1.5 year's worth of DMSP data from three satellites acquired during the recent minimum in the solar cycle has shown that such charging was a common occurrence with 704 charging events found. This is the result of significantly reduced background plasma densities associated with the solar minimum; smaller than ever previously experienced by the DMSP spacecraft. At times, the spacecraft charged for periods of 10s of seconds as they skimmed along an auroral arc instead of cutting across it. We show examples of the observed plasma density and the precipitating electron and ion spectra associated with the charging, and the MLT distribution and the seasonal distribution of the events. The preponderance of events occurred in the premidnight and morning sectors with two types of electron spectra being observed: a sharply peaked distribution indicative of field-aligned acceleration in the premidnight sector and a very hard distribution in the morning sector.
NASA Technical Reports Server (NTRS)
Sherr, Evelyn; Sherr, Barry; Wolfe, Gordon; Kiene, Ronald
1997-01-01
We have explored and identified several novel aspects of dimetylsulfoniopropionate (DMSP) metabolism and dimetylsulfide (DMS) production by microbial food web processes. Processes studied include: microzooplankton herbivory, uptake and retention of dissolved (DMSP) by marine bacteria, coupled with microzooplankton bacterivory, and generation of (DMS) as a byproduct of chemical grazing deterrence by Emiliania huxleyi. Our results illustrate the complexities of DMSP cycling and DMS production, and support the idea that the flux of DMS to the atmosphere is the result of many coupled trophic interactions which are not currently predictable by simple models or observations tied to a few bulk parameters. Although it is highly desirable to measure trophic interactions by remote sensing techniques, satellite methods cannot currently yield information on bacterial or microzooplankton abundances, activities, and processes. We have identified specific processes which must be included in future efforts, but we do not know yet how widespread or important these will be in many natural waters. We believe further work will enable us to simplify our model of DMS production by eliminating second order processes, and help refine our insight into the primary biological and chemical sources of atmospheric DMS. This is fundamental work which should be supported as basic research.
Iceberg B-15, Ross Ice Shelf, Antarctica
NASA Technical Reports Server (NTRS)
2002-01-01
Iceberg B-15 broke from the Ross Ice Shelf in Antarctica in late March. Among the largest ever observed, the new iceberg is approximately 170 miles long x 25 miles wide. Its 4,250 square-mile area is nearly as large as the state of Connecticut. The iceberg was formed from glacial ice moving off the Antarctic continent and calved along pre-existing cracks in the Ross Ice Shelf near Roosevelt Island. The calving of the iceberg essentially moves the northern boundary of the ice shelf about 25 miles to the south, a loss that would normally take the ice shelf as long as 50-100 years to replace. This infrared image was acquired by the DMSP (Defense Meteorological Satellite Program) F-13 satellite on April 13, 2000. For more images see Antarctic Meteorological Research Center Image courtesy of the University of Wisconsin - Madison, Space Science and Engineering Center, Antarctic Meteorological Research Center
Letu, Husi; Hara, Masanao; Tana, Gegen; Bao, Yuhai; Nishio, Fumihiko
2015-09-01
Nighttime lights of the human settlements (hereafter, "stable lights") are seen as a valuable proxy of social economic activity and greenhouse gas emissions at the subnational level. In this study, we propose an improved method to generate the stable lights from Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) daily nighttime light data for 1999. The study area includes Japan, China, India, and other 10 countries in East Asia. A noise reduction filter (NRF) was employed to generate a stable light from DMSP/OLS time-series daily nighttime light data. It was found that noise from amplitude of the 1-year periodic component is included in the stable light. To remove the amplitude of the 1-year periodic component noise included in the stable light, the NRF method was improved to extract the periodic component. Then, new stable light was generated by removing the amplitude of the 1-year periodic component using the improved NRF method. The resulting stable light was evaluated by comparing it with the conventional nighttime stable light provided by the National Oceanic and Atmosphere Administration/National Geophysical Data Center (NOAA/NGDC). It is indicated that DNs of the NOAA stable light image are lower than those of the new stable light image. This might be attributable to the influence of attenuation effects from thin warm water clouds. However, due to overglow effect of the thin cloud, light area in new stable light is larger than NOAA stable light. Furthermore, the cumulative digital numbers (CDNs) and number of light area pixels (NLAP) of the generated stable light and NOAA/NGDC stable light were applied to estimate socioeconomic variables of population, electric power consumption, gross domestic product, and CO2 emissions from fossil fuel consumption. It is shown that the correlations of the population and CO2FF with new stable light data are higher than those in NOAA stable light data; correlations of the EPC and GDP with NOAA stable light data are higher those in the new stable light data.
NASA Astrophysics Data System (ADS)
Duda, James L.; Mulligan, Joseph; Valenti, James; Wenkel, Michael
2005-01-01
A key feature of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) is the Northrop Grumman Space Technology patent-pending innovative data routing and retrieval architecture called SafetyNetTM. The SafetyNetTM ground system architecture for the National Polar-orbiting Operational Environmental Satellite System (NPOESS), combined with the Interface Data Processing Segment (IDPS), will together provide low data latency and high data availability to its customers. The NPOESS will cut the time between observation and delivery by a factor of four when compared with today's space-based weather systems, the Defense Meteorological Satellite Program (DMSP) and NOAA's Polar-orbiting Operational Environmental Satellites (POES). SafetyNetTM will be a key element of the NPOESS architecture, delivering near real-time data over commercial telecommunications networks. Scattered around the globe, the 15 unmanned ground receptors are linked by fiber-optic systems to four central data processing centers in the U. S. known as Weather Centrals. The National Environmental Satellite, Data and Information Service; Air Force Weather Agency; Fleet Numerical Meteorology and Oceanography Center, and the Naval Oceanographic Office operate the Centrals. In addition, this ground system architecture will have unused capacity attendant with an infrastructure that can accommodate additional users.
NASA Technical Reports Server (NTRS)
Shepherd, J. Marshall; Smith, Eric A.; Adams, W. James (Editor)
2002-01-01
Historically, multi-decadal measurements of precipitation from surface-based rain gauges have been available over continents. However oceans remained largely unobserved prior to the beginning of the satellite era. Only after the launch of the first Defense Meteorological Satellite Program (DMSP) satellite in 1987 carrying a well-calibrated and multi-frequency passive microwave radiometer called Special Sensor Microwave/Imager (SSM/I) have systematic and accurate precipitation measurements over oceans become available on a regular basis; see Smith et al. (1994, 1998). Recognizing that satellite-based data are a foremost tool for measuring precipitation, NASA initiated a new research program to measure precipitation from space under its Mission to Planet Earth program in the 1990s. As a result, the Tropical Rainfall Measuring Mission (TRMM), a collaborative mission between NASA and NASDA, was launched in 1997 to measure tropical and subtropical rain. See Simpson et al. (1996) and Kummerow et al. (2000). Motivated by the success of TRMM, and recognizing the need for more comprehensive global precipitation measurements, NASA and NASDA have now planned a new mission, i.e., the Global Precipitation Measurement (GPM) mission. The primary goal of GPM is to extend TRMM's rainfall time series while making substantial improvements in precipitation observations, specifically in terms of measurement accuracy, sampling frequency, Earth coverage, and spatial resolution. This report addresses four fundamental questions related to the transition from current to future global precipitation observations as denoted by the TRMM and GPM eras, respectively.
NASA Technical Reports Server (NTRS)
Watermann, Jurgen; Lummerzheim, Dirk; De La Beaujardiere, Odile; Newell, Patrick T.; Rich, Frederic J.
1994-01-01
We have examined Sondrestrom incoherent scatter radar observations of ionospheric plasma density and temperature distributions and measurements of F region ion drifts that were made during a prenoon pass of the Defense Meteorological Satellite Program (DMSP)-F7 satellite through the radar field of view. The spacecraft traversed a region of intense electron precipitation with a characteristic energy below approximately 200 eV. Particles with such low characteristic energies are believed to be directly or indirectly of magnetosheath origin. The precipitation region had a width about 2 deg invariant latitude and covered the low-latitude boundary layer (LLBL), the cusp, and the equatorward section of the plasma mantle (PM). The corotating radar observed a patch of enhanced electron density and elevated electron temperature in the F2 region between about 10.5 and 12 magnetic local time in the same invariant latitude range where DMSP-F7 detected the soft-electron flux. The ion drift pattern, also obtained by radar, shows that it is unlikely that the plasma patch was produced by solar radiation and advected into the radar field of view. We suggest that the radar observed modifications of the ionospheric plasma distribution, which resulted from direct entry of magnetosheath electrons into the magnetosphere and down to ionospheric altitudes. Model calculations of the ionospheric response to the observed electron precipitation support our interpretation. The spectral characteristics of the electron flux in the LLBL, cusp, and equatorward section of the PM were in this case too similar to allow to distinguish between them by using incoherent scatter radar measurements only.
Two Observed Consequences of Penetration Electric Fields
2008-10-11
satellites are three- axis stabilized spacecraft that fly in circular. Sun -synchronous, polar ( inclination 98.7 ) orbits at an altitude of ~840km. The...350 km. The orbital period was —10 h. CRRES was spin stabilized at a rate of 2 rpm. Its spin axis always pointed within 15 of the Sun . The line of...satellites with flight designations 10 and higher, orbital ascending nodes are on the dusk side of the Earth . Thus, during the Halloween storm DMSP
1991-06-07
precipitating electron spectrometer to gather solar flare effects data, and a microwave imager. Future upgrades of the DMSP satellites, known as the Block 6... Energia . It is capable of placing a 16 ton payload into LEO. This is the booster which the Australians hope to launch at Cape York; 2 12 that effort will
Lühr, Hermann; Huang, Tao; Wing, Simon; Kervalishvili, Guram; Rauberg, Jan; Korth, Haje
2017-01-01
ESA’s Swarm constellation mission makes it possible for the first time to determine field-aligned currents (FACs) in the ionosphere uniquely. In particular at high latitudes, the dual-satellite approach can reliably detect some FAC structures which are missed by the traditional single-satellite technique. These FAC events occur preferentially poleward of the auroral oval and during times of northward interplanetary magnetic field (IMF) orientation. Most events appear on the nightside. They are not related to the typical FAC structures poleward of the cusp, commonly termed NBZ. Simultaneously observed precipitating particle spectrograms and auroral images from Defense Meteorological Satellite Program (DMSP) satellites are consistent with the detected FACs and indicate that they occur on closed field lines mostly adjacent to the auroral oval. We suggest that the FACs are associated with Sun-aligned filamentary auroral arcs. Here we introduce in an initial study features of the high-latitude FAC structures which have been observed during the early phase of the Swarm mission. A more systematic survey over longer times is required to fully characterize the so far undetected field aligned currents. PMID:29056833
Problems with mapping the auroral oval and magnetospheric substorms
NASA Astrophysics Data System (ADS)
Antonova, E. E.; Vorobjev, V. G.; Kirpichev, I. P.; Yagodkina, O. I.; Stepanova, M. V.
2015-10-01
Accurate mapping of the auroral oval into the equatorial plane is critical for the analysis of aurora and substorm dynamics. Comparison of ion pressure values measured at low altitudes by Defense Meteorological Satellite Program (DMSP) satellites during their crossings of the auroral oval, with plasma pressure values obtained at the equatorial plane from Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellite measurements, indicates that the main part of the auroral oval maps into the equatorial plane at distances between 6 and 12 Earth radii. On the nightside, this region is generally considered to be a part of the plasma sheet. However, our studies suggest that this region could form part of the plasma ring surrounding the Earth. We discuss the possibility of using the results found here to explain the ring-like shape of the auroral oval, the location of the injection boundary inside the magnetosphere near the geostationary orbit, presence of quiet auroral arcs in the auroral oval despite the constantly high level of turbulence observed in the plasma sheet, and some features of the onset of substorm expansion.
Problems with mapping the auroral oval and magnetospheric substorms.
Antonova, E E; Vorobjev, V G; Kirpichev, I P; Yagodkina, O I; Stepanova, M V
Accurate mapping of the auroral oval into the equatorial plane is critical for the analysis of aurora and substorm dynamics. Comparison of ion pressure values measured at low altitudes by Defense Meteorological Satellite Program (DMSP) satellites during their crossings of the auroral oval, with plasma pressure values obtained at the equatorial plane from Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellite measurements, indicates that the main part of the auroral oval maps into the equatorial plane at distances between 6 and 12 Earth radii. On the nightside, this region is generally considered to be a part of the plasma sheet. However, our studies suggest that this region could form part of the plasma ring surrounding the Earth. We discuss the possibility of using the results found here to explain the ring-like shape of the auroral oval, the location of the injection boundary inside the magnetosphere near the geostationary orbit, presence of quiet auroral arcs in the auroral oval despite the constantly high level of turbulence observed in the plasma sheet, and some features of the onset of substorm expansion.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhou, Yuyu; Smith, Steven J.; Elvidge, Christopher
Accurate information of urban areas at regional and global scales is important for both the science and policy-making communities. The Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime stable light data (NTL) provide a potential way to map urban area and its dynamics economically and timely. In this study, we developed a cluster-based method to estimate the optimal thresholds and map urban extents from the DMSP/OLS NTL data in five major steps, including data preprocessing, urban cluster segmentation, logistic model development, threshold estimation, and urban extent delineation. Different from previous fixed threshold method with over- and under-estimation issues, in ourmore » method the optimal thresholds are estimated based on cluster size and overall nightlight magnitude in the cluster, and they vary with clusters. Two large countries of United States and China with different urbanization patterns were selected to map urban extents using the proposed method. The result indicates that the urbanized area occupies about 2% of total land area in the US ranging from lower than 0.5% to higher than 10% at the state level, and less than 1% in China, ranging from lower than 0.1% to about 5% at the province level with some municipalities as high as 10%. The derived thresholds and urban extents were evaluated using high-resolution land cover data at the cluster and regional levels. It was found that our method can map urban area in both countries efficiently and accurately. Compared to previous threshold techniques, our method reduces the over- and under-estimation issues, when mapping urban extent over a large area. More important, our method shows its potential to map global urban extents and temporal dynamics using the DMSP/OLS NTL data in a timely, cost-effective way.« less
NASA Technical Reports Server (NTRS)
Ohtani, S.; Potemra, T. A.; Newell, P. T.; Zanetti, L. J.; Iijima, T.; Watanabe, M.; Yamauchi, M.; Elphinstone, R. D.; De La Beauijardie, O.; Blomberg, L. G.
1995-01-01
The spatial structure of dayside large-scale field-aligned current (FAC) systems is examined by using Viking and Defense Meteorological Satellite Program-F7 (DMSP-F7) data. We focus on four events in which the satellites simultaneously observed postnoon and prenoon three FAC systems: the region 2, the region 1, and the mantle (referred to as midday region O) systems, from equatorward to poleward. These events provide the most solid evidence to date that the midday region O system is a separate and unique FAC system, and is not an extension of the region 1 system from other local times. The events are examined comprehensively by making use of a mulit-instrumental data set, which includes magnetic field, particle flux, electric field, auroral UV image data from the satellites, and the Sondrestrom convection data. The results are summarized as follows: (1) Region 2 currents flow mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPD) at their poleward edge. (2) The region 1 system is located in the core part of the auroral oval and is confined in a relatively narrow range in latitude which includes the convection reversal. The low-latitude boundary layer, possibly including the outer part of the plasma sheet, and the external cusp are the major source regions of dayside region 1 currents. (2) Midday region O currents flow on open field lines and are collocated with the shear of antisunward convection flows with velocites decreasing poleward. On the basis of these results we support the view that both prenoon and postnoon current systems consist of the three-sheet structure when the disctortion ofthe convection pattern associated with interplanetary magnetic field (IMF) B(sub Y) is small and both morningside and eveningside convection cells are crescent-shaped. We also propose that the midday region O and a part of the region 1 systems are closely coupled to the same source.
Estimating nitrogen oxides emissions at city scale in China with a nightlight remote sensing model.
Jiang, Jianhui; Zhang, Jianying; Zhang, Yangwei; Zhang, Chunlong; Tian, Guangming
2016-02-15
Increasing nitrogen oxides (NOx) emissions over the fast developing regions have been of great concern due to their critical associations with the aggravated haze and climate change. However, little geographically specific data exists for estimating spatio-temporal trends of NOx emissions. In order to quantify the spatial and temporal variations of NOx emissions, a spatially explicit approach based on the continuous satellite observations of artificial nighttime stable lights (NSLs) from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) was developed to estimate NOx emissions from the largest emission source of fossil fuel combustion. The NSL based model was established with three types of data including satellite data of nighttime stable lights, geographical data of administrative boundaries, and provincial energy consumptions in China, where a significant growth of NOx emission has experienced during three policy stages corresponding to the 9th-11th)Five-Year Plan (FYP, 1995-2010). The estimated national NOx emissions increased by 8.2% per year during the study period, and the total annual NOx emissions in China estimated by the NSL-based model were approximately 4.1%-13.8% higher than the previous estimates. The spatio-temporal variations of NOx emissions at city scale were then evaluated by the Moran's I indices. The global Moran's I indices for measuring spatial agglomerations of China's NOx emission increased by 50.7% during 1995-2010. Although the inland cities have shown larger contribution to the emission growth than the more developed coastal cities since 2005, the High-High clusters of NOx emission located in Beijing-Tianjin-Hebei regions, the Yangtze River Delta, and the Pearl River Delta should still be the major focus of NOx mitigation. Our results indicate that the readily available DMSP/OLS nighttime stable lights based model could be an easily accessible and effective tool for achieving strategic decision making toward NOx reduction. Copyright © 2015 Elsevier B.V. All rights reserved.
16. DETAIL OF TOOL FOR COMPRESSING SPRING IN FAIRING SEPARATION ...
16. DETAIL OF TOOL FOR COMPRESSING SPRING IN FAIRING SEPARATION ACTUATOR AND PLASTIC-WRAPPED ACTUATOR FOR FAIRING THAT WILL ENCLOSE A DMSP SATELLITE. (FAIRING SEPARATION ACTUATOR COMPRESSES TO ONE-THIRD OF ITS SIZE.) - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA
NASA Technical Reports Server (NTRS)
Pfaff, R.; Liebrecht, C.; Berthelier, J.-J.; Parrot, M.; Lebreton, J.-P.
2008-01-01
Detailed observations of the plasma structure and irregularities that characterize the topside ionosphere at sub-auroral, middle, and low-latitudes are presented that were gathered with probes on the DEMETER and DMSP satellites during geomagnetic storms. Data from successive orbits reveal how the density structure and irregularities evolve with changes in the Dst. The observations reveal that precisely during the main phase of severe geomagnetic storms, increased ambient plasma densities and broad regions of irregularities are observed at 700 km, initially at storm commencement near the magnetic equator and then extending to mid- and sub-auroral latitudes within the approximately 8 hour period corresponding to the negative Dst excursions. Furthermore, intense, broadband electric and magnetic field irregularities are often observed at sub-auroral latitudes and are typically associated with the trough region and its poleward plasma density gradient. The observations provide a general framework showing how low, mid, and sub-auroral latitude plasma density structuring and associated irregularities respond to geomagnetic storms.
NASA Astrophysics Data System (ADS)
Lee, Seongsuk; Yi, Yu
2016-12-01
The spatial size and variation of Arctic sea ice play an important role in Earth’s climate system. These are affected by conditions in the polar atmosphere and Arctic sea temperatures. The Arctic sea ice concentration is calculated from brightness temperature data derived from the Defense Meteorological Satellite program (DMSP) F13 Special Sensor Microwave/Imagers (SSMI) and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS) sensors. Many previous studies point to significant reductions in sea ice and their causes. We investigated the variability of Arctic sea ice using the daily sea ice concentration data from passive microwave observations to identify the sea ice melting regions near the Arctic polar ice cap. We discovered the abnormal melting of the Arctic sea ice near the North Pole during the summer and the winter. This phenomenon is hard to explain only surface air temperature or solar heating as suggested by recent studies. We propose a hypothesis explaining this phenomenon. The heat from the deep sea in Arctic Ocean ridges and/ or the hydrothermal vents might be contributing to the melting of Arctic sea ice. This hypothesis could be verified by the observation of warm water column structure below the melting or thinning arctic sea ice through the project such as Coriolis dataset for reanalysis (CORA).
NASA Technical Reports Server (NTRS)
Pfaff, Robert F.; Liebrecht, C; Berthelier, Jean-Jacques; Parrot, M.; Lebreton, Jean-Pierre
2007-01-01
Detailed observations of the plasma structure and irregularities that characterize the topside ionosphere at sub-auroral, middle, and low-latitudes are gathered with probes on the DEMETER and DMSP satellites. In particular, we present DEMETER observations near 700 km altitude that reveal: (1) the electric field irregularities and density depletions at mid-latitudes are remarkably similar to those associated with equatorial spread-F at low latitudes; (2) the mid-latitude density structures contain both depletions and enhancements with scale lengths along the spacecraft trajectory that typically vary from 10's to 100's of km; (3) in some cases, ELF magnetic field irregularities are observed in association with the electric field irregularities on the walls of the plasma density structures and appear to be related to finely-structured spatial currents and/or Alfven waves; (4) during severe geomagnetic storms, broad regions of nightside plasma density structures are typically present, in some instances extending from the equator to the subauroral regions; and (5) intense, broadband electric and magnetic field irregularities are observed at sub-auroral latitudes during geomagnetic storm periods that are typically associated with the trough region. Data from successive DEMETER orbits during storm periods in both the daytime and nighttime illustrate how enhancements of both the ambient plasma density, as well as sub-auroral and mid-latitude density structures, correlate and evolve with changes in the Dst. The DEMETER data are compared with near simultaneous observations gathered by the DMSP satellites near 840 km. The observations are related to theories of sub-auroral and mid-latitude plasma density structuring during geomagnetic storms and penetration electric fields and are highly germane to understanding space weather effects regarding disruption of communication and navigation signals in the near-space environment.
NASA Astrophysics Data System (ADS)
Tardelli, F. C.; Abalde, J. R.; Pimenta, A. A.; Kavutarapu, V.; Tardelli, A.
2016-12-01
Using optical techniques and satellite data a plasma blob case was observed on February 23, 2007, in São José dos Campos (SJC) (23.21°S, 45.86°O; dip. Lat. 17.6°S) in the Brazilian sector. This is the first observation of plasma blob in SJC region using data from optical techniques and satellite measurements. The plasma blob is the enhancements in plasma density by a factor of 2 or more above background plasma. Simultaneous all-sky images were used to map the spatial extent of plasma blob. DMSP satellite data were used to confirm the enhancements in plasma density in the ionosphere, which provides important parameters of the ionospheric behavior during the event. During the night of present study, the plasma blob was associated with a plasma bubble and the average zonal drift velocities are 61±6 m-s and 74±8 m-s, respectively. The average North/South and East/West extension of the blob were 591 km and 328 km, respectively. Furthermore, the average longitudinal drift velocity was 85±13 m-s. In this work plasma density is found to be enhanced by a factor of 2 compared to the background plasma. We report for the first time plasma blob in SJC at low latitude region associated with plasma bubble and present important features of their behavior.
NASA Technical Reports Server (NTRS)
Goodman, Steven J.; Wright, Pat; Christian, Hugh; Blakeslee, Richard; Buechler, Dennis; Scharfen, Greg
1991-01-01
The global lightning signatures were analyzed from the DMSP Optical Linescan System (OLS) imagery archived at the National Snow and Ice Data Center. Transition to analysis of the digital archive becomes available and compare annual, interannual, and seasonal variations with other global data sets. An initial survey of the quality of the existing film archive was completed and lightning signatures were digitized for the summer months of 1986 to 1987. The relationship is studied between: (1) global and regional lightning activity and rainfall, and (2) storm electrical development and environment. Remote sensing data sets obtained from field programs are used in conjunction with satellite/radar/lightning data to develop and improve precipitation estimation algorithms, and to provide a better understanding of the co-evolving electrical, microphysical, and dynamical structure of storms.
Double structure of ionospheric conductivity in the midnight auroral oval during a substorm
NASA Astrophysics Data System (ADS)
Kotikov, A. L.; Shishkina, E. M.; Troshichev, O. A.; Sergienko, T. I.
1995-02-01
Measurements of precipitating particles on board Defense Meteorological Satellite Program (DMSP) F7 spacecraft are used to analyze the distribution of ionospheric conductance in the midnight auroral zone during substorms. The distribution is compared with the meridional profile of ionospheric currents calculated from magnetic data from the Kara meridional chain. Two regions of high Hall conductance are found; one of them is the traditional auroral zone, at latitudes 64-68 deg, and the other is a narrow band at latitudes 70-73 deg. The position of high conductance zones is in agreement with the location of the intense westward currents. The accelerated particle population is typical of electrons E(sub e) greater than 5 keV in the high conductance region.
Synergistic use of multispectral satellite data for monitoring land surface change
NASA Technical Reports Server (NTRS)
Choudhury, Bhaskar J.
1991-01-01
Observations by the Advanced Very High Resolution Radiometer (AVHRR) onboard the NOAA satellites were used to compute visible and near infrared reflectances and surface temperature, while passive microwave observations at 37 GHz frequency by the Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave Imager (SSM/I) on board, respectively, the Nimbus-7 and DMSP-F8 satellites were used to compute polarization difference. These observations were analyzed along transects from rainforest to desert over northern Africa for the period 1979-1987, which included an unprecedented drought during 1984 over the Sahel zone. Model simulations were made to understand the interrelationship among multispectral data.
National Polar-orbiting Operational Environmental Satellite System (NPOESS) Design and Architecture
NASA Astrophysics Data System (ADS)
Hinnant, F.
2008-12-01
The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system - the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS will replace the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD and will provide continuity for the NASA Earth Observing System (EOS) with the launch of the NPOESS Preparatory Project (NPP). This poster will provide an overview of the NPOESS architecture, which includes four segments. The space segment includes satellites in two orbits that carry a suite of sensors to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the Earth, atmosphere, and near-Earth space environment. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users through a Command, Control, and Communication Segment (C3S). The data processing for NPOESS is accomplished through an Interface Data Processing Segment (IDPS)/Field Terminal Segment (FTS) that processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government as well as to remote terminal users. The Launch Support Segment completes the four segments that make up NPOESS that will enhance the connectivity between research and operations and provide critical operational and scientific environmental measurements to military, civil, and scientific users until 2026.
Landcover change and light pollution in Kota Bandarlampung
NASA Astrophysics Data System (ADS)
Rohman, Akmal F.; Hafidz, Muhammad; Hazairin, Azra Q.; Riadini, Fitri
2016-10-01
Excessive emission of light or light pollution at night is one of the elements of environmental pollution. Indirectly light pollution causes increase of fossil fuel use, greenhouse gasses and pollution in the atmosphere. Direct effects of light pollution including: disturbance of animals life, human's psychology and environmental degradation. Light pollution in an area is related with the existence of built-up area and the lack of vegetation as a manifestation of economic and population growth. This research aims to know the relation of land cover changes with light pollution in Bandar Lampung and surrounding with 40 km radius over the last ten years. This research used satellite imagery to obtained data and later does the verification and accuracy tests on the field. The variables used in this research include light pollution radiance value, percentages in the built-up area and vegetation density. Light pollution radiance value is obtained from DMSP-OLS Version 4 satellite images, while the changes of built up and vegetation density data obtained from NDBI dan NDVI from Landsat 8 satellite images. The research area is divided into a grid with a size of 30"×30" which is the same as spatial resolution of DMSP. From sample grids, regression analysis between the percentage of light pollution radiance value with the percentage of NDVI and NDBI index on each grids. The percentages of built up areas and vegetation has 58 % of fair correlation with light emission.
NASA Technical Reports Server (NTRS)
Rodgers, Edward; Pierce, Harold; Adler, Robert
1999-01-01
Tropical cyclone monthly rainfall amounts are estimated from passive microwave satellite observations in the North Atlantic and in three equal geographical regions of the North Pacific (i.e., Western, Central, and Eastern North Pacific). These satellite-derived rainfall amounts are used to assess the impact of tropical cyclone rainfall in altering the geographical, seasonal, and inter-annual distribution of the 1987-1989, 1991-1998 North Atlantic and Pacific rainfall during June-November when tropical cyclones are most abundant. To estimate these tropical cyclone rainfall amounts, mean monthly rain rates are derived from the Defence Meteorological Satellite Program (DMSP) Special Sensor Microwave/ Radiometer (SSM/I) observations within 444 km radius of the center of those North Atlantic and Pacific tropical cyclones that reached storm stage and greater. These rain rate observations are then multiplied by the number of hours in a given month. Mean monthly rainfall amounts are also constructed for all the other North Atlantic and Pacific raining systems during this eleven year period for the purpose of estimating the geographical distribution and intensity of rainfall contributed by non-tropical cyclone systems. Further, the combination of the non-tropical cyclone and tropical cyclone (i.e., total) rainfall is constructed to delineate the fractional amount that tropical cyclones contributed to the total North Pacific rainfall.
Multi-instrumental Analysis of the Ionospheric Density Response to Geomagnetic Disturbances
NASA Astrophysics Data System (ADS)
Zakharenkova, I.; Astafyeva, E.
2014-12-01
Measurements provided by Low Earth Orbit (LEO) satellite missions have already proved to be very efficient in investigations of global redistribution of ionospheric plasma and thermosphere mass density during such phenomena as geomagnetic storms. LEO satellites have various instruments for research of the ionosphere response to the space weather events like GPS receiver for precise orbit determination (POD), total electron content estimation and radio occultation, altimeter, planar Langmuir probe, topside sounder, special detectors for particle fluxes, magnetometer etc. In this paper, we present results of joint analysis of LEO satellite data, in particular CHAMP, DMSP, JASON, as well as data provided by ground-based networks of GPS receivers and ionosonde stations for global ionospheric response to the geomagnetic disturbances. We use in-situ plasma density data from CHAMP and DMSP satellites, along with data of GPS receiver onboard CHAMP-satellite and ground-based GPS-receivers to study occurrence and global distribution of ionospheric irregularities during the main phase of the storm. Using CHAMP GPS measurements, we created maps of GPS phase fluctuation activity and found two specific zones of the most intense irregularities - first is the region of the auroral oval at high latitudes of both hemispheres, the second one is the low-latitudes/equatorial region between Africa and South America. The interhemispheric asymmetry of the ionospheric irregularities intensity and occurrence in polar region is discussed. Analysis of the topside TEC, derived from CHAMP onboard GPS POD antenna, indicate the significant redistribution of the topside ionospheric plasma density in the equatorial, middle and high-latitude ionosphere during main and recovery phases of geomagnetic storm. Multi-instrumental data allow to analyze in detail the complex modification and dynamics of the upper atmosphere in different altitudinal, spatial and temporal scales.
Ion-neutral Coupling During Deep Solar Minimum
NASA Technical Reports Server (NTRS)
Huang, Cheryl Y.; Roddy, Patrick A.; Sutton, Eric K.; Stoneback, Russell; Pfaff, Robert F.; Gentile, Louise C.; Delay, Susan H.
2013-01-01
The equatorial ionosphere under conditions of deep solar minimum exhibits structuring due to tidal forces. Data from instruments carried by the Communication Navigation Outage Forecasting System (CNOFS) which was launched in April 2008 have been analyzed for the first 2 years following launch. The Planar Langmuir Probe (PLP), Ion Velocity Meter (IVM) and Vector Electric Field Investigation (VEFI) all detect periodic structures during the 20082010 period which appear to be tides. However when the tidal features detected by these instruments are compared, there are distinctive and significant differences between the observations. Tides in neutral densities measured by the Gravity Recovery and Climate Experiment (GRACE) satellite were also observed during June 2008. In addition, Broad Plasma Decreases (BPDs) appear as a deep absolute minimum in the plasma and neutral density tidal pattern. These are co-located with regions of large downward-directed ion meridional velocities and minima in the zonal drifts, all on the nightside. The region in which BPDs occur coincides with a peak in occurrence rate of dawn depletions in plasma density observed on the Defense Meterological Satellite Program (DMSP) spacecraft, as well as a minimum in radiance detected by UV imagers on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) and IMAGE satellites
2011-12-30
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The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Status
NASA Technical Reports Server (NTRS)
Hou, Arthur Y.; Azarbarzin, Ardeshir A.; Kakar, Ramesh K.; Neeck, Steven
2011-01-01
The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. Building upon the success of the U.S.-Japan Tropical Rainfall Measuring Mission (TRMM), the National Aeronautics and Space Administration (NASA) of the United States and the Japan Aerospace and Exploration Agency (JAXA) will deploy in 2013 a GPM "Core" satellite carrying a KulKa-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Imager (GMI) to establish a new reference standard for precipitation measurements from space. The combined active/passive sensor measurements will also be used to provide common database for precipitation retrievals from constellation sensors. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer- 2 (AMSR-2) on the GCOM-Wl satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian Megha-Tropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA)-19, (5) MHS instruments on MetOp satellites launched by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), (6) the Advanced Technology Microwave Sounder (ATMS) on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), (7) ATMS instruments on the NOAA-NASA Joint Polar Satellite System (JPSS) satellites, and (8) a microwave imager under planning for the Defense Weather Satellite System (DWSS).
NASA Astrophysics Data System (ADS)
Faouzi, B.; Washaya, P.
2017-09-01
This paper is based on using DMSP-OLS data from satellites nighttime light observations to detect both sources of light emissions in Algeria from human settlement areas and gas flaring from oil-extraction and natural gas production. We used the time series of data from DMSP-OLS images to examine the spatial and temporal characteristics of urban development in 48 Algerian provinces from 1993 to 2012. A systematic nighttime light calibration method was used to improve the consistency and comparability of the DSMPOSL images and then a separation is made between light detected from human settlements and light detected from gas flaring in order to allow us to study human settlements without other light emissions and then assess the suitability of using DMSP data in southern Algeria and its ability to monitor gas flaring. Linear regression methods were developed to identify the dynamic change of nighttime light and estimated its growth directions at pixel level. This work is the first to use nighttime light observations to detect and monitor the growth of human settlements in North Africa. In this study, we made use of DMSP-OLS data as a return ticket to the years of crises and we found the most affected provinces during that period. The DMSP-OLS data proved to be an index of growth in the economy during the period of stability in Algeria expressed by positive dynamic changes in the lighted area in all Algerian provinces. We used NTL data as an alternative to annual growth indexes for each province, which are unavailable, and its help as a monitoring system for socioeconomic parameters to fill the gap of data availability. We also proposed nighttime light remote sensing data as a useful tool to control and reduce CO2 emissions in Algeria's petroleum sector.
NASA Technical Reports Server (NTRS)
Bell, Thomas L.; Kundu, Prasun K.; Einaudi, Franco (Technical Monitor)
2000-01-01
Estimates from TRMM satellite data of monthly total rainfall over an area are subject to substantial sampling errors due to the limited number of visits to the area by the satellite during the month. Quantitative comparisons of TRMM averages with data collected by other satellites and by ground-based systems require some estimate of the size of this sampling error. A method of estimating this sampling error based on the actual statistics of the TRMM observations and on some modeling work has been developed. "Sampling error" in TRMM monthly averages is defined here relative to the monthly total a hypothetical satellite permanently stationed above the area would have reported. "Sampling error" therefore includes contributions from the random and systematic errors introduced by the satellite remote sensing system. As part of our long-term goal of providing error estimates for each grid point accessible to the TRMM instruments, sampling error estimates for TRMM based on rain retrievals from TRMM microwave (TMI) data are compared for different times of the year and different oceanic areas (to minimize changes in the statistics due to algorithmic differences over land and ocean). Changes in sampling error estimates due to changes in rain statistics due 1) to evolution of the official algorithms used to process the data, and 2) differences from other remote sensing systems such as the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I), are analyzed.
Comparison of DMSP SSM/I and Landsat 7 ETM+ Sea Ice Concentrations During Summer Melt
NASA Technical Reports Server (NTRS)
Cavalieri, Donald J.; Markus, Thorsten; Ivanoff, Alvaro; Koblinsky, Chester J. (Technical Monitor)
2001-01-01
As part of NASA's EOS Aqua sea ice validation program for the Advanced Microwave Scanning Radiometer (AMSR-E), Landsat 7 Enhanced Thematic Mapper (ETM+) images were acquired to develop a sea ice concentration data set with which to validate AMSR-E sea ice concentration retrievals. The standard AMSR-E Arctic sea ice concentration product will be obtained with the enhanced NASA Team (NT2) algorithm. The goal of this study is to assess the accuracy to which the NT2 algorithm, using DMSP Special Sensor Microwave Imager radiances, retrieves sea ice concentrations under summer melt conditions. Melt ponds are currently the largest source of error in the determination of Arctic sea ice concentrations with satellite passive microwave sensors. To accomplish this goal, Landsat 7 ETM+ images of Baffin Bay were acquired under clear sky conditions on the 26th and 27th of June 2000 and used to generate high-resolution sea ice concentration maps with which to compare the NT2 retrievals. Based on a linear regression analysis of 116 25-km samples, we find that overall the NT2 retrievals agree well with the Landsat concentrations. The regression analysis yields a correlation coefficient of 0.98. In areas of high melt ponding, the NT2 retrievals underestimate the sea ice concentrations by about 12% compared to the Landsat values.
NASA Astrophysics Data System (ADS)
Wang, Zhao; Yang, Shan; Wang, Shuguang; Shen, Yan
2017-10-01
The assessment of the dynamic urban structure has been affected by lack of timely and accurate spatial information for a long period, which has hindered the measurements of structural continuity at the macroscale. Defense meteorological satellite program's operational linescan system (DMSP/OLS) nighttime light (NTL) data provide an ideal source for urban information detection with a long-time span, short-time interval, and wide coverage. In this study, we extracted the physical boundaries of urban clusters from corrected NTL images and quantitatively analyzed the structure of the urban cluster system based on rank-size distribution, spatial metrics, and Mann-Kendall trend test. Two levels of urban cluster systems in the Yangtze River Delta region (YRDR) were examined. We found that (1) in the entire YRDR, the urban cluster system showed a periodic process, with a significant trend of even distribution before 2007 but an unequal growth pattern after 2007, and (2) at the metropolitan level, vast disparities exist in four metropolitan areas for the fluctuations of Pareto's exponent, the speed of cluster expansion, and the dominance of core cluster. The results suggest that the extracted urban cluster information from NTL data effectively reflect the evolving nature of regional urbanization, which in turn can aid in the planning of cities and help achieve more sustainable regional development.
Solar Cycle and Geomagnetic Activity Variation of Topside Ionospheric Upflow as Measured by DMSP
NASA Astrophysics Data System (ADS)
Coley, W. R.; Hairston, M. R.
2016-12-01
Under the proper conditions a considerable amount of plasma can escape the Earth's ionosphere into the magnetosphere. Indeed, there are indications that at least part of the time the ionosphere may be the dominant source of ions for the plasma sheet and near-Earth portion of the magnetosphere. The upward flux of thermal O+ from the lower part of the topside ionosphere actively provides plasma into intermediate altitudes where they may be given escape energy by various mechanisms. Previous work has indicated that there is considerable time variation of upwelling low energy ionospheric plasma to these intermediate altitudes during moderate to high solar activity. Here we use the SSIES thermal plasma instruments on board the Defense Meteorological Satellite Program (DMSP) F13-F19 series of spacecraft to examine the vertical flux of thermal O+ from the deep solar minimum of 2008-2009 to the moderately active period of 2012-2015. Separately integrating the upward and downward fluxes over the high-latitude region (auroral zone and polar cap) allows the observation of the total upflow/downflow as a function of the current geomagnetic conditions, solar cycle, and solar wind conditions. In particular we investigate the incidence of high upward flux events as a function of solar wind velocity and density during the deepest solar minimum since the space age began.
USC/JPL GAIM: A Real-Time Global Ionospheric Data Assimilation Model
NASA Astrophysics Data System (ADS)
Mandrake, L.; Wilson, B. D.; Hajj, G.; Wang, C.; Pi, X. `; Iijima, B.
2004-12-01
We are in the midst of a revolution in ionospheric remote sensing driven by the illuminating powers of ground and space-based GPS receivers, new UV remote sensing satellites, and the advent of data assimilation techniques for space weather. The University of Southern Califronia (USC) and the Jet Propulsion Laboratory (JPL) have jointly developed a Global Assimilative Ionospheric Model (GAIM) to monitor space weather, study storm effects, and provide ionospheric calibration for DoD customers and NASA flight projects. GAIM is a physics-based 3D data assimilation model that uses both 4DVAR and Kalman filter techniques to solve for the ion & electron density state and key drivers such as equatorial electrodynamics, neutral winds, and production terms. GAIM accepts as input ground GPS TEC data from 900+ sites, occultation links from CHAMP, SAC-C, IOX, and the coming COSMIC constellation, UV limb and nadir scans from the TIMED and DMSP satellites, and in situ data from a variety of satellites (C/NOFS & DMSP). GAIM can ingest multiple data sources in real time, updates the 3D electron density grid every 5 minutes, and solves for improved drivers every 1-2 hours. GAIM density retrievals have been validated by comparisons to vertical TEC measurements from TOPEX & JASON, slant TEC measurements from independent GPS sites, density profiles from ionosondes & incoherent scatter radars, and alternative tomographic retrievals. Daily USC/JPL GAIM runs have been operational since March 2003 using 100-200 ground GPS sites as input and TOPEX/JASON and ionosondes for daily validation. A prototype real-time GAIM system has been running since May 2004. RT GAIM ingests TEC data from 77+ streaming GPS sites every 5 minutes, adds more TEC for better global coverage every hour from hourly GPS sites, and updates the ionospheric state every 5 minutes using the Kalman filter. We plan to add TEC links from COSMIC occultations and UV radiance data from the DMSP satellites, when they become available, to the daily and RT GAIM runs. Our presentation will include results from numerous validation case studies and one year of JASON validation statistics. Customers are currently evaluating the accuracy of USC/JPL GAIM "nowcasts" for ray tracing applications and trans-ionospheric path delay calibration.
Prey-dependent retention of dimethylsulfoniopropionate (DMSP) by mixotrophic dinoflagellates.
Lee, Hyunwoo; Park, Ki-Tae; Lee, Kitack; Jeong, Hae Jin; Yoo, Yeong Du
2012-03-01
We investigated the retention of dimethylsulfoniopropionate (DMSP) in phototrophic dinoflagellates arising from mixotrophy by estimating the cellular content of DMSP in Karlodinium veneficum (mixotrophic growth) fed for 7-10 days on either DMSP-rich Amphidinium carterae (phototrophic growth only) or DMSP-poor Teleaulax sp. (phototrophic growth only). In K. veneficum fed on DMSP-poor prey, the cellular content of DMSP remained almost unchanged regardless of the rate of feeding, whereas the cellular content of DMSP in cells of K. veneficum fed on DMSP-rich prey increased by as much as 21 times the cellular concentration derived exclusively from phototrophic growth. In both cases, significant fractions (10-32% in the former case and 55-65% in the latter) of the total DMSP ingested by K. veneficum were transformed into dimethylsulfide and other biochemical compounds. The results may indicate that the DMSP content of prey species affects temporal variations in the cellular DMSP content of mixotrophic dinoflagellates, and that mixotrophic dinoflagellates produce DMS through grazing on DMSP-rich preys. Additional studies should be performed to examine the universality of our finding in other mixotrophic dinoflagellates feeding on diverse prey species. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.
NASA Astrophysics Data System (ADS)
Wang, C.; Lu, L.
2015-12-01
The Southeast U.S. is listed one of the fastest growing regions by the Census Bureau, covering two of the eleven megaregions of the United States (Florida and Piedmont Atlantic). The Defense Meteorological Satellite Program (DMSP)'s Operational Line-scan System (OLS) nighttime light (NTL) imagery offers a good opportunity for characterizing the extent and dynamics of urban development at global and regional scales. However, the commonly used thresholding technique for NTL-based urban land mapping often underestimates the suburban and rural areas and overestimates urban extents. In this study we developed a novel approach to estimating impervious surface area (ISA) by integrating the NTL and optical reflectance data. A geographically weighted regression model was built to extract ISA from the Vegetation-Adjusted NTL Urban Index (VANUI). The ISA was estimated each year from 1992 to 2013 to generate the ISA time series for the U.S. Southeast region. Using the National Land Cover Database (NLCD) products of percent imperviousness (2001, 2006, and 2010) as our reference data, accuracy assessment indicated that our approach made considerable improvement of the ISA estimation, especially in suburban areas. With the ISA time series, a nonparametric Mann-Kendall trend analysis was performed to detect hotspots of human settlement expansion, followed by the exploration of decennial U.S. census data to link these patterns to migration flows in these hotspots. Our results provided significant insights to human settlement of the U.S. Southeast in the past decades. The proposed approach has great potential for mapping ISA at broad scales with nightlight data such as DMSP/OLS and the new-generation VIIRS products. The ISA time series generated in this study can be used to assess the anthropogenic impacts on regional climate, environment and ecosystem services in the U.S. Southeast.
Accumulation of Dissolved DMSP by Marine Bacteria and its Degradation Via Bacterivory
NASA Technical Reports Server (NTRS)
Wolfe, Gordon V.
1996-01-01
Several bacterial isolates enriched from seawater using complex media were able to accumulate dimethylsulfoniopropionate (DMSP) from media into cells over several hours without degrading it. Uptake only occurred in metabolically active cells, and was repressed in some strains by the presence of additional carbon sources. Accumulation was also more rapid in osmotically-stressed cells, suggesting DMSP is used as an osmotic solute. Uptake could be blocked by inhibitors of active transport systems (2,4-dinitrophenol, azide, arsenate) and of protein synthesis (chloramphenicol). Some structural analogs such as glycine betaine and S-methyl methionine also blocked DMSP uptake, suggesting that the availability of alternate organic osmolytes may influence DMSP uptake. Stresses such as freezing, heating, or osmotic down shock resulted in partial release of DMSP back to the medium. One strain which contained a DMSP-lyase was also able to accumulate DMSP, and DMS was only produced in the absence of alternate carbon sources. Bacteria containing DMSP were prepared as prey for bacterivorous ciliates and flagellates, to examine the fate of the DMSP during grazing. In all cases, predators metabolized the DMSP in bacteria. In some cases, DMS was produced, but it is not clear if this was due to the predators or to associated bacteria in the non-axenic grazer cultures. Bacterivores may influence DMSP cycling by either modulating populations of DMSP-metabolizing bacteria, or by metabolizing DMSP accumulated by bacterial prey.
NASA Astrophysics Data System (ADS)
Scherliess, L.; Schunk, R. W.; Sojka, J. J.; Thompson, D. C.; Zhu, L.
2006-11-01
The Utah State University Gauss-Markov Kalman Filter (GMKF) was developed as part of the Global Assimilation of Ionospheric Measurements (GAIM) program. The GMKF uses a physics-based model of the ionosphere and a Gauss-Markov Kalman filter as a basis for assimilating a diverse set of real-time (or near real-time) observations. The physics-based model is the Ionospheric Forecast Model (IFM), which accounts for five ion species and covers the E region, F region, and the topside from 90 to 1400 km altitude. Within the GMKF, the IFM derived ionospheric densities constitute a background density field on which perturbations are superimposed based on the available data and their errors. In the current configuration, the GMKF assimilates slant total electron content (TEC) from a variable number of global positioning satellite (GPS) ground sites, bottomside electron density (Ne) profiles from a variable number of ionosondes, in situ Ne from four Defense Meteorological Satellite Program (DMSP) satellites, and nighttime line-of-sight ultraviolet (UV) radiances measured by satellites. To test the GMKF for real-time operations and to validate its ionospheric density specifications, we have tested the model performance for a variety of geophysical conditions. During these model runs various combination of data types and data quantities were assimilated. To simulate real-time operations, the model ran continuously and automatically and produced three-dimensional global electron density distributions in 15 min increments. In this paper we will describe the Gauss-Markov Kalman filter model and present results of our validation study, with an emphasis on comparisons with independent observations.
NASA Astrophysics Data System (ADS)
Cossuth, J.; Hart, R. E.
2013-12-01
The structure of a tropical cyclone (TC) is a spatial representation of its organizational pattern and distribution of energy acquisition and release. Physical processes that react to both the external environment and its own internal dynamics manifest themselves in the TC shape. This structure depicts a specific phase in the TC's meteorological lifecycle, reflecting its past and potentially constraining its future development. For a number of reasons, a thorough objective definition of TC structures and an intercomparison of their varieties have been neglected. This lack of knowledge may be a key reason why TC intensity forecasts, despite numerical model improvements and theoretical advances, have been stagnant in recent years relative to track forecasts. Satellite microwave imagers provide multiple benefits in discerning TC structure, but compiling a research quality data set has been problematic due to several inherent technical and logistical issues. While there are multiple satellite sensors that incorporate microwave frequencies, inter-comparison between such sensors is limited by the different available channels, spatial resolutions, and calibration metrics between satellites, all of which provide inconsistencies in resolving TC structural features. To remedy these difficulties, a global archive of TCs as measured by all available US satellite microwave sensors is compiled and standardized. Using global historical best track data, TC microwave data is retrieved from the Defense Meteorological Satellite Program (DMSP) series (including all SSM/I and SSMIS), TMI, AMSR-E, and WindSat sensors. Standardization between sensors for each TC overpass are performed, including: 1) Recalibration of data from the 'ice scattering' channels to a common frequency (89GHz); 2) Resampling the DMSP series to a higher resolution using the Backus-Gilbert technique; and 3) Re-centering the TC center more precisely using the ARCHER technique (Wimmers and Velden 2010) to analyze the storm's rainband and eyewall organization. Ultimately, this project develops a consistent climatology of TC structures using a new database of research-quality historical TC satellite microwave observations. Not only can such data sets more accurately study TC structural evolution, but they may facilitate automated TC intensity estimates and provide methods to enhance current operational and research products, such as at the NRL TC webpage (http://www.nrlmry.navy.mil/TC.html). The process of developing the dataset and possible objective definitions of TC structures using passive microwave imagery will be described, with preliminary results suggesting new methods to identify TC structures that may interrogate and expand upon physical and dynamical theories. Structural metrics such as threshold analysis of the outlines of the TC shape as well as methods to diagnose the inner-core size, completion, and magnitude will be introduced.
NASA Astrophysics Data System (ADS)
Shen, Y.; Knudsen, D. J.; Burchill, J. K.; Howarth, A. D.; Yau, A. W.; Redmon, R. J.
2015-12-01
Low-energy (<10 eV) ion upflows associated with ambipolar ion acceleration in the cusp/cleft and polar cap regions are investigated using conjunctions of the Enhanced Polar Outflow Probe (e-POP) satellite, the Resolute Bay Incoherent Scatter Radar (RISR-N) and the DMSP satellites in June 2014. e-POP encountered the cusp/cleft ion fountain at 10-14 MLT and around 1000 km altitude during these experiments. Such intermediate-altitude observations of ion upflow have been sampled only rarely by previous satellite missions and ground-based radars. The Suprathermal Electron Imager (SEI) onboard e-POP measures two-dimensional ion distribution functions with a frame rate of 100 images per second, from which, high-precision energy and angle information of entering ions can be inferred. Large field-aligned ion bulk flow velocities (2.5 km/s) are estimated from the angle information with a resolution of the order of 25 m/s. The ion velocities were, in general, upward in the cusp region and downward in the polar cap region. The ion temperatures have been resolved by investigating the slop shape of the distribution function. It has been found that only weak perpendicular (to B) heating occurred during these events, which when combined with the simultaneous soft electron precipitation observed by the DMSP SSJ/4 instrument, suggests that ambipolar electric fields play a dominant role in accelerating ions upward at and below 1000 km. Also, structured DC field-aligned currents derived from the magnetic field instrument (MGF) onboard e-POP are found to be well-correlated with upflow velocities. In addition, ion composition information is available from e-POP's ion mass spectrometer (IRM). Oxygen ions (O+) were found to dominate (85%) in the identified events, accompanied by a small fraction (15%) of hydrogen ions (H+) and helium ions (He+). We will compare these in situ measurements with RISR-N observations in order to further our understanding of the mechanisms responsible for, and the three-dimensional structure of, the cusp ion fountain. Acknowledgement: This research is supported by Eyes High Doctoral Recruitment Scholarship at University of Calgary.
UV Observations of Hemispheric Asymmetry
NASA Astrophysics Data System (ADS)
Schaefer, R. K.; Paxton, L. J.; Wolven, B. C.; Zhang, Y.; Romeo, G.
2015-12-01
Asymmetry in the auroral patterns can be an important diagnostic for understanding the dynamics of solar wind interaction with the magnetosphere-ionosphere-thermosphere system (e.g., Newel and Meng, 1998; Fillingrim et al., 2005). Molecular nitrogen emission in the UV Lyman-Birge-Hopfield bands can be used to determine energy flux and electron mean energy (Sotirelis, et al, 2013) and thereby Hall and Pederson integrated conductances (Gjerloev, et al., 2014). UV imagery provided by the 4 SSUSI instruments on the Defense Meteorological Satellite Program (DMSP) F16-F19 spacecraft provide two dimensional maps of this emission at different local times. Often there are near simultaneous observations of both poles by some combination of the satellites. (see figure 1) The SSUSI auroral data products are well suited to this study, as they have the following features.: - dayglow has been subtracted on dayside aurora - electron energy flux and mean energy are pre-calculated - individual arcs have been identified through image processing. In order to intercompare data from multiple satellites, we must first ensure that the instrument calibrations are consistent. In this work we show that the instruments are consistently calibrated, and that results generated from the SSUSI data products can be trusted. Several examples of storm time asymmetries captured by the SSUSI instruments will be discussed. Fillingim, M. O., G. K. Parks, H. U. Frey, T. J. Immel, and S. B. Mende (2005), Hemispheric asymmetry of the afternoon electron aurora, Geophys. Res. Lett., 32, L03113, doi:10.1029/2004GL021635. Gjerloev, J., Schaefer, R., Paxton, L, and Zhang, Y. (2014), A comprehensive empirical model of the ionospheric conductivity derived from SSUSI/GUVI, SuperMAG and SuperDARN data, SM51G-4339, Fall 2014 AGU meeting, San Francisco. Newell, P. T., and C.-I. Meng (1988), Hemispherical asymmetry in cusp precipitation near solstices, J. Geophys. Res., 93(A4), 2643-2648, doi:10.1029/JA093iA04p02643. Sotirelis, T., Korth, H., Hsieh, S. - Y., Zhang, Y., Morrison, D., and Paxton, L., (2013), "Empirical relationship between electron precipitation and far-ultraviolet auroral emissions from DMSP observations", Journal of Geophysical Research: Space Physics, vol. 118, no. 3, pp. 1203 - 1209.
NASA Astrophysics Data System (ADS)
Miller, S. W.; Grant, K. D.; Jamilkowski, M. L.
2012-12-01
The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS will contribute the afternoon orbit component and ground processing system. As such, the Joint Polar Satellite System replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. It also replaces the ground processing component of both Polar-orbiting Operational Environmental Satellites, as well as components of the Defense Meteorological Satellite Program (DMSP) replacement, previously known as the Defense Weather Satellite System (DWSS), managed by the Department of Defense (DoD). The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and solar-geophysical observations of the earth, atmosphere and space. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS), which consists of a Command, Control and Communications Segment (C3S) and an Interface Data Processing Segment (IDPS). Both segments are developed by Raytheon Intelligence and Information Systems (IIS). The C3S is currently flying the Suomi National Polar Partnership (Suomi NPP) satellite and transfers mission data from Suomi NPP and between the ground facilities. The IDPS processes Suomi NPP satellite data to provide Environmental Data Records (EDRs) to NOAA and DoD processing centers operated by the United States government. When the JPSS-1 satellite is launched in early 2017, the responsibilities of the C3S and the IDPS will be expanded to support both Suomi NPP and JPSS-1. The CGS also employs its ground stations at Svalbard, Norway and McMurdo Station, Antarctica, along with a global fiber communications network, to provide data acquisition and routing for multiple additional missions. These include POES, DMSP, NASA Space Communications and Navigation (SCaN, which includes the Earth Observing System [EOS]), Metop for the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), Coriolis/WindSat for the DoD, as well as research activities of the National Science Foundation (NSF). The CGS architecture is evolving over the next few years for several key reasons: 1. "Operationalizing" Suomi NPP, which had originally been intended as a risk reduction mission 2. Leveraging lessons learned to date in multi-mission support 3. Taking advantage of newer, more reliable and efficient technologies 4. Satisfying new requirements and constraints due to the continually evolving budgetary environment Three key aspects of the CGS architecture are being prototyped as part of the path to improve operations in the 2015 timeframe. First, the front end architecture for mission data transport is being re-architected to improve reliability and address the incorporation of new ground stations. Second, the IDPS is undergoing a decoupling process to enhance its flexibility and modularity for supporting an array of potential new missions beyond those listed above. Finally, a solution for complete situational awareness across the CGS is being developed, to facilitate quicker and more efficient identification and resolution of system anomalies. This paper discusses the evolution of the CGS architecture to address these future mission needs.
How wide in magnetic local time is the cusp? An event study
NASA Astrophysics Data System (ADS)
Maynard, N. C.; Weber, E. J.; Weimer, D. R.; Moen, J.; Onsager, T.; Heelis, R. A.; Egeland, A.
1997-03-01
A unique pass of the DMSP F11 satellite, longitudinally cutting through the cusp and mantle, combined with simultaneous optical measurements of the dayside cusp from Svalbard has been used to determine the width in local time of the cusp. We have shown from this event study that the cusp was at least 3.7 hours wide in magnetic local time. These measurements provide a lower limit for the cusp width. The observed cusp optical emissions are relatively constant, considering the processes which lead to the 630.0 nm emissions, and require precipitating electron flux to be added each minute during the DMSP pass throughout the local time extent observed by the imaging photometer and probably over the whole extent of the cusp defined by DMSP data. We conclude that the electron fluxes which produce the cusp aurora are from a process which must have been operable sometime during each minute but could have had both temporal and spatial variations. The measured width along with models of cusp precipitation provide the rationale to conclude that the region of flux tube opening in the dayside merging process involves the whole frontside magnetopause and can extend beyond the dawn-dusk terminator. The merging process for this event was found to be continuous, although spatially and temporally variable.
A multifaceted approach to understanding dynamic urban processes: satellites, surveys, and censuses.
NASA Astrophysics Data System (ADS)
Jones, B.; Balk, D.; Montgomery, M.; Liu, Z.
2014-12-01
Urbanization will arguably be the most significant demographic trend of the 21st century, particularly in fast-growing regions of the developing world. Characterizing urbanization in a spatial context, however, is a difficult task given only the moderate resolution data provided by traditional sources of demographic data (i.e., censuses and surveys). Using a sample of five world "mega-cities" we demonstrate how new satellite data products and new analysis of existing satellite data, when combined with new applications of census and survey microdata, can reveal more about cities and urbanization in combination than either data type can by itself. In addition to the partially modelled Global Urban-Rural Mapping Project (GRUMP) urban extents we consider four sources of remotely sensed data that can be used to estimate urban extents; the NOAA Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) intercallibrated nighttime lights time series data, the newer NOAA Visible Infrared Imager Radiometer Suite (VIIRS) nighttime lights data, the German Aerospace Center (DLR) radar satellite data, and Dense Sampling Method (DSM) analysis of the NASA scatterometer data. Demographic data come from national censuses and/or georeferenced survey data from the Demographic & Health Survey (DHS) program. We overlay demographic and remotely sensed data (e.g., Figs 1, 2) to address two questions; (1) how well do satellite derived measures of urban intensity correlate with demographic measures, and (2) how well are temporal changes in the data correlated. Using spatial regression techniques, we then estimate statistical relationships (controlling for influences such as elevation, coastal proximity, and economic development) between the remotely sensed and demographic data and test the ability of each to predict the other. Satellite derived imagery help us to better understand the evolution of the built environment and urban form, while the underlying demographic data provide information regarding composition of urban population change. Combining these types of data yields important, high resolution spatial information that provides a more accurate understanding of urban processes.
Remote sensing of the low-latitude daytime ionosphere: ICON simulations and retrievals
NASA Astrophysics Data System (ADS)
Stephan, A. W.; Korpela, E.; England, S.; Immel, T. J.
2016-12-01
The Ionospheric Connection Explorer (ICON) sensor suite includes a spectrograph that will provide altitude profiles of the OII 61.7 and 83.4 nm airglow features, from which the daytime F-region ionosphere can be inferred. To make the connection between these extreme-ultraviolet (EUV) airglow emissions and ionospheric densities, ICON will use a method that has matured significantly in the last decade with the analysis of data from the Remote Atmospheric and Ionospheric Detection System (RAIDS) on the International Space Station, and the Special Sensor Ultraviolet Limb Imager (SSULI) sensors on the Defense Meteorological Satellite Program (DMSP) series of satellites. We will present end-to-end simulations of ICON EUV airglow measurements and data inversion for the expected viewing geometry and sensor capabilities, including noise. While we will focus on the performance of the algorithm for ICON within the context of the current state of knowledge, we will also identify areas where fundamental information can be gained from the high-sensitivity ICON measurements that could be used as feedback to directly improve the overall performance of the algorithm itself.
NASA Astrophysics Data System (ADS)
Archer, M. O.; Horbury, T. S.; Brown, P.; Eastwood, J. P.; Oddy, T. M.; Whiteside, B. J.; Sample, J. G.
2015-06-01
We present the first in-flight results from a novel miniaturised anisotropic magnetoresistive space magnetometer, MAGIC (MAGnetometer from Imperial College), aboard the first CINEMA (CubeSat for Ions, Neutrals, Electrons and MAgnetic fields) spacecraft in low Earth orbit. An attitude-independent calibration technique is detailed using the International Geomagnetic Reference Field (IGRF), which is temperature dependent in the case of the outboard sensor. We show that the sensors accurately measure the expected absolute field to within 2% in attitude mode and 1% in science mode. Using a simple method we are able to estimate the spacecraft's attitude using the magnetometer only, thus characterising CINEMA's spin, precession and nutation. Finally, we show that the outboard sensor is capable of detecting transient physical signals with amplitudes of ~ 20-60 nT. These include field-aligned currents at the auroral oval, qualitatively similar to previous observations, which agree in location with measurements from the DMSP (Defense Meteorological Satellite Program) and POES (Polar-orbiting Operational Environmental Satellites) spacecraft. Thus, we demonstrate and discuss the potential science capabilities of the MAGIC instrument onboard a CubeSat platform.
DMSP Uptake and Retention by Natural Marine Bacteria Relieves Osmotic Stress
NASA Astrophysics Data System (ADS)
Motard-Coté, J.; Kiene, R. P.
2016-02-01
Dimethylsulfoniopropionate (DMSP) is synthesized and used by many marine phytoplankton species as an osmolyte. Grazing on phytoplankton results in formation of extracellular dissolved DMSP (DMSPd), which is rapidly taken up by bacterioplankton and used as an important carbon and sulfur source. Previous studies have, however, shown that some of the dissolved DMSP (DMSPd) in seawater is taken up by bacterioplankton and not degraded. We tested the hypothesis that retention of untransformed DMSP in cells provides some benefits to marine bacteria. In experiments with coastal seawater filtrates containing mainly bacteria, acute osmotic stresses of +5 and +10 ppt NaCl significantly inhibited bacterial production (BP) over 6 h, while the availability of 20 nM DMSPd relieved most of the BP inhibition. Partial relief of salt-induced inhibition of BP was observed with DMSPd concentrations as low as 2.5 nM, and DMSP was more effective at relieving osmotic stress than other low molecular weight compounds tested. Osmotic stresses resulted in a faster and greater overall uptake of DMSPd and accumulation of untransformed DMSP in bacterial cells (DMSPcell). Retained DMSP reached osmotically-significant intracellular concentrations of 54 mM in salt stressed bacterial populations. Retention of DMSP was accompanied by a lower production of methanethiol (MeSH), suggesting a down regulation of the demethylation/demethylation pathway under osmotic stress. These results show that estuarine bacterioplankton can use DMSP as an osmoprotectant, retaining up to 54% of the available dissolved DMSP untransformed in their cells. This benefit provided by DMSP may help explain why some DMSP is retained in bacteria in the ocean, even under unchanging salinity. This retention slows down the cycling of DMSP, with potential implications for the trophic transfer of DMSP through the food web and its contributions to sulfur and carbon fluxes in the ocean.
Observations of the earth using nighttime visible imagery
NASA Technical Reports Server (NTRS)
Foster, J. L.
1983-01-01
The earth as viewed from space in visible light at night reveals some features not easily discernible during the day such as aurora, forest fires, city lights and gas flares. In addition, those features having a high albedo such as snow and ice can be identified on many moonlit nights nearly as well as they can in sunlight. The Air Force DMSP satellites have been operating in the visible wavelengths at night since the mid 1960s. Most all other satellites having optical sensors are incapable of imaging at night. Imaging systems having improved light sensitivity in the visible portion of the spectrum should be considered when planning future earth resources satellite missions in order to utilize nighttime as well as daytime visual observations.
SSH-2 measurements of cirrus at 18-28 micrometers from the King Air during FIRE 2
NASA Technical Reports Server (NTRS)
Griffin, Michael K.
1993-01-01
In November of 1991, the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) Phase II cirrus study took place at Coffeyville, Kansas. The field experiment incorporated instrumentation from surface, aircraft, and satellite to attempt to define the optical, radiative, and microphysical characteristics of these high altitude, predominantly ice clouds. The NCAR King Air research aircraft was outfitted with a variety of radiative and microphysical instrumentation for the FIRE II project. Included for this project was the SSH-2, a 16-channel passive radiometer. The SSH-2 was originally designed as a space-qualified infrared (IR) temperature and water vapor sounder for deployment onboard the Defense Meteorological Satellite Program (DMSP) series of environmental satellites. For this experiment, only those channels associated with the water vapor profiling function have been examined although downwelling radiance measurements were taken at all channels during the project. With supporting information from the aircraft telemetry observations it may be possible to relate these SSH-2 measurements to cloud radiative and microphysical properties. The following sections will describe the spectral characteristics of the instrument, the calibration scheme used to convert the raw measured counts into calibrated radiances, and the case studies that will be covered in this paper. This will be followed by a discussion of the results of this preliminary investigation and a description of future work to be done.
Global Snow-Cover Evolution from Twenty Years of Satellite Passive Microwave Data
Mognard, N.M.; Kouraev, A.V.; Josberger, E.G.
2003-01-01
Starting in 1979 with the SMMR (Scanning Multichannel Microwave Radiometer) instrument onboard the satellite NIMBUS-7 and continuing since 1987 with the SSMI (Special Sensor Microwave Imager) instrument on board the DMSP (Defence Meteorological Satellite Program) series, more then twenty years of satellite passive microwave data are now available. This dataset has been processed to analyse the evolution of the global snow cover. This work is part of the AICSEX project from the 5th Framework Programme of the European Community. The spatio-temporal evolution of the satellite-derived yearly snow maximum extent and the timing of the spring snow melt were estimated and analysed over the Northern Hemisphere. Significant differences between the evolution of the yearly maximum snow extent in Eurasia and in North America were found. A positive correlation between the maximum yearly snow cover extent and the ENSO index was obtained. High interannual spatio-temporal variability characterises the timing of snow melt in the spring. Twenty-year trends in the timing of spring snow melt have been computed and compared with spring air temperature trends for the same period and the same area. In most parts of Eurasia and in the central and western parts of North America the tendency has been for earlier snow melt. In northeastern Canada, a large area of positive trends, where snow melt timing starts later than in the early 1980s, corresponds to a region of positive trends of spring air temperature observed over the same period.
Antarctic Ultraviolet Radiation Climatology from Total Ozone Mapping Spectrometer Data
NASA Technical Reports Server (NTRS)
Lubin, Dan
2004-01-01
This project has successfully produced a climatology of local noon spectral surface irradiance covering the Antarctic continent and the Southern Ocean, the spectral interval 290-700 nm (UV-A, UV-B, and photosynthetically active radiation, PAR), and the entire sunlit part of the year for November 1979-December 1999. Total Ozone Mapping Spectrometer (TOMS) data were used to specify column ozone abundance and UV-A (360- or 380-nm) reflectivity, and passive microwave (MW) sea ice concentrations were used to specify the surface albedo over the Southern Ocean. For this latter task, sea ice concentration retrievals from the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) and its successor, the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I) were identified with ultraviolet/visible-wavelength albedos based on an empirical TOMS/MW parameterization developed for this purpose (Lubin and Morrow, 2001). The satellite retrievals of surface albedo and UV-A reflectivity were used in a delta-Eddington radiative transfer model to estimate cloud effective optical depth. These optical depth estimates were then used along with the total ozone and surface albedo to calculate the downwelling spectral UV and PAR irradiance at the surface. These spectral irradiance maps were produced for every usable day of TOMS data between 1979-1999 (every other day early in the TOMS program, daily later on).
Night-time lights: A global, long term look at links to socio-economic trends
Zavala-Araiza, Daniel; Wagner, Gernot
2017-01-01
We use a parallelized spatial analytics platform to process the twenty-one year totality of the longest-running time series of night-time lights data—the Defense Meteorological Satellite Program (DMSP) dataset—surpassing the narrower scope of prior studies to assess changes in area lit of countries globally. Doing so allows a retrospective look at the global, long-term relationships between night-time lights and a series of socio-economic indicators. We find the strongest correlations with electricity consumption, CO2 emissions, and GDP, followed by population, CH4 emissions, N2O emissions, poverty (inverse) and F-gas emissions. Relating area lit to electricity consumption shows that while a basic linear model provides a good statistical fit, regional and temporal trends are found to have a significant impact. PMID:28346500
False-color display of special sensor microwave/imager (SSM/I) data
NASA Technical Reports Server (NTRS)
Negri, Andrew J.; Adler, Robert F.; Kummerow, Christian D.
1989-01-01
Displays of multifrequency passive microwave data from the Special Sensor Microwave/Imager (SSM/I) flying on the Defense Meteorological Satellite Program (DMSP) spacecraft are presented. Observed brightness temperatures at 85.5 GHz (vertical and horizontal polarizations) and 37 GHz (vertical polarization) are respectively used to 'drive' the red, green, and blue 'guns' of a color monitor. The resultant false-color images can be used to distinguish land from water, highlight precipitation processes and structure over both land and water, and detail variations in other surfaces such as deserts, snow cover, and sea ice. The observations at 85.5 GHz also add a previously unavailable frequency to the problem of rainfall estimation from space. Examples of mesoscale squall lines, tropical and extra-tropical storms, and larger-scale land and atmospheric features as 'viewed' by the SSM/I are shown.
False-color display of special sensor microwave/imager (SSM/I) data
NASA Astrophysics Data System (ADS)
Negri, Andrew J.; Adler, Robert F.; Kummerow, Christian D.
1989-02-01
Displays of multifrequency passive microwave data from the Special Sensor Microwave/Imager (SSM/I) flying on the Defense Meteorological Satellite Program (DMSP) spacecraft are presented. Observed brightness temperatures at 85.5 GHz (vertical and horizontal polarizations) and 37 GHz (vertical polarization) are respectively used to 'drive' the red, green, and blue 'guns' of a color monitor. The resultant false-color images can be used to distinguish land from water, highlight precipitation processes and structure over both land and water, and detail variations in other surfaces such as deserts, snow cover, and sea ice. The observations at 85.5 GHz also add a previously unavailable frequency to the problem of rainfall estimation from space. Examples of mesoscale squall lines, tropical and extra-tropical storms, and larger-scale land and atmospheric features as 'viewed' by the SSM/I are shown.
The fate of dissolved dimethylsulfoniopropionate (DMSP) in seawater: tracer studies using 35S-DMSP
NASA Astrophysics Data System (ADS)
Kiene, Ronald P.; Linn, Laura J.
2000-08-01
The algal osmolyte dimethylsulfoniopropionate (DMSP) is distributed globally in the marine euphotic zone, where it represents a major form of reduced sulfur. Previous investigations of DMSP cycling have focused mainly on its degradation to the volatile sulfur species dimethylsulfide (DMS) and little is known about the other possible fates of the sulfur. In this study 35S-DMSP was used to trace the biogeochemical fate of sulfur in the natural pool of dissolved DMSP in seawater. Dissolved 35S-DMSP added to seawater was degraded within hours, with the 35S partitioning into three major, relatively stable, operational pools: particulates, dissolved non-volatile degradation products (DNVS), and volatiles. The mean values for partitioning of DMSP obtained from 20 different seawater incubations were (in terms of sulfur): particulates (33%; range 6-85%;); DNVS (46%; range 21-74%); and volatiles (9%; range 2-21%). Oceanic water samples had lower incorporation of DMSP-S into particulates and higher incorporation into DNVS as compared with coastal-shelf samples. Transient accumulation of untransformed 35S-DMSP in bacteria accounted for some of the particulate 35S, but most of the cell-associated DMSP was rapidly transformed and the sulfur incorporated into relatively stable macromolecules. 35S-labeled DNVS accumulated steadily during DMSP metabolism and approximately half of this pool was confirmed to be sulfate, implying that oxidation of DMSP-sulfur takes place on time scales of minutes to hours. Volatile products were produced rapidly from 35S-DMSP, but most were consumed within 1-3 h. Experiments showed that methanethiol (MeSH) was the major volatile compound produced from tracer DMSP, with longer-lived DMS formed in lower amounts. Tracer additions of 35S-MeSH to seawater resulted in incorporation of sulfur into cellular macromolecules and DNVS, suggesting MeSH was an intermediate in the conversion of DMSP into these pools. Experiments with 35S-DMS revealed that turnover of DMS was much slower than for DMSP or MeSH, and the retention of the DMS-sulfur in particles was only a minor fraction of the total amount metabolized. The majority of the 35S-DMS was transformed into DNVS including sulfate. Temperature and DMSP concentration significantly affected the partitioning of sulfur during DMSP degradation, with lower temperatures and higher substrate concentrations causing a shift from particulate into volatile and non-volatile dissolved products. Our work demonstrates that natural turnover of dissolved DMSP results in minor net production of sulfur gases, and substantial production of previously unrecognized products (particulate and dissolved non-volatile sulfur). The main fates of DMSP are tied to assimilation and oxidation of the reduced sulfur by microorganisms, both of which may act as important controls on the production of climatically active DMS.
Assessment of the Relative Accuracy of Hemispheric-Scale Snow-Cover Maps
NASA Technical Reports Server (NTRS)
Hall, Dorothy K.; Kelly, Richard E.; Riggs, George A.; Chang, Alfred T. C.; Foster, James L.; Houser, Paul (Technical Monitor)
2001-01-01
There are several hemispheric-scale satellite-derived snow-cover maps available, but none has been fully validated. For the period October 23 - December 25, 2000, we compare snow maps of North America derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the National Oceanic and Atmospheric Administration (NOAA) National Operational Hydrologic Remote Sensing Center (NOHRSC), which both rely on satellite data from the visible and near-infrared parts of the spectrum; we also compare MODIS and Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) passive-microwave snow maps. The maps derived from visible and near-infrared data are more accurate for mapping snow cover than are the passive-microwave-derived maps, however discrepancies exist as to the location and extent of the snow cover among those maps. The large (approx. 30 km) footprint of the SSM/I data and the difficulty in distinguishing wet and shallow snow from wet or snow-free ground, reveal differences up to 5.32 million sq km in the amount of snow mapped using MODIS versus SSM/I data. Algorithms that utilize both visible and passive-microwave data, which would take advantage of the all-weather mapping ability of the passive-microwave data, will be refined following the launch of the Advanced Microwave Scanning Radiometer (AMSR) in the fall of 2001.
NASA Astrophysics Data System (ADS)
Schaefer, R. K.; Wolven, B. C.; Paxton, L.; Romeo, G.; Selby, C.; Hsieh, S. W.
2013-12-01
The South Atlantic Anomaly (SAA) is a region where the Earth's inner radiation belt dips down and bathes low earth orbit satellites with energetic charged particles sometimes causing problems for satellite operations. We will describe data from a series of UV spectrographic imagers (DMSP/SSUSI) that remain on through 4 daily SAA passages. Using spectrographic information, we are able to separate, study, and remove the detector counts due to energetic (~ 1 MeV and above) particle hits. We have made a model of the SAA at Defense Meteorological Satellite Program altitudes (~850 km), and we are able to monitor the intensity of the SAA over the long term (> a decade). Using this window into the inner radiation belt, we are able to see seasonal and solar cycle variations in intensity. In this talk we will describe the techniques, the model, and show results of our study, and and indicate directions for future development and usefulness of using SSUSI as an inner radiation belt particle intensity monitor. Nighttime 427 nm Photometer count rates as seen by SSUSI binned onto a 3 x 3 degree grid and accumulated over the year 2006. The classic shape of the South Atlantic Anomaly is clearly traced by the data.
SSULI/SSUSI UV Tomographic Images of Large-Scale Plasma Structuring
NASA Astrophysics Data System (ADS)
Hei, M. A.; Budzien, S. A.; Dymond, K.; Paxton, L. J.; Schaefer, R. K.; Groves, K. M.
2015-12-01
We present a new technique that creates tomographic reconstructions of atmospheric ultraviolet emission based on data from the Special Sensor Ultraviolet Limb Imager (SSULI) and the Special Sensor Ultraviolet Spectrographic Imager (SSUSI), both flown on the Defense Meteorological Satellite Program (DMSP) Block 5D3 series satellites. Until now, the data from these two instruments have been used independently of each other. The new algorithm combines SSULI/SSUSI measurements of 135.6 nm emission using the tomographic technique; the resultant data product - whole-orbit reconstructions of atmospheric volume emission within the satellite orbital plane - is substantially improved over the original data sets. Tests using simulated atmospheric emission verify that the algorithm performs well in a variety of situations, including daytime, nighttime, and even in the challenging terminator regions. A comparison with ALTAIR radar data validates that the volume emission reconstructions can be inverted to yield maps of electron density. The algorithm incorporates several innovative new features, including the use of both SSULI and SSUSI data to create tomographic reconstructions, the use of an inversion algorithm (Richardson-Lucy; RL) that explicitly accounts for the Poisson statistics inherent in optical measurements, and a pseudo-diffusion based regularization scheme implemented between iterations of the RL code. The algorithm also explicitly accounts for extinction due to absorption by molecular oxygen.
Ground System Extensibility Considerations
NASA Astrophysics Data System (ADS)
Miller, S. W.; Greene, E.
2017-12-01
The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners, such as NASA's Earth Observation System (EOS), NOAA's current POES, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), and DoD's Defense Meteorological Satellite Program (DMSP). The CGS provides a wide range of support to a number of national and international missions, including command and control, mission management, data acquisition and routing, and environmental data processing and distribution. The current suite of CGS-supported missions has demonstrated the value of interagency and international partnerships to address global observation needs. With its established infrastructure and existing suite of missions, the CGS is extensible to a wider array of potential new missions. This paper will describe how the inherent scalability and extensibility of the CGS enables the addition of these new missions, with an eye on global enterprise needs in the 2020's and beyond.
NASA Technical Reports Server (NTRS)
Ahlnas, Kristina; Royer, Thomas C.
1989-01-01
In the present investigation of the ability of various satellite-borne imaging systems to detect surface-suspended sediments, which tracked mushroom-shaped dipole eddies in a near shore current during April 22, 1985, it was found that the radiometric resolutions of the NOAA and DMSP satellites are insufficient to distinguish such eddies in low concentrations of suspended sediments. The Landsat TM can, however, detect the spiral structure of the dipole eddies in all three of its visible bands; the Landsat MSS can detect such details in Band 1, and the overall shape in Band 2.
Demethylation and cleavage of dimethylsulfoniopropionate in marine intertidal sediments
Visscher, P.T.; Kiene, R.P.; Taylor, B.F.
1994-01-01
Demethylation and cleavage of dimethylsulfoniopropionate (DMSP) was measured in three different types of,intertidal marine sediments: a cyanobacterial mat, a diatom-covered tidal flat and a carbonate sediment. Consumption rates of added DMSP were highest in cyanobacterial mat slurries (59 ?? mol DMSP l-1 slurry h-1) and lower in slurries from a diatom mat and a carbonate tidal sediment (24 and 9 ??mol DMSP l-1 h-1, respectively). Dimethyl sulfide (DMS) and 3-mercaptopropionate (MPA) were produced simultaneously during DMSP consumption, indicating that cleavage and demethylation occurred at the same time. Viable counts of DMSP-utilizing bacteria revealed a population of 2 x 107 cells cm-3 sediment (90% of these cleaved DMSP to DMS, 10% demethylated DMSP to MPA) in the cyanobacterial mat, 7 x 105 cells cm-3 in the diatom mat (23% cleavers, 77% demethylators), and 9 x 104 cells cm-3 (20% cleavers and 80% demethylators) in the carbonate sediment. In slurries of the diatom mat, the rate of MPA production from added 3-methiolpropionate (MMPA) was 50% of the rate of MPA formation from DMSP. The presence of a large population of demethylating bacteria and the production of MPA from DMSP suggest that the demethylation pathway, in addition to cleavage, contributes significantly to DMSP consumption in coastal sediments.
Cusp and LLBL as Sources of the Isolated Dayside Auroral Feature During Northward IMF
NASA Technical Reports Server (NTRS)
Chang, S.-W.; Gallagher, D. L.; Spann, J. F.; Mende, S. B.; Greenwald, R. A.; Newell, P. T.
2004-01-01
An intense dayside proton aurora was observed by Imager for Magnetopause-to- Aurora Global Exploration Far Ultra-Violet imager (IMAGE FUV) for an extensive period of northward interplanetary magnetic field (IMF) on 17 and 18 September 2000. This aurora partially coincided with the auroral oval and intruded farther poleward into the polar cap, and it showed longitudinal motions in response to IMF By variation. Intense magnetosheath-like electron and ion precipitations have been simultaneously detected by Defense Meteorological Satellite Program (DMSP) above the poleward portion of the high-latitude dayside aurora. They resemble the typical plasmas observed in the low-altitude cusp. However, less intense electrons and more energetic ions were detected over the equatonvard part of the aurora. These plasmas are closer to the low-latitude boundary layer (LLBL) plasmas. Under strongly northward IMF, global ionospheric convection derived from Super Dual Auroral Radar Network (SuperDARN) radar measurements showed a four-cell pattern with sunward convection in the middle of the dayside polar cap and the dayside aurora corresponded to two different convection cells. This result further supports two source regions for the aurora. The cusp proton aurora is on open magnetic field lines convecting sunward whereas the LLBL proton aurora is on closed field lines convecting antisunward. These IMAGE, DMSP, and SuperDARN observations reveal the structure and dynamics of the aurora and provide strong evidence for magnetic merging occurring at the high-latitude magnetopause poleward from the cusp. This merging process was very likely quasi-stationary.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Jing; Todd, Jonathan D.; Thrash, J. Cameron
2016-05-16
Marine phytoplankton produce ~109 tons of dimethylsulfoniopropionate (DMSP) per year1,2, an estimated 10% of which is catabolized by bacteria through the DMSP cleavage pathway to the climatically active gas dimethyl sulfide (DMS)3,4. SAR11 Alphaproteobacteria (order Pelagibacterales), the most abundant chemoorganotrophic bacteria in the oceans, have been shown to assimilate DMSP into biomass, thereby supplying this cell’s unusual requirement for reduced sulfur5,6. Here we report that Pelagibacter HTCC1062 produces the gas methanethiol (MeSH) and that simultaneously a second DMSP catabolic pathway, mediated by a DMSP lyase, shunts as much as 59% of DMSP uptake to DMS production. We propose a modelmore » in which the allocation of DMSP between these pathways is kinetically controlled to release increasing amounts of DMS as the supply of DMSP exceeds cellular sulfur demands for biosynthesis. These findings suggest that DMSP supply and demand relationships in Pelagibacter metabolism are important to determining rates of oceanic DMS production.« less
2007-03-01
arc at a substorm pseudo-breakup Sb. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHORS 5d. PROJECT NUMBER K. Yago ,, K. Shiokawa, K. Yumoto...Distribution Unlimited Simultaneous DMSP, all-sky camera, and IMAGE FUV observations of the brightening arc at a substorm pseudo-breakup K. Yago "•. K. Shiokawa...2003; Mende et al., particles, field-aligned currents, and plasma convection as- 2003: Yago et al., 2005: Shiokawa et al., 2005). These sociated with
Swan, Hilton B; Deschaseaux, Elisabeth S M; Jones, Graham B; Eyre, Bradley D
2017-03-01
Dimethylsulfoniopropionate (DMSP) in scleractinian coral is usually analysed indirectly as dimethylsulfide (DMS) using gas chromatography (GC) with a sulfur-specific detector. We developed a headspace GC method for mass spectral analysis of DMSP in branching coral where hexa-deuterated DMSP (d 6 -DMSP) was added to samples and standards to optimise the analytical precision and quantitative accuracy. Using this indirect HS-GC-MS method, we show that common coral sample handling techniques did not alter DMSP concentrations in Acropora aspera and that endogenous DMS was insignificant compared to the store of DMSP in A. aspera. Field application of the indirect HS-GC-MS method in all seasons over a 5-year period at Heron Island in the southern Great Barrier Reef indicated that healthy colonies of A. aspera ordinarily seasonally conserve their branch tip store of DMSP; however, this store increased to a higher concentration under extended thermal stress conditions driven by a strong El Niño Southern Oscillation event. A liquid chromatography mass spectral method (LC-MS) was subsequently developed for direct analysis of DMSP in branching coral, also utilising the d 6 -DMSP internal standard. The quantitative comparison of DMSP in four species of Acropora coral by indirect HS-GC-MS and direct LC-MS analyses gave equivalent concentrations in A. aspera only; in the other three species, HS-GC-MS gave consistently higher concentrations, indicating that indirect analysis of DMSP may lead to artificially high values for some coral species. Graphical Abstract Dimethylsulfoniopropionate (DMSP) was quantified in Acropora spp. of branching coral using deuterated stable isotope dilution mass spectrometry.
Joint Polar Satellite System (JPSS) Common Ground System (CGS) Overview and Architectural Tenets
NASA Astrophysics Data System (ADS)
Miller, S. W.; Grant, K. D.; Jamilkowski, M. L.
2013-12-01
The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence and Information Systems (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners. The CGS provides a wide range of support to a number of missions: 1) Command and control and mission management for the Suomi National Polar Partnership (S-NPP) mission today, expanding this support to the JPSS-1 satellite and the Polar Free Flyer mission in 2017 2) Data acquisition via a Polar Receptor Network (PRN) for S-NPP, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the Department of Defense (DoD) 3) Data routing over a global fiber Wide Area Network (WAN) for S-NPP, JPSS-1, Polar Free Flyer, GCOM-W1, POES, DMSP, Coriolis/WindSat, the NASA Space Communications and Navigation (SCaN, which includes several Earth Observing System [EOS] missions), MetOp for the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Science Foundation (NSF) 4) Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 The CGS architecture will receive a technology refresh in 2015 to satisfy several key objectives: 1) 'Operationalizing' Suomi NPP, which had originally been intended as a risk reduction mission 2) Leveraging lessons learned to date in multi-mission support 3) Taking advantage of newer, more reliable and efficient technologies 4) Satisfying new requirements and constraints due to the continually evolving budgetary environment To meet these needs, we are upgrading the CGS in the following ways: 1) Performing a system-wide technology refresh for enhanced performance and security 2) Establishing a new front end architecture and augmenting the PRN for mission data transport 3) Standardizing data protocols to accommodate an even wider variety of missions 4) Enhancing flexibility and modularity in IDPS for new and evolving algorithms 5) Achieving comprehensive situational awareness 6) Deploying a full backup capability for Continuity of Operations (COOP) 7) Providing an enclave in compliance with the latest security standards from the National Institute of Standards and Technology (NIST) 800-53 This paper will provide an overview of the CGS as it is deployed and operating today, along with a summary of the architectural tenets that will facilitate even easier incorporation of new missions and applications in 2015.
Equatorial measurement of SAID electric fields and relation with the plasmapause location
NASA Astrophysics Data System (ADS)
Nishimura, Y.; Wygant, J.; Ono, T.; Iizima, M.; Kumamoto, A.; Brautigam, D.; Rich, F.
2007-12-01
In order to investigate the equatorial source of subauroral ion drifts (SAID) and its association with the plasmapause position, multi-spacecraft measurements of SAID are presented using the CRRES, Akebono, and DMSP. Direct measurement of the convection electric field and plasmapause density close to the equator is measured by the electric field instrument onboard the CRRES satellite, and the plasmasheet electrons and low energy part of the ring current ions are measured by the low energy plasma instrument. The CRRES satellite is on the dusk inner magnetosphere, and the DMSP-F8 and Akebono satellites are approximately on the same field line. Associated with a substorm onset at 16:40 UT on February 20, 1991, the DMSP-F8 satellite at 19 MLT measures SAID with a maximum westward velocity of 1,500 m/s. The CRRES satellite is on outbound in the inner magnetosphere at ~21 MLT and ~5 RE at the onset of the substorm. It measures increase of DC electric field with 0.4 mV/m in the plasmasphere just after the substorm onset. Thirty minutes later, injection of ring current ions are observed in the plasmasphere with Bz decrease. After the crossing of the plasmapause, the electric field increases to 0.8 mV/m. At the same time, the spacecraft enters the plasmasheet, and the DC electric field disappears. The same time sequence is also identified in other SAID events detected on the dusk inner magnetosphere. The above CRRES measurement indicates that DC electric field is intensified in a narrow region between the ring current and electron plasmasheet after the onset of the substorm. Although the E*B drift points sunward in this region, this region with enhanced electric field is filled with plasmaspheric plasma without abrupt density change. The position where the convection electric field is equal to the corotation electric field locates inside the plasmapause. The plasmapause coincides with inner edge of the plasmasheet. This association suggests that the plasmaspheric plasma is depleted by the plasmasheet electrons, possibly by the enhanced E*B drift earthward of the plasmasheet. During the SAID event on 16:40 UT on February 20, 1991, the Akebono satellite was approximately on the same field line of the CRRES satellite (21 MLT and 5 RE) 40 minutes later the substorm onset. It measures enhancement of electric field with 2 mV/m between L=5 and 6. The inner edge of the electric field corresponds to the inner edge of ring current ions, and the outer edge coincides with the plasmasheet electrons. This signature of the electric field intensification in the charge-separated region is in accordance with the CRRES measurement. This study has clarified that the equatorial source of SAID electric fields is charge separation of ring current ions and plasmasheet electrons by electric field associated with substorms. This is consistent with the theoretical study by Southwood and Wolf [1978] and low-altitude measurements by Anderson et al. [2001] by that the charge separation provides current and voltage sources and the electric field is increased by the low conductance of the subauroral ionosphere.
Rousseau, Hélène; Rousseau-Gueutin, Mathieu; Dauvergne, Xavier; Boutte, Julien; Simon, Gaëlle; Marnet, Nathalie; Bouchereau, Alain; Guiheneuf, Solène; Bazureau, Jean-Pierre; Morice, Jérôme; Ravanel, Stéphane; Cabello-Hurtado, Francisco; Ainouche, Abdelkader; Salmon, Armel; Wendel, Jonathan F; Ainouche, Malika L
2017-09-01
DMSP (dimethylsulfoniopropionate) is an ecologically important sulfur metabolite commonly produced by marine algae and by some higher plant lineages, including the polyploid salt marsh genus Spartina (Poaceae). The molecular mechanisms and genes involved in the DMSP biosynthesis pathways are still unknown. In this study, we performed comparative analyses of DMSP amounts and molecular phylogenetic analyses to decipher the origin of DMSP in Spartina that represents one of the major source of terrestrial DMSP in coastal marshes. DMSP content was explored in 14 Spartina species using 1 H Nuclear Magnetic Resonance (NMR) spectroscopy and Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS). Putative genes encoding the four enzymatic steps of the DMSP biosynthesis pathway in Spartina were examined and their evolutionary dynamics were studied. We found that the hexaploid lineage containing S. alterniflora, S. foliosa and S. maritima and their derived hybrids and allopolyploids are all able to produce DMSP, in contrast to species in the tetraploid clade. Thus, examination of DMSP synthesis in a phylogenetic context implicated a single origin of this physiological innovation, which occurred in the ancestor of the hexaploid Spartina lineage, 3-6MYA. Candidate genes specific to the Spartina DMSP biosynthesis pathway were also retrieved from Spartina transcriptomes, and provide a framework for future investigations to decipher the molecular mechanisms involved in this plant phenotypic novelty that has major ecological impacts in saltmarsh ecosystems. Copyright © 2017 Elsevier Inc. All rights reserved.
Synoptic aspects of Antarctic mesocyclones
NASA Astrophysics Data System (ADS)
Carleton, Andrew M.; Fitch, Mark
1993-07-01
The characteristic regimes (formation and dissipation areas, tracks) and synoptic environments of cold air mesocyclones over Antarctic and Subantarctic latitudes are determined for the contrasting winters (June, July, and August) of 1988 and 1989. Defense Meteorological Satellite Program (DMSP) thermal infrared (IR) imagery is used in conjunction with southern hemisphere pressure/height analyses. Outbreaks of mesocyclones ("active periods") are frequent in the Ross Sea sector in 1988. They are associated most often with areas of maximum horizontal gradient of the 1000- to 500-mbar thickness. Over higher latitudes of the Southeast Pacific in 1989, mesocyclones develop in association with a "cold pool" that migrates equatorward. The between-winter differences in mesocyclone frequencies are examined for associations with sea ice conditions and the continental katabatic winds using correlation and "superposed epoch" analysis of temperature data from selected automatic weather stations (AWSs). The results support a katabatic wind-sea ice extent-mesocyclone link for key sectors of the Antarctic.
Global Night-Time Lights for Observing Human Activity
NASA Technical Reports Server (NTRS)
Hipskind, Stephen R.; Elvidge, Chris; Gurney, K.; Imhoff, Mark; Bounoua, Lahouari; Sheffner, Edwin; Nemani, Ramakrishna R.; Pettit, Donald R.; Fischer, Marc
2011-01-01
We present a concept for a small satellite mission to make systematic, global observations of night-time lights with spatial resolution suitable for discerning the extent, type and density of human settlements. The observations will also allow better understanding of fine scale fossil fuel CO2 emission distribution. The NASA Earth Science Decadal Survey recommends more focus on direct observations of human influence on the Earth system. The most dramatic and compelling observations of human presence on the Earth are the night light observations taken by the Defence Meteorological System Program (DMSP) Operational Linescan System (OLS). Beyond delineating the footprint of human presence, night light data, when assembled and evaluated with complementary data sets, can determine the fine scale spatial distribution of global fossil fuel CO2 emissions. Understanding fossil fuel carbon emissions is critical to understanding the entire carbon cycle, and especially the carbon exchange between terrestrial and oceanic systems.
NASA Astrophysics Data System (ADS)
Mishin, E. V.; Milikh, G. M.
2014-12-01
In situ observations from the DMSP and Demeter satellites established that high-power HF heating of the ionosphere F-region results in significant ion outflows associated with 10-30% density enhancements in the topside ionosphere magnetically-conjugate to the heated region. As follows from the SAMI2 two-fluid model calculations, their formation time should exceed 5-7 minutes. However, specially designed DMSP-HAARP experiments have shown that artificial ducts and ion outflows appear on the topside within 2 minutes. We describe the results of these observations and present a semi-quantitative explanation of the fast timescale due to suprathermal electrons accelerated by HF-induced plasma turbulence. There are two possible effects of suprathermal electrons: (1) the increase of the ambipolar electric field over the usual thermal ambipolar diffusion and (2) excitation of heat flux-driven plasma instability resulting in an anomalous electron-ion momentum exchange. Both effects result in faster upward ion flows.
GEM-CEDAR Study of Ionospheric Energy Input and Joule Dissipation
NASA Technical Reports Server (NTRS)
Rastaetter, Lutz; Kuznetsova, Maria M.; Shim, Jasoon
2012-01-01
We are studying ionospheric model performance for six events selected for the GEM-CEDAR modeling challenge. DMSP measurements of electric and magnetic fields are converted into Poynting Flux values that estimate the energy input into the ionosphere. Models generate rates of ionospheric Joule dissipation that are compared to the energy influx. Models include the ionosphere models CTIPe and Weimer and the ionospheric electrodynamic outputs of global magnetosphere models SWMF, LFM, and OpenGGCM. This study evaluates the model performance in terms of overall balance between energy influx and dissipation and tests the assumption that Joule dissipation occurs locally where electromagnetic energy flux enters the ionosphere. We present results in terms of skill scores now commonly used in metrics and validation studies and we can measure the agreement in terms of temporal and spatial distribution of dissipation (i.e, location of auroral activity) along passes of the DMSP satellite with the passes' proximity to the magnetic pole and solar wind activity level.
Suzuki, Shotaro; Omori, Yuko; Wong, Shu-Kuan; Ijichi, Minoru; Kaneko, Ryo; Kameyama, Sohiko; Tanimoto, Hiroshi; Hamasaki, Koji
2015-01-01
Dimethylsulfoniopropionate (DMSP) is mainly produced by marine phytoplankton but is released into the microbial food web and degraded by marine bacteria to dimethyl sulfide (DMS) and other products. To reveal the abundance and distribution of bacterial DMSP degradation genes and the corresponding bacterial communities in relation to DMS and DMSP concentrations in seawater, we collected surface seawater samples from DMS hot spot sites during a cruise across the Pacific Ocean. We analyzed the genes encoding DMSP lyase (dddP) and DMSP demethylase (dmdA), which are responsible for the transformation of DMSP to DMS and DMSP assimilation, respectively. The averaged abundance (±standard deviation) of these DMSP degradation genes relative to that of the 16S rRNA genes was 33% ± 12%. The abundances of these genes showed large spatial variations. dddP genes showed more variation in abundances than dmdA genes. Multidimensional analysis based on the abundances of DMSP degradation genes and environmental factors revealed that the distribution pattern of these genes was influenced by chlorophyll a concentrations and temperatures. dddP genes, dmdA subclade C/2 genes, and dmdA subclade D genes exhibited significant correlations with the marine Roseobacter clade, SAR11 subgroup Ib, and SAR11 subgroup Ia, respectively. SAR11 subgroups Ia and Ib, which possessed dmdA genes, were suggested to be the main potential DMSP consumers. The Roseobacter clade members possessing dddP genes in oligotrophic subtropical regions were possible DMS producers. These results suggest that DMSP degradation genes are abundant and widely distributed in the surface seawater and that the marine bacteria possessing these genes influence the degradation of DMSP and regulate the emissions of DMS in subtropical gyres of the Pacific Ocean. PMID:25862229
NASA Technical Reports Server (NTRS)
Foster, J. L.; Hall, D. K.; Chiu, L.; Kelly, R. E.; Powell, H.; Chiu, L.
2007-01-01
Seasonal snow cover in South America was examined in this study using passive microwave satellite data from the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-satellite and the Special Sensor Microwave Imagers (SSM/I) on board Defense Meteorological Satellite Program (DMSP) satellites. For the period from 1979-2003, both snow cover extent and snow depth (snow mass) were investigated during coldest months (May-September), primarily in the Patagonia area of Argentina and in Chile. Most of the seasonal snow in South America is in the Patagonia region of Argentina. Since winter temperatures in this region are often above freezing, the coldest winter month was found to be the month having the most extensive snow cover and also usually the month having the deepest snow cover as well. Sharp year-to-year differences were recorded using the passive microwave observations. The average snow cover extent for July, the month with the greatest average snow extent during the 25-year period of record, is 320,700 km(exp 2). In July of 1984, the average monthly snow cover was 701,250 km(exp 2) - the most extensive coverage observed between 1979 and 2003. However, in July of 1989, snow cover extent was only 120 km(exp 2). The 25-year period of record shows a sinusoidal like pattern, though there appears to be no obvious trend in either increasing or decreasing snow extent or snow mass between 1979 and 2003.
Microwave Brightness Temperatures of Tilted Convective Systems
NASA Technical Reports Server (NTRS)
Hong, Ye; Haferman, Jeffrey L.; Olson, William S.; Kummerow, Christian D.
1998-01-01
Aircraft and ground-based radar data from the Tropical Ocean and Global Atmosphere Coupled-Ocean Atmosphere Response Experiment (TOGA COARE) show that convective systems are not always vertical. Instead, many are tilted from vertical. Satellite passive microwave radiometers observe the atmosphere at a viewing angle. For example, the Special Sensor Microwave/Imager (SSM/I) on Defense Meteorological Satellite Program (DMSP) satellites and the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) on the TRMM satellite have an incident angle of about 50deg. Thus, the brightness temperature measured from one direction of tilt may be different than that viewed from the opposite direction due to the different optical depth. This paper presents the investigation of passive microwave brightness temperatures of tilted convective systems. To account for the effect of tilt, a 3-D backward Monte Carlo radiative transfer model has been applied to a simple tilted cloud model and a dynamically evolving cloud model to derive the brightness temperature. The radiative transfer results indicate that brightness temperature varies when the viewing angle changes because of the different optical depth. The tilt increases the displacements between high 19 GHz brightness temperature (Tb(sub 19)) due to liquid emission from lower level of cloud and the low 85 GHz brightness temperature (Tb(sub 85)) due to ice scattering from upper level of cloud. As the resolution degrades, the difference of brightness temperature due to the change of viewing angle decreases dramatically. The dislocation between Tb(sub 19) and Tb(sub 85), however, remains prominent.
NASA Technical Reports Server (NTRS)
Foster, J. L.; Hall, D. K.; Kelly, R. E. J.; Chiu, L.
2008-01-01
Seasonal snow cover in South America was examined in this study using passive microwave satellite data from the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7 satellite and the Special Sensor Microwave Imagers (SSM/I) onboard Defense Meteorological Satellite Program (DMSP) satellites. For the period from 1979-2006, both snow cover extent and snow water equivalent (snow mass) were investigated during the coldest months (May-September), primarily in the Patagonia area of Argentina and in the Andes of Chile, Argentina and Bolivia, where most of the seasonal snow is found. Since winter temperatures in this region are often above freezing, the coldest winter month was found to be the month having the most extensive snow cover and usually the month having the deepest snow cover as well. Sharp year-to-year differences were recorded using the passive microwave observations. The average snow cover extent for July, the month with the greatest average extent during the 28-year period of record, is 321,674 km(exp 2). In July of 1984, the average monthly snow cover extent was 701,250 km(exp 2) the most extensive coverage observed between 1979 and 2006. However, in July of 1989, snow cover extent was only 120,000 km(exp 2). The 28-year period of record shows a sinusoidal like pattern for both snow cover and snow mass, though neither trend is significant at the 95% level.
Preparing the remote sensing community toward the NPP/NPOESS era
NASA Astrophysics Data System (ADS)
Kuciauskas, A. P.; Lee, T. F.; Turk, F. J.; Richardson, K. A.; Hawkins, J. D.; Kent, J. E.; Miller, S. D.; McWilliams, G.
2008-12-01
Under the auspices of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Integrated Program Office (IPO), the Naval Research Laboratory in Monterey (NRLMRY) was tasked to develop NexSat, a weather satellite web-based resource, to illustrate future sensing capabilities within the Visible/Infrared Imager Radiometer Suite (VIIRS) sensor onboard the NPOESS Preparatory Project (NPP) and NPOESS era. NexSat acquires and processes data from polar orbiters (AVHRR, MODIS, SeaWiFS, DMSP, and TRMM) that serve as heritage instruments to the VIIRS. Geostationary sensors and numerical weather prediction (NWP) overlays supplement the image products suite, making NexSat a one-stop shop for current and future environmental monitoring. NRLMRY collaborates with the Cooperative Institute for Research in the Atmosphere (CIRA) and the Cooperative Institute for Meteorological Satellite Studies (CIMSS) for product development. Together with the Cooperative Program for Operational Meteorology, Education and Training (COMET®), NRLMRY provides educational outreach to research and development communities as well as to the general public. This paper intends to describe the products within the NexSat webpage and its training resources. The product suite consists of generic and state of the art images. Along with the standard visible, IR, and water vapor products, NexSat also includes dust enhancement, cloud properties, cloud profiling, snow cloud discrimination, volcanic ash plumes, hot spots, aerosol content over land and water. NexSat training resources will be described, including on-line product tutorials, a course module, as well as outreach efforts to the National Weather Service, government agencies, academic institutions, and international organizations.
The distribution of dimethylsulfoniopropionate in tropical Pacific coral reef invertebrates
NASA Astrophysics Data System (ADS)
van Alstyne, Kathryn L.; Schupp, Peter; Slattery, Marc
2006-08-01
Dimethylsulfoniopropionate (DMSP) is an important component of the global sulfur cycle and may be involved, via its cleavage product dimethylsulfide, in climate regulation. Although it is common in many algae, reports of DMSP in animals, particularly tropical invertebrates, are limited. This study examined the distribution of DMSP in a diverse group of coral reef invertebrates. DMSP was present in all 22 species of cnidarians and ranged from 9 to 723 μmol g-1 of dry mass (DM) with a mean (± 1SD) of 110 ± 180 μmol g-1 DM. It was not detected in a flatworm and an ascidian or in two of five sponges. Concentrations in sponges ranged from undetectable to 16 μmol g-1 DM with a mean of 4 ± 7 μmol g-1 DM. Within the cnidarians, DMSP concentrations did not differ among orders. Among cnidarian species, DMSP concentrations were correlated with symbiotic zooxanthellae densities. Within cnidarian species, DMSP concentrations of individuals were positively correlated with zooxanthellae densities in three of the four species examined. We speculate that DMSP is dietarily derived in sponges and derived from zooxanthellae in the cnidarians. The functions of DMSP in coral reef invertebrates are not known.
CubeSat Nighttime Earth Observations
NASA Astrophysics Data System (ADS)
Pack, D. W.; Hardy, B. S.; Longcore, T.
2017-12-01
Satellite monitoring of visible emissions at night has been established as a useful capability for environmental monitoring and mapping the global human footprint. Pioneering work using Defense Meteorological Support Program (DMSP) sensors has been followed by new work using the more capable Visible Infrared Imaging Radiometer Suite (VIIRS). Beginning in 2014, we have been investigating the ability of small visible light cameras on CubeSats to contribute to nighttime Earth science studies via point-and-stare imaging. This paper summarizes our recent research using a common suite of simple visible cameras on several AeroCube satellites to carry out nighttime observations of urban areas and natural gas flares, nighttime weather (including lighting), and fishing fleet lights. Example results include: urban image examples, the utility of color imagery, urban lighting change detection, and multi-frame sequences imaging nighttime weather and large ocean areas with extensive fishing vessel lights. Our results show the potential for CubeSat sensors to improve monitoring of urban growth, light pollution, energy usage, the urban-wildland interface, the improvement of electrical power grids in developing countries, light-induced fisheries, and oil industry flare activity. In addition to orbital results, the nighttime imaging capabilities of new CubeSat sensors scheduled for launch in October 2017 are discussed.
Assessment of Light Pollution Impact on Protected Areas in China
NASA Astrophysics Data System (ADS)
Jiang, W.; He, G.; Ni, Y.
2017-09-01
The Protected Areas (PAs) with natural, ecological and cultural value play important role in biological processes, biodiversity and ecosystem service. During the past years of rapid urban expansion in China, the spatial range and intensity of light pollution unprecedented increase. Historically, optical remote sensing and field survey data had been used to reveal that human activities impacted on PAs for individual areas and few papers documented the issue of light pollution impact on PAs at national scale. Here, time series night-time light satellite images of Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS) were selected to assess the light pollution impacted on PAs in China. The method we proposed can be effectively applied to assess the impact of light pollution on PAs and the percent of dark PAs decreased by 35.38 % from 1992 to 2012 at nationwide. The trend of light pollution of most PAs in stable, however, light pollution of the local area is increase significantly, especially in northern Xinjiang, Gansu, Xizang, Yunnan, Jiangsu and Shandong. Considering the current status of light pollution encroach into PAs, two strategies of appropriate buffer zone and wide measured for light pollution are also recommend.
How will we ensure the long-term sea ice data record continues?
NASA Astrophysics Data System (ADS)
Stroeve, J. C.; Kaleschke, L.
2017-12-01
The multi-channel satellite passive microwave record has been of enormous benefit to the science community and society at large since the late 1970s. Starting with the launch of the Nimbus-7 Scanning Multi-Channel Microwave Radiometer (SMMR) in October 1978, and continuing with the launch of a series of Special Sensor Microwave Imagers (SSM/Is) in June 1987 by the Defense Meteorological Satellite Program (DMSP), places previously difficult to monitor year-round, such as the polar regions, came to light. Together these sensors have provided nearly 4 decades of climate data records on the state of sea ice cover over the ocean and snow on land. This data has also been used to map melt extent on the large ice sheets, timing of snow melt onset over land and sea ice. Application also extend well beyond the polar regions, mapping important climate variables, such as soil moisture content, oceanic wind speed, rainfall, water vapor, cloud liquid water and total precipitable water. Today the current SSMIS operational satellite (F18) is 7 years old and there is no follow-on mission planned by the DMSP. With the end of the SSMI family of Sensors, will the polar regions once again be in the dark? Other sensors that may contribute to the long-term data record include the JAXA AMSR2 (5 years old as of May 2017), the Chinese Fen-Yung-3 and the Russian Meteor-N2. Scatterometry and L-band radiometry from SMOS and NASA's SMOS may also provide some potential means of extending the sea ice extent data record, as well as future sensors by the DoD, JAXA and ESA. However, this will require considerable effort to intercalibrate the different sensors to ensure consistency in the long-term data record. Differences in measurement approach, frequency and spatial resolution make this a non-trivial matter. The passive microwave sea ice extent data record is one of the longest and most consistent climate data records available. It provides daily monitoring of one of the most striking changes in our climate system, the loss of the Arctic sea ice cover. A series of replacement sensors is urgently needed, preferably at higher spatial resolution to better delineate the ice edge for marine applications such as ship routing.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Elvidge, Christopher D.; Sutton, Paul S.; Ghosh, Tilottama
A global poverty map has been produced at 30 arc sec resolution using a poverty index calculated by dividing population count (LandScan2004) by the brightness of satellite observed lighting (DMSP nighttimelights). Inputs to the LandScan product include satellite-derived landcover and topography, plus human settlement outlines derived from high-resolution imagery. The poverty estimates have been calibrated using national level poverty data from the World Development Indicators (WDI) 2006 edition. The total estimate of the numbers of individuals living in poverty is 2.2billion, slightly under the WDI estimate of 2.6 billion. We have demonstrated a new class of poverty map that shouldmore » improve over time through the inclusion of new reference data for calibration of poverty estimates and as improvements are made in the satellite observation of human activities related to economic activity and technology access.« less
Aguilar, Catalina; Raina, Jean-Baptiste; Motti, Cherie A; Fôret, Sylvain; Hayward, David C; Lapeyre, Bruno; Bourne, David G; Miller, David J
2017-08-14
Dimethylsulfoniopropionate (DMSP) is a small sulphur compound which is produced in prodigious amounts in the oceans and plays a pivotal role in the marine sulfur cycle. Until recently, DMSP was believed to be synthesized exclusively by photosynthetic organisms; however we now know that corals and specific bacteria can also produce this compound. Corals are major sources of DMSP, but the molecular basis for its biosynthesis is unknown in these organisms. Here we used salinity stress, which is known to trigger DMSP production in other organisms, in conjunction with transcriptomics to identify coral genes likely to be involved in DMSP biosynthesis. We focused specifically on both adults and juveniles of the coral Acropora millepora: after 24 h of exposure to hyposaline conditions, DMSP concentrations increased significantly by 2.6 fold in adult corals and 1.2 fold in juveniles. Concomitantly, candidate genes enabling each of the necessary steps leading to DMSP production were up-regulated. The data presented strongly suggest that corals use an algal-like pathway to generate DMSP from methionine, and are able to rapidly change expression of the corresponding genes in response to environmental stress. However, our data also indicate that DMSP is unlikely to function primarily as an osmolyte in corals, instead potentially serving as a scavenger of ROS and as a molecular sink for excess methionine produced as a consequence of proteolysis and osmolyte catabolism in corals under hypo-osmotic conditions.
Burdett, Heidi L.; Donohue, Penelope J. C.; Hatton, Angela D.; Alwany, Magdy A.; Kamenos, Nicholas A.
2013-01-01
Oceanic pH is projected to decrease by up to 0.5 units by 2100 (a process known as ocean acidification, OA), reducing the calcium carbonate saturation state of the oceans. The coastal ocean is expected to experience periods of even lower carbonate saturation state because of the inherent natural variability of coastal habitats. Thus, in order to accurately project the impact of OA on the coastal ocean, we must first understand its natural variability. The production of dimethylsulphoniopropionate (DMSP) by marine algae and the release of DMSP’s breakdown product dimethylsulphide (DMS) are often related to environmental stress. This study investigated the spatiotemporal response of tropical macroalgae (Padina sp., Amphiroa sp. and Turbinaria sp.) and the overlying water column to natural changes in reefal carbonate chemistry. We compared macroalgal intracellular DMSP and water column DMSP+DMS concentrations between the environmentally stable reef crest and environmentally variable reef flat of the fringing Suleman Reef, Egypt, over 45-hour sampling periods. Similar diel patterns were observed throughout: maximum intracellular DMSP and water column DMS/P concentrations were observed at night, coinciding with the time of lowest carbonate saturation state. Spatially, water column DMS/P concentrations were highest over areas dominated by seagrass and macroalgae (dissolved DMS/P) and phytoplankton (particulate DMS/P) rather than corals. This research suggests that macroalgae may use DMSP to maintain metabolic function during periods of low carbonate saturation state. In the reef system, seagrass and macroalgae may be more important benthic producers of dissolved DMS/P than corals. An increase in DMS/P concentrations during periods of low carbonate saturation state may become ecologically important in the future under an OA regime, impacting larval settlement and increasing atmospheric emissions of DMS. PMID:23724073
Cui, Yingshun; Suzuki, Shotaro; Omori, Yuko; Wong, Shu-Kuan; Ijichi, Minoru; Kaneko, Ryo; Kameyama, Sohiko; Tanimoto, Hiroshi; Hamasaki, Koji
2015-06-15
Dimethylsulfoniopropionate (DMSP) is mainly produced by marine phytoplankton but is released into the microbial food web and degraded by marine bacteria to dimethyl sulfide (DMS) and other products. To reveal the abundance and distribution of bacterial DMSP degradation genes and the corresponding bacterial communities in relation to DMS and DMSP concentrations in seawater, we collected surface seawater samples from DMS hot spot sites during a cruise across the Pacific Ocean. We analyzed the genes encoding DMSP lyase (dddP) and DMSP demethylase (dmdA), which are responsible for the transformation of DMSP to DMS and DMSP assimilation, respectively. The averaged abundance (±standard deviation) of these DMSP degradation genes relative to that of the 16S rRNA genes was 33% ± 12%. The abundances of these genes showed large spatial variations. dddP genes showed more variation in abundances than dmdA genes. Multidimensional analysis based on the abundances of DMSP degradation genes and environmental factors revealed that the distribution pattern of these genes was influenced by chlorophyll a concentrations and temperatures. dddP genes, dmdA subclade C/2 genes, and dmdA subclade D genes exhibited significant correlations with the marine Roseobacter clade, SAR11 subgroup Ib, and SAR11 subgroup Ia, respectively. SAR11 subgroups Ia and Ib, which possessed dmdA genes, were suggested to be the main potential DMSP consumers. The Roseobacter clade members possessing dddP genes in oligotrophic subtropical regions were possible DMS producers. These results suggest that DMSP degradation genes are abundant and widely distributed in the surface seawater and that the marine bacteria possessing these genes influence the degradation of DMSP and regulate the emissions of DMS in subtropical gyres of the Pacific Ocean. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
NASA Technical Reports Server (NTRS)
Robertson, Franklin R.; Huang, Huo-Jin
1989-01-01
Data from the Special Sensor Microwave Imager/I on the DMSP satellite are used to study atmospheric moisture and cloud structure. Column-integrated water vapor and total liquid water retrievals are obtained using an algorithm based on a radiative model for brightness temperature (Wentz, 1983). The results from analyzing microwave and IR measurements are combined with independent global gridpoint analyses to study the distribution and structure of atmospheric moisture over oceanic regions.
Collateral Damage to Satellites from an EMP Attack
2010-08-01
peak dose is computed in an infinite half plane of silicon. The resulting in- plane stresses in silicon are shown in Figure VI.23. In- plane refers to...achieved by the SLAR coating 81 Figure VIII.6. Ratio of the peak in- plane compressive stress to the maximum compressive stress for the SLAR coating...82 Figure VIII.7. Maximum in- plane compressive stress in a SLAR coating on DMSP/NOAA subjected to the threat events 83 Figure VIII.8. Maximum in
Search for Best Astronomical Observatory Sites in the MENA Region using Satellite Measurements
NASA Astrophysics Data System (ADS)
Abdelaziz, G.; Guebsi, R.; Guessoum, N.; Flamant, C.
2017-06-01
We perform a systematic search for astronomical observatory sites in the MENA (Middle-East and North Africa) region using space-based data for all the relevant factors, i.e. altitude (DEM), cloud fraction (CF), light pollution (NTL), precipitable water vapor (PWV), aerosol optical depth (AOD), relative humidity (RH), wind speed (WS), Richardson Number (RN), and diurnal temperature range (DTR). We look for the best locations overall even where altitudes are low (the threshold that we normally consider being 1,500 m) or where the combination of the afore-mentioned determining factors had previously excluded all locations in a given country. In this aim, we use the rich data that Earth-observing satellites provide, e.g. the Terra and Aqua multi-national NASA research satellites, with their MODIS (Moderate Resolution Imaging Spectroradiometer) and AIRS (Atmospheric Infrared Sounder) instruments, the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS), and other products from climate diagnostics archives (e.g. MERRA). We present preliminary results on the best locations for the region.
NASA Technical Reports Server (NTRS)
1998-01-01
The main objectives of the previously funded work were: (1) to determine the rates of DMSP and DMS production as a function of phytoplankton growth rate; (2) to determine the light dependence (quantity and quality) of DiMethylSulfonioPropionate (DMSP) and DiMethylSulfide (DMS) production by phytoplankton; and (3) to study intraspecific differences in DMSP and DMS production by phytoplankton.
NASA Astrophysics Data System (ADS)
Zhang, J.; Miller, S. D.; Reid, J. S.; Hyer, E. J.; McHardy, T. M.
2015-12-01
Compared to abundant daytime satellite-based observations of atmospheric aerosol, observations at night are relatively scarce. In particular, conventional satellite passive imaging radiometers, which offer expansive swaths of spatial coverage compared to non-scanning lidar systems, lack sensitivity to most aerosol types via the available thermal infrared bands available at night. In this talk, we make the fundamental case for the importance of nighttime aerosol information in forecast models, and the need to mitigate the existing nocturnal gap. We review early attempts at estimating nighttime aerosol optical properties using the modulation of stable artificial surface lights. Initial algorithm development using DMSP Operational Linescan System (OLS) has graduated to refined techniques based on the Suomi-NPP Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB). We present examples of these retrievals for selected cases and compare the results to available surface-based point-source validation data.
NASA Astrophysics Data System (ADS)
Kobayashi, Shinya; Poli, Paul; John, Viju O.
2017-02-01
The near-global and all-sky coverage of satellite observations from microwave humidity sounders operating in the 183 GHz band complement radiosonde and aircraft observations and satellite infrared clear-sky observations. The Special Sensor Microwave Water Vapor Profiler (SSM/T-2) of the Defense Meteorological Satellite Program began operations late 1991. It has been followed by several other microwave humidity sounders, continuing today. However, expertise and accrued knowledge regarding the SSM/T-2 data record is limited because it has remained underused for climate applications and reanalyses. In this study, SSM/T-2 radiances are characterised using several global atmospheric reanalyses. The European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Reanalysis (ERA-Interim), the first ECMWF reanalysis of the 20th-century (ERA-20C), and the Japanese 55-year Reanalysis (JRA-55) are projected into SSM/T-2 radiance space using a fast radiative transfer model. The present study confirms earlier indications that the polarisation state of SSM/T-2 antenna is horizontal (not vertical) in the limit of nadir viewing. The study also formulates several recommendations to improve use of the SSM/T-2 measurement data in future fundamental climate data records or reanalyses. Recommendations are (1) to correct geolocation errors, especially for DMSP 14; (2) to blacklist poor quality data identified in the paper; (3) to correct for inter-satellite biases, estimated here on the order of 1 K, by applying an inter-satellite recalibration or, for reanalysis, an automated (e.g., variational) bias correction; and (4) to improve precipitating cloud filtering or, for reanalysis, consider an all-sky assimilation scheme where radiative transfer simulations account for the scattering effect of hydrometeors.
NASA Astrophysics Data System (ADS)
van Alstyne, K. L.; Dominique, V. J.; Muller-Parker, G.
2009-03-01
Many groups of tropical cnidarians including scleractinian corals, octocorals, corallimorphs, and anemones contain the tertiary sulfonium compound dimethylsulfoniopropionate (DMSP). It is not known if the compound is synthesized by the animals, their microalgal symbionts, or derived through their diet. We determined the source of the DMSP in several species of tropical and temperate anemones using three approaches: (1) conducting comparative measurements of DMSP in aposymbiotic and zooxanthellate anemones of three species that harbor zooxanthellae, and similar measurements in one species that can harbor both zooxanthellae and zoochlorellae, (2) manipulating the presence or absence of zooxanthellae by inoculating juvenile aposymbiotic anemones ( Aiptasia pallida) with their symbiont, Symbiodinium bermudense, and (3) manipulating the numbers of S. bermudense by growing aposymbiotic and zooxanthellate A. pallida in the light and the dark. DMSP was present in zooxanthellate anemones in concentrations of 3.4-15 μmol g-1 fresh mass (FM). In aposymbiotic Aiptasia spp. and Anthopleura elegantissima that lacked large numbers of zooxanthellae, concentrations ranged from being undetectable to 0.43 μmol g-1 FM. When aposymbiotic A. pallida were inoculated with zooxanthellae, concentrations of DMSP were an average of 4.24 μmol g-1 FM after 5 weeks; DMSP was undetectable in uninoculated control animals. Aposymbiotic anemones maintained in the light or the dark for 6 weeks contained no DMSP or zooxanthellae. Zooxanthellate anemones in the light contained five times as many zooxanthellae and approximately 7.5 times as much DMSP as zooxanthellate anemones maintained in the dark. Taken together, these data show that the zooxanthellae are the sole source of DMSP in A. pallida. The trends in DMSP concentrations in other species of zooxanthellate anemones suggest that this phenomenon is not limited to A. pallida but may be more generally true for other anemones or even other cnidarians hosting species of Symbiodinium.
Brummett, Adam E.; Schnicker, Nicholas J.; Crider, Alexander; Todd, Jonathan D.; Dey, Mishtu
2015-01-01
The osmolyte dimethylsulfoniopropionate (DMSP) is a key nutrient in marine environments and its catabolism by bacteria through enzymes known as DMSP lyases generates dimethylsulfide (DMS), a gas of importance in climate regulation, the sulfur cycle, and signaling to higher organisms. Despite the environmental significance of DMSP lyases, little is known about how they function at the mechanistic level. In this study we biochemically characterize DddW, a DMSP lyase from the model roseobacter Ruegeria pomeroyi DSS-3. DddW is a 16.9 kDa enzyme that contains a C-terminal cupin domain and liberates acrylate, a proton, and DMS from the DMSP substrate. Our studies show that as-purified DddW is a metalloenzyme, like the DddQ and DddP DMSP lyases, but contains an iron cofactor. The metal cofactor is essential for DddW DMSP lyase activity since addition of the metal chelator EDTA abolishes its enzymatic activity, as do substitution mutations of key metal-binding residues in the cupin motif (His81, His83, Glu87, and His121). Measurements of metal binding affinity and catalytic activity indicate that Fe(II) is most likely the preferred catalytic metal ion with a nanomolar binding affinity. Stoichiometry studies suggest DddW requires one Fe(II) per monomer. Electronic absorption and electron paramagnetic resonance (EPR) studies show an interaction between NO and Fe(II)-DddW, with NO binding to the EPR silent Fe(II) site giving rise to an EPR active species (g = 4.29, 3.95, 2.00). The change in the rhombicity of the EPR signal is observed in the presence of DMSP, indicating that substrate binds to the iron site without displacing bound NO. This work provides insight into the mechanism of DMSP cleavage catalyzed by DddW. PMID:25993446
Li, Chun-Yang; Wei, Tian-Di; Zhang, Sheng-Hui; Chen, Xiu-Lan; Gao, Xiang; Wang, Peng; Xie, Bin-Bin; Su, Hai-Nan; Qin, Qi-Long; Zhang, Xi-Ying; Yu, Juan; Zhang, Hong-Hai; Zhou, Bai-Cheng; Yang, Gui-Peng; Zhang, Yu-Zhong
2014-01-01
The microbial cleavage of dimethylsulfoniopropionate (DMSP) generates volatile DMS through the action of DMSP lyases and is important in the global sulfur and carbon cycles. When released into the atmosphere from the oceans, DMS is oxidized, forming cloud condensation nuclei that may influence weather and climate. Six different DMSP lyase genes are found in taxonomically diverse microorganisms, and dddQ is among the most abundant in marine metagenomes. Here, we examine the molecular mechanism of DMSP cleavage by the DMSP lyase, DddQ, from Ruegeria lacuscaerulensis ITI_1157. The structures of DddQ bound to an inhibitory molecule 2-(N-morpholino)ethanesulfonic acid and of DddQ inactivated by a Tyr131Ala mutation and bound to DMSP were solved. DddQ adopts a β-barrel fold structure and contains a Zn2+ ion and six highly conserved hydrophilic residues (Tyr120, His123, His125, Glu129, Tyr131, and His163) in the active site. Mutational and biochemical analyses indicate that these hydrophilic residues are essential to catalysis. In particular, Tyr131 undergoes a conformational change during catalysis, acting as a base to initiate the β-elimination reaction in DMSP lysis. Moreover, structural analyses and molecular dynamics simulations indicate that two loops over the substrate-binding pocket of DddQ can alternate between “open” and “closed” states, serving as a gate for DMSP entry. We also propose a molecular mechanism for DMS production through DMSP cleavage. Our study provides important insight into the mechanism involved in the conversion of DMSP into DMS, which should lead to a better understanding of this globally important biogeochemical reaction. PMID:24395783
Satellite-derived attributes of cloud vortex systems and their application to climate studies
NASA Technical Reports Server (NTRS)
Carleton, Andrew M.
1987-01-01
Defense Meteorological Satellite Program (DMSP) visible and infrared mosaics are analyzed in conjunction with synoptic meteorological observations of sea level pressure (SLP) and upper-air height to derive composite patterns of cyclonic cloud vortices for the Northern Hemisphere. The patterns reveal variations in the structure and implied dynamics of cyclonic systems at different stages of development that include: (1) increasing vertical symmetry of the lower-level and upper-air circulations and (2) decreasing lower-tropospheric thicknesses and temperature advection, associated with increasing age of the vortex. Cloud vortices are more intense in winter than in summer and typically reach maximum intensity in the short-lived prespiral signature stage. There are major structural differences among frontal wave, polar air, and 'instant occlusion' cyclogenesis types. Cyclones in the dissipation stage may reintensify (deepen), as denoted by the appearance in the imagery of an asymmetric cloud band or a tightened spiral vortex. The satellite-derived statistics on cloud vortex intensity, which are seasonal- and latitude- as well as type-dependent, are applied to a preliminary examination of the synoptic manifestations of seasonal climate variability. An apparently close relationship is found, for two winter and spring seasons, between Northern Hemisphere cyclonic activity and variations in cryosphere variables, particularly the extent of Arctic sea ice. The results may indicate that increased snow and ice extent accompany a southward displacement of cyclonic activity and/or a predominance of deeper systems. However, there is also a strong regional dependence to the ice-synoptics feedback. This study demonstrates the utility of high resolution meteorological satellite imagery for studies of climate variations (climate dynamics).
NASA Astrophysics Data System (ADS)
Solorzano, N. N.; Thomas, J. N.; Hutchins, M. L.; Holzworth, R. H.
2016-10-01
We investigate lightning strokes and deep convection through the examination of cloud-to-ground (CG) lightning from the World Wide Lightning Location Network (WWLLN) and passive microwave radiometer data. Microwave channels at 37 to 183.3 GHz are provided by the Tropical Rainfall Measuring Mission satellite (TRMM) Microwave Imager (TMI) and the Special Sensor Microwave Imager/Sounder (SSMIS) on the Defense Meteorological Satellite Program (DMSP) satellite F16. The present study compares WWLLN stroke rates and minimum radiometer brightness temperatures (Tbs) for two Northern Hemisphere and Southern Hemisphere summers (2009-2011) in the broad tropics (35°S to 35°N). To identify deep convection, we use lightning data and Tbs derived from all channels and differences in the Tbs (ΔTbs) of the three water vapor channels near 183.3 GHz. We find that stroke probabilities increase with increasing Tb depressions for all frequencies examined. Moreover, we apply methods that use the 183.3 GHz channels to pinpoint deep convection associated with lightning. High lightning stroke probabilities are found over land regions for both intense and relatively weak convective systems, although the TMI 85 GHz results should be used with caution as they are affected by a 7 km gap between the conical scans. Over the ocean, lightning is associated mostly with larger Tb depressions. Generally, our results support the noninductive thundercloud charging mechanism but do not rule out the inductive mechanism during the mature stages of storms. Lastly, we present a case study in which lightning stroke rates are used to reconstruct microwave radiometer Tbs.
NASA Astrophysics Data System (ADS)
Shume, E. B.; Komjathy, A.; Langley, R. B.; Verkhoglyadova, O. P.; Butala, M.; Mannucci, A. J.
2014-12-01
In this research, we report intermediate scale plasma density irregularities in the high-latitude ionosphere inferred from high-resolution radio occultation (RO) measurements in the CASSIOPE (CAScade Smallsat and IOnospheric Polar Explorer) - GPS (Global Positioning System) satellites radio link. The high inclination of the CASSIOPE satellite and high rate of signal receptionby the occultation antenna of the GPS Attitude, Positioning and Profiling (GAP) instrument on the Enhanced Polar Outflow Probe platform on CASSIOPE enable a high temporal and spatial resolution investigation of the dynamics of the polar ionosphere, magnetosphere-ionospherecoupling, solar wind effects, etc. with unprecedented details compared to that possible in the past. We have carried out high spatial resolution analysis in altitude and geomagnetic latitude of scintillation-producing plasma density irregularities in the polar ionosphere. Intermediate scale, scintillation-producing plasma density irregularities, which corresponds to 2 to 40 km spatial scales were inferred by applying multi-scale spectral analysis on the RO phase delay measurements. Using our multi-scale spectral analysis approach and Polar Operational Environmental Satellites (POES) and Defense Meteorological Satellite Program (DMSP) observations, we infer that the irregularity scales and phase scintillations have distinct features in the auroral oval and polar cap regions. In specific terms, we found that large length scales and and more intense phase scintillations are prevalent in the auroral oval compared to the polar cap region. Hence, the irregularity scales and phase scintillation characteristics are a function of the solar wind and the magnetospheric forcing. Multi-scale analysis may become a powerful diagnostic tool for characterizing how the ionosphere is dynamically driven by these factors.
Global Specification of the Post-Sunset Equatorial Ionization Anomaly
NASA Astrophysics Data System (ADS)
Coker, C.; Dandenault, P. B.; Dymond, K.; Budzien, S. A.; Nicholas, A. C.; Chua, D. H.; McDonald, S. E.; Metzler, C. A.; Walker, P. W.; Scherliess, L.; Schunk, R. W.; Gardner, L. C.; Zhu, L.
2012-12-01
The Special Sensor Ultraviolet Limb Imager (SSULI) on the Defense Meteorological Satellite Program (DMSP) is used to specify the post-sunset Equatorial Ionization Anomaly. Ultraviolet emission profiles of 135.6 nm and 91.1 nm emissions from O++ e recombination are measured in successive altitude scans along the orbit of the satellite. The overlapping sample geometry provides for a high resolution reconstruction of the ionosphere in altitude and latitude for each pass of the satellite. Emission profiles are ingested by the Global Assimilation of Ionospheric Measurements (GAIM) space weather model, which was developed by Utah State University and is run operationally at the Air Force Weather Agency (AFWA). The resulting specification of the equatorial ionosphere reveals significant variability in the postsunset anomaly, which is reflective of the driving space weather processes, namely, electric fields and neutral winds. Significant longitudinal and day-to-day variability in the magnitude (or even existence) of the post-sunset anomaly reveal the influence of atmospheric tides and waves as well as geomagnetic disturbances on the pre-reversal enhancement of the electric field. Significant asymmetry between anomaly crests reveals the influence of atmospheric tides and waves on meridional neutral winds. A neutral wind parallel to the magnetic field line pushes plasma up (or down) the field lines, which raises (or lowers) the altitude of the crests and modifies the horizontal location and magnitude of the crests. The variability in the post-sunset anomaly is one of the largest sources of error in ionospheric specification models. The SSULI instrument provides critical data towards the reduction of this specification error and the determination of key driver parameters used in ionospheric forecasting. Acknowledgements: This research was supported by the USAF Space and Missile Systems Center (SMC), the Naval Research Laboratory (NRL) Base Program, and the Office of Naval Research (ONR).
NASA Technical Reports Server (NTRS)
Watermann, Jurgen; Delabeaujardiere, Odile; Lummerzheim, Dirk; Woch, Joachim; Newell, Patrick T.; Potemra, Thomas A.; Rich, Frederick J.; Shapshak, Mans
1992-01-01
A case study involving data from three satellites and a ground-based radar are presented. Focus is on a detailed discussion of observations of the dynamic cusp made on 24 Sep. 1986 in the dayside high-latitude ionosphere and interior magnetosphere. The relevant data from space-borne and ground-based sensors is presented. They include in-situ particle and field measurements from the DMSP-F7 and Viking spacecraft and Sondrestrom radar observations of the ionosphere. These data are augmented by observations of the IMF and the solar wind plasma. The observations are compared with predictions about the ionospheric response to the observed particle precipitation, obtained from an auroral model. It is shown that observations and model calculations fit well and provide a picture of the ionospheric footprint of the cusp in an invariant latitude versus local time frame. The combination of Viking, Sondrestrom radar, and IMP-8 data suggests that we observed an ionospheric signature of the dynamic cusp. Its spatial variation over time which appeared closely related to the southward component of the IMF was monitored.
Earth observations from space: History, promise, and reality. Executive summary
NASA Technical Reports Server (NTRS)
1995-01-01
In this report the Committee on Earth Studies (CES), a standing committee of the Space Studies Board (SSB) within the National Research Council (NRC), reviews the recent history (nominally from 1981 to 1995) of the U.S. earth observations programs that serve civilian needs. The principal observations programs examined are those of NASA and the National Oceanic and Atmospheric Administration (NOAA). The Air Force' s Defense Meteorological Satellite Program (DMSP) is discussed, but only from the perspective of its relationship to civil needs and the planned merger with the NOAA polar-orbiting system. The report also reviews the interfaces between the earth observations satellite programs and the major national and international environmental monitoring and research programs. The monitoring and research programs discussed are the U.S. Global Change Research Program (USGCRP), the International Geosphere-Biosphere Program (IGBP), the World Climate Research Program (WCRP), related international scientific campaigns, and operational programs for the sharing and application of environmental data. The purpose of this report is to provide a broad historical review and commentary based on the views of the CES members, with particular emphasis on tracing the lengthy record of advisory committee recommendations. Any individual topic could be the subject of an extended report in its own right. Indeed, extensive further reviews are already under way to that end. If the CES has succeeded in the task it has undertaken. This report will serve as a useful starting point for any such more intensive study. The report is divided into eight chapters: ( I ) an introduction, (2) the evolution of the MTPE, (3) its relationship to the USGCRP, (4) applications of earth observations data, (5) the role that smaller satellites can play in research and operational remote sensing, (6) earth system modeling and information systems, (7) a number of associated activities that contribute to the MTPE and the USGCRP, and (8) organizational issues in the conduct of civil earth observations programs. Following the body of the report is a series of appendixes: after a list of acronyms and abbreviations and collected short biographies of CES members, six brief tutorials discuss several scientific topics important to the science and applications of earth observations. Highlights from the eight chapters follow.
The brightness of lights on Earth at night, digitally recorded by DMSP satellite
Croft, Thomas A.
1979-01-01
The U.S. Air Force has operated its Defense Meteorological Satellite Program (DMSP) for nearly a decade, and film images from the system have been openly available since 1973. Films are well suited for the study of weather, and users of such films have derived much useful data. For many potential remote sensing applications, however, a quantitative measurement of the brightness of the imaged light patterns is needed, and it cannot be extracted with adequte accuracy from the films. Such information is contained in the telemetry from the spacecraft and is retained on digital tapes, which store the images for a few days while they await filming. For practical reasons, it has not heretofore been feasible for the Air Force to provide a remote-sensing user with these digital data, and the quantitative brightness information has been lost with the erasure of tapes for re-use. For the purpose of evaluation of tapes as a means for remote sensing, the Air Force recently did provide to the author six examples containing records of nighttime DMSP imagery similar to that which has previously 1 been evaluated by SRI International in a film format. The digital data create many new applications for these images, owing to a combination of several factors, the most important of which are the preservation of photometric information and of full spatial resolution. In this evaluation, stress has been placed upon determination of the broad potential value of the data rather than the full exploitation of any one aspect of it. The effort was guided by an objective to develop handling methods for the vast body of numbers--methods which will be practical for use in a research or engineering environment where budgets are limited, and specialized capabilities and image reproduction equipment has not already been developed. We report the degree of success obtained in this effort, pointing out the relative strengths and the relative limitations, as compared to the sophisticated, weather-oriented data processing which is well suited for the Air Force requirements. Both geometric and photometric calibration methods are evaluated. An image can be considered as a 3-dimensional array, X, Y, Z, in which X and Y are the coordinates of a picture element (pixel) and Z is the brightness at that location. A method of approach to handling these parameters, particularly Y and Z, is developed in a form quite different from that which serves the operational applications. The user of digital data will need the film images which are generated by the Air Force from the same data as is provided on digital tape. In the first stages of analysis, the films provide both a convenient index and a guide to identification of large patterns in the data. Additionally, the infrared (8 to 13 0 film provides a valuable indicator of cloud cover. Two general conclusions are drawn from this study. Firstly, the digital DMSP data have great potential value but their cost, in terms of the interruption of the present operational routine, is quite high. Therefore, if a program is undertaken to provide for the open availability of an archive of digital records, great care must be exercised in selecting only those records which have unusually high value in order that the effort will be cost-effective. Secondly, it is concluded that several aspects of the program, well designed for Air Force operational purposes, are not adapted to earth-sensing needs. This is probably inevitable, since the two applications are largely different and in some ways incompatible. For example, the nighttime visual sensor saturates in the center of major cities and in moderately large fires (such as gas flares). This saturation prevents the analyst from integrating photometric parameters. For weather observation, this inability is unimportant, and acceptance of such saturation makes feasible a decrease in the data rate. Such limitations in the data will probably be overcome only through modifying the existing system or the implementation of a similar system designed specifically to serve earth-sensing needs.
Ansede, John H.; Pellechia, Perry J.; Yoch, Duane C.
1999-01-01
Dimethylsulfoniopropionate (DMSP) is degraded to dimethylsulfide (DMS) and acrylate by the enzyme DMSP lyase. DMS or acrylate can serve as a carbon source for both free-living and endophytic bacteria in the marine environment. In this study, we report on the mechanism of DMSP-acrylate metabolism by Alcaligenes faecalis M3A. Suspensions of citrate-grown cells expressed a low level of DMSP lyase activity that could be induced to much higher levels in the presence of DMSP, acrylate, and its metabolic product, β-hydroxypropionate. DMSP was degraded outside the cell, resulting in an extracellular accumulation of acrylate, which in suspensions of citrate-grown cells was then metabolized at a low endogenous rate. The inducible nature of acrylate metabolism was evidenced by both an increase in the rate of its degradation over time and the ability of acrylate-grown cells to metabolize this molecule at about an eight times higher rate than citrate-grown cells. Therefore, acrylate induces both its production (from DMSP) and its degradation by an acrylase enzyme. 1H and 13C nuclear magnetic resonance analyses were used to identify the products resulting from [1-13C]acrylate metabolism. The results indicated that A. faecalis first metabolized acrylate to β-hydroxypropionate outside the cell, which was followed by its intracellular accumulation and subsequent induction of DMSP lyase activity. In summary, the mechanism of DMSP degradation to acrylate and the subsequent degradation of acrylate to β-hydroxypropionate in the aerobic β-Proteobacterium A. faecalis has been described. PMID:10543825
NASA Astrophysics Data System (ADS)
Yost, D. M.; Jones, R.; Rowe, C. L.; Mitchelmore, Carys Louise
2012-06-01
The symbiotic dinoflagellate microalgae of corals ( Symbiodinium spp.) contain high concentrations of dimethylsulfoniopropionate (DMSP), a multifunctional metabolite commonly found in many species of marine algae and dinoflagellates. A photoprotective antioxidant function for DMSP and its breakdown products has often been inferred in algae, but its role(s) in the coral-algal symbiosis remains elusive. To examine potential correlations between environmental and physiological parameters and DMSP, total DMSP (DMSPt, from the host coral and zooxanthellae), particulate DMSP (DMSPp, from the zooxanthellae only), coral surface area, and total protein, as well as zooxanthellae density, chlorophyll concentration, cell volume and genotype (i.e., clade) were measured in five coral species from the Diploria- Montastraea- Porites species complex in Bermuda along a depth gradient of 4, 12, 18, and 24 m. DMSPt concentrations were consistently greater than DMSPp concentrations in all species suggesting the possible translocation of DMSP from symbiont to host. D. labyrinthiformis was notably different from the other corals examined, showing DMSPp and DMSPt increases (per coral surface area or tissue biomass) with increasing water depth. However, overall, there were no consistent depth-related patterns in DMSPp and DMSPt concentrations. Further research, investigating dimethylsulfide (DMS), dimethylsulfoxide, and acrylate levels and DMSP-lyase activity in correlation with other biomarker endpoints that have been shown to be depth (i.e., temperature and light) responsive are needed to substantiate the significance of these findings.
NASA Astrophysics Data System (ADS)
Jarníková, Tereza; Dacey, John; Lizotte, Martine; Levasseur, Maurice; Tortell, Philippe
2018-04-01
We present seawater concentrations of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) measured across a transect from the Labrador Sea to the Canadian Arctic Archipelago during summer 2015. Using an automated ship-board gas chromatography system and a membrane-inlet mass spectrometer, we measured a wide range of DMS (˜ 1 to 18 nM) and DMSP (˜ 1 to 150 nM) concentrations. The highest DMS and DMSP concentrations occurred in a localized region of Baffin Bay, where surface waters were characterized by high chlorophyll a (chl a) fluorescence, indicative of elevated phytoplankton biomass. Across the full sampling transect, there were only weak relationships between DMS(P), chl a fluorescence and other measured variables, including positive relationships between DMSP : chl a ratios and several taxonomic marker pigments, and elevated DMS(P) concentrations in partially ice-covered areas. Our high spatial resolution measurements allowed us to examine DMS variability over small scales (< 1 km), documenting strong DMS concentration gradients across surface hydrographic frontal features. Our new observations fill in an important observational gap in the Arctic Ocean and provide additional information on sea-air DMS fluxes from this ocean region. In addition, this study constitutes a significant contribution to the existing Arctic DMS(P) dataset and provides a baseline for future measurements in the region.
Antarctic mesocyclone regimes from satellite and conventional data
NASA Astrophysics Data System (ADS)
Fitch, Mark; Carleton, Andrew M.
1992-03-01
Mesoscale vortices in the Antarctic, poleward of 50°S, are examined in the synoptic context for the Ross Sea sector (100°E eastward to 80°W) for transition and winter months of 1988, using DMSP (Defense Meteorological Satellite Program) thermal infrared (TIR) images. Mesoscale vortices are classified and tracked and the dominant characteristics, such as life span, speed of movement and preferred geographical locations of formation, are defined and discussed. A "superposed epoch" (compositing) method utilizing 1000 and 500mb height data identifies the dominant synoptic regimes in which mesoscale vortices tend to develop. This analysis indicates that during active or outbreak periods, a negative thickness anomaly ("cold pool") is located northeast of the Ross Sea, and mesoscale vortices tend to occur on the poleward side of that anomaly. In addition, an enhanced trough-ridge pattern is evident for the Ross Sea sector compared with the composite pattern for inactive, or dearth, periods. The active periods of mesoscale vortices appear to originate from Antarctica, possibly via the persistent katabatic outflows from the ice sheet, rather than from teleconnections to lower latitudes. Analysis of Automatic Weather Station (AWS) data for the Ross Sea region supports this notion, at least for individual cases. Confirmation of these findings for the corresponding months of additional years is continuing.
Estimating global per-capita carbon emissions with VIIRS nighttime lights satellite data
NASA Astrophysics Data System (ADS)
Jasmin, T.; Desai, A. R.; Pierce, R. B.
2015-12-01
With the launch of the Suomi National Polar-orbiting Partnership (NPP) satellite in November 2011, we now have nighttime lights remote sensing capability vastly improved over the predecessor Defense Meteorological Satellite Program (DMSP), owing to improved spatial and radiometric resolution provided by the Visible Infrared Imaging Radiometer Suite (VIIRS) Day Night Band (DNB) along with technology improvements in data transfer, processing, and storage. This development opens doors for improving novel scientific applications utilizing remotely sensed low-level visible light, for purposes ranging from estimating population to inferring factors relating to economic development. For example, the success of future international agreements to reduce greenhouse gas emissions will be dependent on mechanisms to monitor remotely for compliance. Here, we discuss implementation and evaluation of the VRCE system (VIIRS Remote Carbon Estimates), developed at the University of Wisconsin-Madison, which provides monthly independent, unbiased estimates of per-capita carbon emissions. Cloud-free global composites of Earth nocturnal lighting are generated from VIIRS DNB at full spatial resolution (750 meter). A population equation is derived from a linear regression of DNB radiance sums at state level to U.S. Census data. CO2 emissions are derived from a linear regression of VIIRS DNB radiance sums to U.S. Department of Energy emission estimates. Regional coefficients for factors such as percentage of energy use from renewable sources are factored in, and together these equations are used to generate per-capita CO2 emission estimates at the country level.
SSUSI-Lite: a far-ultraviolet hyper-spectral imager for space weather remote sensing
NASA Astrophysics Data System (ADS)
Ogorzalek, Bernard; Osterman, Steven; Carlsson, Uno; Grey, Matthew; Hicks, John; Hourani, Ramsey; Kerem, Samuel; Marcotte, Kathryn; Parker, Charles; Paxton, Larry J.
2015-09-01
SSUSI-Lite is a far-ultraviolet (115-180nm) hyperspectral imager for monitoring space weather. The SSUSI and GUVI sensors, its predecessors, have demonstrated their value as space weather monitors. SSUSI-Lite is a refresh of the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) design that has flown on the Defense Meteorological Satellite Program (DMSP) spacecraft F16 through F19. The refresh updates the 25-year-old design and insures that the next generation of SSUSI/GUVI sensors can be accommodated on any number of potential platforms. SSUSI-Lite maintains the same optical layout as SSUSI, includes updates to key functional elements, and reduces the sensor volume, mass, and power requirements. SSUSI-Lite contains an improved scanner design that results in precise mirror pointing and allows for variable scan profiles. The detector electronics have been redesigned to employ all digital pulse processing. The largest decrease in volume, mass, and power has been obtained by consolidating all control and power electronics into one data processing unit.
Light pollution from the ground, the air and the space
NASA Astrophysics Data System (ADS)
Sánchez de Miguel, A.; Zamorano, J.; Gómez Castaño, J.; Aubé, M.; Bará, S.; Gallego, J.; Kyba, C. C. M.; Lombraña, D.; Nievas, M.; Pascual, S.; Tapia, C.
2015-05-01
The sky brightness is one of the things that most harms astronomical observation, near cities and on mountain observatories. Currently there are several initiatives to control light pollution, but the sky brightness measurements are usually local. To exercise adequate control of light pollution is necessary measurements of light pollution sources and their relation to the spatiotemporal variation of the sky brightness. We use various approaches: data taken ashore with photometers SQM and relate emissions and detected with VIIRS and DMSP satellites. We also use multispectral data taken from the International Space Station to distinguish different types of lamps that contribute to light pollution. Finally we used a spectrograph SAND for temporal analysis of the evolution of the contribution of the lights in the sky brightness of a big city like Madrid. Also we have performed a citizen science program to classify the night time images taken from the ISS (Sánchez de Miguel et al. 2014, A&G, 55, 4, 36).
South Atlantic anomaly and CubeSat design considerations
NASA Astrophysics Data System (ADS)
Fennelly, Judy A.; Johnston, William R.; Ober, Daniel M.; Wilson, Gordon R.; O'Brien, T. Paul; Huston, Stuart L.
2015-09-01
Effects of the South Atlantic Anomaly (SAA) on spacecraft in low Earth orbit (LEO) are well known and documented. The SAA exposes spacecraft in LEO to high dose of ionizing radiation as well as higher than normal rates of Single Event Upsets (SEU) and Single Event Latch-ups (SEL). CubeSats, spacecraft built around 10 x 10 x 10 cm cubes, are even more susceptible to SEUs and SELs due to the use of commercial off-the-shelf components for electronics and payload instrumentation. Examination of the SAA using both data from the Defense Meteorological Satellite Program (DMSP) and a new set of models for the flux of particles is presented. The models, AE9, AP9, and SPM for energetic electrons, energetic protons and space plasma, were developed for use in space system design. These models introduce databased statistical constraints on the uncertainties from measurements and climatological variability. Discussion of the models' capabilities and limitations with regard to LEO CubeSat design is presented.
A large‐scale view of Space Technology 5 magnetometer response to solar wind drivers
Kilcommons, L. M.; Gjerloev, J.; Redmon, R. J.; Slavin, J.; Le, G.
2015-01-01
Abstract In this data report we discuss reprocessing of the Space Technology 5 (ST5) magnetometer database for inclusion in NASA's Coordinated Data Analysis Web (CDAWeb) virtual observatory. The mission consisted of three spacecraft flying in elliptical orbits, from 27 March to 27 June 2006. Reprocessing includes (1) transforming the data into the Modified Apex Coordinate System for projection to a common reference altitude of 110 km, (2) correcting gain jumps, and (3) validating the results. We display the averaged magnetic perturbations as a keogram, which allows direct comparison of the full‐mission data with the solar wind values and geomagnetic indices. With the data referenced to a common altitude, we find the following: (1) Magnetic perturbations that track the passage of corotating interaction regions and high‐speed solar wind; (2) unexpectedly strong dayside perturbations during a solstice magnetospheric sawtooth oscillation interval characterized by a radial interplanetary magnetic field (IMF) component that may have enhanced the accompanying modest southward IMF; and (3) intervals of reduced magnetic perturbations or “calms,” associated with periods of slow solar wind, interspersed among variable‐length episodic enhancements. These calms are most evident when the IMF is northward or projects with a northward component onto the geomagnetic dipole. The reprocessed ST5 data are in very good agreement with magnetic perturbations from the Defense Meteorological Satellite Program (DMSP) spacecraft, which we also map to 110 km. We briefly discuss the methods used to remap the ST5 data and the means of validating the results against DMSP. Our methods form the basis for future intermission comparisons of space‐based magnetometer data. PMID:27981071
A large-scale view of Space Technology 5 magnetometer response to solar wind drivers.
Knipp, D J; Kilcommons, L M; Gjerloev, J; Redmon, R J; Slavin, J; Le, G
2015-04-01
In this data report we discuss reprocessing of the Space Technology 5 (ST5) magnetometer database for inclusion in NASA's Coordinated Data Analysis Web (CDAWeb) virtual observatory. The mission consisted of three spacecraft flying in elliptical orbits, from 27 March to 27 June 2006. Reprocessing includes (1) transforming the data into the Modified Apex Coordinate System for projection to a common reference altitude of 110 km, (2) correcting gain jumps, and (3) validating the results. We display the averaged magnetic perturbations as a keogram, which allows direct comparison of the full-mission data with the solar wind values and geomagnetic indices. With the data referenced to a common altitude, we find the following: (1) Magnetic perturbations that track the passage of corotating interaction regions and high-speed solar wind; (2) unexpectedly strong dayside perturbations during a solstice magnetospheric sawtooth oscillation interval characterized by a radial interplanetary magnetic field (IMF) component that may have enhanced the accompanying modest southward IMF; and (3) intervals of reduced magnetic perturbations or "calms," associated with periods of slow solar wind, interspersed among variable-length episodic enhancements. These calms are most evident when the IMF is northward or projects with a northward component onto the geomagnetic dipole. The reprocessed ST5 data are in very good agreement with magnetic perturbations from the Defense Meteorological Satellite Program (DMSP) spacecraft, which we also map to 110 km. We briefly discuss the methods used to remap the ST5 data and the means of validating the results against DMSP. Our methods form the basis for future intermission comparisons of space-based magnetometer data.
Spacecraft Charging Hazards In Low-earth Orbit
NASA Astrophysics Data System (ADS)
Anderson, P. C.
The space environment in low-Earth orbit (LEO) has until recently been considered quite benign to high levels of spacecraft charging. However, it has been found that the DMSP spacecraft at 840 km can charge to very large negative voltages (up to - 2000 V) when encountering intense precipitating electron events (auroral arcs) while traversing the auroral zone. The occurrence frequency of charging events, defined as when the spacecraft charged to levels exceeding 100 V negative, was highly correlated with the 11-year solar cycle with the largest number of events occurring during solar minimum. This was due to the requirement that the background thermal plasma den- sity be low, at most 104 cm-2. During solar maximum, the plasma density is typically well above that level due to the solar EUV ionizing radiation, and although the oc- currence frequency of auroral arcs is considerably greater than at solar minimum, the occurrence of high-level charging is minimal. Indeed, of the over 1200 events found during the most recent solar cycle, none occurred during the last solar maximum. This has implications to a number of LEO satellite programs, including the International Space Station (ISS). The plasma density in the ISS orbit, at a much lower altitude than DMSP, is well above that at 840 km and rarely below 104 cm-2. However, in the wake of the ISS, the plasma density can be 2 orders of magnitude or more lower than the background density and thus conditions are ripe for significant charging effects. With an inclination of 51.6 degrees, the ISS does enter the auroral zone, particularly during geomagnetic storms and substorms when the auroral boundary can penetrate to very low latitudes. This has significant implications for EVA operations in the ISS wake.
Equatorial Ionospheric Disturbance Field-Aligned Plasma Drifts Observed by C/NOFS
NASA Astrophysics Data System (ADS)
Zhang, Ruilong; Liu, Libo; Balan, N.; Le, Huijun; Chen, Yiding; Zhao, Biqiang
2018-05-01
Using C/NOFS satellite observations, this paper studies the disturbance field-aligned plasma drifts in the equatorial topside ionosphere during eight geomagnetic storms in 2011-2015. During all six storms occurred in the solstices, the disturbance field-aligned plasma drift is from winter to summer hemisphere especially in the morning-midnight local time sector and the disturbance is stronger in June solstice. The two storms occurred at equinoxes have very little effect on the field-aligned plasma drift. Using the plasma temperature data from DMSP satellites and Global Positioning System-total electron content, it is suggested that the plasma density gradient seems likely to cause the disturbance winter-to-summer plasma drift while the role of plasma temperature gradient is opposite to the observed plasma drift.
De Royer Dupré, N; Schneider, R; Payan, J C; Salançon, E; Razungles, A
2014-04-02
We studied the effect of vine water status on the dimethyl sulfur potential (DMSP), ammonium, and amino acid contents of the berry during the maturation of Grenache Noir grapes. Water deficit increased the accumulation of amino acids in berries and favored yeast assimilable amino nitrogen. Similarly, ammonium content was higher in berries from vines subjected to moderate water deficit. DMSP content followed the same trend as yeast assimilable amino acid content, with higher concentrations observed in the berries of vines subjected to water deficit. The high DMSP and yeast assimilable nitrogen contents of musts from vines subjected to water deficit resulted in a better preservation of DMSP during winemaking. The wines produced from these musts had a higher DMSP level and would therefore probably have a higher aroma shelf life, because the DMSP determines the rate of release of dimethyl sulfur during wine storage, and this compound enhances fruity notes.
The physiology of dimethylsulfoniopropionate (DMSP) production in phytoplankton
DOE Office of Scientific and Technical Information (OSTI.GOV)
Keller, M.D.; Bellows, W.K.
1990-06-01
Dimethylsulfoniopropionate (DMSP) is the precursor of dimethyl sulfide (DMS), the primary volatile organic sulfur compound released from the world's oceans. DMS flux from the oceans is estimated currently at {approximately}1.2 Tmol S.y{sup {minus}1}, or about half the amount of sulfur resulting from anthroprogenic activities, and has been implicated in important global atmospheric processes. Significant production of DMSP is confined to a few classes of marine phytoplankton, primarily the Dinophyceae and Prymnesiophyceae. In these groups, DMSP can account for up to 80% of total organic sulfur. DMSP remains intracellular and fairly constant over the growth cycle until late stationary phase whenmore » extracellular levels begin to rise, suggesting leakage. We have examined the effects of a number of environmental variables on DMSP production and release in several marine phytoplankton. In particular the effects of perturbations in light, temperature and nutrient status have been determined. These results will be discussed in relation to marine sulfur chemistry, with ancillary comments on freshwater phytoplankton.« less
Kettles, Nicola Louise; Kopriva, Stanislav; Malin, Gill
2014-01-01
Despite the importance of dimethylsulphoniopropionate (DMSP) in the global sulphur cycle and climate regulation, the biological pathways underpinning its synthesis in marine phytoplankton remain poorly understood. The intracellular concentration of DMSP increases with increased salinity, increased light intensity and nitrogen starvation in the diatom Thalassiosira pseudonana. We used these conditions to investigate DMSP synthesis at the cellular level via analysis of enzyme activity, gene expression and proteome comparison. The activity of the key sulphur assimilatory enzyme, adenosine 5′-phosphosulphate reductase was not coordinated with increasing intracellular DMSP concentration. Under all three treatments coordination in the expression of sulphur assimilation genes was limited to increases in sulphite reductase transcripts. Similarly, proteomic 2D gel analysis only revealed an increase in phosphoenolpyruvate carboxylase following increases in DMSP concentration. Our findings suggest that increased sulphur assimilation might not be required for increased DMSP synthesis, instead the availability of carbon and nitrogen substrates may be important in the regulation of this pathway. This contrasts with the regulation of sulphur metabolism in higher plants, which generally involves up-regulation of several sulphur assimilatory enzymes. In T. pseudonana changes relating to sulphur metabolism were specific to the individual treatments and, given that little coordination was seen in transcript and protein responses across the three growth conditions, different patterns of regulation might be responsible for the increase in DMSP concentration seen under each treatment. PMID:24733415
Ramifications of a potential gap in passive microwave data for the long-term sea ice climate record
NASA Astrophysics Data System (ADS)
Meier, W.; Stewart, J. S.
2017-12-01
The time series of sea ice concentration and extent from passive microwave sensors is one of the longest satellite-derived climate records and the significant decline in Arctic sea ice extent is one of the most iconic indicators of climate change. However, this continuous and consistent record is under threat due to the looming gap in passive microwave sensor coverage. The record started in late 1978 with the launch of the Scanning Multichannel Microwave Radiometer (SMMR) and has continued with a series of Special Sensor Microwave Imager (SSMI) and Special Sensor Microwave Imager and Sounder (SSMIS) instruments on U.S. Defense Meteorological Satellite Program (DMSP) satellites. The data from the different sensors are intercalibrated at the algorithm level by adjusting algorithm coefficients so that the output sea ice data is as consistent as possible between the older and the newer sensor. A key aspect in constructing the time series is to have at least two sensors operating simultaneously so that data from the older and newer sensor can be obtained from the same locations. However, with recent losses of the DMSP F19 and F20, the remaining SSMIS sensors are all well beyond their planned mission lifetime. This means that risk of failure is not small and is increasing with each day of operation. The newest passive microwave sensor, the JAXA Advanced Microwave Scanning Radiometer-2 (AMSR2), is a potential contributor to the time series (though it too is now beyond it's planned 5-year mission lifetime). However, AMSR2's larger antenna and higher spatial resolution presents a challenge in integrating its data with the rest of the sea ice record because the ice edge is quite sensitive to the sensor resolution, which substantially affects the total sea ice extent and area estimates. This will need to be adjusted for if AMSR2 is used to continue the time series. Here we will discuss efforts at NSIDC to integrate AMSR2 estimates into the sea ice climate record if needed. We will also discuss potential contingency plans, such as using operational sea ice charts, to fill any gaps. This would allow the record to continue, but the consistency of the time series will be degraded because the ice charts use human analysis and differing sources, amounts and quality of input data, which makes them sub-optimal for long-term climate records.
NASA Astrophysics Data System (ADS)
Heckmann, G.; Route, G.
2009-12-01
The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes NPOESS satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to NOAA and DoD processing centers operated by the United States government. The IDPS will process EDRs beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. IDPS also provides the software and requirements for the Field Terminal Segment (FTS). NPOESS provides support to deployed field terminals by providing mission data in the Low Rate and High Rate downlinks (LRD/HRD), mission support data needed to generate EDRs and decryption keys needed to decrypt mission data during Selective data Encryption (SDE). Mission support data consists of globally relevant data, geographically constrained data, and two line element sets. NPOESS provides these mission support data via the Internet accessible Mission Support Data Server and HRD/LRD downlinks. This presentation will illustrate and describe the NPOESS capabilities in support of Field Terminal users. This discussion will include the mission support data available to Field Terminal users, content of the direct broadcast HRD and LRD downlinks identifying differences between the direct broadcast downlinks including the variability of the LRD downlink and NPOESS management and distribution of decryption keys to approved field terminals using Public Key Infrastructure (PKI) AES standard with 256 bit encryption and elliptical curve cryptography.
THE EFFECT OF ATRAZINE ON DIMETHYL SULFUR IN MARINE PHYTOPLANKTON
It is anticipated that under stress, the cellular DMSP concentration should drop, as sulfur is transferred from the DMSP pool to DMS. Sulfur in the DMS pool will be transferred to the DMSO pool as radicals are scavenged. Enzyme activities such as DMSP lyase, which converts D...
Release and Consumption of DMSP from Emiliania Huxleyi during grazing by Oxyrrhis Marina
NASA Technical Reports Server (NTRS)
Wolfe, Gordon V.; Sherr, Evelyn B.; Sherr, Barry F.
1994-01-01
Degradation and release to solution of intracellular dimethylsulfoniopropionate (DMSP) from Emiliania huxleyi 370 was observed during grazing by the heterotrophic dinoflagellate Oxyrrhis marina in 24 h bottle incubations. Between 30 and 70% of the lost algal DMSP was metabolized by the grazers without production of dimethylsulfide (DMS) when grazer densities were 150 to 450/ml. The rest was released to solution and about 30% was converted to DMS by bacteria associated with the grazer culture. These experiments demonstrate that grazing by herbivorous protists may be an important sink for DMSP in marine waters, removing a potential source of DMS. Microzooplankton grazing may also indirectly increase the production of DMS by transferring algal DMSP to the dissolved pool, making it available for bacterial metabolism.
Swan, Hilton B; Deschaseaux, Elisabeth S M; Jones, Graham B; Eyre, Bradley D
2017-07-01
Dimethylsulfoniopropionate (DMSP) and eleven other target zwitterions were quantified in the branch tips of six Acropora species and Stylophora pistillata hard coral growing on the reef flat surrounding Heron Island in the southern Great Barrier Reef (GBR), Australia. Hydrophilic interaction liquid chromatography mass spectrometry (HILIC-MS) was used for sample analysis with isotope dilution MS applied to quantify DMSP. The concentration of DMSP was ten times greater in A. aspera than A. valida, with this difference being maintained throughout the spring, summer and winter seasons. In contrast, glycine betaine was present in significantly higher concentrations in these species during the summer than the winter. Exposure of branch tips of A. aspera to air and hypo-saline seawater for up to 1 h did not alter the concentrations of DMSP present in the coral when compared with control samples. DMSP was the most abundant target zwitterion in the six Acropora species examined, ranging from 44-78% of all target zwitterions in A. millepora and A. aspera, respectively. In contrast, DMSP only accounted for 7% in S. pistillata, with glycine betaine and stachydrine collectively accounting for 88% of all target zwitterions in this species. The abundance of DMSP in the six Acropora species examined points to Acropora coral being an important source for the biogeochemical cycling of sulfur throughout the GBR, since this reef-building branching coral dominates the coral cover of the GBR. Graphical Abstract HILIC-MS extracted ion chromatogram showing zwitterionic metabolites from the branching coral Acropora isopora.
Spatial resolution requirements for urban land cover mapping from space
NASA Technical Reports Server (NTRS)
Todd, William J.; Wrigley, Robert C.
1986-01-01
Very low resolution (VLR) satellite data (Advanced Very High Resolution Radiometer, DMSP Operational Linescan System), low resolution (LR) data (Landsat MSS), medium resolution (MR) data (Landsat TM), and high resolution (HR) satellite data (Spot HRV, Large Format Camera) were evaluated and compared for interpretability at differing spatial resolutions. VLR data (500 m - 1.0 km) is useful for Level 1 (urban/rural distinction) mapping at 1:1,000,000 scale. Feature tone/color is utilized to distinguish generalized urban land cover using LR data (80 m) for 1:250,000 scale mapping. Advancing to MR data (30 m) and 1:100,000 scale mapping, confidence in land cover mapping is greatly increased, owing to the element of texture/pattern which is now evident in the imagery. Shape and shadow contribute to detailed Level II/III urban land use mapping possible if the interpreter can use HR (10-15 m) satellite data; mapping scales can be 1:25,000 - 1:50,000.
Muiti-Sensor Historical Climatology of Satellite-Derived Global Land Surface Moisture
NASA Technical Reports Server (NTRS)
Owe, Manfred; deJeu, Richard; Holmes, Thomas
2007-01-01
A historical climatology of continuous satellite derived global land surface soil moisture is being developed. The data set consists of surface soil moisture retrievals from observations of both historical and currently active satellite microwave sensors, including Nimbus-7 SMMR, DMSP SSM/I, TRMM TMI, and AQUA AMSR-E. The data sets span the period from November 1978 through the end of 2006. The soil moisture retrievals are made with the Land Parameter Retrieval Model, a physically-based model which was developed jointly by researchers from the above institutions. These data are significant in that they are the longest continuous data record of observational surface soil moisture at a global scale. Furthermore, while previous reports have intimated that higher frequency sensors such as on SSM/I are unable to provide meaningful information on soil moisture, our results indicate that these sensors do provide highly useful soil moisture data over significant parts of the globe, and especially in critical areas located within the Earth's many arid and semi-arid regions.
NASA Astrophysics Data System (ADS)
Oduro, Harry; Van Alstyne, Kathryn L.; Farquhar, James
2012-06-01
Oceanic dimethylsulfoniopropionate (DMSP) is the precursor to dimethylsulfide (DMS), which plays a role in climate regulation through transformation to methanesulfonic acid (MSA) and non-seasalt sulfate (NSS-SO42-) aerosols. Here, we report measurements of the abundance and sulfur isotope compositions of DMSP from one phytoplankton species (Prorocentrum minimum) and five intertidal macroalgal species (Ulva lactuca, Ulva linza, Ulvaria obscura, Ulva prolifera, and Polysiphonia hendryi) in marine waters. We show that the sulfur isotope compositions (δ34S) of DMSP are depleted in 34S relative to the source seawater sulfate by ∼1-3‰ and are correlated with the observed intracellular content of methionine, suggesting a link to metabolic pathways of methionine production. We suggest that this variability of δ34S is transferred to atmospheric geochemical products of DMSP degradation (DMS, MSA, and NSS-SO42-), carrying implications for the interpretation of variability in δ34S of MSA and NSS-SO42- that links them to changes in growth conditions and populations of DMSP producers rather than to the contributions of DMS and non-DMS sources.
NASA Astrophysics Data System (ADS)
Cordero, D.; Kiene, R. P.
2016-02-01
Dimethylsulfoniopropionate (DMSP) is an osmolyte produced by various macroalgae and phytoplankton in the marine environment. DMSP is known to be the main precursor for dimethyl sulfide (DMS), the major natural sulfur gas emitted from the oceans to the atmosphere. DMS contributes to formation and growth of sulfur-containing aerosols in our stratosphere. These aerosols influence Earth's solar radiation balance and potentially affect the formation of clouds, which could function as a counter-effect to global warming. Bacterioplankton are capable of converting DMSP into DMS via the enzyme DMSP lyase. But not all DMSP in the ocean is converted into DMS. A significant fraction of the DMSP available in the ocean is converted to methanethiol (MeSH) via the bacterial demethylation/demethiolation pathway, with a portion of the MeSH being assimilated as both a carbon and sulfur source. Here we test whether several other naturally-occurring dimethyl sulfonium compounds could be precursors of DMS and MeSH. To test this, we carried out experiments with estuarine water samples from Mobile Bay in the Northern Gulf of Mexico. After collection, unfiltered seawater and seawater filtrate samples, the later containing bacteria only, were treated with 50 nM additions of either 2-dimethylsulfononioacetate (DMSA) or S-Methylmethionine (SMM). After addition of the dimethyl sulfonium compounds, samples were analyzed for sulfur gases with Gas Chromatography-Flame Photometric Detection, using cryogenic-trapping techniques. Addition of DMSA resulted in an immediate increase in MeSH production in both seawater and seawater filtrate containing bacteria only, producing even more MeSH than DMSP. This suggests that DMSA is potentially a significant precursor for MeSH. DMS was not produced in significant amounts from DMSA. Addition of SMM resulted in low rates of both DMS and MeSH accumulation in both seawater samples, indicating that SMM may be a minor precursor for both gases compared to DMSP.
NASA Astrophysics Data System (ADS)
Wolfe, Gordon V.; Levasseur, Maurice; Cantin, Guy; Michaud, Sonia
2000-12-01
We adapted the dilution technique to study microzooplankton grazing of algal dimethylsulfoniopropionate (DMSP) vs. Chl a, and to estimate the impact of microzooplankton grazing on dimethyl sulfide (DMS) production in the Labrador Sea. Phytoplankton numbers were dominated by autotrophic nanoflagellates in the Labrador basin, but diatoms and colonial Phaeocystis pouchetii contributed significantly to phytomass at several high chlorophyll stations and on the Newfoundland and Greenland shelfs. Throughout the region, growth of algal Chl a and DMSP was generally high (0.2-1 d -1), but grazing rates were lower and more variable, characteristic of the early spring bloom period. Production and consumption of Chl a vs. DMSP followed no clear pattern, and sometimes diverged greatly, likely because of their differing distributions among algal prey taxa and size class. In several experiments where Phaeocystis was abundant, we observed DMS production proportional to grazing rate, and we found clear evidence of DMS production by this haptophyte following physical stress such as sparging or filtration. It is possible that grazing-activated DMSP cleavage by Phaeocystis contributes to grazer deterrence: protozoa and copepods apparently avoided healthy colonies (as judged by relative growth and grazing rates of Chl a and DMSP), and grazing of Phaeocystis was significant only at one station where cells were in poor condition. Although we hoped to examine selective grazing on or against DMSP-containing algal prey, the dilution technique cannot differentiate selective ingestion and varying digestion rates of Chl a and DMSP. We also found that the dilution method alone was poorly suited for assessing the impact of grazing on dissolved sulfur pools, because of rapid microbial consumption and the artifactual release of DMSP and DMS during filtration. Measuring and understanding the many processes affecting organosulfur cycling by the microbial food web in natural populations remain a technical challenge that will likely require a combination of techniques to address.
NASA Astrophysics Data System (ADS)
Ryu, Kwangsun; Kwak, Youngsil; Kim, Yong Ha; Park, Jaeheung; Lee, Junchan; Min, Kyoungwook
2016-07-01
Using the ionospheric measurements of CHAMP, DEMETER, and DMSP F15, the seasonal and spatial variations of the topside ionosphere during the last solar minimum period were investigated and compared with ionospheric models. In all the satellite measurements, equatorial ionization anomaly (EIA) shows clearly longitudinal asymmetry with wave number -3 or -4 patterns. Anomalous increases of Ne in the nighttime surpassing daytime Ne, known as the Weddell Sea anomaly (WSA) or midlatitude summer nighttime anomaly (MSNA), were also observed in the global Ne distribution with differences in detailed geometry of the geomagnetic field according to the altitude. In the nighttime ionosphere, the reduced Te in the equatorial region at the DMSP altitude, identified as the equatorial plasma temperature anomaly (EPTA), was ascribed to the leftover of the prereversal enhancement of the upward plasma drift. Though the EIA, WSA, MSNA, and EPTA are all associated with the upward plasma movement, the difference in the thermal evolution is ascribable to the geometry of drift in which the plasma moves across the geomagnetic field line for the EIA and the EPTA, while along the field line for the WSA and the MSNA.
Ionization rate from the electron precipitation during August 2011 storm
NASA Astrophysics Data System (ADS)
Huang, Y.; Huang, C. Y.; Su, Y.
2013-12-01
We apply a parameterization by Fang et al. [2010] (Fang2010) to the complex energy spectra measured by DMSP F16 satellites to calculate the ionization rate from electron precipitation during a moderate storm on August 6th, 2011. The DMSP electron flux measurements show that there is clear enhancement of electron fluxes in the polar cap. The mean energy in the polar cap is mostly above 100 eV, while the mean energy of auroral zone is above 1 keV. F16 also captures a strong Poynting flux enhancement in the polar cap. The electron impact ionization rates using thermospheric densities and temperatures from NRLMSISE-00, TIE-GCM and GITM show clear enhancement at F-region altitudes in the polar cap region due to the low-energy electrons precipitated. Using the default empirical formulations of electron impact ionization in GCMs, TIE-GCM and GITM do not capture the F-region ionization shown in the results of Fang2010 parameterization. Fang, X, C. E. Randall, D. Lummerzheim, W. Wang, G. Lu, S. C. Solomon, and R. A. Frahm (2010), Geophys. Res. Lett., 37, L22106, doi:10.1029/2010GL045406.
Trapped Radiation Model Uncertainties: Model-Data and Model-Model Comparisons
NASA Technical Reports Server (NTRS)
Armstrong, T. W.; Colborn, B. L.
2000-01-01
The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties. Model comparisons are made with flux and dose measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP, LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Cosmos-1887, Cosmos-2044), and on the Russian Mir Space Station. This report gives the details of the model-data comparisons-summary results in terms of empirical model uncertainty factors that can be applied for spacecraft design applications are given in a combination report. The results of model-model comparisons are also presented from standard AP8 and AE8 model predictions compared with the European Space Agency versions of AP8 and AE8 and with Russian-trapped radiation models.
Trapped Radiation Model Uncertainties: Model-Data and Model-Model Comparisons
NASA Technical Reports Server (NTRS)
Armstrong, T. W.; Colborn, B. L.
2000-01-01
The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties. Model comparisons are made with flux and dose measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP. LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Cosmos-1887, Cosmos-2044), and on the Russian Mir space station. This report gives the details of the model-data comparisons -- summary results in terms of empirical model uncertainty factors that can be applied for spacecraft design applications are given in a companion report. The results of model-model comparisons are also presented from standard AP8 and AE8 model predictions compared with the European Space Agency versions of AP8 and AE8 and with Russian trapped radiation models.
NASA Astrophysics Data System (ADS)
Kervalishvili, G.; Lühr, H.
2016-12-01
This study reports on the results obtained by a superposed epoch analysis (SEA) method applied to the electron temperature, vertical ion velocity, field-aligned current (FAC), and thermospheric zonal wind velocity at high-latitudes in the Northern Hemisphere. The SEA study is performed in a magnetic latitude versus magnetic local time (MLat-MLT) frame. The obtained results are based on observations collected during the years 2001-2005 by the CHAMP and DMSP (F13 and F15) satellites. The dependence on interplanetary magnetic field (IMF) orientations is also investigated using data from the NASA/GSFC's OMNI database. Further, the obtained results are subdivided into three Lloyd seasons of 130 days each, which are defined as follows: local winter (1 January ± 65 days), combined equinoxes (1 April and 1 October ± 32days), and local summer (1 July ± 65 days). A period of 130 days is needed by the CHAMP satellite to pass through all local times. The time and location of the electron temperature peaks from CHAMP measurements near the cusp region are used as the reference parameter for the SEA method to investigate the relationship between the electron temperature and other ionospheric quantities. The SEA derived MLat profiles of the electron temperature show a seasonal dependence, increasing from winter to summer, as expected. But, the temperature rise (difference between the reference temperature peak and the background electron temperature) strongly decreases towards local summer. The SEA derived MLat profiles of the ion vertical velocity at DMSP altitude show the same seasonal behaviour as the electron temperature rice. There exists a clear linear relation between these two variables with a quiet large correlation coefficient value, >0.9. The SEA derived MLat profiles of both, thermospheric zonal wind velocity and FAC, show a clear IMF By orientation dependence for all local seasons. The zonal wind velocity is prominently directed towards west in the MLat-MLT frame for both signs of IMF By, but speeds are larger for positive By. FAC shows a systematic imbalance between downward (upward) and upward (downward) peaks equatorward and poleward of the reference point for positive (negative) IMF By. The influence of upflow events depends strongly on the amplitude of IMF By, to a lesser extend on Bz.
1980-12-01
1 October 1979 -30 September 1980 December 1 LAJ Apposei tr pr*i leg;dsgtUm *~c :vim, Quailified requestoz’u mq obtWi 04d4$09L aslptw hDefense...RECIPIENT’S CATALOG NUMBER 7, AFGI-, TR -8i -0AD-A/6’ 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED K Magnetospheric and Geomagnetic...polar region electron precipitations based on USAF DMSP observations. In the previous report (AFGL- TR -80-0070), it has been discussed in great detail
NASA Technical Reports Server (NTRS)
Andrews, Jane C.; Knowlton, Kelly
2007-01-01
Light pollution has significant adverse biological effects on humans, animals, and plants and has resulted in the loss of our ability to view the stars and planets of the universe. Over half of the U.S. population resides in coastal regions where it is no longer possible to see the stars and planets in the night sky. Forty percent of the entire U.S. population is never exposed to conditions dark enough for their eyes to convert to night vision capabilities. In coastal regions, urban lights shine far out to sea where they are augmented by the output from fishing boat, cruise ship and oil platform floodlights. The proposed candidate solution suggests using HSCs (high sensitivity cameras) onboard the SAC-C and Aquarius/SAC-D satellites to quantitatively evaluate light pollution at high spatial resolution. New products modeled after pre-existing, radiance-calibrated, global nighttime lights products would be integrated into a modified Garstang model where elevation, mountain screening, Rayleigh scattering, Mie scattering by aerosols, and atmospheric extinction along light paths and curvature of the Earth would be taken into account. Because the spatial resolution of the HSCs on SAC-C and the future Aquarius/SAC-D missions is greater than that provided by the DMSP (Defense Meteorological Satellite Program) OLS (Operational Linescan System) or VIIRS (Visible/Infrared Imager/Radiometer Suite), it may be possible to obtain more precise light intensity data for analytical DSSs and the subsequent reduction in coastal light pollution.
A multi-sensor data-driven methodology for all-sky passive microwave inundation retrieval
NASA Astrophysics Data System (ADS)
Takbiri, Zeinab; Ebtehaj, Ardeshir M.; Foufoula-Georgiou, Efi
2017-06-01
We present a multi-sensor Bayesian passive microwave retrieval algorithm for flood inundation mapping at high spatial and temporal resolutions. The algorithm takes advantage of observations from multiple sensors in optical, short-infrared, and microwave bands, thereby allowing for detection and mapping of the sub-pixel fraction of inundated areas under almost all-sky conditions. The method relies on a nearest-neighbor search and a modern sparsity-promoting inversion method that make use of an a priori dataset in the form of two joint dictionaries. These dictionaries contain almost overlapping observations by the Special Sensor Microwave Imager and Sounder (SSMIS) on board the Defense Meteorological Satellite Program (DMSP) F17 satellite and the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Aqua and Terra satellites. Evaluation of the retrieval algorithm over the Mekong Delta shows that it is capable of capturing to a good degree the inundation diurnal variability due to localized convective precipitation. At longer timescales, the results demonstrate consistency with the ground-based water level observations, denoting that the method is properly capturing inundation seasonal patterns in response to regional monsoonal rain. The calculated Euclidean distance, rank-correlation, and also copula quantile analysis demonstrate a good agreement between the outputs of the algorithm and the observed water levels at monthly and daily timescales. The current inundation products are at a resolution of 12.5 km and taken twice per day, but a higher resolution (order of 5 km and every 3 h) can be achieved using the same algorithm with the dictionary populated by the Global Precipitation Mission (GPM) Microwave Imager (GMI) products.
The EUMETSAT sea ice concentration climate data record
NASA Astrophysics Data System (ADS)
Tonboe, Rasmus T.; Eastwood, Steinar; Lavergne, Thomas; Sørensen, Atle M.; Rathmann, Nicholas; Dybkjær, Gorm; Toudal Pedersen, Leif; Høyer, Jacob L.; Kern, Stefan
2016-09-01
An Arctic and Antarctic sea ice area and extent dataset has been generated by EUMETSAT's Ocean and Sea Ice Satellite Application Facility (OSISAF) using the record of microwave radiometer data from NASA's Nimbus 7 Scanning Multichannel Microwave radiometer (SMMR) and the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager and Sounder (SSMIS) satellite sensors. The dataset covers the period from October 1978 to April 2015 and updates and further developments are planned for the next phase of the project. The methodology for computing the sea ice concentration uses (1) numerical weather prediction (NWP) data input to a radiative transfer model for reduction of the impact of weather conditions on the measured brightness temperatures; (2) dynamical algorithm tie points to mitigate trends in residual atmospheric, sea ice, and water emission characteristics and inter-sensor differences/biases; and (3) a hybrid sea ice concentration algorithm using the Bristol algorithm over ice and the Bootstrap algorithm in frequency mode over open water. A new sea ice concentration uncertainty algorithm has been developed to estimate the spatial and temporal variability in sea ice concentration retrieval accuracy. A comparison to US National Ice Center sea ice charts from the Arctic and the Antarctic shows that ice concentrations are higher in the ice charts than estimated from the radiometer data at intermediate sea ice concentrations between open water and 100 % ice. The sea ice concentration climate data record is available for download at www.osi-saf.org, including documentation.
Brock, Nelson L; Menke, Markus; Klapschinski, Tim A; Dickschat, Jeroen S
2014-07-07
Dimethylsulfoniopropionate (DMSP) is a versatile sulfur source for the production of sulfur-containing secondary metabolites by marine bacteria from the Roseobacter clade. (34)S-labelled DMSP and cysteine, and several DMSP derivatives with modified S-alkyl groups were synthesised and used in feeding experiments that gave insights into the biosynthesis of sulfur volatiles from these bacteria.
A bacterial pathogen uses dimethylsulfoniopropionate as a cue to target heat-stressed corals.
Garren, Melissa; Son, Kwangmin; Raina, Jean-Baptiste; Rusconi, Roberto; Menolascina, Filippo; Shapiro, Orr H; Tout, Jessica; Bourne, David G; Seymour, Justin R; Stocker, Roman
2014-05-01
Diseases are an emerging threat to ocean ecosystems. Coral reefs, in particular, are experiencing a worldwide decline because of disease and bleaching, which have been exacerbated by rising seawater temperatures. Yet, the ecological mechanisms behind most coral diseases remain unidentified. Here, we demonstrate that a coral pathogen, Vibrio coralliilyticus, uses chemotaxis and chemokinesis to target the mucus of its coral host, Pocillopora damicornis. A primary driver of this response is the host metabolite dimethylsulfoniopropionate (DMSP), a key element in the global sulfur cycle and a potent foraging cue throughout the marine food web. Coral mucus is rich in DMSP, and we found that DMSP alone elicits chemotactic responses of comparable intensity to whole mucus. Furthermore, in heat-stressed coral fragments, DMSP concentrations increased fivefold and the pathogen's chemotactic response was correspondingly enhanced. Intriguingly, despite being a rich source of carbon and sulfur, DMSP is not metabolized by the pathogen, suggesting that it is used purely as an infochemical for host location. These results reveal a new role for DMSP in coral disease, demonstrate the importance of chemical signaling and swimming behavior in the recruitment of pathogens to corals and highlight the impact of increased seawater temperatures on disease pathways.
Kageyama, Hakuto; Tanaka, Yoshito; Shibata, Ayumi; Waditee-Sirisattha, Rungaroon; Takabe, Teruhiro
2018-05-01
Dimethylsulfoniopropionate (DMSP) is one of the most abundant molecules on earth and plays a pivotal role in the marine sulfur cycle. DMSP is believed to be synthesized from methionine by a four-step reaction pathway in marine algae. The genes responsible for biosynthesis of DMSP remain unidentified. A diatom Thalassiosira pseudonana CCMP1335 is an important component of marine ecosystems and contributes greatly to the world's primary production. In this study, through genome search, in vivo activity and functional studies of cDNA products, a gene encoding Thalassiosira methyltransferase (TpMMT) which catalyzes the key step of DMSP synthesis formation of 4-methylthio-2-hydroxybutyrate (DMSHB) from 4-methylthio-2-oxobutyrate (MTHB), was identified. The amino acid sequence of TpMMT was homologous to the methyltransferase from Phaeodactylum tricornutum CCAP 1055/1, but not the recently identified bacterium gene. High salinity and nitrogen limitation stresses caused the increase of DMSP content and TpMMT protein in Thalassiosira. In addition to TpMMT, the enzyme activities for the first three steps could be detected and enhanced under high salinity, suggesting the importance of four-step DMSP synthetic pathway in Thalassiosira. Copyright © 2018 Elsevier Inc. All rights reserved.
Speeckaert, Gaëlle; Borges, Alberto V; Champenois, Willy; Royer, Colin; Gypens, Nathalie
2018-05-01
The influence of abiotic and biotic variables on the concentration of dimethyl sulfide (DMS), dimethylsulfoniopropionate (DMSP), and dimethylsulfoxide (DMSO), were investigated during an annual cycle in 2016 in the Belgian Coastal Zone (BCZ, North Sea). We reported strong seasonal variations in the concentration of these compounds linked to the phytoplankton succession with high DMS(P,O) producers (mainly Phaeocystis globosa) occurring in spring and low DMS(P,O) producers (various diatoms species) occurring in early spring and autumn. Spatial gradients of DMS and DMSP were related to those of phytoplankton biomass itself related to the inputs of nutrients from the Scheldt estuary. However, the use of a relationship with Chlorophyll-a (Chl-a) concentration is not sufficient to predict DMSP. Accounting for the phytoplankton composition, two different DMSP versus Chl-a correlations could be established, one for diatoms and another one for Phaeocystis colonies. We also reported high nearshore DMSO concentrations uncoupled to Chl-a and DMSP concentrations but linked to high suspended particulate matter (SPM) presumably coming from the Scheldt estuary as indicated by the positive relationship between annual average SPM and salinity. Copyright © 2017 Elsevier B.V. All rights reserved.
New Developments in NOAA's Comprehensive Large Array-Data Stewardship System
NASA Astrophysics Data System (ADS)
Ritchey, N. A.; Morris, J. S.; Carter, D. J.
2012-12-01
The Comprehensive Large Array-data Stewardship System (CLASS) is part of the NOAA strategic goal of Climate Adaptation and Mitigation that gives focus to the building and sustaining of key observational assets and data archives critical to maintaining the global climate record. Since 2002, CLASS has been NOAA's enterprise solution for ingesting, storing and providing access to a host of near real-time remote sensing streams such as the Polar and Geostationary Operational Environmental Satellites (POES and GOES) and the Defense Meteorological Satellite Program (DMSP). Since October, 2011 CLASS has also been the dedicated Archive Data Segment (ADS) of the Suomi National Polar-orbiting Partnership (S-NPP). As the ADS, CLASS receives raw and processed S-NPP records for archival and distribution to the broad user community. Moving beyond just remote sensing and model data, NOAA has endorsed a plan to migrate all archive holdings from NOAA's National Data Centers into CLASS while retiring various disparate legacy data storage systems residing at the National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC) and the National Oceanographic Data Center (NODC). In parallel to this data migration, CLASS is evolving to a service-oriented architecture utilizing cloud technologies for dissemination in addition to clearly defined interfaces that allow better collaboration with partners. This evolution will require implementation of standard access protocols and metadata which will lead to cost effective data and information preservation.
NASA Technical Reports Server (NTRS)
Foster, James
2009-01-01
Seasonal snow cover in extra-tropical areas of South America was examined in this study using passive microwave satellite data from the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7 satellite and from the Special Sensor Microwave Imagers (SSM/I) on board the Defense Meteorological Satellite Program (DMSP) satellites. For the period from 1979-2006, both snow cover extent and snow mass were estimated for the months of May-September. Most of the seasonal snow in South America occurs in the Patagonia region of Argentina. The average snow cover extent for July, the month with the greatest average extent during the 28-year period of record, is 321,674 sq km. The seasonal (May-September) 2 average snow cover extent was greatest in 1984 (464,250 sq km) and least in 1990 (69,875 sq km). In terms of snow mass, 1984 was also the biggest year (1.19 x 10(exp 13) kg) and 1990 was the smallest year (0.12 X 10(exp 13) kg). A strong relationship exists between the snow cover area and snow mass, correlated at 0.95, though no significant trend was found over the 28 year record for either snow cover extent or snow mass. For this long term climatology, snow mass and snow cover extent are shown to vary considerably from month to month and season to season. This analysis presents a consistent approach to mapping and measuring snow in South America utilizing an appropriate and readily available long term snow satellite dataset. This is the optimal dataset available, thus far, for deriving seasonal snow cover and snow mass in this region. Nonetheless, shallow snow, wet snow, snow beneath forests, as well as snow along coastal areas all may confound interpretation using passive microwave approaches. More work needs to be done to reduce the uncertainties in the data and hence, increase the confidence of the interpretation
NASA Astrophysics Data System (ADS)
Bazzano, Magalí; Elmer, Wade
2017-11-01
Sudden Vegetation Dieback (SVD) has been associated with multiple factors affecting the health of Spartina alterniflora. These include altered nutrition (N, Si and various metals), herbivory from the purple marsh crab, and the association with a fungal pathogen (Fusarium palustre). A metabolite produced by Spartina alterniflora that has been associated with plant health is dimethylsulfoniopropionate (DMSP), but little information exist on how these biotic stressors and nutrition interact to affect DMSP levels. Understanding how these factors might be interrelated might provide insight into the etiology of SVD. Surveys of a marsh affected by SVD confirmed lower levels of DMSP and higher concentrations of Si and other metals were present in Sp. alterniflora when compared to plants from marsh that exhibited no signs of SVD. In repeated greenhouse experiments, the application of Si to Sp. alterniflora had no effect on DMSP concentrations. However, when plants were inoculated with the pathogenic fungus, Fusarium palustre, and then treated with Si, DMSP levels were elevated 27%. Inoculation alone had no effect on DMSP levels. Si application neither favor growth nor suppress the stunting effect of disease by F. palustre. Furthermore, grazing by Sesarma reticulatum, a herbivorous crab, was not affected by Si nutrition. Grazing was increased by nitrogen fertilization and inoculation with F. palustre. Deciphering the role of Si nutrition in Sp. alterniflora and dieback remains unresolved, but no evidence suggests enhancing Si nutrition would directly favor marsh health.
The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Status
NASA Technical Reports Server (NTRS)
Hou, Arthur Y.; Azarbarzin, Ardeshir A.; Kakar, Ramesh K.; Neeck, Steven
2011-01-01
The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. The cornerstone of the GPM mission is the deployment of a Core Observatory in a 65 deg non-Sun-synchronous orbit to serve as a physics observatory and a transfer standard for inter-calibration of constellation radiometers. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The first space-borne dual-frequency radar will provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles needed for improving precipitation retrievals from passive microwave sensors. The combined use of DPR and GMI measurements will place greater constraints on radiometer retrievals to improve the accuracy and consistency of precipitation estimates from all constellation radiometers. The GPM constellation is envisioned to comprise five or more conical-scanning microwave radiometers and four or more cross-track microwave sounders on operational satellites. NASA and the Japan Aerospace Exploration Agency (JAXA) plan to launch the GPM Core in July 2013. NASA will provide a second radiometer to be flown on a partner-provided GPM Low-Inclination Observatory (L10) to improve near real-time monitoring of hurricanes and mid-latitude storms. NASA and the Brazilian Space Program (AEB/IPNE) are currently engaged in a one-year study on potential L10 partnership. JAXA will contribute to GPM data from the Global Change Observation Mission-Water (GCOM-W) satellite. Additional partnerships are under development to include microwave radiometers on the French-Indian Megha-Tropiques satellite and U.S. Defense Meteorological Satellite Program (DMSP) satellites, as well as cross-track scanning humidity sounders on operational satellites such as the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), POES, the NASA/NOAA Joint Polar Satellite System (JPSS), and EUMETSAT MetOp satellites. Data from Chinese and Russian microwave radiometers may also become available through international collaboration under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). The current generation of global rainfall products combines observations from a network of uncoordinated satellite missions using a variety of merging techniques. Relative to current data products, GPM's "nextgeneration" precipitation products will be characterized by: (1) more accurate instantaneous precipitation estimate (especially for light rain and cold-season solid precipitation), (2) more frequent sampling by an expanded constellation of microwave radiometers including operational humidity sounders over land, (3) intercalibrated microwave brightness temperatures from constellation radiometers within a unified framework, and (4) physical-based precipitation retrievals from constellation radiometers using a common a priori hydrometeor database constrained by combined radar/radiometer measurements provided by the GPM Core Observatory. An overview of the GPM mission concept, the U.S. GPM program status and updates on international science collaborations on GPM will be presented.
NASA Astrophysics Data System (ADS)
Lizotte, Martine; Levasseur, Maurice; Law, Cliff S.; Walker, Carolyn F.; Safi, Karl A.; Marriner, Andrew; Kiene, Ronald P.
2017-11-01
The oceanic frontal region above the Chatham Rise east of New Zealand was investigated during the late austral summer season in February and March 2012. Despite its potential importance as a source of marine-originating and climate-relevant compounds, such as dimethyl sulfide (DMS) and its algal precursor dimethylsulfoniopropionate (DMSP), little is known of the processes fuelling the reservoirs of these sulfur (S) compounds in the water masses bordering the subtropical front (STF). This study focused on two opposing short-term fates of DMSP-S following its uptake by microbial organisms (either its conversion into DMS or its assimilation into bacterial biomass) and has not considered dissolved non-volatile degradation products. Sampling took place in three phytoplankton blooms (B1, B2, and B3) with B1 and B3 occurring in relatively nitrate-rich, dinoflagellate-dominated subantarctic waters, and B2 occurring in nitrate-poor subtropical waters dominated by coccolithophores. Concentrations of total DMSP (DMSPt) and DMS were high across the region, up to 160 and 14.5 nmol L-1, respectively. Pools of DMSPt showed a strong association with overall phytoplankton biomass proxied by chlorophyll a (rs = 0.83) likely because of the persistent dominance of dinoflagellates and coccolithophores, both DMSP-rich taxa. Heterotrophic microbes displayed low S assimilation from DMSP (less than 5 %) likely because their S requirements were fulfilled by high DMSP availability. Rates of bacterial protein synthesis were significantly correlated with concentrations of dissolved DMSP (DMSPd, rs = 0.86) as well as with the microbial conversion efficiency of DMSPd into DMS (DMS yield, rs = 0.84). Estimates of the potential contribution of microbially mediated rates of DMS production (0.1-27 nmol L-1 day-1) to the near-surface concentrations of DMS suggest that bacteria alone could not have sustained DMS pools at most stations, indicating an important role for phytoplankton-mediated DMS production. The findings from this study provide crucial information on the distribution and cycling of DMS and DMSP in a critically under-sampled area of the global ocean, and they highlight the importance of oceanic fronts as hotspots of the production of marine biogenic S compounds.
NASA Astrophysics Data System (ADS)
Steinke, M.; Malin, G.; Turner, S. M.; Liss, P. S.
2000-08-01
The osmolyte dimethylsulphoniopropionate (DMSP) can be enzymatically cleaved to dimethylsulphide (DMS), acrylate and a proton. The enzyme involved in this reaction is dimethylpropiothetin dethiomethylase (DMSP lyase; enzyme classification number 4.4.1.3.). Although the importance of this reaction for the global sulphur cycle, the influence of DMS on atmospheric acidity and the possible effect on climate regulation have been widely recognised, our knowledge of DMSP lyases is limited to just a few studies. Activity measurements of DMSP lyases offer an important step towards a better understanding of the conditions under which DMS is produced. In the available published data somewhat similar methods have been used before, but a critical examination of the method limitations has not been reported. To encourage further research on this enzyme, we suggest and detail two protocols for measurements of DMSP lyase activity: An in vitro assay for crude cell extracts or purified enzyme and an in vivo method for whole cells, which we recently started to use. After addition of DMSP, samples incubated in a gas tight vial may produce DMS from enzymatic cleavage under suitable conditions, and a DMS production rate can be estimated from time-series measurements of DMS in the headspace of the vial. Headspace analysis of DMS is a useful and rapid technique to estimate and compare DMSP lyase activities from different sources. The relative rates of DMS production in the liquid and of the gas transfer between liquid and headspace, determine the rate of DMS production measured via headspace analysis. If DMS production in the liquid is higher than the rate of transfer, headspace measurements will not reflect the actual amount of DMS produced in the liquid. In this case, extracts have to be diluted to a level that ensures linearity between dilution factor and reduction of enzyme activity. Additionally, incubation volumes and vials should be selected to provide a high surface-to-volume ratio to ensure maximum flux of DMS from the aqueous phase into the headspace. The methods can be adapted to further investigate species- and strain-specific activities, biogeographical distribution, cellular location and biochemical properties of various DMSP lyases.
120. INERTIAL MEASUREMENT UNIT (IMU) NITROGEN PURGE REGULATOR PANEL FOR ...
120. INERTIAL MEASUREMENT UNIT (IMU) NITROGEN PURGE REGULATOR PANEL FOR DEFENSE METEOROLOGICAL SYSTEM PROGRAM (DMSP) PAYLOADS IN SOUTHWEST CORNER OF VEHICLE MECHANICAL SYSTEMS ROOM (111), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA
Atmospheric effects on SMMR and SSM/I 37 GHz polarization difference over the Sahel
NASA Technical Reports Server (NTRS)
Choudhury, B. J.; Major, E. R.; Smith, E. A.; Becker, F.
1992-01-01
The atmospheric effects on the difference of vertically and horizontally polarized brightness temperatures, Delta(T) observed at 37 GHz frequency of the SMMR on board the Nimbus-7 satellite and SSM/I on board the DMSP-F8 satellite are studied over two 2.5 by 2.5 deg regions within the Sahel and Sudan zones of Africa from January 1985 to December 1986 through radiative transfer analysis using surface temperature, atmospheric water vapor, and cloud optical thickness. It is found that atmospheric effects alone cannot explain the observed temporal variation of Delta(T), although the atmosphere introduces important modulations on the observed seasonal variations of Delta(T) due to rather significant seasonal variation of precipitable water vapor. These Delta(T) data should be corrected for atmospheric effects before any quantitative analysis of land surface change over the Sahel and Sudan zones.
Evaluation of Trapped Radiation Model Uncertainties for Spacecraft Design
NASA Technical Reports Server (NTRS)
Armstrong, T. W.; Colborn, B. L.
2000-01-01
The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties. Model comparisons are made with flux, dose, and activation measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP, LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Cosmos-1887, Cosmos-2044), and on the Russian Mir Space Station. This report gives a summary of the model-data comparisons-detailed results are given in a companion report. Results from the model comparisons with flic,ht data show, for example, the AP8 model underpredicts the trapped proton flux at low altitudes by a factor of about two (independent of proton energy and solar cycle conditions), and that the AE8 model overpredicts the flux in the outer electron belt by an order of magnitude or more.
Evaluation of Trapped Radiation Model Uncertainties for Spacecraft Design
NASA Technical Reports Server (NTRS)
Armstrong, T. W.; Colborn, B. L.
2000-01-01
The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties. Model comparisons are made with flux, dose, and activation measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP. LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Cosmos-1887, Cosmos-2044), and on the Russian Mir space station. This report gives a summary of the model-data given in a companion report. Results from the model comparisons with flight data show, for example, that the AP8 model underpredicts the trapped proton flux at low altitudes by a factor of about two (independent of proton energy and solar cycle conditions), and that the AE8 model overpredict the flux in the outer electron belt be an order of magnitude or more.
NASA Astrophysics Data System (ADS)
Antonova, E. E.; Vorobjev, V. G.; Kirpichev, I. P.; Yagodkina, O. I.
2014-05-01
The distribution of plasma pressure over the equatorial plane is compared with the plasma pressure and the position of the electron precipitation boundaries at low altitudes under the conditions of low geomagnetic activity. The pressure at the equatorial plane is determined using data of the THEMIS international five-satellite mission; the pressure at low altitudes, using data of the DMSP satellites. Plasma pressure isotropy and the validity of the condition of the magnetostatic equilibrium at a low level of geomagnetic activity are taken into account. Plasma pressure in such a case is constant along the magnetic field line and can be considered a "natural tracer" of the field line. It is shown that the plasma ring surrounding the Earth at geocentric distances of ˜6 to ˜10-12 R E is the main source of the precipitations in the auroral oval.
Multisensor satellite data integration for sea surface wind speed and direction determination
NASA Technical Reports Server (NTRS)
Glackin, D. L.; Pihos, G. G.; Wheelock, S. L.
1984-01-01
Techniques to integrate meteorological data from various satellite sensors to yield a global measure of sea surface wind speed and direction for input to the Navy's operational weather forecast models were investigated. The sensors were launched or will be launched, specifically the GOES visible and infrared imaging sensor, the Nimbus-7 SMMR, and the DMSP SSM/I instrument. An algorithm for the extrapolation to the sea surface of wind directions as derived from successive GOES cloud images was developed. This wind veering algorithm is relatively simple, accounts for the major physical variables, and seems to represent the best solution that can be found with existing data. An algorithm for the interpolation of the scattered observed data to a common geographical grid was implemented. The algorithm is based on a combination of inverse distance weighting and trend surface fitting, and is suited to combing wind data from disparate sources.
Evolution of Ionospheric Convection during a Double Transpolar Arc Phenomenon on February 11, 1999
NASA Technical Reports Server (NTRS)
Narita, Y.; Maezawa, K.; Spann, J. F.; Parks, G. K.; Marklund, G. T.; Kullen, A.; Ivchenko, N.; Greenwald, R. A.; Sato, N.; Yamagishi, H.;
2002-01-01
An evolution of ionospheric convection was studied for a double transpolar arc phenomenon on February 11, 1999. While one transpolar arc split from the auroral oval in the morning sector and drifted duskward, another arc appeared in the evening sector. The convection was investigated with three velocity data sets: E B drift velocities from the ASTRID-2 satellite; Ion Driftmeter data from the DMSP satellites; and Doppler-shift data from the Super-DARN radars. We inferred convection cells from these data sets and found that the number of convection cells changed from three to four as the dominance of IMF changed from a negative By to a positive Bz. Our result suggests that the ionospheric convection that has been so far discussed for various conditions of IMF may be applied even to the cases accompanied by transpolar arcs.
NASA Astrophysics Data System (ADS)
Collins Petersen, Carolyn; Erickson, P. J.; Needles, M.
2009-01-01
The topic of space weather is the subject of a series of vodcasts (video podcasts) produced by MIT Haystack Observatory (Westford, MA) and Loch Ness Productions (Groton, MA). This paper discusses the production and distribution of the series via Webcast, Youtube, and other avenues. It also presents preliminary evaluation of the effectiveness and outreach of the project through feedback from both formal and information education venues. The vodcast series is linked to the NASA Living With a Star Targeted Research and Technology project award "Multi-Instrument Investigation of Inner-Magnetospheric/Ionosphere Disturbances.” It is being carried out by Principal Investigator Dr. John Foster, under the auspices of NASA Grant # NNX06AB86G. The research involves using ionospheric total electron content (TEC) observations to study the location, extent, and duration of perturbations within stormtime ionospheric electric fields at mid- to low latitudes. It combines ground-based global positioning system (GPS) TEC data, incoherent scatter radar measurements of the mid-latitude ionospheric state, and DMSP satellite observations to characterize conditions which lead to severe low-latitude ionospheric perturbations. Each vodcast episode covers a certain aspect of space weather and the research program.
NASA Astrophysics Data System (ADS)
Zhang, Y. Z.; Wang, P.; Chen, X. L.; Li, C. Y.; Gao, X.; Zhu, D.; Xie, B. B.; Qin, Q. L.; Zhang, X. Y.; Su, H. N.; Zhou, B. C.; Xun, L.
2015-12-01
The microbial cleavage of dimethylsulfoniopropionate (DMSP) generates volatile dimethyl sulfide (DMS) and is an important step in global sulfur and carbon cycles. DddP is a DMSP lyase in marine bacteria and the deduced dddP gene product is abundant in marine metagenomic data sets. However, DddP belongs to the M24 peptidase family according to sequence alignment. Peptidases hydrolyze C-N bonds but DddP is deduced to cleave C-S bonds. Mechanisms responsible for this striking functional shift are currently unknown. We determined the structures of DMSP lyase RlDddP (the DddP from Ruegeria lacuscaerulensis ITI_1157) bound to inhibitory 2-(N-morpholino) ethanesulfonic acid or PO43- and of two mutants of RlDddP bound to acrylate. Based on structural, mutational and biochemical analyses, we characterized a new ion-shift catalytic mechanism of RlDddP for DMSP cleavage. Further, we suggested the structural mechanism leading to the loss of peptidase activity and the subsequent development of DMSP lyase activity in DddP. This study sheds light on the catalytic mechanism and the divergent evolution of DddP, leading to a better understanding of marine bacterial DMSP catabolism and global DMS production.
Kessler, Ralf W; Weiss, Anne; Kuegler, Stefan; Hermes, Cornelia; Wichard, Thomas
2018-04-01
The marine macroalga Ulva mutabilis (Chlorophyta) develops into callus-like colonies consisting of undifferentiated cells and abnormal cell walls under axenic conditions. Ulva mutabilis is routinely cultured with two bacteria, the Roseovarius sp. MS2 strain and the Maribacter sp. MS6 strain, which release morphogenetic compounds and ensure proper algal morphogenesis. Using this tripartite community as an emerging model system, we tested the hypothesis that the bacterial-algal interactions evolved as a result of mutually taking advantage of signals in the environment. Our study aimed to determine whether cross-kingdom crosstalk is mediated by the attraction of bacteria through algal chemotactic signals. Roseovarius sp. MS2 senses the known osmolyte dimethylsulfoniopropionate (DMSP) released by Ulva into the growth medium. Roseovarius sp. is attracted by DMSP and takes it up rapidly such that DMSP can only be determined in axenic growth media. As DMSP did not promote bacterial growth under the tested conditions, Roseovarius benefited solely from glycerol as the carbon source provided by Ulva. Roseovarius quickly catabolized DMSP into methanethiol (MeSH) and dimethylsulphide (DMS). We conclude that many bacteria can use DMSP as a reliable signal indicating a food source and promote the subsequent development and morphogenesis in Ulva. © 2017 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Wu, Xi; Li, Pei-Feng; Liu, Chun-Ying; Zhang, Hong-Hai; Yang, Gui-Peng; Zhang, Sheng-Hui; Zhu, Mao-Xu
2017-12-01
The distributions of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), and acrylic acid (AA) were investigated in the Changjiang Estuary during winter (dry season) and summer (wet season) 2014 and in the East China Sea (ECS) during summer 2015. The rates of dissolved DMSP (DMSPd) degradation with DMS and AA production, DMS degradation, and AA degradation in the ECS were also studied. Significant seasonal variations in DMS(P) and AA concentrations were observed in the Changjiang Estuary with higher values during the wet season than during the dry season. The maximum ratio of AA/chlorophyll a (Chl a) occurred at the mouth of the Changjiang Estuary due to the combined effects of production from DMSP and terrestrial inputs from the Changjiang Estuary. The distributions of DMS(P) and AA in the ECS were dramatically influenced by the Kuroshio Current and the upwelling caused by the Taiwan Warm Current. The ratios of DMS(P)/Chl a and AA/Chl a exhibited similar patterns in the surface seawater of the ECS, which indicated that phytoplankton species and biomass might play important roles in controlling the distributions of DMS(P) and AA. In vertical profiles, high values of AA emerged in the upper water column and bottom seawater of the Changjiang Estuary. Meanwhile, the maxima of DMS(P) and AA generally appeared in the surface or euphotic layer, whereas their minima arose in the bottom seawater of the ECS. The degradation rates of DMSPd, DMS, and AA in the inshore waters were higher than those in the open sea.
Ruiz-González, Clara; Simó, Rafel; Vila-Costa, Maria; Sommaruga, Ruben; Gasol, Josep M
2012-01-01
There is a large body of evidence supporting a major role of heterotrophic bacteria in dimethylsulphoniopropionate (DMSP) utilisation as a source of reduced sulphur. However, a role for phototrophic microorganisms has been only recently described and little is known about their contribution to DMSP consumption and the potential modulating effects of sunlight. In an attempt to ascertain the relative quantitative roles of heterotrophic bacteria and picophytoplankton in the osmoheterotrophic uptake of DMSP-sulphur upon exposure to natural sunlight conditions, we incubated northwestern Mediterranean waters under various optical filters and used an array of bulk and single-cell activity methods to trace the fate of added 35S-DMSP. Flow cytometry cell sorting confirmed dark 35S uptake by Prochlorococcus, Synechococcus and heterotrophic bacteria, the latter being the most efficient in terms of uptake on a cell volume basis. Under exposure to full sunlight, however, the relative contribution of Synechococcus was significantly enhanced, mainly because of the inhibition of heterotrophic bacteria. Microautoradiography showed a strong increase in the proportion of Synechococcus cells actively taking up 35S-DMSP, which, after full sunlight exposure, made up to 15% of total active Bacteria. Parallel incubations with 3H-leucine generally showed no clear responses to light. Finally, size-fractionated assimilation experiments showed greater relative cyanobacterial assimilation during the day than at night compared with that of heterotrophic bacteria. Our results show for the first time a major influence of sunlight in regulating the competition among autotrophic and heterotrophic picoplankton for DMSP uptake at both the daily and seasonal time scales. PMID:21955992
A meta-analysis of oceanic DMS and DMSP cycling processes: Disentangling the summer paradox
NASA Astrophysics Data System (ADS)
Galí, Martí; Simó, Rafel
2015-04-01
The biogenic volatile compound dimethylsulfide (DMS) is produced in the ocean mainly from the ubiquitous phytoplankton osmolyte dimethylsulfoniopropionate (DMSP). In the upper mixed layer, DMS concentration and the daily averaged solar irradiance are roughly proportional across latitudes and seasons. This translates into a seasonal mismatch between DMS and phytoplankton biomass at low latitudes, termed the "DMS summer paradox," which remains difficult to reproduce with biogeochemical models. Here we report on a global meta-analysis of DMSP and DMS cycling processes and their relationship to environmental factors. We show that DMS seasonality reflects progressive changes in a short-term dynamic equilibrium, set by the quotient between gross DMS production rates and the sum of biotic and abiotic DMS consumption rate constants. Gross DMS production is the principal driver of DMS seasonality, due to the synergistic increases toward summer in two of its underlying factors: phytoplankton DMSP content (linked to species succession) and short-term community DMSP-to-DMS conversion yields (linked to physiological stress). We also show that particulate DMSP transformations (linked to grazing-induced phytoplankton mortality) generally contribute a larger share of gross DMS production than dissolved-phase DMSP metabolism. The summer paradox is amplified by a decrease in microbial DMS consumption rate constants toward summer. However, this effect is partially compensated by a concomitant increase in abiotic DMS loss rate constants. Besides seasonality, we identify consistent covariation between key sulfur cycling variables and trophic status. These findings should improve the modeling projections of the main natural source of climatically active atmospheric sulfur.
Borell, Esther M; Steinke, Michael; Horwitz, Rael; Fine, Maoz
2014-01-01
Marine anthozoans maintain a mutualistic symbiosis with dinoflagellates that are prolific producers of the algal secondary metabolite dimethylsulfoniopropionate (DMSP), the precursor of the climate-cooling trace gas dimethyl sulfide (DMS). Surprisingly, little is known about the physiological role of DMSP in anthozoans and the environmental factors that regulate its production. Here, we assessed the potential functional role of DMSP as an antioxidant and determined how future increases in seawater pCO2 may affect DMSP concentrations in the anemone Anemonia viridis along a natural pCO2 gradient at the island of Vulcano, Italy. There was no significant difference in zooxanthellae genotype and characteristics (density of zooxanthellae, and chlorophyll a) as well as protein concentrations between anemones from three stations along the gradient, V1 (3232 μatm CO2), V2 (682 μatm) and control (463 μatm), which indicated that A. viridis can acclimate to various seawater pCO2. In contrast, DMSP concentrations in anemones from stations V1 (33.23 ± 8.30 fmol cell−1) and V2 (34.78 ± 8.69 fmol cell−1) were about 35% lower than concentrations in tentacles from the control station (51.85 ± 12.96 fmol cell−1). Furthermore, low tissue concentrations of DMSP coincided with low activities of the antioxidant enzyme superoxide dismutase (SOD). Superoxide dismutase activity for both host (7.84 ± 1.37 U·mg−1 protein) and zooxanthellae (2.84 ± 0.41 U·mg−1 protein) at V1 was 40% lower than at the control station (host: 13.19 ± 1.42; zooxanthellae: 4.72 ± 0.57 U·mg−1 protein). Our results provide insight into coastal DMSP production under predicted environmental change and support the function of DMSP as an antioxidant in symbiotic anthozoans. PMID:24634728
Borell, Esther M; Steinke, Michael; Horwitz, Rael; Fine, Maoz
2014-02-01
Marine anthozoans maintain a mutualistic symbiosis with dinoflagellates that are prolific producers of the algal secondary metabolite dimethylsulfoniopropionate (DMSP), the precursor of the climate-cooling trace gas dimethyl sulfide (DMS). Surprisingly, little is known about the physiological role of DMSP in anthozoans and the environmental factors that regulate its production. Here, we assessed the potential functional role of DMSP as an antioxidant and determined how future increases in seawater pCO2 may affect DMSP concentrations in the anemone Anemonia viridis along a natural pCO2 gradient at the island of Vulcano, Italy. There was no significant difference in zooxanthellae genotype and characteristics (density of zooxanthellae, and chlorophyll a) as well as protein concentrations between anemones from three stations along the gradient, V1 (3232 μatm CO2), V2 (682 μatm) and control (463 μatm), which indicated that A. viridis can acclimate to various seawater pCO2. In contrast, DMSP concentrations in anemones from stations V1 (33.23 ± 8.30 fmol cell(-1)) and V2 (34.78 ± 8.69 fmol cell(-1)) were about 35% lower than concentrations in tentacles from the control station (51.85 ± 12.96 fmol cell(-1)). Furthermore, low tissue concentrations of DMSP coincided with low activities of the antioxidant enzyme superoxide dismutase (SOD). Superoxide dismutase activity for both host (7.84 ± 1.37 U·mg(-1) protein) and zooxanthellae (2.84 ± 0.41 U·mg(-1) protein) at V1 was 40% lower than at the control station (host: 13.19 ± 1.42; zooxanthellae: 4.72 ± 0.57 U·mg(-1) protein). Our results provide insight into coastal DMSP production under predicted environmental change and support the function of DMSP as an antioxidant in symbiotic anthozoans.
Satellite Observation Systems for Polar Climate Change Studies
NASA Technical Reports Server (NTRS)
Comiso, Josefino C.
2012-01-01
The key observational tools for detecting large scale changes of various parameters in the polar regions have been satellite sensors. The sensors include passive and active satellite systems in the visible, infrared and microwave frequencies. The monitoring started with Tiros and Nimbus research satellites series in the 1970s but during the period, not much data was stored digitally because of limitations and cost of the needed storage systems. Continuous global data came about starting with the launch of ocean color, passive microwave, and thermal infrared sensors on board Nimbus-7 and Synthetic Aperture Radar, Radar Altimeter and Scatterometer on board SeaSat satellite both launched in 1978. The Nimbus-7 lasted longer than expected and provided about 9 years of useful data while SeaSat quit working after 3 months but provided very useful data that became the baseline for follow-up systems with similar capabilities. Over the years, many new sensors were launched, some from Japan Aeronautics and Space Agency (JAXA), some from the European Space Agency (ESA) and more recently, from RuSSia, China, Korea, Canada and India. For polar studies, among the most useful sensors has been the passive microwave sensor which provides day/night and almost all weather observation of the surface. The sensor provide sea surface temperature, precipitation, wind, water vapor and sea ice concentration data that have been very useful in monitoring the climate of the region. More than 30 years of such data are now available, starting with the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7, the Special Scanning Microwave/Imager (SSM/I) on board a Defense Meteorological Satellite Program (DMSP) and the Advanced Microwave Scanning Radiometer on board the EOS/ Aqua satellite. The techniques that have been developed to derive geophysical parameters from data provided by these and other sensors and associated instrumental and algorithm errors and validation techniques will be discussed. An important issue is the organization and storage of hundreds of terabytes of data collected by even just a few of these satellite sensors. Advances in mass storage and computer technology have made it possible to overcome many of the collection and archival problems and the availability of comprehensive satellite data sets put together by NASA's Earth Observing System project will be discussed.
Arctic Sea ice studies with passive microwave satellite observations
NASA Technical Reports Server (NTRS)
Cavalieri, D. J.
1988-01-01
The objectives of this research are: (1) to improve sea ice concentration determinations from passive microwave space observations; (2) to study the role of Arctic polynyas in the production of sea ice and the associated salinization of Arctic shelf water; and (3) to study large scale sea ice variability in the polar oceans. The strategy is to analyze existing data sets and data acquired from both the DMSP SSM/I and recently completed aircraft underflights. Special attention will be given the high resolution 85.5 GHz SSM/I channels for application to thin ice algorithms and processes studies. Analysis of aircraft and satellite data sets is expected to provide a basis for determining the potential of the SSM/I high frequency channels for improving sea ice algorithms and for investigating oceanic processes. Improved sea ice algorithms will aid the study of Arctic coastal polynyas which in turn will provide a better understanding of the role of these polynyas in maintaining the Arctic watermass structure. Analysis of satellite and archived meteorological data sets will provide improved estimates of annual, seasonal and shorter-term sea ice variability.
Grazing-Activated Production of Dimethyl Sulfide (DMS) by two clones of Emiliania huxleyi
NASA Technical Reports Server (NTRS)
Wolfe, Gordon V.; Steinke, Michael
1996-01-01
Emiliania huxleyi clones CCMP 370 and CCMP 373 produced similar amounts of dimethylsulfoniopropionate (DMSP) during axenic exponential growth, averaging 109 mM internal DMSP. Both clones had detectable DMSP lyase activity, as measured by production of dimethyl sulfide (DMS) during in vitro assays of crude cell preparations, but activities and conditions differed considerably between clones. Clone 373 had high activity; clone 370 had low activity and required chloride. For both strains, enzyme activity per cell was constant during exponential growth, but little DMS was produced by healthy cells. Rather, DMS production was activated when cells were subjected to physical or chemical stresses that caused cell lysis. We propose that DMSP lyase and DMSP are segregated within these cells and re-action only under conditions that result in cell stress or damage. Such activation occurs during microzooplankton grazing. When these clones were grazed by the dinoflagellate Oxyrrhis marina, DMS was produced; ungrazed cells, as well as those exposed to grazer exudates and associated bacteria, generated no DMS. Grazing of clone 373 produced much more DMS than grazing of clone 370, consistent with their relative in vitro DMSP lyase activities. DMS was only generated when cells were actually being grazed, indicating that ingested cells were responsible for the DMS formation. We suggest that even low levels of grazing can greatly accelerate DMS production.
High Resolution Monthly Oceanic Rainfall Based on Microwave Brightness Temperature Histograms
NASA Astrophysics Data System (ADS)
Shin, D.; Chiu, L. S.
2005-12-01
A statistical emission-based passive microwave retrieval algorithm has been developed by Wilheit, Chang and Chiu (1991) to estimate space/time oceanic rainfall. The algorithm has been applied to Special Sensor Microwave Imager (SSM/I) data taken on board the Defense Meteorological Satellite Program (DMSP) satellites to provide monthly oceanic rainfall over 2.5ox2.5o and 5ox5o latitude-longitude boxes by the Global Precipitation Climatology Project-Polar Satellite Precipitation Data Center (GPCP-PSPDC, URL: http://gpcp-pspdc.gmu.edu/) as part of NASA's contribution to the GPCP. The algorithm has been modified and applied to the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) data to produce a TRMM Level 3 standard product (3A11) over 5ox5o latitude/longitude boxes. In this study, the algorithm code is modified to retrieve rain rates at 2.5ox2.5o and 1ox1o resolutions for TMI. Two months of TMI data have been tested and the results compared with the monthly mean rain rates derived from TRMM Level 2 TMI rain profile algorithm (2A12) and the original 5ox5o data from 3A11. The rainfall pattern is very similar to the monthly average of 2A12, although the intensity is slightly higher. Details in the rain pattern, such as rain shadow due to island blocking, which were not discernible from the low resolution products, are now easily discernible. The spatial average of the higher resolution rain rates are in general slightly higher than lower resolution rain rates, although a Student-t test shows no significant difference. This high resolution product will be useful for the calibration of IR rain estimates for the production of the GPCP merge rain product.
Extreme Thunderstorms as Seen by Satellite
NASA Technical Reports Server (NTRS)
Cecil, Daniel J.
2014-01-01
Extreme events by their nature fall outside the bounds of routine experience. With imperfect or ambiguous measuring systems, it is appropriate to question whether an unusual measurement represents an extreme event or is the result of instrument errors or other sources of noise. About three weeks after the Tropical Rainfall Measuring Mission (TRMM) satellite began collecting data in Dec 1997, a thunderstorm was observed over northern Argentina with 85 GHz brightness temperatures below 50 K and 37 GHz brightness temperatures below 70 K (Zipser et al. 2006). These values are well below what had previously been observed from satellite sensors with lower resolution. The 37 GHz brightness temperatures are also well below those measured by TRMM for any other storm in the subsequent 16 years. Without corroborating evidence, it would be natural to suspect a problem with the instrument, or perhaps an irregularity with the platform during the first weeks of the satellite mission. But the TRMM satellite also carries a radar and a lightning sensor, both confirming the presence of an intense thunderstorm. The radar recorded 40+ dBZ (decibels relative to Z) reflectivity up to about 19 km altitude. More than 200 lightning flashes per minute were recorded. That same storm's 19 GHz brightness temperatures below 150 K would normally be interpreted as the result of a low-emissivity water surface (e.g., a lake, or flood waters) if not for the simultaneous measurements of such intense convection. This paper will examine records from TRMM and related satellite sensors including SSMI and AMSR-E to find the strongest signatures resulting from thunderstorms, and distinguishing those from sources of noise. The lowest brightness temperatures resulting from thunderstorms as seen by TRMM have been in Argentina in November and December. For SSMI sensors carried on five DMSP satellites examined so far, the lowest thunderstorm-related brightness temperatures have been from Argentina in November - December and from Minnesota in June-July. The Minnesota cases were associated with spotter reports of large hail, significant severe wind, and tornadoes. Those locations have the record holders for each satellite. This paper will show examples of cases with the lowest brightness temperatures, and map the locations of these and other storms with brightness temperatures nearly as low. Higher resolution data from the field program MC3E and possibly from IPHEX will be considered for context.
NASA Astrophysics Data System (ADS)
Forsythe, J. M.; Jones, A. S.; Kidder, S. Q.; Fuell, K.; LeRoy, A.; Bikos, D.; Szoke, E.
2015-12-01
Forecasters have been using the NOAA operational blended total precipitable water (TPW) product, developed by the Cooperative Institute for Research in the Atmosphere (CIRA), since 2009. Blended TPW has a wide variety of uses related to heavy precipitation and flooding, such as measuring the amount of moisture in an atmospheric river originating in the tropics. But blended TPW conveys no information on the vertical distribution of moisture, which is relevant to a variety of forecast concerns. Vertical profile information is particularly lacking over the oceans for landfalling storms. A blended six-satellite, four-layer, layered water vapor product demonstrated by CIRA and the NASA Short-term Prediction Research and Transition Center (SPoRT) in allows forecasters to see the vertical distribution of water vapor in near real-time. National Weather Service (NWS) forecaster feedback indicated that this new, vertically-resolved view of water vapor has a substantial impact on forecasts. This product uses NOAA investments in polar orbiting satellite sounding retrievals from passive microwave radiances, in particular, the Microwave Integrated Retrieval System (MIRS). The product currently utilizes data from the NOAA-18 and -19 spacecraft, Metop-A and -B, and the Defense Meteorological Program (DMSP) F18 spacecraft. The sounding instruments onboard the Suomi-NPP and JPSS spacecraft will be cornerstone instruments in the future evolution of this product. Applications of the product to heavy rain cases will be presented and compared to commonly used data such as radiosondes and Geostationary Operational Environmental Satellite (GOES) water vapor channel imagery. Research is currently beginning to implement advective blending, where model winds are used to move the water vapor profiles to a common time. Interactions with the NOAA Satellite Analysis Branch (SAB), National Center for Environmental Prediction (NCEP) centers including the Ocean Prediction Center (OPC) and Weather Prediction Center (WPC) will be discussed.
AF-GEOSpace Version 2.1 Release
NASA Astrophysics Data System (ADS)
Hilmer, R. V.; Ginet, G. P.; Hall, T.; Holeman, E.; Madden, D.; Perry, K. L.; Tautz, M.; Roth, C.
2006-05-01
AF-GEOSpace Version 2.1 is a graphics-intensive software program with space environment models and applications developed recently by the Space Weather Center of Excellence at AFRL. A review of new and planned AF-GEOSpace capabilities will be given. The software addresses a wide range of physical domains and addresses such topics as solar disturbance propagation, geomagnetic field and radiation belt configurations, auroral particle precipitation, and ionospheric scintillation. Building on the success of previous releases, AF-GEOSpace has become a platform for the rapid prototyping of automated operational and simulation space weather visualization products and helps with a variety of tasks, including: orbit specification for radiation hazard avoidance; satellite design assessment and post-event anomaly analysis; solar disturbance effects forecasting; determination of link outage regions for active ionospheric conditions; satellite magnetic conjugate studies, scientific model validation and comparison, physics research, and education. Previously, Version 2.0 provided a simplified graphical user interface, improved science and application modules, significantly enhanced graphical performance, common input data archive sets, and 1-D, 2-D, and 3- D visualization tools for all models. Dynamic capabilities permit multiple environments to be generated at user- specified time intervals while animation tools enable the display of satellite orbits and environment data together as a function of time. Building on the Version 2.0 software architecture, AF-GEOSpace Version 2.1 includes a host of new modules providing, for example, plasma sheet charged particle fluxes, neutral atmosphere densities, 3-D cosmic ray cutoff maps, low-altitude trapped proton belt flux specification, DMSP particle data displays, satellite magnetic field footprint mapping determination, and meteor sky maps and shower/storm fluxes with spacecraft impact probabilities. AF-GEOSpace Version 2.1 was developed for Windows XP and Linux systems. To receive a copy of the AF-GEOSpace 2.1 software, please submit requests via e-mail to the first author.
NASA Astrophysics Data System (ADS)
Kawakami, Todd Mori
In April of 1995, the launch of the GPS Meteorology Experiment (GPS/MET) onboard the Orbview-1 satellite, formerly known as Microlab-1, provided the first technology demonstration of active limb sounding of the Earth's atmosphere with a low Earth orbiting spacecraft utilizing the signals transmitted by the satellites of the Global Positioning System (GPS). Though the experiment's primary mission was to probe the troposphere and stratosphere, GPS/MET was also capable of making radio occultation observations of the ionosphere. The application of the GPS occultation technique to the upper atmosphere created a unique opportunity to conduct ionospheric research with an unprecedented global distribution of observations. For operational support requirements, the Abel transform could be employed to invert the horizontal TEC profiles computed from the L1 and L2 phase measurements observed by GPS/MET into electron density profiles versus altitude in near real time. The usefulness of the method depends on how effectively the TEC limb profiles can be transformed into vertical electron density profiles. An assessment of GPS/MET's ability to determine electron density profiles needs to be examined to validate the significance of the GPS occultation method as a new and complementary ionospheric research tool to enhance the observational databases and improve space weather modeling and forecasting. To that end, simulations of the occultation observations and their inversions have been conducted to test the Abel transform algorithm and to provide qualitative information about the type and range of errors that might be experienced during the processing of real data. Comparisons of the electron density profiles inferred from real GPS/MET observations are then compared with coincident in situ measurements from the satellites of Defense Meteorological Satellite Program (DMSP) and ground-based remote sensing from digisonde and incoherent scatter radar facilities. The principal focus of this study is the validation of the electron density profiles inferred from GPS occultation observations using the Abel transform.
Does artificial light-at-night exposure contribute to the worldwide obesity pandemic?
Rybnikova, N A; Haim, A; Portnov, B A
2016-05-01
Worldwide overweight and obesity rates are on the rise, with about 1 900 billion adults being defined as overweight and about 600 million adults being defined as obese by the World Health Organization (WHO). Increasing exposure to artificial light-at-night (ALAN) may influence body mass, by suppression of melatonin production and disruption of daily rhythms, resulting in physiological or behavioral changes in the human body, and may thus become a driving force behind worldwide overweight and obesity pandemic. We analyzed most recent satellite images of night time illumination, available from the US Defense Meteorological Satellite Program (DMSP), combining them with country-level data on female and male overweight and obesity prevalence rates, reported by the WHO. The study aims to identify and measure the strength of association between ALAN and country-wide overweight and obesity rates, controlling for per capita GDP, level of urbanization, birth rate, food consumption and regional differences. ALAN emerged as a statistically significant and positive predictor of overweight and obesity (t>1.97; P<0.05), helping to explain, together with other factors, about 70% of the observed variation of overweight and obesity prevalence rates among females and males in more than 80 countries worldwide. Regional differences in the strength of association between ALAN and excessive body mass are also noted. This study is the first population-level study that confirms the results of laboratory research and cohort studies in which ALAN was found to be a contributing factor to excessive body mass in humans.
NASA Technical Reports Server (NTRS)
Pfaff, R. F.; Bounds, S.; Acuna, M.; Maynard, N. C.; Moen, J.; Egeland, A.; Holtet, J.; Maseide, K.; Sandholt, P. E.; Soraas, F.
1999-01-01
Two Black Brant IX sounding rockets were launched into the dark, dayside cusp near magnetic noon on December 2 and 3, 1997, from Ny Alesund, Spitzbergen at 79degN reaching altitudes of approximately 450 km. Real-time ground-based and Wind (interplanetary magnetic field) IMF data were used to determine the launch conditions. The first launch, with Bz north conditions, crossed into and back out of an open field region with merging poleward of the projected trajectory. The second flight, into Bz south conditions, was timed to coincide with an enhancement in the merging rate from a increase in the negative Bz, while the (Defense Meteorological Satellite Program) DMSP F13 satellite was situated slightly to the north of the rocket trajectory. Each payload returned DC electric and magnetic fields, plasma waves, energetic particles, photometer data, and thermal plasma data. Data from both flights will be shown, with an emphasis on the DC electric field results. In particular, the data gathered on December 2, 1997 will be used to discuss ionospheric signatures of merging and the open/closed character of the the cusp/low latitude boundary layer. In contrast, the data gathered on December 3, 1997 shows evidence of pulsed electric field structures which will be examined in the context of cusp plasma entry processes. Both data sets returned a rich variety of plasma waves, as well as optical emissions and thermal plasma data.
NPOESS C3S Expandability: SafetyNetTM and McMurdo Improvements
NASA Astrophysics Data System (ADS)
Jamilkowski, M. L.; Paciaroni, J.; Pela, F.
2010-12-01
The National Oceanic & Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics & Space Administration (NASA) are jointly acquiring the next-generation weather & environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current NOAA Polar-orbiting Operational Environmental Satellites (POES) and Dod's Defense Meteorological Satellite Program (DMSP). The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The command & telemetry portion of NPOESS is the Command, Control and Communications Segment (C3S), developed by Raytheon Intelligence & Information Systems. C3S is responsible for managing the overall NPOESS mission from control and status of the space and ground assets to ensuring delivery of timely, high quality data from the Space Segment (SS) to the Interface Data Processing Segment (IDPS) for processing. In addition, the C3S provides the globally distributed ground assets necessary to collect and transport mission, telemetry, and command data between the satellites and the processing locations. The C3S provides all functions required for day-to-day commanding & state-of-health monitoring of the NPP & NPOESS satellites, and delivery of Stored Mission Data (SMD) to each US Weather Central Interface Data Processor (IDP) for data products development and transfer to System subscribers. The C3S also monitors and reports system-wide health and status & data communications with external systems and between NPOESS segments. Two crucial elements of NPOESS C3S expandability are SafetyNetTM and communications improvements to McMurdo Station, Antarctica. SafetyNetTM is a key feature of NPOESS and a vital element of the C3S and Northrop Grumman Aerospace Systems patented data collection architecture. The centerpiece of SafetyNetTM is the system of fifteen globally-distributed ground receptors developed by Raytheon Company. These antennae will collect up to five times as much environmental data approximately four times faster than current polar-orbiting weather satellites. Once collected, these data will be forwarded near-instantaneously to US weather centrals via the global fiber optic network for processing in environmental prediction models. In January 2008, Raytheon Company achieved a significant milestone for the NPOESS program by successfully completing the first phase of a major communications upgrade for Antarctica. The upgrade of the off-continent satellite communications link at McMurdo Station more than tripled the bandwidth available for scientific research, weather prediction, and health & safety of those stationed at McMurdo. The project is part of the company’s C3S under development for NPOESS. This upgrade paves the way for a second major communications upgrade planned for 2012 in preparation for the use of McMurdo Station as one of the 15 NPOESS ground stations worldwide that will be receiving environmental data collected by the NPOESS satellites. SafetyNet is a trademark of Northrop Grumman Aerospace Systems.
Precipitation Estimation Using Combined Radar/Radiometer Measurements Within the GPM Framework
NASA Technical Reports Server (NTRS)
Hou, Arthur
2012-01-01
The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. The GPM mission centers upon the deployment of a Core Observatory in a 65o non-Sun-synchronous orbit to serve as a physics observatory and a transfer standard for intersatellite calibration of constellation radiometers. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will be the first dual-frequency radar in space to provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles needed for improving precipitation retrievals from microwave sensors. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will be used as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1 satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian Megha- Tropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA)-19, (5) MHS instruments on MetOp satellites launched by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), (6) the Advanced Technology Microwave Sounder (ATMS) on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), and (7) ATMS instruments on the NOAA-NASA Joint Polar Satellite System (JPSS) satellites. Data from Chinese and Russian microwave radiometers may also become available through international collaboration under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). The current generation of global rainfall products combines observations from a network of uncoordinated satellite missions using a variety of merging techniques. GPM will provide next-generation precipitation products characterized by: (1) more accurate instantaneous precipitation estimate (especially for light rain and cold-season solid precipitation), (2) intercalibrated microwave brightness temperatures from constellation radiometers within a consistent framework, and (3) unified precipitation retrievals from constellation radiometers using a common a priori hydrometeor database constrained by combined radar/radiometer measurements provided by the GPM Core Observatory.
Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA E-Theater 2003
NASA Technical Reports Server (NTRS)
Hasler, Fritz
2003-01-01
The NASA/NOAA Electronic Theater presents Earth science observations from space in a spectacular way. Fly in from outer space to the conference location as well as the site of the 2002 Olympic Winter Games using data from NASA satellites and the IKONOS 'Spy Satellite". See HDTV movie Destination Earth 2002 incorporating the Olympic Zooms, NBC footage of the 2002 Olympics, the shuttle, & the best NASA/NOAA Earth science visualizations. See the latest US and international global satellite weather movies including hurricanes, typhoons & "tornadoes". See the latest visualizations from NASA/NOAA and International remote sensing missions like Terra, Aqua, GOES, GMS, SeaWiFS, & Landsat. Feel the pulse of OUT planet. See how land vegetation, ocean plankton, clouds and temperatures respond to the sun & seasons. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP satellite. The presentation will be made using the latest HDTV and video projection technology by: Dr. Fritz Hasler NASA/Goddard Space Flight Center.
Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA E-Theater 2003
NASA Technical Reports Server (NTRS)
Hasler, Fritz
2003-01-01
The NASA/NOAA Electronic Theater presents Earth science observations from space in a spectacular way. Fly in from outer space to the conference location as well as the site of the 2002 Olympic Winter Games using data from NASA satellites and the IKONOS "Spy Satellite". See HDTV movie Destination Earth 2002 incorporating the Olympic Zooms, NBC footage of the 2002 Olympics, the shuttle, & the best NASA/NOAA Earth science visualizations. See the latest US and international global satellite weather movies including hurricanes, typhoons & "tornadoes". See the latest visualizations from NASA/NOAA and International remote sensing missions like Terra, Aqua, GOES, GMS, SeaWiFS, & Landsat. Feel the pulse of our planet. See how land vegetation, ocean plankton, clouds and temperatures respond to the sun & seasons. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP satellite. The presentation will be made using the latest HDTV and video projection technology by: Dr. Fritz Hasler NASA/Goddard Space Flight Center
Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA E-Theater 2003
NASA Technical Reports Server (NTRS)
Hasler, Fritz
2003-01-01
The NASA/NOAA Electronic Theater presents Earth science observations from space in a spectacular way. Fly in from outer space to the conference location as well as the site of the 2002 Olympic Winter Games using data from NASA satellites and the IKONOS "Spy Satellite". See HDTV movie Destination Earth 2002 incorporating the Olympic Zooms, NBC footage of the 2002 Olympics, the shuttle, & the best NASA/NOAA Earth science visualizations. See the latest US and international global satellite weather movies including hurricanes, typhoons & "tornadoes". See the latest visualizations from NASA/NOAA and International remote sensing missions like Terra, Aqua, GOES, GMS , SeaWiFS, & Landsat. Feel the pulse of our planet. See how land vegetation, ocean plankton, clouds and temperatures respond to the sun & seasons. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the the "night-vision" DMSP satellite. The presentation will be made using the latest HDTV and video projection technology by: Dr. Fritz Hasler NASA/Goddard Space Flight Center
Gypens, Nathalie; Borges, Alberto V.; Speeckaert, Gaelle; Lancelot, Christiane
2014-01-01
We developed a module describing the dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) dynamics, including biological transformations by phytoplankton and bacteria, and physico-chemical processes (including DMS air-sea exchange). This module was integrated in the MIRO ecological model and applied in a 0D frame in the Southern North Sea (SNS). The DMS(P) module is built on parameterizations derived from available knowledge on DMS(P) sources, transformations and sinks, and provides an explicit representation of bacterial activity in contrast to most of existing models that only include phytoplankton process (and abiotic transformations). The model is tested in a highly productive coastal ecosystem (the Belgian coastal zone, BCZ) dominated by diatoms and the Haptophyceae Phaeocystis, respectively low and high DMSP producers. On an annual basis, the particulate DMSP (DMSPp) production simulated in 1989 is mainly related to Phaeocystis colonies (78%) rather than diatoms (13%) and nanoflagellates (9%). Accordingly, sensitivity analysis shows that the model responds more to changes in the sulfur:carbon (S:C) quota and lyase yield of Phaeocystis. DMS originates equally from phytoplankton and bacterial DMSP-lyase activity and only 3% of the DMS is emitted to the atmosphere. Model analysis demonstrates the sensitivity of DMS emission towards the atmosphere to the description and parameterization of biological processes emphasizing the need of adequately representing in models both phytoplankton and bacterial processes affecting DMS(P) dynamics. This is particularly important in eutrophied coastal environments such as the SNS dominated by high non-diatom blooms and where empirical models developed from data-sets biased towards open ocean conditions do not satisfactorily predict the timing and amplitude of the DMS seasonal cycle. In order to predict future feedbacks of DMS emissions on climate, it is needed to account for hotspots of DMS emissions from coastal environments that, if eutrophied, are dominated not only by diatoms. PMID:24465753
Yancey, Paul H; Heppenstall, Marina; Ly, Steven; Andrell, Raymond M; Gates, Ruth D; Carter, Virginia L; Hagedorn, Mary
2010-01-01
Most marine invertebrates and algae are osmoconformers whose cells accumulate organic osmolytes that provide half or more of cellular osmotic pressure. These solutes are primarily free amino acids and glycine betaine in most invertebrates and small carbohydrates and dimethylsulfoniopropionate (DMSP) in many algae. Corals with endosymbiotic dinoflagellates (Symbiodinium spp.) have been reported to obtain from the symbionts potential organic osmolytes such as glycerol, amino acids, and DMSP. However, corals and their endosymbionts have not been fully analyzed for osmolytes. We quantified small carbohydrates, free amino acids, methylamines, and DMSP in tissues of the corals Fungia scutaria, Pocillopora damicornis, Pocillopora meandrina, Montipora capitata, Porites compressa, and Porites lobata (all with symbionts) plus Tubastrea aurea (asymbiotic) from Kaneohe Bay, Oahu (Hawaii). Glycine betaine, at 33-69 mmol/kg wet mass, was found to constitute 90% or more of the measured organic solutes in all except the Porites species. Those were dominated by proline betaine and dimethyltaurine. DMSP was found at 0.5-3 mmol/kg in all species with endosymbionts. Freshly isolated Symbiodinium from Fungia, P. damicornis, and P. compressa were also analyzed. DMSP and glycine betaine dominated in the first two; Porites endosymbionts had DMSP, proline betaine, and dimethyltaurine. In all specimens, glycerol and glucose were detected by high-performance liquid chromatography only at 0-1 mmol/kg wet mass. An enzymatic assay for glycerol plus glycerol 3-phosphate and dihydroxyacetone phosphate yielded 1-10 mmol/kg. Cassiopeia andromeda (upside-down jelly; Scyphozoan) and Aiptasia puchella (solitary anemone; Anthozoan) were also analyzed; both have endosymbiotic dinoflagellates. In both, glycine betaine, taurine, and DMSP were the dominant osmolytes. In summary, methylated osmolytes dominate in many Cnidaria; in those with algal symbionts, host and symbiont have similar methylated amino acids, as do congeners. However, little glycerol was present as an osmolyte and was probably metabolized before it could accumulate.
The sub-auroral electric field as observed by DMSP and the new SuperDARN mid-latitude radars
NASA Astrophysics Data System (ADS)
Talaat, E. R.; Sotirelis, T.; Hairston, M. R.; Ruohoniemi, J. M.; Greenwald, R. A.; Lester, M.
2008-12-01
In this paper we present analyses of the sub-auroral electric field environment as observed from both space and ground. We discuss the dependency of the configuration and strength of the sub-auroral electric field on IMF and geomagnetic activity, longitudinal, seasonal, and solar cycle variability. Primarily, e use ~20 years of electric field measurement dataset derived from the suite of DMSP ion drift meters. A major component of our analysis is correctly specifying the aurora boundary, as the behavior and magnitude of these fields will be drastically different away from the high-conductance auroral oval. As such, we use the coincident particle flux measurements from the DMSP SSJ4 monitors. We also present the solar minimum observations of the sub-auroral flow newly available from the mid-latitude SuperDARN radars at Wallops and Blackstone in Virginia. Preliminary comparisons between these flows and the DMSP climatology are discussed.
Estimation of Land Surface Temperature from GCOM-W1 AMSR2 Data over the Chinese Landmass
NASA Astrophysics Data System (ADS)
Zhou, Ji; Dai, Fengnan; Zhang, Xiaodong
2016-04-01
As one of the most important parameter at the interface between the earth's surface and atmosphere, land surface temperature (LST) plays a crucial role in many fields, such as climate change monitoring and hydrological modeling. Satellite remote sensing provides the unique possibility to observe LST of large regions at diverse spatial and temporal scales. Compared with thermal infrared (TIR) remote sensing, passive microwave (PW) remote sensing has a better ability in overcoming the influences of clouds; thus, it can be used to improve the temporal resolution of current satellite TIR LST. However, most of current methods for estimation LST from PW remote sensing are empirical and have unsatisfied generalization. In this study, a semi-empirical method is proposed to estimate LST from the observation of the Advanced Microwave Scanning Radiometer 2 (AMSR2) on board the Global Change Observation Mission 1st-WATER "SHIZUKU" satellite (GCOM-W1). The method is based on the PW radiation transfer equation, which is simplified based on (1) the linear relationship between the emissivities of horizontal and vertical polarization channels at the same frequency and (2) the significant relationship between atmospheric parameters and the atmospheric water vapor content. An iteration approach is used to best fit the pixel-based coefficients in the simplified radiation transfer equation of the horizontal and vertical polarization channels at each frequency. Then an integration approach is proposed to generate the ensemble estimation from estimations of multiple frequencies for different land cover types. This method is trained with the AMSR2 brightness temperature and MODIS LST in 2013 over the entire Chinese landmass and then it is tested with the data in 2014. Validation based on in situ LSTs measured in northwestern China demonstrates that the proposed method has a better accuracy than the polarization radiation method, with a root-mean squared error of 3 K. Although the proposal method is applied to AMSR2 data, it has good ability to extend to other satellite PW sensors, such as the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) on board the Aqua satellite and the Special Sensor Microwave/Imager (SSM/I) on board the Defense Meteorological Satellite Program (DMSP) satellite. It would be beneficial in providing LST to applications at continental and global scales.
Catola, Stefano; Kaidala Ganesha, Srikanta Dani; Calamai, Luca; Loreto, Francesco; Ranieri, Annamaria; Centritto, Mauro
2016-01-01
Dimethylsulfoniopropionate (DMSP) and dimethyl sulphide (DMS) are compounds found mainly in marine phytoplankton and in some halophytic plants. DMS is a globally important biogenic volatile in regulating of global sulfur cycle and planetary albedo, whereas DMSP is involved in the maintenance of plant-environment homeostasis. Plants emit minute amounts of DMS compared to marine phytoplankton and there is a need for hypersensitive analytic techniques to enable its quantification in plants. Solid Phase Micro Extraction from Head Space (HS-SPME) is a simple, rapid, solvent-free and cost-effective extraction mode, which can be easily hyphenated with GC-MS for the analysis of volatile organic compounds. Using tomato (Solanum lycopersicum) plants subjected to water stress as a model system, we standardized a sensitive and accurate protocol for detecting and quantifying DMSP pool sizes, and potential DMS emissions, in cryoextracted leaves. The method relies on the determination of DMS free and from DMSP pools before and after the alkaline hydrolysis via Headspace-Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS). We found a significant (2.5 time) increase of DMSP content in water-stressed leaves reflecting clear stress to the photosynthetic apparatus. We hypothesize that increased DMSP, and in turn DMS, in water-stressed leaves are produced by carbon sources other than direct photosynthesis, and function to protect plants either osmotically or as antioxidants. Finally, our results suggest that SPME is a powerful and suitable technique for the detection and quantification of biogenic gasses in trace amounts. PMID:27602039
MRP- and BCL-2-mediated drug resistance in human SCLC: effects of apoptotic sphingolipids in vitro.
Khodadadian, M; Leroux, M E; Auzenne, E; Ghosh, S C; Farquhar, D; Evans, R; Spohn, W; Zou, Y; Klostergaard, J
2009-10-01
Multidrug-resistance-associated protein (MRP) and BCL-2 contribute to drug resistance expressed in SCLC. To establish whether MRP-mediated drug resistance affects sphingolipid (SL)-induced apoptosis in SCLC, we first examined the human SCLC cell line, UMCC-1, and its MRP over-expressing, drug-resistant subline, UMCC-1/VP. Despite significantly decreased sensitivity to doxorubicin (Dox) and to the etoposide, VP-16, the drug-selected line was essentially equally as sensitive to treatment with exogenous ceramide (Cer), sphingosine (Sp) or dimethyl-sphingosine (DMSP) as the parental line. Next, we observed that high BCL-2-expressing human H69 SCLC cells, that were approximately 160-fold more sensitive to Dox than their combined BCL-2 and MRP-over-expressing (H69AR) counterparts, were only approximately 5-fold more resistant to DMSP. Time-lapse fluorescence microscopy of either UMCC cell line treated with DMSP-Coumarin revealed comparable extents and kinetics of SL uptake, further ruling out MRP-mediated effects on drug uptake. DMSP potentiated the cytotoxic activity of VP-16 and Taxol, but not Dox, in drug-resistant UMCC-1/VP cells. However, this sensitization did not appear to involve DMSP-mediated effects on the function of MRP in drug export; nor did DMSP strongly shift the balance of pro-apoptotic Sps and anti-apoptotic Sp-1-Ps in these cells. We conclude that SL-induced apoptosis markedly overcomes or bypasses MRP-mediated drug resistance relevant to SCLC and may suggest a novel therapeutic approach to chemotherapy for these tumors.
Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels
NASA Technical Reports Server (NTRS)
Gasiewski, A. J.; Adelberg, L. K.; Kunkee, D. B.; Jackson, D. M.
1993-01-01
Progress by investigators at the Georgia Institute of Technology in the development of techniques for passive microwave retrieval of water vapor, cloud, and precipitation parameters using millimeter- and sub-millimeter wavelength channels is reviewed. Channels of particular interest are in the tropospheric transmission windows at 90, 166, 220, 340, and 410 GHz and centered around the water vapor lines at 183 and 325 GHz. Collectively, these channels have potential application in high-resolution mapping (e.g., from geosynchronous orbit), remote sensing of cloud and precipitation parameters, and retrieval of water vapor profiles. During the period from 1 Jan. 1993 through 30 Jun. 1993 the Millimeter-wave Imaging Radiometer (MIR) completed data flights during a two-month long deployment in conjunction with TOGA/COARE. Coincident data was collected from several other ground-based, airborne, and satellite sensors, including the NASA/MSFC AMPR, MIT MTS, DMSP SSM/T-2 satellite, collocated radiosondes, ground- and aircraft-based radiometers and cloud lidars, airborne infrared imagers, solar flux probes, and airborne cloud particle sampling probes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Watermann, J.; DeLaBeaujar, O.; Lummerzheim, D.
1994-12-31
Coincident multi-instrument magnetospheric and ionospheric observations have made it possible to determine the position of the ionospheric footprint of the magnetospheric cusp and to monitor its evolution over time. The data used include charged particle and magnetic field measurements from the Earth-orbiting Viking and DMSP-F7 satellites, electric field measurements from Viking, interplanetary magnetic field and plasma data from IMP-8 and Sondrestrom incoherent scatter radar observations of the ionospheric plasma density, temperature, and convection. Viking detected cusp precipitation poleward of 75.5 degrees invariant latitude. The ionospheric response to the observed electron precipitation was simulated using an auroral model. It predicts enhancedmore » plasma density and elevated electron temperature in the upper E- and F-regions. Sondrestrom radar observations are in agreement with the predictions. The radar detected a cusp signature on each of five consecutive antenna elevation scans covering 1.2 h local time. The cusp appeared to be about 2 degrees invariant latitude wide, and its ionospheric footprint shifted equatorward by nearly 2 degrees during this time, possibly influenced by an overall decrease in the IMF B{sub Z} component The radar plasma drift data and the Viking magnetic and electric field data suggest that the cusp was associated with a continuous, rather than a patchy, merging between the IMF and the geomagnetic field.« less
NASA Technical Reports Server (NTRS)
Watermann, J.; De La Beaujardiere, O.; Lummerzheim, D.; Woch, J.; Newell, P. T.; Potemra, T. A.; Rich, F. J.; Shapshak, M.
1994-01-01
Coincident multi-instrument magnetospheric and ionospheric observations have made it possible to determine the position of the ionospheric footprint of the magnetospheric cusp and to monitor its evolution over time. The data used include charged particle and magnetic field measurements from the Earth-orbiting Viking and DMSP-F7 satellites, electric field measurements from Viking, interplanetary magnetic field and plasma data from IMP-8, and Sondrestrom incoherent scatter radar observations of the ionospheric plasma density, temperature, and convection. Viking detected cusp precipitation poleward of 75.5 deg invariant latitude. The ionospheric response to the observed electron precipitation was simulated using an auroral model. It predicts enhanced plasma density and elevated electron temperature in the upper E- and F- regions. Sondrestrom radar observations are in agreement with the predictions. The radar detected a cusp signature on each of five consecutive antenna elevation scans covering 1.2h local time. The cusp appeared to be about 2 deg invariant latitude wide, and its ionospheric footprint shifted equatorward by nearly 2 deg during this time, possibly influenced by an overall decrease in the interplanetary magnetic field (IMF) B(sub z) component. The radar plasma drift data and the Viking magnetic and electric field data suggest that the cusp was associated with a continuous, rather than a patchy, merging between the IMF and the geomagnetic field.
Exposure of tropical ecosystems to artificial light at night: Brazil as a case study.
Freitas, Juliana Ribeirão de; Bennie, Jon; Mantovani, Waldir; Gaston, Kevin J
2017-01-01
Artificial nighttime lighting from streetlights and other sources has a broad range of biological effects. Understanding the spatial and temporal levels and patterns of this lighting is a key step in determining the severity of adverse effects on different ecosystems, vegetation, and habitat types. Few such analyses have been conducted, particularly for regions with high biodiversity, including the tropics. We used an intercalibrated version of the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS) images of stable nighttime lights to determine what proportion of original and current Brazilian vegetation types are experiencing measurable levels of artificial light and how this has changed in recent years. The percentage area affected by both detectable light and increases in brightness ranged between 0 and 35% for native vegetation types, and between 0 and 25% for current vegetation (i.e. including agriculture). The most heavily affected areas encompassed terrestrial coastal vegetation types (restingas and mangroves), Semideciduous Seasonal Forest, and Mixed Ombrophilous Forest. The existing small remnants of Lowland Deciduous and Semideciduous Seasonal Forests and of Campinarana had the lowest exposure levels to artificial light. Light pollution has not often been investigated in developing countries but our data show that it is an environmental concern.
Advances in remote sensing of the daytime ionosphere with EUV airglow
NASA Astrophysics Data System (ADS)
Stephan, Andrew W.
2016-09-01
This paper summarizes recent progress in developing a method for characterizing the daytime ionosphere from limb profile measurements of the OII 83.4 nm emission. This extreme ultraviolet emission is created by solar photoionization of atomic oxygen in the lower thermosphere and is resonantly scattered by O+ in the ionosphere. The brightness and shape of the measured altitude profile thus depend on both the photoionization source in the lower thermosphere and the ionospheric densities that determine the resonant scattering contribution. This technique has greatly matured over the past decade due to measurements by the series of Naval Research Laboratory Special Sensor Ultraviolet Limb Imager (SSULI) instruments flown on Defense Meteorological Satellite Program (DMSP) missions and the Remote Atmospheric and Ionospheric Detection System (RAIDS) on the International Space Station. The volume of data from these missions has enabled a better approach to handling specific biases and uncertainties in both the measurement and retrieval process that affect the accuracy of the result. This paper identifies the key measurement and data quality factors that will enable the continued evolution of this technique into an advanced method for characterization of the daytime ionosphere.
UV Observations of Atomic Oxygen in the Cusp Region
NASA Astrophysics Data System (ADS)
Fritz, B.; Lessard, M.; Dymond, K.; Kenward, D. R.; Lynch, K. A.; Clemmons, J. H.; Hecht, J. H.; Hysell, D. L.; Crowley, G.
2017-12-01
The Rocket Experiment for Neutral Upwelling (RENU) 2 launched into the dayside cusp on 13 December, 2015. The sounding rocket payload carried a comprehensive suite of particle, field, and remote sensing instruments to characterize the thermosphere in a region where pockets of enhanced neutral density have been detected [Lühr et al, 2004]. An ultraviolet photomultiplier tube (UV PMT) was oriented to look along the magnetic field line and remotely detect neutral atomic oxygen (OI) above the payload. The UV PMT measured a clear enhancement as the payload descended through a poleward moving auroral form, an indicator of structure in both altitude and latitude. Context for the UV PMT measurement is provided by the Special Sensor Ultraviolet Imager (SSULI) instrument on the Defense Meteorological Space Program (DMSP) satellite, which also measured OI as it passed through the cusp. UV tomography of SSULI observations produces a two-dimensional cross-section of volumetric emission rates in the high-latitude thermosphere prior to the RENU 2 flight. The volume emission rate may then be inverted to produce a profile of neutral density in the thermosphere. A similar technique is used to interpret the UV PMT measurement and determine structure in the thermosphere as RENU 2 descended through the cusp.
Intense uniform precipitation of low-energy electrons over the polar cap
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meng, C.; Kroehl, H.W.
1977-06-01
Analysis of precipitating electron data from the Defense Meteorological Satellite Program (DMSP) revealed significant enhancements (as large as two orders of magnitude) over the quiet time level of the low-energy electron flux over the polar cap during magnetic storms in September and October 1974. Strong asymmetry between the two polar caps was observed, and it may indicate that these electrons are of interplanetary (i.e., solar) origin and that their entry is influenced by the interplanetary magnetic field as illustrated by Yeager and Frank (1976) and Fennell et al., (1975). Energy spectra showing the spatial and temporal variations of the phenomenamore » are presented. There also is a region between the equatorward edge of the polar cap enhancement and the poleward edge of the evening auroral precipitation in which the electron flux drops down to the background level. If the observed intense polar cap precipitation is indeed of interplanetary origin, this void region implies that the poleward boundary of the auroral precipitation does not coincide with the equatorward boundary of the open field lines and that their separation cna be as wide as a few degrees in latitude.« less
SAPS simulation with GITM/UCLA-RCM coupled model
NASA Astrophysics Data System (ADS)
Lu, Y.; Deng, Y.; Guo, J.; Zhang, D.; Wang, C. P.; Sheng, C.
2017-12-01
Abstract: SAPS simulation with GITM/UCLA-RCM coupled model Author: Yang Lu, Yue Deng, Jiapeng Guo, Donghe Zhang, Chih-Ping Wang, Cheng Sheng Ion velocity in the Sub Aurora region observed by Satellites in storm time often shows a significant westward component. The high speed westward stream is distinguished with convection pattern. These kind of events are called Sub Aurora Polarization Stream (SAPS). In March 17th 2013 storm, DMSP F18 satellite observed several SAPS cases when crossing Sub Aurora region. In this study, Global Ionosphere Thermosphere Model (GITM) has been coupled to UCLA-RCM model to simulate the impact of SAPS during March 2013 event on the ionosphere/thermosphere. The particle precipitation and electric field from RCM has been used to drive GITM. The conductance calculated from GITM has feedback to RCM to make the coupling to be self-consistent. The comparison of GITM simulations with different SAPS specifications will be conducted. The neutral wind from simulation will be compared with GOCE satellite. The comparison between runs with SAPS and without SAPS will separate the effect of SAPS from others and illustrate the impact on the TIDS/TADS propagating to both poleward and equatorward directions.
Gardner, Stephanie G; Nielsen, Daniel A; Laczka, Olivier; Shimmon, Ronald; Beltran, Victor H; Ralph, Peter J; Petrou, Katherina
2016-02-10
Corals are among the most active producers of dimethylsulfoniopropionate (DMSP), a key molecule in marine sulfur cycling, yet the specific physiological role of DMSP in corals remains elusive. Here, we examine the oxidative stress response of three coral species (Acropora millepora, Stylophora pistillata and Pocillopora damicornis) and explore the antioxidant role of DMSP and its breakdown products under short-term hyposalinity stress. Symbiont photosynthetic activity declined with hyposalinity exposure in all three reef-building corals. This corresponded with the upregulation of superoxide dismutase and glutathione in the animal host of all three species. For the symbiont component, there were differences in antioxidant regulation, demonstrating differential responses to oxidative stress between the Symbiodinium subclades. Of the three coral species investigated, only A. millepora provided any evidence of the role of DMSP in the oxidative stress response. Our study reveals variability in antioxidant regulation in corals and highlights the influence life-history traits, and the subcladal differences can have on coral physiology. Our data expand on the emerging understanding of the role of DMSP in coral stress regulation and emphasizes the importance of exploring both the host and symbiont responses for defining the threshold of the coral holobiont to hyposalinity stress. © 2016 The Author(s).
Hehemann, Jan-Hendrik; Law, Adrienne; Redecke, Lars; Boraston, Alisdair B.
2014-01-01
Marine microbes degrade dimethylsulfoniopropionate (DMSP), which is produced in large quantities by marine algae and plants, with DMSP lyases into acrylate and the gas dimethyl sulfide (DMS). Approximately 10% of the DMS vents from the sea into the atmosphere and this emission returns sulfur, which arrives in the sea through rivers and runoff, back to terrestrial systems via clouds and rain. Despite their key role in this sulfur cycle DMSP lyases are poorly understood at the molecular level. Here we report the first X-ray crystal structure of the putative DMSP lyase RdDddP from Roseobacter denitrificans, which belongs to the abundant DddP family. This structure, determined to 2.15 Å resolution, shows that RdDddP is a homodimeric metalloprotein with a binuclear center of two metal ions located 2.7 Å apart in the active site of the enzyme. Consistent with the crystallographic data, inductively coupled plasma mass spectrometry (ICP-MS) and total reflection X-ray fluorescence (TRXF) revealed the bound metal species to be primarily iron. A 3D structure guided analysis of environmental DddP lyase sequences elucidated the critical residues for metal binding are invariant, suggesting all proteins in the DddP family are metalloenzymes. PMID:25054772
NPOESS C3S Expandability: SafetyNet(TM) and McMurdo Improvements
NASA Astrophysics Data System (ADS)
Paciaroni, J.; Jamilkowski, M. L.
2009-12-01
The National Oceanic & Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The command and telemetry portion of NPOESS is the Command, Control and Communications Segment (C3S), developed by Raytheon Intelligence & Information Systems. C3S is responsible for managing the overall NPOESS mission from control and status of the space and ground assets to ensuring delivery of timely, high quality data from the Space Segment (SS) to the Interface Data Processing Segment (IDPS) for processing. In addition, the C3S provides the globally distributed ground assets necessary to collect and transport mission, telemetry, and command data between the satellites and the processing locations. The C3S provides all functions required for day-to-day commanding and state-of-health monitoring of the NPP and NPOESS satellites, and delivery of Stored Mission Data (SMD) to each U.S. Weather Central Interface Data Processor (IDP) for data products development and transfer to System subscribers. The C3S also monitors and reports system-wide health and status and data communications with external systems and between the NPOESS segments. Two crucial elements of NPOESS C3S expandability are SafetyNet(TM) and communications improvements to McMurdo Station, Antarctica. ‘SafetyNet(TM)’ is a key feature of the National Polar-orbiting Operational Environmental Satellite System (NPOESS), vital element of the C3S and Northrop Grumman Space Technology patented data collection architecture. The centerpiece of SafetyNet(TM) is the system of fifteen globally-distributed ground receptors developed by Raytheon Company. These receptors or antennae will collect up to five times as much environmental data approximately four times faster than current polar-orbiting weather satellites. Once collected, these data will be forwarded near-instantaneously to U.S. weather centrals via global fiber optic network for processing and production of data records for use in environmental prediction models. In January 2008, Raytheon Company achieved a significant milestone for the NPOESS program by successfully completing the first phase of a major communications upgrade for Antarctica. The upgrade of the off-continent satellite communications link at McMurdo Station more than tripled the bandwidth available for scientific research, weather prediction, and health and safety of those stationed at McMurdo. The project is part of the company’s C3S under development for NPOESS. This upgrade paves the way for a second major communications upgrade planned for 2012 in preparation for the use of McMurdo Station as one of the 15 NPOESS ground stations worldwide that will be receiving environmental data collected by the NPOESS satellites.
NASA Astrophysics Data System (ADS)
Komjathy, A.; Wilson, B.; Akopian, V.; Pi, X.; Mannucci, A.; Wang, C.
2008-12-01
We seem to be in the midst of a revolution in ionospheric remote sensing driven by the abundance of ground and space-based GPS receivers, new UV remote sensing satellites, and the advent of data assimilation techniques for space weather. In particular, the COSMIC 6-satellite constellation was launched in April 2006. COSMIC now provides unprecedented global coverage of GPS occultations measurements, each of which yields electron density information with unprecedented ~1 km vertical resolution. Calibrated measurements of ionospheric delay (total electron content or TEC) suitable for input into assimilation models is currently made available in near real-time (NRT) from the COSMIC with a latency of 30 to 120 minutes. The University of Southern California (USC) and the Jet Propulsion Laboratory (JPL) have jointly developed a real-time Global Assimilative Ionospheric Model (GAIM) to monitor space weather, study storm effects, and provide ionospheric calibration for DoD customers and NASA flight projects. JPL/USC GAIM is a physics- based 3D data assimilation model that uses both 4DVAR and Kalman filter techniques to solve for the ion and electron density state and key drivers such as equatorial electrodynamics, neutral winds, and production terms. Daily (delayed) GAIM runs can accept as input ground GPS TEC data from 1200+ sites, occultation links from CHAMP, SAC-C, and the COSMIC constellation, UV limb and nadir scans from the TIMED and DMSP satellites, and in situ data from a variety of satellites (DMSP and C/NOFS). Real-Time GAIM (RTGAIM) ingests multiple data sources in real time, updates the 3D electron density grid every 5 minutes, and solves for improved drivers every 1-2 hours. Since our forward physics model and the adjoint model were expressly designed for data assimilation and computational efficiency, all of this can be accomplished on a single dual- processor Unix workstation. Customers are currently evaluating the accuracy of JPL/USC GAIM 'nowcasts' for ray tracing applications and trans-ionospheric path delay calibration. In the presentation, we will discuss the expected impact of NRT COSMIC occultation and NRT ground-based measurements and present validation results for ingest of COSMIC data into GAIM using measurements from World Days. We will quality check our COSMIC-derived products by comparing Abel profiles and JPL- processed results. Furthermore, we will validate GAIM assimilation results using Incoherent Scatter Radar measurements from Arecibo, Jicamarca and Millstone Hill datasets. We will conclude by characterizing the improved electron density states using dual-frequency altimeter-derived Jason vertical TEC measurements.
Impact of Vitamin B12 and Nitrate on Transcript and Metabolite Abundances in Marine Diatoms.
NASA Astrophysics Data System (ADS)
Pound, H. L.; Schanke, N. L.; Penta, W. B.; Zavala, J.; Casu, F.; Bearden, D. W.; Lee, P. A.
2016-02-01
Phytoplankton play countless roles in the support and regulation of marine ecosystems, as well as in global biogeochemical cycling processes. They are also, to varying extents, reliant on other physical and biological processes to supply their nutrient demands, such as the production of vitamin B12 by bacteria and archaea or the regeneration and upwelling of nitrate. One such process in the global biogeochemical sulfur cycle is the pathway that begins with the production of dimethylsulfoniopropionate (DMSP) by marine phytoplankton and leads to the atmospheric formation of sulfate-based cloud condensation nuclei, which contribute to the Earth's albedo. Nutrient limitation is thought to play a major role in the amount of DMSP produced by phytoplankton. Vitamin B12 and nitrate are of particular interest due to their involvement as a co-factor and nitrogen source, respectively, in the synthesis of methionine, the precursor for DMSP. Laboratory-based nutrient limitation experiments have been performed on cultures of the diatom Phaeodactylum tricornutum. In addition to the B12-dependent methionine synthase (MetH) P. tricornutum has a unique B12-independent methionine synthase gene (MetE). Based on classic techniques, B12 limitation had little impact on cell growth, whereas nitrate limitation had a significant effect on both culture health and DMSP concentration. Yet, targeted transcriptomic analysis (using Nanostring nCounter technology) and metabolomics analysis (using Nuclear Magnetic Resonance (NMR)) revealed complex changes in transcript abundance towards upregulated gene expression associated with the MetE gene in B12 limited cultures, and shifts away from nitrogen-based metabolites towards DMSP in nitrate-limited cultures. These experiments help verify the role of B12 in DMSP production and link the underlying metabolic pathways that drive the cellular portion of the sulfur cycle to ecosystem and global scale processes.
Cooling in the Post-Sunrise Equatorial Topside Ionosphere During the 22-23 June 2015 Superstorm
NASA Astrophysics Data System (ADS)
Stoneback, R.; Hairston, M. R.; Coley, W. R.; Heelis, R. A.
2015-12-01
During the recovery phase of the 22-23 June 2015 superstorm multiple DMSP spacecraft observed two separate and short-lived (~ 30 minutes) events of localized cooling in the topside equatorial ionosphere (~840 km) in the post-sunrise region (between 6:15 and 7:30 local time). The ion temperatures dropped from the nominal 2000-3000° observed in these regions to 1000 to 1500°. This cooling effect was not observed on the corresponding duskside equatorial crossings of the DMSP spacecraft during this storm. Further, these cooling events do not normally occur during major storms; no such phenomenon was observed by DMSP during the March 2015 superstorm. Flow data from DMSP and the CINDI instruments on the C/NOFS spacecraft indicate these cooling events are associated with short-lived vertical flows bringing up cooler plasma from lower altitudes. The two cooling events correspond to large northward turnings of the IMF during the storm and these are being explored as a possible trigger mechanism.
The National Polar-orbiting Operational Environmental Satellite System
NASA Astrophysics Data System (ADS)
Hoffman, C. W.; Mango, S.; Schneider, S.; Duda, J.; Haas, J.; Bloom, H.
2005-12-01
Over the last decade, the tri-agency Integrated Program Office (IPO), comprised of the National Oceanic and Atmospheric Administration (NOAA), the Department of Defense (DoD), and the National Aeronautics and Space Administration (NASA), has been managing the development of the National Polar-orbiting Operational Environmental Satellite System (NPOESS). Once operational later this decade, NPOESS will replace NOAA's Polar-orbiting Operational Environmental Satellites (POES) and DoD's Defense Meteorological Satellite Program (DMSP) systems. The IPO, through its Acquisition and Operations contractor, Northrop Grumman, will launch NPOESS spacecraft into three orbital planes to provide a single, national system capable of satisfying both civil and national security requirements for space-based, remotely sensed environmental data. With the development of NPOESS, we are evolving the existing 'weather' satellites into integrated environmental observing systems by expanding our capabilities to observe, assess, and predict the total Earth system - ocean, atmosphere, land, and the space environment. NPOESS will transform today's short-term, space-based ocean research missions into a sustained, operational ocean remote sensing observation program. Ocean measurements comprise one-fourth of the 55 user-validated requirements for geophysical measurements that will be made by NPOESS sensors. In 1997, the IPO initiated a robust sensor risk reduction effort for early development of the critical sensor suites and algorithms necessary to support NPOESS. In 2001, preliminary design efforts were completed for the last of five critical imaging/sounding instruments for NPOESS. Ocean requirements have directly and substantially 'driven' the design of three NPOESS sensors: the Visible/Infrared Imager Radiometer Suite (VIIRS); the Conical-scanning Microwave Imager/Sounder (CMIS); and the Altimeter. With these instruments, NPOESS will deliver higher resolution (spatial and temporal) and more accurate measurements of sea surface temperature (SST), ocean surface wind vectors/stress, ocean color and suspended matter, sea ice (edge motion, age, surface temperature, thickness), oceanic heat flux, significant wave height, and sea surface topography. Infrared and microwave measurements of sea surface temperature from VIIRS and CMIS, respectively, will be combined to produce 'all weather' SST products. VIIRS imagery and altimeter measurements will be used to derive ocean circulation parameters to meet monitoring requirements for both operational and research purposes. The advanced technology visible, infrared, and microwave imagers and sounders that will fly on NPOESS will deliver higher spatial and temporal resolution oceanic, atmospheric, terrestrial, climatic, and solar-geophysical data, enabling more accurate short-term weather forecasts and severe storm warnings and improved real-time monitoring of coastal and open ocean phenomena. NPOESS will also provide continuity of critical data for monitoring, understanding, and predicting climate change and assessing the impacts of climate change on seasonal and longer time scales. The NPOESS team is well along the path to creating a high performance, polar-orbiting satellite system that will be more responsive to user requirements, deliver more capability at less cost, and provide sustained, space-based measurements as a cornerstone of an Integrated Global Observing System.
UV Remote Sensing Data Products - Turning Data Into Knowledge
NASA Astrophysics Data System (ADS)
Weiss, M.; Paxton, L.; Schaefer, R. K.; Comberiate, J.; Hsieh, S. W.; Romeo, G.; Wolven, B. C.; Zhang, Y.
2013-12-01
The DMSP/SSUSI instruments have been taking UV images of the upper atmosphere for more than a decade. Each of the SSUSI instruments takes complete global UV images on a daily basis. Although this scientific data is very valuable, it is not actionable information. Perhaps the simplest use of SSUSI data is the assimilation of radiances into the GAIM ionospheric forecast model; even then, the data must be massaged to get it into a GAIM-ingestable form. We describe a development effort funded by the DMSP program and the Air Force Weather Agency to turn the raw data into actionable information in the form of SSUSI environmental data parameters and other derived information. We will describe current nowcasts, forecasts, and other related actionable information (e.g. auroral oval forecasts) that is currently generated by the SSUSI ground processing system for AFWA, and also concepts we have for future tools (e.g., geomagnetic storm alerts, scintillation forecasts, HF radio propagation information, auroral radar clutter) to turn more of the SSUSI dataset into actionable knowledge.
NASA Technical Reports Server (NTRS)
Perkey, Donald J.; Doty, Kevin G.; Robertson, Franklin R.
1989-01-01
A preliminary 140-km simulation of a rapid cyclogenesis, using the Limited Area Mesoscale Prediction System (LAMPS) is discussed. A three-dimensional version of LAMPS used in the simulation is described, along with a trajectory model utilizing the three-hourly output history files from the LAMPS model. Preliminary integrations of the LAMPS code as well as passive microwave digital data from SSM/I aboard the DMSP satellite are used for exploring the evolving baroclinic structure and moisture field of the cyclone event. A trajectory analysis of the model histories reveals a significant role for preconditioning of the low-level upstream air, which is then drawn into the ascending warm conveyor belt ahead of the storm.
The Role of the Auroral Processes in the Formation of the Outer Electron Radiation Belt
NASA Astrophysics Data System (ADS)
Stepanova, M. V.; Antonova, E. E.; Pinto, V. A.; Moya, P. S.; Riazantseva, M.; Ovchinnikov, I.
2016-12-01
The role of the auroral processes in the formation of the outer electron radiation belt during storms is analyzed using the data of RBSP mission, low orbiting satellites and ground based observations. We analyze fluxes of the low energy precipitating ions using data of the Defense Meteorological Satellite Program (DMSP). The location of the auroral electrojet is obtained from the IMAGE magnetometer network, and of the electron distribution in the outer radiation belt from the RBSP mission. We take into account the latest results on the auroral oval mapping in accordance with which the most part of the auroral oval maps not to the plasma sheet. It maps into the surrounding the Earth plasma ring in which transverse currents are closed inside the magnetosphere. Such currents constitute the high latitude continuation of the ordinary ring current. The development of the ring current and its high latitude continuation generates strong distortion of the Earth's magnetic field and corresponding adiabatic variation of the relativistic electron fluxes. This adiabatic variation should be considered for the analysis of the processes of the acceleration of relativistic electrons and formation of the outer radiation belt. We also analyze the plasma pressure profiles during storms and demonstrate the formation of sharp plasma pressure peak at the equatorial boundary of the auroral oval. It is shown that the observed this peak is directly connected to the creation of the seed population of relativistic electrons. We discuss the possibility to predict the position of new radiation belt during recovery phase of the magnetic storm using data of low orbiting and ground based observations.
The effect of visible light stress on chemical signaling in two life stages of Emiliania huxleyi
NASA Astrophysics Data System (ADS)
Valentin-Alvarado, L.; Cooney, E.; Bright, K.; Strom, S.
2016-02-01
The cosmopolitan marine phytoplankton species Emiliania huxleyi presents a digenetic heteromorphic life cycle, with the non-motile diploid phase bearing coccoliths and the flagellated haploid phase being non-calcified. E. huxleyi contains high concentrations of dimethylsulphoniopropionate (DMSP), the precursor of dimethylsulphide (DMS). DMSP is a multifactorial compound; it acts as a compatible solute in cell metabolism and as a chemical signal influencing bacterial and protist behavior. In the atmosphere DMS enhances cloud formation influencing climate. However, little has been documented on E. huxleyi chemical signal responses to high light stress, and how this relates to the heteromorphic life cycle. To this end, low light acclimated cultures of both haploid and diploid E. huxleyi were exposed to high light for 2 hr and allowed to recover in low light for 2 hr. During and after these treatments, growth, photosynthetic efficiency (Fv/Fm), DMSP (intracellular and released) and cell chlorophyll content were measured. Our preliminary results suggest that presence of high light decreased Fv/Fm to a greater extent in haploid than in diploid (calcified) cells, while recovery of Fv/Fm was rapid in both life stages. The chlorophyll content and intracellular DMSP was not different in both life stages. However, the dissolved DMSP increased after light stress in diploid cells suggesting a possible advantage as antioxidant protection or another cellular function, such as grazing protection in this life stage.
NASA Technical Reports Server (NTRS)
Sitar, R. J.; Clauer, C. R.; Baker, J. B.; Ridley, A. J.; Cumnock, J.; Germany, G. A.; Spann, J. F., Jr.; Brittnacher, M. J.; Parks, G. K.
1998-01-01
We present the analysis of a coordinated set of observations from the POLAR Ultraviolet Imager (UVI), ground magnetometers, incoherent scatter radar, solar wind monitors, DMSP and GOES satellites, focused on a traveling convection vortex (TCV) event on 24th July 1996. Starting at approximately 10:48 UT, around magnetometers in Greenland and northern Canada observe pulsations consistent with the passing overhead of a series of alternating TCV filed-aligned current pairs. Azimuthal scans by the Sondrestrom incoherent scatter radar located near Kangerlussuaq (formerly Sondrestrom), Greenland, at this time show strong modulation in the strength and direction of ionospheric plasma flow. The magnetometer pulsations grow in magnitude over the next hour, peaking in intensity at 11:39 UT, at which time images form the UVI instrument show a localized intensification of auroral emissions over central and western Greenland. Subsequent images show the intensification grow in strength and propagate westward (tailward) until approximately 11:58 UT at which time the intensification fades. These observations are consistent with the westward passage of two pairs of moderately intense TCVs over central Greenland followed by a third very intense TCV pair. The intensification of auroral emissions at 11:39 UT is associated with the trailing vortex of the third TCV pair, thought to be the result of an upward field aligned current. The modulated flow observed by the radar is the result of the strong electric fields associated with the impulsive TCV related field aligned current systems as they pass through the field of view of the radar. Measurements of the solar wind from the V;IND and IMP-8 spacecraft suggest that a pressure change may be responsible for triggering the first two pairs of TCVS, and that a subsequent sudden change in the orientation of the interplanetary magnetic field may have produced the intensification of the third TCV pair and the associated auroral brightening. Magnetometer data from the GOES satellite located over the eastern United States at geostationary orbit is consistent with a series of field-aligned moving tailward past the satellite. DMSP particle data indicated that the TCVs occur on field lines which map to the boundary plasma sheet (BPS).
DMSP AND ITS ROLE AS AN ANTIOXIDANT IN THE SALT MARSH MACROPHYTE SPARTINA ALTERNIFLORA
We will continue to measure seasonal patterns of DMSP and its oxidation products in natural populations of S. alterniflora throughout the 2002-2003 project period. We will carry out tests using antibiotics and antifungal agents to evaluate whether leaf micro...
NASA Astrophysics Data System (ADS)
Zakharenkova, I. E.; Cherniak, Iu. V.; Shagimuratov, I. I.; Klimenko, M. V.
2018-01-01
The dynamic picture of the response of the high- and mid-latitude ionosphere to the strong geomagnetic disturbances on March 17-18, 2015, has been studied with ground-based and satellite observations, mainly, by transionospheric measurements of delays of GPS (Global Positioning System) signals. The advantages of the joint use of ground-based GPS measurements and GPS measurements on board of the Swarm Low-Earth-Orbit satellite mission for monitoring of the appearance of ionospheric irregularities over the territory of Russia are shown for the first time. The results of analysis of ground-based and space-borne GPS observations, as well as satellite, in situ measurements, revealed large-scale ionospheric plasma irregularities observed over the territory of Russia in the latitude range of 50°-85° N during the main phase of the geomagnetic storm. The most intense ionospheric irregularities were detected in the auroral zone and in the region of the main ionospheric trough (MIT). It has been found that sharp changes in the phase of the carrier frequency of the navigation signal from all tracked satellites were recorded at all GPS stations located to the North from 55° MLAT. The development of a deep MIT was related to dynamic processes in the subauroral ionosphere, in particular, with electric fields of the intense subauroral polarization stream. Analysis of the electron and ion density values obtained by instruments on board of the Swarm and DMSP satellites showed that the zone of highly structured auroral ionosphere extended at least to heights of 850-900 km.
Detection of the Equatorial Ionospheric Irregularities Using the POD GPS Measurements
NASA Astrophysics Data System (ADS)
Zakharenkova, I.; Astafyeva, E.; Cherniak, I.
2015-12-01
By making use of GPS measurements from Precise Orbit Determination (POD) GPS antenna onboard Low Earth Orbit (LEO) satellites we present results of the equatorial irregularities/plasma bubbles detection. For a given research we use data from a multi-satellite constellation consisting of the three Swarm satellites and the TerraSAR-X satellite. The major advantage of such LEO constellation is rather similar orbit altitude of ~500 km. The GPS-based indices, characterizing the occurrence and the strength of the ionospheric irregularities, were derived from the LEO GPS observations of a zenith-looking onboard GPS antenna. To study GPS fluctuation activity at the topside equatorial ionosphere we used TEC-based indices ROT (rate of TEC change) and ROTI (rate of TEC Index), proposed by Pi et al. (1997). We demonstrate a successful implementation of this technique for several case studies of the equatorial plasma bubbles occurrence in the post-midnight and morning LT hours during the year 2014. The ionospheric irregularities detected with GPS technique in Swarm/TerrasSAR-X data are consistent with the in situ plasma density variations registered by the three Swarm satellites (PLP measurements), as well as by three DMSP satellites at ~840 km orbital height, which indicate a large altitudinal extent of the observed phenomenon. Also we analyzed the global/seasonal distribution of the ionospheric irregularities at the topside equatorial region caused the phase fluctuations in GPS measurements onboard LEO satellite. We demonstrate that ROT/ROTI technique can be applied to LEO GPS data for geomagnetically quiet and disturbed conditions, as well as detection of the storm-induced equatorial irregularities in the morning local time.
NASA Technical Reports Server (NTRS)
Halpern, D.; Wentz, F.
1993-01-01
Development of decade-long time series of global surface wind measurements for studies ofseasonal-to-interannual climate variability presents unique challenges for space- borne instrumentationbecause of the necessity to combine data sets of 3- to 5-year lifetimes. Before the first Special SensorMicrowave Imager (SSMI), which was launched on the Defence Meteorological Satellite Program(DMSP) F8 spacecraft in July 1987, stopped recording wind speed in December 1991, another SSMIwas launched on DMSP F10 in December 1991. Interpretation of the 1987 - 1993 composite timeseries is dependent upon the space and time characteristics of the differences between concurrent F8and F10 SSMI measurements. This paper emphasizes large geographical regions and 1-month timescale. The F8-F10 area-weighted difference between 60 degrees S and 60 degrees S during 305 daysof 1991 (-0.12 m s^(-1)) was comparable to the year-to-year wind speed variations during 1988-1991. The 10 degree-zonal averaged monthly mean F8-F10 difference was negative (positive) forwind speeds less (greater) than 7.9 m s^(-1), reaching - 0.43(0.32) m s^(-1) at 5(10) m s^(-1). The10 degree-zonal averaged monthly mean F8-F10 bias had considerable variations throughout the yearand between 60 degrees S - 60 degrees N, with the largest temporal variation (1.4 m s^(-1)) in the 50degrees - 60 degrees N region from February to April. The 1991 average value of the monthly meanroot-mean-square (rms) difference between F8 and F10 daily wind speeds in 10 degree-longitudinalbands was 2.0 m s^(-1) over 60 degrees S - 60 degrees N, the amplitude of the annual cycle of therms difference was largest in the northern hemisphere middle latitudes, and the rms difference wasrelated to the wind speed (e.g., at 6 and 10 m s^(-1), the rms difference was 1.7 and 2.7 m s^(-1),respectively). The relationship between monthly mean 1/3 degrees x 1/3 degrees F8-F10 SSMI windspeed differences and integrated water vapor and liquid water content in the atmosphere is discussed.
Physics of the Geospace Response to Powerful HF Radio Waves
2012-10-31
studies of the response of the Earth’s space plasma to high-power HF radio waves from the High-frequency Active Auroral Research Program ( HAARP ...of HF heating and explored to simulate artificial ducts. DMSP- HAARP experiments revealed that HF-created ion outflows and artificial density ducts...in the topside ionosphere appeared faster than predicted by the models, pointing to kinetic (suprathermal) effects. CHAMP/GRACE- HAARP experiments
AURORA: The Next Generation Space Weather Sensor for NPOESS
NASA Astrophysics Data System (ADS)
Paxton, L.; Morrison, D.; Santo, A.; Ogorzalek, B.; Goldsten, J.; Boldt, J.; Kil, H.; Zhang, Y.; Demajistre, R.; Wolven, B.; Meng, C.
2005-12-01
The AURORA sensor slated for flight on the NPOESS satellites represents the culmination of over 20 years of experience at JHU/APL in the design, manufacture, flight, operation and analysis of compact, cost-effective far ultraviolet sensors for space weather data collection. The far ultraviolet covers the spectral range from about 115 to 185 nm. This region is ideal for observations of the upper atmosphere because, at these wavelengths, the lower atmosphere and Earth's surface are black. AURORA will observe the mid- and low-latitude F-region ionosphere, the auroral E-region ionosphere, the day thermosphere composition, auroral energy deposition and map ionospheric irregularities. AURORA implements the flight-proven design derived from SSUSI on the DMSP Block 5D spacecraft and GUVI on the NASA TIMED spacecraft. These instruments have provided the instrument and algorithm heritage for NPOESS/AURORA. In this talk the performance capabilities of the AURORA instrument will be summarized along with the design of the instrument and algorithms. Example products will be shown for each of the measurement regimes. We acknowldge support from DMSP and NASA and the collaboration with our science colleagues at the Aerospace Corporation (Paul Straus, Jim Hecht, Dave McKenzie, and Andy Christensen) and Computational Physics (Doug Strickland, Hal Knight, and Scott Evans) and Naval Research Laboratory (Robert Meier, Mike Picone, Stefan Thonnard, Pat Dandenault, and Andy Stefan) and our colleagues at APL (Michele Weiss, Doug Holland, Bill Wood, and Jim Eichert) among others.
A new global anthropogenic heat estimation based on high-resolution nighttime light data
Yang, Wangming; Luan, Yibo; Liu, Xiaolei; Yu, Xiaoyong; Miao, Lijuan; Cui, Xuefeng
2017-01-01
Consumption of fossil fuel resources leads to global warming and climate change. Apart from the negative impact of greenhouse gases on the climate, the increasing emission of anthropogenic heat from energy consumption also brings significant impacts on urban ecosystems and the surface energy balance. The objective of this work is to develop a new method of estimating the global anthropogenic heat budget and validate it on the global scale with a high precision and resolution dataset. A statistical algorithm was applied to estimate the annual mean anthropogenic heat (AH-DMSP) from 1992 to 2010 at 1×1 km2 spatial resolution for the entire planet. AH-DMSP was validated for both provincial and city scales, and results indicate that our dataset performs well at both scales. Compared with other global anthropogenic heat datasets, the AH-DMSP has a higher precision and finer spatial distribution. Although there are some limitations, the AH-DMSP could provide reliable, multi-scale anthropogenic heat information, which could be used for further research on regional or global climate change and urban ecosystems. PMID:28829436
Applications of a time-dependent polar ionosphere model for radio modification experiments
NASA Astrophysics Data System (ADS)
Fallen, Christopher Thomas
A time-dependent self-consistent ionosphere model (SLIM) has been developed to study the response of the polar ionosphere to radio modification experiments, similar to those conducted at the High-Frequency Active Auroral Research Program (HAARP) facility in Gakona, Alaska. SCIM solves the ion continuity and momentum equations, coupled with average electron and ion gas energy equations; it is validated by reproducing the diurnal variation of the daytime ionosphere critical frequency, as measured with an ionosonde. Powerful high-frequency (HF) electromagnetic waves can drive naturally occurring electrostatic plasma waves, enhancing the ionospheric reflectivity to ultra-high frequency (UHF) radar near the HF-interaction region as well as heating the electron gas. Measurements made during active experiments are compared with model calculations to clarify fundamental altitude-dependent physical processes governing the vertical composition and temperature of the polar ionosphere. The modular UHF ionosphere radar (MUIR), co-located with HAARP, measured HF-enhanced ion-line (HFIL) reflection height and observed that it ascended above its original altitude after the ionosphere had been HF-heated for several minutes. The HFIL ascent is found to follow from HF-induced depletion of plasma surrounding the F-region peak density layer, due to temperature-enhanced transport of atomic oxygen ions along the geomagnetic field line. The lower F-region and topside ionosphere also respond to HF heating. Model results show that electron temperature increases will lead to suppression of molecular ion recombination rates in the lower F region and enhancements of ambipolar diffusion in the topside ionosphere, resulting in a net enhancement of slant total electron content (TEC); these results have been confirmed by experiment. Additional evidence for the model-predicted topside ionosphere density enhancements via ambipolar diffusion is provided by in-situ measurements of ion density and vertical velocity over HAARP made by a Defense Meteorological Satellite Program (DMSP) satellite.
Stefels, Jacqueline; van Leeuwe, Maria A; Jones, Elizabeth M; Meredith, Michael P; Venables, Hugh J; Webb, Alison L; Henley, Sian F
2018-06-28
The Southern Ocean is a hotspot of the climate-relevant organic sulfur compound dimethyl sulfide (DMS). Spatial and temporal variability in DMS concentration is higher than in any other oceanic region, especially in the marginal ice zone. During a one-week expedition across the continental shelf of the West Antarctic Peninsula (WAP), from the shelf break into Marguerite Bay, in January 2015, spatial heterogeneity of DMS and its precursor dimethyl sulfoniopropionate (DMSP) was studied and linked with environmental conditions, including sea-ice melt events. Concentrations of sulfur compounds, particulate organic carbon (POC) and chlorophyll a in the surface waters varied by a factor of 5-6 over the entire transect. DMS and DMSP concentrations were an order of magnitude higher than currently inferred in climatologies for the WAP region. Particulate DMSP concentrations were correlated most strongly with POC and the abundance of haptophyte algae within the phytoplankton community, which, in turn, was linked with sea-ice melt. The strong sea-ice signal in the distribution of DMS(P) implies that DMS(P) production is likely to decrease with ongoing reductions in sea-ice cover along the WAP. This has implications for feedback processes on the region's climate system.This article is part of the theme issue 'The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change'. © 2018 The Author(s).
Global precipitation measurement (GPM)
NASA Astrophysics Data System (ADS)
Neeck, Steven P.; Flaming, Gilbert M.; Adams, W. James; Smith, Eric A.
2001-12-01
The National Aeronautics and Space Administration (NASA) is studying options for future space-based missions for the EOS Follow-on Era (post 2003), building upon the measurements made by Pre-EOS and EOS First Series Missions. One mission under consideration is the Global Precipitation Measurement (GPM), a cooperative venture of NASA, Japan, and other international partners. GPM will capitalize on the experience of the highly successful Tropical Rainfall Measurement Mission (TRMM). Its goal is to extend the measurement of rainfall to high latitudes with high temporal frequency, providing a global data set every three hours. A reference concept has been developed consisting of an improved TRMM-like primary satellite with precipitation radar and microwave radiometer to make detailed and accurate estimates of the precipitation structure and a constellation of small satellites flying compact microwave radiometers to provide the required temporal sampling of highly variable precipitation systems. Considering that DMSP spacecraft equipped with SSMIS microwave radiometers, successor NPOESS spacecraft equipped with CMIS microwave radiometers, and other relevant international systems are expected to be in operation during the timeframe of the reference concept, the total number of small satellites required to complete the constellation will be reduced. A nominal plan is to begin implementation in FY'03 with launches in 2007. NASA is presently engaged in advanced mission studies and advanced instrument technology development related to the mission.
2009-06-17
Electric and magnetic-field perturbations were measured by ion drift meters (IDM) and triaxial fluxgate magnetometers on DMSP F13. F15, and F16...we also regard DMSP as providing lower-bound estimates of the true *pc. The triaxial fluxgate SSM sensors are either mounted on the spacecraft
Scale Sizes of High-Latitude Neutral Mass Density Perturbations
NASA Astrophysics Data System (ADS)
Huang, C. Y.; Huang, Y.; Su, Y. J.; Huang, T.; Sutton, E. K.
2017-12-01
In a statistical study of neutral mass density maxima, we found for a select interval, that 57% of the maxima have correlated field-aligned current (FAC) signatures, indicative of localized Ohmic heating. However the remaining 43% do not, and we suggested that these maxima may be due to gravity waves generated by neutral heating. We follow up on this study by an investigation into the spatial scale sizes of the mass density maxima using high-resolution neutral density and FAC data from CHAMP, when the satellite is in conjunction with DMSP, which provides the corresponding ion drift velocity, particle precipitation and Poynting flux. The study shows the average scale sizes of the perturbations due to J x B heating, as well as the sizes of the waves generated by Joule heating.
Communications/Navigation Outage Forecasting System (C/NOFS)
2010-02-21
al., 2002]. They are also lower than values predicted by the International Reference Iono- sphere ( IRI ) model [Gulyaeva and Titheridge, 2006] run for...based on the IRI model or other observations. At present no mechanism has been proposed which accounts for the basic formation of BPDs or their...funding by the DMSP program office. We thank J. Retterer for the IRI model results. This research was supported by Air Force Office of Scientific Research
NASA Astrophysics Data System (ADS)
Liu, J.; Zhang, D.
2017-12-01
With datasets of electron density, neutral wind, ionosonde, neutral temperature, and geomagnetism, we studied the low-latitudinal ionosphere in East-Asia sector during Stratospheric Sudden Warming (SSW) Event in 2016/2017 winter, and some periodic variations in several parameters were revealed. A notable quasi-14.5-day (Q14.5D) period was detected in the strength and location of the northern equatorial ionospheric anomaly (EIA) crest shown with total electron content (TEC). As comparison, northern EIA crest in the American sector had similar characters. With data from Wuhan meteor radar and Yunnan MF radar, we found that, within altitude ranging from 80-100 km, wind field also showed above-mentioned periodic variation, which varied in different heights and stations. The Q14.5D period was also revealed in critical frequency (foF2) and peak altitude (hmF2) of F2 layer from two ionosonde stations in southern China. From electron density of Defense Meteorological Satellite Program (DMSP) and TEC of Metop-A, it was shown that this period component is also noticeable in the topside ionosphere above 800 km. However, this character is different in EEJ, of which the Morlet wavelet showed higher strength in quasi-7.5-day period compared to its Q14.5D component.
Coupled urbanization and agricultural ecosystem services in Guanzhong-Tianshui Economic Zone.
Zhou, Z X; Li, J; Zhang, W
2016-08-01
Ecosystems offer material and environmental support for human habitation and development in those areas of the earth where people choose to live. However, urbanization is an inexorable trend of human social development and threatens the health of those ecosystems inhabited by humans. This study calculates the values of NPP (net primary productivity), carbon sequestration, water interception, soil conservation, and agricultural production in the Guanzhong-Tianshui Economic Zone. At the same time, we combined DMSP/OLS (Defense Meteorological Satellite Program Operational Line Scanner) night lights remote sensing data and statistical data to analyze the level of urbanization. Quantitative analysis was performed on the interactions between the ecosystem service functions and urbanization based on the calculations of their coupled coordination degrees. The results were the following: (1) The values of NPP, carbon sequestration, and agricultural production showed a trend of increase. However, water interception decreased before increasing, while soil conservation showed the reverse trend; (2) Urbanization levels in the Guanzhong-Tianshui Economic Zone for the last 10 years have proceeded at a fast pace with comprehensive promotion; and (3) Coupled and coupled coordination degrees between urbanization and ecosystem services show increasing trends. This research can provide a theoretical basis for the region's rapid economic development in the balance.
Determination of Polar Cap Boundary for the Substorm Event of 8 March 2008
NASA Astrophysics Data System (ADS)
Wang, Chi; Wang, Jiangyan; Lopez, Ramon; Li, Hui; Zhang, Jiaojiao; Tang, Binbin
2018-05-01
The polar cap boundary (PCB) is a fundamental indicator of magnetospheric activities especially during a substorm cycle. Taking a period on 8 March 2008 as an example, we investigate the location of PCB and its dynamics during a substorm event. The PCB location is determined from the Piecewise Parabolic Method with a Lagrangian Remap (PPMLR) -Magnetohydrodynamic (MHD) simulation data and Defense Meteorological Satellite Program (DMSP) observations, respectively. Model-observation comparison indicates that the PPMLR-MHD model gives a reliable estimate of PCB location during a complex substorm sequence. We further analyze the evolution of PCB in that period. The polar cap expands under southward interplanetary magnetic field (IMF), since the low-latitude dayside reconnection produces new open magnetic flux. Meanwhile, more solar wind energy enters and stores in the magnetosphere with the decreasing SML (SuperMAG Auroral Lower) index. After the substorm expansion onset, the polar cap contracts for a while due to the explosive increase of nightside reconnection. When the IMF direction turns northward, the polar cap contracts continuously, since the dayside reconnection ceases and no more open magnetic flux are supplied, and the storage energy in the magnetosphere releases with the increasing SML index. The model results are in good accord with the features from observations.
Yau, Sheree; Lauro, Federico M; Williams, Timothy J; DeMaere, Matthew Z; Brown, Mark V; Rich, John; Gibson, John AE; Cavicchioli, Ricardo
2013-01-01
Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment. PMID:23619305
Production of quorum-sensing signals by bacteria in the coral mucus layer
NASA Astrophysics Data System (ADS)
Li, Jie; Kuang, Weiqi; Long, Lijuan; Zhang, Si
2017-12-01
Quorum sensing is an integral part of bacterial communication and interaction, but has not been well characterized in coral mucus microbiota. In this study, of 61 coral mucus isolates, five alphaproteobacteria and one Vibrio species were found to produce N-acyl homoserine lactone (AHL), a quorum-sensing signal in bacteria. Eight gammaproteobacteria isolates were found to produce autoinducer-2 (AI-2) quorum-sensing signals along with two actinobacteria of the genus Rothia. Coral mucus is rich in the antioxidant dimethylsulfoniopropionate (DMSP), the concentration of which has been found to increase under heat stress. Neither AHL nor AI-2 activity was induced by DMSP in those coral mucus isolates that did not initially produce quorum-sensing signals. However, the AI-2 activities of one Rothia isolate (SCSIO 13017) from coral mucus and of Vibrio shilonii (DSM 13774 isolated from a bleached coral) were found to increase in response to 5 μM DMSP but decreased in response to 50 μM DMSP for the first time. These findings suggest that the production of quorum-sensing signals in the coral mucus microbiota may play a role in structuring the surface microbial community as they respond to environmental stress.
Tropical Cyclone Lightning Distribution and Its Relationship to Convection and Intensity Change
NASA Technical Reports Server (NTRS)
Rodgers, Edward; Wienman, James; Pierce, Harold; Olson, William
2000-01-01
The long distance National Lightning Detection Network (NLDN) was used to monitor the distribution of lightning strokes in various 1998 and 1999 western North Atlantic tropical cyclones. These ground-based lightning observations together with the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) and the Tropical Rain Mapping Mission (TRMM) Microwave Instrument (TMI) derived convective rain rates were used to monitor the propagation of electrically charged convective rain bands aid to qualitatively estimate intensification. An example of the lightning analyses was performed on hurricane George between 25-28 September, 1998 when the system left Key West and moved towards the Louisiana coast. During this period of time, George's maximum winds increased from 38 to 45 meters per second on 25 September and then remained steady state until it made landfall. Time-radius displays of the lightning strokes indicated that the greatest number of lightning strokes occurred within the outer core region (greater than 165 km) with little or no lightning strokes at radii less than 165 km. The trend in these lightning strokes decreased as George move into the Gulf of Mexico and showed no inward propagation. The lack inward propagating lightning strokes with time indicated that there was no evidence that an eye wall replacement was occurring that could alter George's intensity. Since George was steady state at this time, this result is not surprising. Time-azimuth displays of lightning strokes in an annulus whose outer and inner radii were respectively, 222 and 333 km from George's center were also constructed. A result from this analysis indicated that the maximum number of strokes occurred in the forward and rear right quadrant when George was over the Gulf of Mexico. This result is, consistent with the aircraft and satellite observations of maximum rainfall.
Multi-instrumental Study of Storm-induced Ionospheric Irregularities at Midlatitudes
NASA Astrophysics Data System (ADS)
Cherniak, I.; Zakharenkova, I.; Sokolovskiy, S. V.
2017-12-01
We present multi-instrumental analysis of the unusually intense plasma density irregularities occurred over European midlatitudes during geomagnetic storm of 22-23 June 2015. We combine GPS/GLONASS observations derived from the dense ground-based networks ( 1500 stations) with in situ plasma density onboard Swarm and DMSP satellites and COSMIC Radio Occultation (RO) ionospheric electron density profiles. During this geomagnetic storm, the strong ionospheric irregularities of auroral origin were registered over the Northern Europe sub-auroral and midlatitudes. Meanwhile, another kind of ionospheric irregularities of equatorial origin reached European midlatitudes from the south. The prompt penetration electric fields caused the occurrence of plasma bite-outs in the post-sunset sector over the Western Africa low latitudes and extension of the large-scale plasma bubbles toward Europe. Using GPS/GLONASS observations, the plasma bubble signatures were mapped in Europe. They were observed for more than 8 h (20-04 UT) and covered a broad area within 30o-40o N and 20o W-10o E. In this region, the steep plasma gradients, as large as 5-10 TECU/degree, and numerous embedded deep plasma depletions were developed on the background of high plasma density. For low latitude region, the bite-out signature was recognized in the form of the significantly modified shape of the COSMIC-derived ionospheric electron density profiles. These unique results were confirmed by the in situ density and upward-looking GPS data onboard the Swarm satellites at 500 km altitude, in situ density measured by DMSP and ground-based absolute TEC observations. It was found that close similarity between in situ Ne and Swarm-derived topside vertical TEC suggests that plasma density enhancements and depletions are developed in the topside ionosphere (>500 km). The intensity of plasma gradients at different altitudes was also estimated by COSMIC-based measurements of GPS signal intensity and phase fluctuations as well as by rate of TEC changes on COSMIC-GPS links. Occurrence of the plasma bubbles in Europe affected GNSS measurements over number of reference stations and led to performance degradation of SBAS EGNOS.
NASA Astrophysics Data System (ADS)
Brandt, Pontus C.:son; Barabash, Stas; Norberg, Olle; Lundin, Rickard; Roelof, Edmond C.; Chase, Christopher J.
1999-02-01
Observations of energetic neutral atoms (ENA) in the energy range 26-52 keV are reported from four occasions during geomagnetically disturbed periods. The data were acquired by the ENA imager flown on the Swedish microsatellite Astrid in a 1000 km circular orbit with 83° inclination. The ENA imager separates charged particles from neutrals through an electrostatic deflection system in the energy range between 0.1 and 114 keV. ENA images obtained from vantage points in the polar cap and in the afternoon magnetic local time (MLT) hours looking into the antisunward hemisphere show intense ENA fluxes (~104(cm2srs)-1 over 26-37 keV) coming from the dusk region and low altitudes (~300 km). The morphology shows no relation to local magnetic field excluding the possibility of charged particle detection. It is concluded that the source of these ENAs are precipitating/mirroring ions from the ring current/trapped radiation interacting with the exobase on auroral L-shells and in the dusk region. The observed ENA fluxes show a relation with Kp and Dst geomagnetic indices. The observed ENA spectrum from a geomagnetic storm on February 8, 1995, is investigated in more detail and compared to the parent ion spectrum obtained by the Defense Meteorological Satellite Project (DMSP) satellite, F12, during the same period on L=6+/-2 around dusk. The observed ENA spectral slope is used to derive the parent ion spectral temperature. The derived ion temperatures range is 3.0-6.0 keV for H and 4.5-8.5 keV for O. The higher of these ion temperatures comes closest in agreement to the extrapolated DMSP spectrum leading us to favor O over H as the species of the detected ENAs. It is shown that the detected ENAs must have been produced at L>=6 to reach the detector without atmospheric attenuation and that the main energy dependence of the ENA spectrum, apart from the parent ion spectrum, is governed by the energy dependence of the charge exchange cross section between ions and exospheric oxygen.
NASA Astrophysics Data System (ADS)
Scarratt, M. G.; Marchetti, A.; Hale, M. S.; Rivkin, R. B.; Michaud, S.; Matthews, P.; Levasseur, M.; Sherry, N.; Merzouk, A.; Li, W. K. W.; Kiyosawa, H.
2006-10-01
A microcosm experiment was conducted in the NE Pacific in July 2002 to compare the microbial response between microcosms and the Subarctic Ecosystem Response to Iron-Enrichment Study (SERIES) in situ iron-enrichment experiment. Seawater microcosms (20 L) were incubated aboard ship under natural light using three treatments: (1) low-iron seawater amended with 4 nmol l -1 FeSO 4 (+Fe); (2) low-iron seawater amended with 4 nmol l -1 FeSO 4 and 86 nmol l -1 GeO 2 (+Fe+Ge); (3) seawater collected from the in situ Fe-enriched patch (PW). The +Fe+Ge treatment used germanium to control diatom growth to assess the role of diatoms in dimethylsulfoniopropionate (DMSP) production. The following variables were measured in the microcosms and in situ: chlorophyll a (chl a), nitrate ( NO3-), silicic acid (Si(OH) 4), phytoplankton abundance and species identification, bacterial abundance (including estimates of low- and high-DNA bacteria), bacterial production, bacterial specific growth rate, particulate and dissolved DMSP and dimethylsulfide (DMS) concentrations. There was little or no significant difference (ANCOVA) in the response of most variables between the +Fe and PW microcosms, but large differences were observed between both these treatments and the in situ data from the enriched patch. Chl a in all microcosms increased from ambient levels (approx. 0.5-1 μg l -1) to approx. 4.5-6.2 μg l -1 after 11 d incubation, when NO3- was fully depleted from all microcosms. During this same period, in situ chl a increased more slowly to a maximum of 2.9 μg l -1 on day 11. Nanophytoplankton and picophytoplankton were more abundant in the microcosms relative to the in situ community, which became dominated by large diatoms. Bacterial abundance was similar in the microcosms and in situ, but bacterial production was significantly higher in the microcosms. While neither DMSP d nor DMS accumulation showed significant differences between the microcosms and in situ , particulate DMSP concentrations increased significantly faster in the +Fe and PW treatments. These differences represent bottle effects resulting from the containment of the microcosms, which suppresses grazing, alters community and food web structure, enhances iron and nutrient regeneration, and isolates the community from physical transport and export processes including sinking. Thus during this experiment, the microcosms were not a good model for the in situ system in terms of the effects of iron on the phytoplankton biomass, nutrient uptake, bacterial dynamics and DMSP p production. In the germanium-amended treatment, the inhibition of diatom growth resulted in enhanced growth of other taxa and a suppression of bacterial production, leading to increased production of DMSP and DMS and strong correlations between DMSP, DMS and non-diatom phytoplankton taxa. Diatoms did not contribute significantly to particulate DMSP concentrations.
GEM-CEDAR Challenge: Poynting Flux at DMSP and Modeled Joule Heat
NASA Technical Reports Server (NTRS)
Rastaetter, Lutz; Shim, Ja Soon; Kuznetsova, Maria M.; Kilcommons, Liam M.; Knipp, Delores J.; Codrescu, Mihail; Fuller-Rowell, Tim; Emery, Barbara; Weimer, Daniel R.; Cosgrove, Russell;
2016-01-01
Poynting flux into the ionosphere measures the electromagnetic energy coming from the magnetosphere. This energy flux can vary greatly between quiet times and geomagnetic active times. As part of the Geospace Environment Modeling-coupling energetics and dynamics of atmospheric regions modeling challenge, physics-based models of the 3-D ionosphere and ionospheric electrodynamics solvers of magnetosphere models that specify Joule heat and empirical models specifying Poynting flux were run for six geomagnetic storm events of varying intensity. We compared model results with Poynting flux values along the DMSP-15 satellite track computed from ion drift meter and magnetic field observations. Although being a different quantity, Joule heat can in practice be correlated to incoming Poynting flux because the energy is dissipated primarily in high latitudes where Poynting flux is being deposited. Within the physics-based model group, we find mixed results with some models overestimating Joule heat and some models agreeing better with observed Poynting flux rates as integrated over auroral passes. In contrast, empirical models tend to underestimate integrated Poynting flux values. Modeled Joule heat or Poynting flux patterns often resemble the observed Poynting flux patterns on a large scale, but amplitudes can differ by a factor of 2 or larger due to the highly localized nature of observed Poynting flux deposition that is not captured by the models. In addition, the positioning of modeled patterns appear to be randomly shifted against the observed Poynting flux energy input. This study is the first to compare Poynting flux and Joule heat in a large variety of models of the ionosphere.
Status Update on the GPM Ground Validation Iowa Flood Studies (IFloodS) Field Experiment
NASA Astrophysics Data System (ADS)
Petersen, Walt; Krajewski, Witold
2013-04-01
The overarching objective of integrated hydrologic ground validation activities supporting the Global Precipitation Measurement Mission (GPM) is to provide better understanding of the strengths and limitations of the satellite products, in the context of hydrologic applications. To this end, the GPM Ground Validation (GV) program is conducting the first of several hydrology-oriented field efforts: the Iowa Flood Studies (IFloodS) experiment. IFloodS will be conducted in the central to northeastern part of Iowa in Midwestern United States during the months of April-June, 2013. Specific science objectives and related goals for the IFloodS experiment can be summarized as follows: 1. Quantify the physical characteristics and space/time variability of rain (rates, DSD, process/"regime") and map to satellite rainfall retrieval uncertainty. 2. Assess satellite rainfall retrieval uncertainties at instantaneous to daily time scales and evaluate propagation/impact of uncertainty in flood-prediction. 3. Assess hydrologic predictive skill as a function of space/time scales, basin morphology, and land use/cover. 4. Discern the relative roles of rainfall quantities such as rate and accumulation as compared to other factors (e.g. transport of water in the drainage network) in flood genesis. 5. Refine approaches to "integrated hydrologic GV" concept based on IFloodS experiences and apply to future GPM Integrated GV field efforts. These objectives will be achieved via the deployment of the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms with attendant soil moisture and temperature probes, a large network of both 2D Video and Parsivel disdrometers, and USDA-ARS gauge and soil-moisture measurements (in collaboration with the NASA SMAP mission). The aforementioned measurements will be used to complement existing operational WSR-88D S-band polarimetric radar measurements, USGS streamflow, and Iowa Flood Center stream monitoring measurements. Coincident satellite datasets will be archived from current microwave imaging and sounding radiometers flying on NOAA, DMSP, NASA, and EU (METOP) low-earth orbiters, and rapid-scanned IR datasets collected from geostationary (GOES) platforms. Collectively the observational assets will provide a means to create high quality (time and space sampling) ground "reference" rainfall and stream flow datasets. The ground reference radar and rainfall datasets will provide a means to assess uncertainties in both satellite algorithms (physics) and products. Subsequently, the impact of uncertainties in the satellite products can be evaluated in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction.
Microbiomes of Ecologically Dominant Zooxanthellate Anthozoans: A Tropical-Temperate Comparison
NASA Astrophysics Data System (ADS)
Campbell, T. L.; Geller, J. B.; Schmeltzer, E.; Little, M.
2016-02-01
Marine bacteria are known to play an important role in cnidarian health, the cycling of organic matter and dimethylsulfionopropionate (DMSP) in reef ecosystems. The breadth of investigation surrounding this relationship in tropical reefs is vast; however, little work has been done in temperate non-reef building systems. Anthopleura elegantissima is a common zooxanthellate anthozoan on the Northeastern (NE) Pacific coast, also known to produce DMSP, yet relatively little is known about the bacterial community it harbors. In this study, we compare the bacterial communities of tropical Porites and Pocillopora species with the temperate Anthopleura elegantissima. We further compare bleached A. elegantissima polyps to polyps dark with zooxanthellae to investigate the complex relationship between host, symbiodinium, and bacteria. We sampled coral mucus from 45 individual coral colonies of Porites rus and Pocillopora damicornis, and Porites lutea in Moorea, French Polynesia and capitulum from 6 individual A. elegantissima polyps, which strikingly varied in color attributable to symbionts, from Moss Landing, California. All samples were processed according to the environmental microbiome project (EMP) protocols. The A. elegantissima samples also underwent microbial metagenome sequencing in an attempt to infer environmental function of these symbionts. In corals, major bacterial groups included Alteromonas, Rhodobacteraceae, and Vibrio. Vibrio, along with Rhodobacteraceae, are associated with DMSP metabolism. Pseudoalteromonadaceae varied greatly among samples, without correlation to species, similar to previous studies. Data analysis for anemones is in progress. DMSP and DMS have been studied for their role in forming cloud condensation nuclei, potentially leading to climate cooling. Anthopleura is thought to be the most abundant upper intertidal invertebrate in the NE Pacific, potentially making it an important player in coastal DMSP cycling.
Methanethiol Concentrations and Sea-Air Fluxes in the Subarctic NE Pacific Ocean
NASA Astrophysics Data System (ADS)
Kiene, R. P.; Williams, T. E.; Esson, K.; Tortell, P. D.; Dacey, J. W. H.
2017-12-01
Exchange of volatile organic sulfur from the ocean to the atmosphere impacts the global sulfur cycle and the climate system and is thought to occur mainly via the gas dimethylsulfide (DMS). DMS is produced during degradation of the abundant phytoplankton osmolyte dimethylsulfoniopropionate (DMSP) but bacteria can also convert dissolved DMSP into the sulfur gas methanethiol (MeSH). MeSH has been difficult to measure in seawater because of its high chemical and biological reactivity and, thus, information on MeSH concentrations, distribution and sea-air fluxes is limited. We measured MeSH in the northeast subarctic Pacific Ocean in July 2016, along transects with strong phytoplankton abundance gradients. Water samples obtained with Niskin bottles were analyzed for MeSH by purge-and-trap gas chromatography. Depth profiles showed that MeSH concentrations were high near the surface and declined with depth. Surface waters (5 m depth) had an average MeSH concentration of 0.75 nM with concentrations reaching up to 3nM. MeSH concentrations were correlated (r = 0.47) with microbial turnover of dissolved DMSP which ranged up to 236 nM per day. MeSH was also correlated with total DMSP (r = 0.93) and dissolved DMS (r = 0.63), supporting the conclusion that DMSP was a major precursor of MeSH. Surface water MeSH:DMS concentration ratios averaged 0.19 and ranged up to 0.50 indicating that MeSH was a significant fraction of the volatile sulfur pool in surface waters. Sea-air fluxes of MeSH averaged 15% of the combined DMS+MeSH flux, therefore MeSH contributed an important fraction of the sulfur emitted to the atmosphere from the subarctic NE Pacific Ocean.
Global Precipitation Measurement (GPM) Mission: Overview and Status
NASA Technical Reports Server (NTRS)
Hou, Arthur Y.
2012-01-01
The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. NASA and JAXA will deploy a Core Observatory in 2014 to serve as a reference satellite to unify precipitation measurements from the constellation of sensors. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will be the first dual-frequency radar in space to provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will be used as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1 satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian MeghaTropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA)-19, (5) MHS instruments on MetOp satellites launched by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), (6) the Advanced Technology Microwave Sounder (ATMS) on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), and (7) ATMS instruments on the NOAA-NASA Joint Polar Satellite System (JPSS) satellites. Data from Chinese and Russian microwave radiometers may also become available through international collaboration under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). The current generation of global rainfall products combines observations from a network of uncoordinated satellite missions using a variety of merging techniques. GPM will provide "next-generation" precipitation products characterized by: (1) more accurate instantaneous precipitation estimate (especially for light rain and cold-season solid precipitation), (2) intercalibrated microwave brightness temperatures from constellation radiometers within a consistent framework, and (3) unified precipitation retrievals from constellation radiometers using a common a priori hydrometeor database constrained by combined radar/radiometer measurements provided by the GPM Core Observatory. GPM is a science mission with integrated applications goals. GPM will provide a key measurement to improve understanding of global water cycle variability and freshwater availability in a changing climate. The DPR and GMI measurements will offer insights into 3-dimensional structures of hurricanes and midlatitude storms, microphysical properties of precipitating particles, and latent heat associated with precipitation processes. The GPM mission will also make data available in near realtime (within 3 hours of observations) forocietal applications ranging from position fixes of storm centers, numerical weather prediction, flood forecasting, freshwater management, landslide warning, crop prediction, to tracking of water-borne diseases. An overview of the GPM mission design, retrieval strategy, ground validation activities, and international science collaboration will be presented.
NASA Astrophysics Data System (ADS)
Alcolombri, Uria; Ben-Dor, Shifra; Feldmesser, Ester; Levin, Yishai; Tawfik, Dan S.; Vardi, Assaf
2015-06-01
Algal blooms produce large amounts of dimethyl sulfide (DMS), a volatile with a diverse signaling role in marine food webs that is emitted to the atmosphere, where it can affect cloud formation. The algal enzymes responsible for forming DMS from dimethylsulfoniopropionate (DMSP) remain unidentified despite their critical role in the global sulfur cycle. We identified and characterized Alma1, a DMSP lyase from the bloom-forming algae Emiliania huxleyi. Alma1 is a tetrameric, redox-sensitive enzyme of the aspartate racemase superfamily. Recombinant Alma1 exhibits biochemical features identical to the DMSP lyase in E. huxleyi, and DMS released by various E. huxleyi isolates correlates with their Alma1 levels. Sequence homology searches suggest that Alma1 represents a gene family present in major, globally distributed phytoplankton taxa and in other marine organisms.
NASA Astrophysics Data System (ADS)
Boscher, Daniel; Rochel Grimald, Sandrine
2013-04-01
Using DMSP satellites, low altitude measurements has demonstrated to give a good picture of the plasmasheet population. The NOAA POES satellites are a constellation of five spacecraft orbiting in a polar orbit between 800 and 850 km and covering a wide L-shell range. They provide fourteen years of data without interruption which allow to make statistical study of the inner magnetosphere and the plasmasheet population. Moreover, since 2002, three of the NOAA POES satellites are located at different local times allowing to deduce the plasmasheet properties, even for huge magnetic activity. This paper present a statistical study of the warm and hot electron density over an energy range [0.16 ; 300] keV and between 1 and 12 Re. We present here maps in Mac Ilwain L paramater / MLT and we use the magnetic indices and solar wind parameter to classify our observations. The results show a clear motion of the plasmapause when Kp increase, which is in agreement with previous results, but it also show changes of the plasmapause shape and strong density variations in the night side sector. Moreover, a clear link between the solar wind parameters, in particular Bz, and the density distribution has been established. Unexpected distributions have been observed in the dayside and will be discussed here.
NASA Astrophysics Data System (ADS)
Asher, Elizabeth; Dacey, John W.; Ianson, Debby; Peña, Angelica; Tortell, Philippe D.
2017-04-01
Concentrations of dimethylsulfide (DMS), measured in the Subarctic Pacific during summer 2010 and 2011, ranged from ˜1 to 40 nM, while dissolved dimethylsulfoxide (DMSO) concentrations (range 13-23 nM) exceeded those of dissolved dimethyl sulfoniopropionate (DMSP) (range 1.3-8.8 nM). Particulate DMSP dominated the reduced sulfur pool, reaching maximum concentrations of 100 nM. Coastal and off shore waters exhibited similar overall DMS concentration ranges, but sea-air DMS fluxes were lower in the oceanic waters due to lower wind speeds. Surface DMS concentrations showed statistically significant correlations with various hydrographic variables including the upwelling intensity (r2 = 0.52, p < 0.001) and the Chlorophyll a/mixed layer depth ratio (r2 = 0.52, p < 0.001), but these relationships provided little predictive power at small scales. Stable isotope tracer experiments indicated that the DMSP cleavage pathway always exceeded the DMSO reduction pathway as a DMS source, leading to at least 85% more DMS production in each experiment. Gross DMS production rates were positively correlated with the upwelling intensity, while net rates of DMS production were significantly correlated to surface water DMS concentrations. This latter result suggests that our measurements captured dominant processes driving surface DMS accumulation across a coastal-oceanic gradient.
Factors controlling dimethylsulfide emission from salt marshes
NASA Technical Reports Server (NTRS)
Dacey, John W. H.; Wakeham, S. G.; Howes, B. L.
1985-01-01
The factors that control the emission of methylated gases from salt marshes are being studied. Research focusses on dimethylsulfide (DMS) formation and the mechanism of DMS and CH4 emission to the atmosphere. The approach is to consider the plants as valves regulating the emission of methylated gases to the atmosphere with the goal of developing appropriate methods for emission measurement. In the case of CH4, the sediment is the source and transport to the atmosphere occurs primarily through the internal gas spaces in the plants. The source of DMS appears to be dimethyl sulfoniopropionate (DMSP) which may play a role in osmoregulation in plant tissues. Concentrations of DMSP in leaves are typically several-fold higher than in roots and rhizomes. Even so, the large below ground biomass of this plant means that 2/3 of the DMSP in the ecosystem is below ground on the aerial basis. Upon introduction to sediment water, DMSP rapidly decomposes to DMS and acrylic acid. The solubility of a gas (its equilibrium vapor pressure) is a fundamental aspect of gas exchange kinetics. The first comprehensive study was conducted of DMS solubility in freshwater and seawater. Data suggest that the Setchenow relation holds for H at intermediate salinities collected. These data support the concept that the concentration of DMS in the atmosphere is far from equilibrium with seawater.
Johnson, Winifred M; Kido Soule, Melissa C; Kujawinski, Elizabeth B
2016-09-01
Microbes, the foundation of the marine foodweb, do not function in isolation, but rather rely on molecular level interactions among species to thrive. Although certain types of interactions between autotrophic and heterotrophic microorganisms have been well documented, the role of specific organic molecules in regulating inter-species relationships and supporting growth are only beginning to be understood. Here, we examine one such interaction by characterizing the metabolic response of a heterotrophic marine bacterium, Ruegeria pomeroyi DSS-3, to growth on dimethylsulfoniopropionate (DMSP), an abundant organosulfur metabolite produced by phytoplankton. When cultivated on DMSP, R. pomeroyi synthesized a quorum-sensing molecule, N-(3-oxotetradecanoyl)-l-homoserine lactone, at significantly higher levels than during growth on propionate. Concomitant with the production of a quorum-sensing molecule, we observed differential production of intra- and extracellular metabolites including glutamine, vitamin B2 and biosynthetic intermediates of cyclic amino acids. Our metabolomics data indicate that R. pomeroyi changes regulation of its biochemical pathways in a manner that is adaptive for a cooperative lifestyle in the presence of DMSP, in anticipation of phytoplankton-derived nutrients and higher microbial density. This behavior is likely to occur on sinking marine particles, indicating that this response may impact the fate of organic matter.
Satellite Contributions to the Quantitative Characterization of Biomass Burning for Climate Modeling
NASA Technical Reports Server (NTRS)
Ichoku, Charles; Kahn, Ralph; Chin, Mian
2012-01-01
Characterization of biomass burning from space has been the subject of an extensive body of literature published over the last few decades. Given the importance of this topic, we review how satellite observations contribute toward improving the representation of biomass burning quantitatively in climate and air-quality modeling and assessment. Satellite observations related to biomass burning may be classified into five broad categories: (i) active fire location and energy release, (ii) burned areas and burn severity, (iii) smoke plume physical disposition, (iv) aerosol distribution and particle properties, and (v) trace gas concentrations. Each of these categories involves multiple parameters used in characterizing specific aspects of the biomass-burning phenomenon. Some of the parameters are merely qualitative, whereas others are quantitative, although all are essential for improving the scientific understanding of the overall distribution (both spatial and temporal) and impacts of biomass burning. Some of the qualitative satellite datasets, such as fire locations, aerosol index, and gas estimates have fairly long-term records. They date back as far as the 1970s, following the launches of the DMSP, Landsat, NOAA, and Nimbus series of earth observation satellites. Although there were additional satellite launches in the 1980s and 1990s, space-based retrieval of quantitative biomass burning data products began in earnest following the launch of Terra in December 1999. Starting in 2000, fire radiative power, aerosol optical thickness and particle properties over land, smoke plume injection height and profile, and essential trace gas concentrations at improved resolutions became available. The 2000s also saw a large list of other new satellite launches, including Aqua, Aura, Envisat, Parasol, and CALIPSO, carrying a host of sophisticated instruments providing high quality measurements of parameters related to biomass burning and other phenomena. These improved data products have enabled significant progress in the study of biomass burning from space. However, appreciable uncertainty remains in many of the measurements that still needs to be addressed. Nevertheless, climate and other atmospheric models are
NASA Astrophysics Data System (ADS)
Bennett, M.; Smith, L. C.
2016-12-01
To date, no studies have examined the transition from communism to capitalism in Russia or China with night light (NTL) data despite the availability of DMSP-OLS satellite imagery dating back to 1992, one year after the dissolution of the Soviet Union. This paper uses the DMSP-OLS Version 4 stable lights annual image composites for every year from 1992-2012 to reveal the complex and sometimes divergent trajectories of regional development in Russia and China. We first characterize the spatial patterns and characteristics of NTL intensity and extensivity in Russia versus China at national and regional scales across this 21-year period. Although GDP rises in both countries during this time, NTL tells a different story: total night light (tNTL) in Russia in 2012 is slightly lower than in 1992, while tNTL in China is significantly higher. Next, we generate regional-level tNTL from each annual composite and examine their relationships with population, GDP, and fixed capital investment data from the Russian Federal State Statistics Service and the National Bureau of Statistics of China using a fixed effects model. We determine that while the fixed effects "between" model explains more of the differences in tNTL between Russia's federal subjects, the "within" model better explains differences over time within China's provinces. This suggests that on the one hand, Russia's regions are more heterogeneous than China's. On the other hand, whereas change over time in population and GRP explains change over time in tNTL in China's regions, they hardly do so at all for Russia's. Finally, we attempt to combine these socioeconomic variables with NTL data to build an NTL-based typology of regional development, representing a step beyond existing research. The preliminary creation of a regional development typology allows us to begin identifying emerging resource frontiers (places with increases in NTL but decreases in population) along with areas experiencing a reversal of development (places with decreases in both NTL and population). Our research also demonstrates that although NTL increase is often taken as a proxy for population increase, the case of post-Soviet Russia shows that there are important exceptions to this relationship that merit further investigation.
A gridded global description of the ionosphere and thermosphere for 1996 - 2000
NASA Astrophysics Data System (ADS)
Ridley, A.; Kihn, E.; Kroehl, H.
The modeling and simulation community has asked for a realistic representation of the near-Earth space environment covering a significant number of years to be used in scientific and engineering applications. The data, data management systems, assimilation techniques, physical models, and computer resources are now available to construct a realistic description of the ionosphere and thermosphere over a 5 year period. DMSP and NOAA POES satellite data and solar emissions were used to compute Hall and Pederson conductances in the ionosphere. Interplanetary magnetic field measurements on the ACE satellite define average electrostatic potential patterns over the northern and southern Polar Regions. These conductances, electric field patterns, and ground-based magnetometer data were input to the Assimilative Mapping of Ionospheric Electrodynamics model to compute the distribution of electric fields and currents in the ionosphere. The Global Thermosphere Ionosphere Model (GITM) used the ionospheric electrodynamic parameters to compute the distribution of particles and fields in the ionosphere and thermosphere. GITM uses a general circulation approach to solve the fundamental equations. Model results offer a unique opportunity to assess the relative importance of different forcing terms under a variety of conditions as well as the accuracies of different estimates of ionospheric electrodynamic parameters.
Coordinated field study for CaPE: Analysis of energy and water budgets
NASA Technical Reports Server (NTRS)
Goodman, Steven J.; Duchon, Claude; Kanemasu, Edward T.; Smith, Eric A.; Crosson, William; Laymon, Chip; Luvall, Jeff
1993-01-01
The objectives of this hydrologic cycle study are to understand and model (1) surface energy and land-atmosphere water transfer processes, and (2) interactions between convective storms and surface energy fluxes. A surface energy budget measurement campaign was carried out by an interdisciplinary science team during the period July 8 - August 19, 1991 as part of the Convection and Precipitation/Electrification Experiment (CaPE) in the vicinity of Cape Canaveral, FL. Among the research themes associated with CaPE is the remote estimation of rainfall. Thus, in addition to surface radiation and energy budget measurements, surface mesonet, special radiosonde, precipitation, high-resolution satellite (SPOT) data, geosynchronous (GOES) and polar orbiting (DMSP SSM/I, OLS; NOAA AVHRR) satellite data, and high altitude airplane data (AMPR, MAMS, HIS) were collected. Initial quality control of the seven surface flux station data sets has begun. Ancillary data sets are being collected and assembled for analysis. Browsing of GOES and radar data has begun to classify days as disturbed/undisturbed to identify the larger scale forcing of the pre-convective environment, convection storms and precipitation. The science analysis plan has been finalized and tasks assigned to various investigators.
High-latitude Daytime Magnetic Bays as Effects of Strong Positive IMF Bz: Case study
NASA Astrophysics Data System (ADS)
Gromova, L. I.; Kleimenova, N. G.; Levitin, A. E.; Dremukhina, L. A.; Antonova, E. E.; Gromov, S. V.
2017-08-01
We present unusual negative magnetic bay-like disturbances occurred in the dayside polar geomagnetic latitudes under positive IMF Bz. The considered events were observed during the recovery phase of the storm of May 30, 2003 and the main phase of the storm of Nov 24, 2001. We call such magnetic disturbances "dayside polar substorms". It is supposed that the development of dayside polar substorms can be represented as a magnetospheric response to a significant change of the IMF Bz from negative to high positive values. The vector construction of the geomagnetic data (Scandinavian magnetometer chain IMAGE) demonstrated a clockwise vortex during the storm of Nov 24, 2001, and two opposing vortices in the event of May 30, 2003. These vortices could be regarded as a proxy of an intensification of downward and upward field-aligned currents. This assumption is based on the IZMIRAN model estimations and the simultaneous DMSP and CHAMP satellite data. According to the OVATION model and the electron images from IMAGE satellite, the Scandinavian polar stations that registered these dayside polar magnetic substorms, were mapped into the dayside auroral oval, i.e. inside the closed magnetosphere.
Alcolombri, Uria; Ben-Dor, Shifra; Feldmesser, Ester; Levin, Yishai; Tawfik, Dan S; Vardi, Assaf
2015-06-26
Algal blooms produce large amounts of dimethyl sulfide (DMS), a volatile with a diverse signaling role in marine food webs that is emitted to the atmosphere, where it can affect cloud formation. The algal enzymes responsible for forming DMS from dimethylsulfoniopropionate (DMSP) remain unidentified despite their critical role in the global sulfur cycle. We identified and characterized Alma1, a DMSP lyase from the bloom-forming algae Emiliania huxleyi. Alma1 is a tetrameric, redox-sensitive enzyme of the aspartate racemase superfamily. Recombinant Alma1 exhibits biochemical features identical to the DMSP lyase in E. huxleyi, and DMS released by various E. huxleyi isolates correlates with their Alma1 levels. Sequence homology searches suggest that Alma1 represents a gene family present in major, globally distributed phytoplankton taxa and in other marine organisms. Copyright © 2015, American Association for the Advancement of Science.
JPL/USC GAIM: Using COSMIC Occultations in a Real-Time Global Ionospheric Data Assimilation Model
NASA Astrophysics Data System (ADS)
Mandrake, L.; Komjathy, A.; Wilson, B. D.; Pi, X.; Hajj, G.; Iijima, B.; Wang, C.
2006-12-01
We are in the midst of a revolution in ionospheric remote sensing driven by the illuminating powers of ground and space-based GPS receivers, new UV remote sensing satellites, and the advent of data assimilation techniques for space weather. In particular, the COSMIC 6-satellite constellation launched in April 2006. COSMIC will provide unprecedented global coverage of GPS occultations (~5000 per day), each of which yields electron density information with unprecedented ~1 km vertical resolution. Calibrated measurements of ionospheric delay (total electron content or TEC) suitable for input into assimilation models will be available in near real-time (NRT) from the COSMIC project with a latency of 30 to 120 minutes. Similarly, NRT TEC data are available from two worldwide NRT networks of ground GPS receivers (~75 5-minute sites and ~125 more hourly sites, operated by JPL and others). The combined NRT ground and space-based GPS datasets provide a new opportunity to more accurately specify the 3-dimensional ionospheric density with a time lag of only 15 to 120 minutes. With the addition of the vertically-resolved NRT occultation data, the retrieved profile shapes will model the hour-to-hour ionospheric "weather" much more accurately. The University of Southern California (USC) and the Jet Propulsion Laboratory (JPL) have jointly developed a real-time Global Assimilative Ionospheric Model (GAIM) to monitor space weather, study storm effects, and provide ionospheric calibration for DoD customers and NASA flight projects. JPL/USC GAIM is a physics- based 3D data assimilation model that uses both 4DVAR and Kalman filter techniques to solve for the ion & electron density state and key drivers such as equatorial electrodynamics, neutral winds, and production terms. Daily (delayed) GAIM runs can accept as input ground GPS TEC data from 1000+ sites, occultation links from CHAMP, SAC-C, and the COSMIC constellation, UV limb and nadir scans from the TIMED and DMSP satellites, and in situ data from a variety of satellites (DMSP and C/NOFS). RTGAIM ingests multiple data sources in real time, updates the 3D electron density grid every 5 minutes, and solves for improved drivers every 1-2 hours. Since our forward physics model and the adjoint model were expressly designed for data assimilation and computational efficiency, all of this can be accomplished on a single dual-processor Unix workstation. Customers are currently evaluating the accuracy of JPL/USC GAIM "nowcasts" for ray tracing applications and trans-ionospheric path delay calibration. In the talk, we will discuss the expected impact of COSMIC occultation data; show first results for ingest of COSMIC data using the GAIM Kalman filter; present validation of the GAIM electron density grid by comparisons to Abel profiles and independent datasets; describe recent improvements to the JPL/USC GAIM model; and describe our plans for NRT ingest of COSMIC data into RTGAIM.
DMSP Special Sensor Microwave/Imager Calibration/Validation
1991-05-20
degrade , regardless of the algorithm, seems to be about 2 mm/hr. SSMAI wind speed retrieval accuracy in... the U.S. and ;ome rangeland of the western U.S. at peak vegetation cover. 2. The " cerrado " vegetation regior, of central Brazil. These are savanna tye...presented; with and without the 85 GIIz channels as a con.;_tcuence of the degradation of the 85 GHz channels on the SSM/I on DMSP F-8. The primary data
Sunlight Effects on the Osmotrophic Uptake of DMSP-Sulfur and Leucine by Polar Phytoplankton
Ruiz-González, Clara; Galí, Martí; Sintes, Eva; Herndl, Gerhard J.; Gasol, Josep M.; Simó, Rafel
2012-01-01
Even though the uptake and assimilation of organic compounds by phytoplankton has been long recognized, very little is still known about its potential ecological role in natural marine communities and whether it varies depending on the light regimes the algae experience. We combined measurements of size-fractionated assimilation of trace additions of 3H-leucine and 35S-dimethylsulfoniopropionate (DMSP) with microautoradiography to assess the extent and relevance of osmoheterotrophy in summer phytoplankton assemblages from Arctic and Antarctic waters, and the role of solar radiation on it was further investigated by exposing samples to different radiation spectra. Significant assimilation of both substrates occurred in the size fraction containing most phytoplankton (>5 µm), sunlight exposure generally increasing 35S-DMSP-sulfur assimilation and decreasing 3H-leucine assimilation. Microautoradiography revealed that the capacity to take up both organic substrates seemed widespread among different polar algal phyla, particularly in pennate and centric diatoms, and photosynthetic dinoflagellates. Image analysis of the microautoradiograms showed for the first time interspecific variability in the uptakes of 35S-DMSP and 3H-leucine by phytoplankton depending on the solar spectrum. Overall, these results suggest that the role of polar phytoplankton in the utilization of labile dissolved organic matter may be significant under certain conditions and further confirm the relevance of solar radiation in regulating heterotrophy in the pelagic ocean. PMID:23029084
SA13B-1900 Auroral Charging of the International Space Station
NASA Technical Reports Server (NTRS)
Minow, Joseph I.; Chandler, Michael O.; Wright, Kenneth H., Jr.
2011-01-01
Electrostatic potential variations of the International Space Station (ISS) relative to the space plasma environment are dominated by interaction of the negatively grounded 160 volt US photovoltaic power system with the plasma environment in sunlight and inductive potential variations across the ISS structure generated by motion of the vehicle across the Earth's magnetic field. Auroral charging is also a source of potential variations because the 51.6? orbital inclination of ISS takes the vehicle to sufficiently high magnetic latitudes to encounter precipitating electrons during geomagnetic storms. Analysis of auroral charging for small spacecraft or isolated insulating regions on ISS predict rapid charging to high potentials of hundreds of volts but it has been thought that the large capacitance of the entire ISS structure on the order of 0.01 F will limit frame potentials to less than a volt when exposed to auroral conditions. We present three candidate auroral charging events characterized by transient ISS structure potentials varying from approximately 2 to 17 volts. The events occur primarily at night when the solar arrays are unbiased and cannot therefore be due to solar array current collection. ISS potential decreases to more negative values during the events indicating electron current collection and the events are always observed at the highest latitudes along the ISS trajectory. Comparison of the events with integral >30 keV electron flux measurements from NOAA TIROS spacecraft demonstrate they occur within regions of precipitating electron flux at levels consistent with the energetic electron thresholds reported for onset of auroral charging of the DMSP and Freja satellites. In contrast to the DMSP and Freja events, one of the ISS charging events occur in sunlight.
NASA Technical Reports Server (NTRS)
Clauer, C. R.; Baker, J. B.; Ridley, A. J.; Sitar, R. J.; Papitashvili, V. O.; Cumnock, J.; Spann, J. F., Jr.; Brittnacher, M. J.; Parks, G. K.
1997-01-01
Coordinated analysis of data from the POLAR UVI instrument, ground magnetometers, incoherent scatter radar, solar wind monitors IMP-8 and WIND, and DMSP satellite is focused on a traveling convection vortex (TCV) event on 24 July 1966. Starting at 10:48 UT, ground magnetometers in Greenland and eastern Canada measure pulsations consistent with the passing overhead of a series of alternating TCV field-aligned current pairs. Sondrestrom incoherent scatter radar measures strong modulation of the strength and direction of ionospheric plasma flow, The magnetometer pulsations grow in magnitude over the next hour, peaking in intensity at 11:39 UT, at which time the UVI instrument measures a localized intensification of auroral emissions over central and western Greenland. Subsequent images show the intensification grow in strength and propagate westward (tailward) until approximately 11:58 UT at which time the emissions fade. These observations are consistent with the westward passage of two pairs of moderately intense TCVs over central Greenland followed by a third very intense TCV pair. The intensification of auroral emissions at 11:39 UT is associated with the trailing vortex of the third TCV pair, thought to be the result of an upward field-aligned current. Measurements of the solar wind suggest that a pressure change may be responsible for triggering the first two pairs of TCVS, and that a subsequent sudden change in orientation of the IMF may have produced the intensification of the third TCV pair and the associated aurora] brightening. DMSP particle data indicate that the TCVs occur on field lines which map to the boundary plasma sheet or outer edge of the low latitude boundary layer.
NASA Astrophysics Data System (ADS)
Grocott, A.; Milan, S. E.; Baker, J. B. H.; Freeman, M. P.; Lester, M.; Yeoman, T. K.
2011-11-01
We present an analysis of ionospheric electric field data observed during a geomagnetic storm by the recently deployed HF radar located on the Falkland Islands. On 3 August 2010 at ˜1800 UT evidence of the onset of a geomagnetic storm was observed in ground magnetometer data in the form of a decrease in the Sym-H index of ˜100 nT. The main phase of the storm was observed to last ˜24 hours before a gradual recovery lasting ˜3 days. On 4 August, during the peak magnetic disturbance of the storm, a high velocity (>1000 m s-1) channel of ionospheric plasma flow, which we interpret as a subauroral ion drift (SAID), located between 53° and 58° magnetic south and lasting ˜6.5 hours, was observed by the Falkland Islands radar in the pre-midnight sector. Coincident flow data from the DMSP satellites and the magnetically near-conjugate northern hemisphere Blackstone HF radar reveal that the SAID was embedded within the broader subauroral polarization streams (SAPS). DMSP particle data indicate that the SAID location closely followed the equatorward edge of the auroral electron precipitation boundary, while remaining generally poleward of the equatorward boundary of the ion precipitation. The latitude of the SAID varied throughout the interval on similar timescales to variations in the interplanetary magnetic field and auroral activity, while variations in its velocity were more closely related to ring current dynamics. These results are consistent with SAID electric fields being generated by localized charge separation in the partial ring current, but suggest that their location is more strongly governed by solar wind driving and associated large-scale magnetospheric dynamics.
Structure and Variability in the Ionosphere using DMSP/SSUSI and TIMED/GUVI Data
NASA Astrophysics Data System (ADS)
Bruntz, R. J.; Paxton, L. J.; Kil, H.; Schaefer, R. K.; Zhang, Y.; Miller, E. S.
2016-12-01
In this paper we report the results of our characterization of the nightside ionospheric variability using data from SSUSI and GUVI. Both instruments observe the recombination of O+ ions and electrons in the ionosphere. The signatures are clearest on the nightside, where they are not obscured by the photoelectron impact excitation of O atoms, as is the case for dayside observations, or energetic particle precipitation, as is the case for auroral emissions. SSUSI also flies a 630nm photometer oriented towards nadir. When in darkness, the O2+ recombination red signature can be observed. We will consider these observations in light of groundbased observations of waves (including GPS-TEC measurements of MSTIDs) and observations by other satellites. We place these measurements in context by comparing our existing capability to what we will be able to do with GOLD and ICON.
Characterizing Space Weather Effects in the Post-DMSP Era
NASA Astrophysics Data System (ADS)
Groves, K. M.
2015-12-01
Space weather generally refers to heliophysical phenomena or events that produce a negative impact on manmade systems. While many space weather events originate with impulsive disturbances on the sun, others result from complex internal interactions in the ionosphere-thermosphere system. The reliance of mankind on satellite-based services continues to increase rapidly, yet the global capacity for sensing space weather in the ionosphere seems headed towards decline. A number of recent ionospheric-focused space-based missions are either presently, or soon-to-be, no longer available, and the end of the multi-decade Defense Meteorological Satellite Program is now in sight. The challenge facing the space weather community is how to maintain or increase sensing capabilities in an operational environment constrained by a decreasing numbers of sensors. The upcoming launch of COSMIC-2 in 2016/2018 represents the most significant new capability planned for the future. GNSS RO data has some benefit for background ionospheric models, particularly over regions where ground-based GNSS TEC measurements are unavailable, but the space weather community has a dire need to leverage such missions for far more knowledge of the ionosphere, and specifically for information related to space weather impacts. Meanwhile, the number of ground-based GNSS sensors worldwide has increased substantially, yet progress instrumenting some vastly undersampled regions, such as Africa, remains slow. In fact, the recent loss of support for many existing ground stations in such areas under the former Scintillation Network Decision Aid (SCINDA) program may actually result in a decrease in such sensing sites over the next 1-2 years, abruptly reversing a positive trend established over the last decade. Here we present potential solutions to the challenges these developments pose to the space weather enterprise. Specific topics include modeling advances required to detect and accurately characterize irregularities and associated scintillations from GNSS RO measurements, the exploitation of existing/planned radio beacons for improved bottomside definition and scintillations, and an affordable approach to leverage existing ground stations to expand sensing capacity at critical locations in otherwise data-sparse regions.
The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Science Status
NASA Astrophysics Data System (ADS)
Hou, Arthur Y.; Skofronick-Jackson, Gail; Stocker, Erich F.
2013-04-01
The Global Precipitation Measurement (GPM) Mission is a satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors provided by a consortium of international partners. NASA and JAXA will deploy a Core Observatory in 2014 to serve as a reference satellite for precipitation measurements by the constellation sensors. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR, the first dual-frequency radar in space, will provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will serve as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. In addition to the Core Observatory, the GPM constellation consists of (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1 satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian Megha-Tropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA) Polar Orbiting Environmental Satellites (POES), (5) MHS instruments on MetOp satellites launched by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), (6) the Advanced Technology Microwave Sounder (ATMS) on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), and (7) ATMS instruments on the NOAA-NASA Joint Polar Satellite System (JPSS) satellites. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. Currently global rainfall products combine observations from a network of uncoordinated satellite missions using a variety of merging techniques. GPM is designed to provide the next-generation of precipitation products characterized by: (1) more accurate instantaneous precipitation estimate (especially for light rain and cold-season solid precipitation), (2) intercalibrated microwave brightness temperatures from constellation radiometers within a consistent framework, and (3) unified precipitation retrievals from constellation radiometers using a common a priori hydrometeor database consistent with combined radar/radiometer measurements by the GPM Core Observatory. As a science mission with integrated applications goals, GPM will advance the understanding of global water cycle variability in a changing climate by offering insights into 3-dimensional structures of hurricanes and midlatitude storms, microphysical properties of precipitating particles, and latent heat associated with precipitation processes. The GPM Mission will also make data available in near realtime (within 3 hours of observations) for societal applications ranging from position fixes of storm centers, numerical weather prediction, flood forecasting, freshwater management, landslide warning, crop prediction, to tracking of water-borne diseases. This presentation will give an overview of the GPM mission and its development status approximately one-year prior to launch.
NASA Technical Reports Server (NTRS)
Zlotnicki, Victor
1999-01-01
Several research efforts exist to use Topography Experiment (TOPEX)/ Projet d'Observatorie de Surveillance et d'Etudes Integrees de la Dynamique des Oceans (Poseidon) (T/P) to detect changes in global sea level possibly associated with climate change. This requires much better than 1 mm/yr accuracy, something that none of the instruments in T/P [or the European Remote Sensing (ERS-2) satellite, or the U.S. Navy's Geosat Follow-On (GFO) satellite] were designed for. This work focuses on the ability of the T/P microwave radiometer (TMR) to retrieve the path delay due to atmospheric water vapor along the altimeter's path with accuracy in the time changes below 1 mm/yr on global average. In collaboration with Stephen Keihm of JPL and Christopher Ruf of Pennsylvania State University, we compared TMR path delay (PD) estimates with atmospheric precipitable water (PW) from the Special Sensor Microwave Imager (SSMI) aboard the Defense Meteorological Satellite Program (DMSP) series of satellites for 1992-1998 to selected radiosondes, and we also looked at the brightness temperatures measured by TMR in the lowest 1% of the histogram. The conclusion is that TMR had a slow instrumental drift, associated with the 18-GHz channel, which causes an approximate underestimation of water vapor at a rate equivalent to 1.2 mm/yr in path delay between 1992 and 1996; this effect stopped and no drift is detected in 1997. The same study concluded that there is no detectable scale error (one which is proportional to measured vapor) in TMR. In related work, carried out with graduate student Damien Cailliau, we investigated the relative abilities of TMR, SSMI and the UP dual-frequency radar altimeter to detect rain, relative to a climatology of shipborne observations. Rain is a crucial but poorly measured variable in studies of the climate system, and a dedicated mission, Tropical Rainfall Measuring Mission (TRMM), was recently launched to measure it. However, the climatologies built over the past 10 years used passive radiometers, such as SSMI, or infrared observation from National Oceanic and Atmospheric Administration (NOAA) geostationary satellites. We concluded that the dual-frequency altimeter does an excellent job at retrieving rain on scales much smaller than the passive radiometer, and a better job at retrieving total precipitation (rain as well as snow) at high latitudes. This work improves the sea level observations by allowing better flagging of observations contaminated by rain, and more importantly, provides an alternative way to measure rainfall over the oceans.
NASA Astrophysics Data System (ADS)
Kibler, J. M.; Ruminski, M. G.; Simko, J. J.; McNamara, D. P.; Kasheta, T.
2004-12-01
The Hazard Mapping System (HMS) is a multiplatform remote sensing approach to detecting fires and smoke over the US, Canada, Mexico and Central America. This system is an integral part of the Satellite Services Division's near realtime hazards detection and mitigation efforts. The system utilizes NOAA's Geostationary Operational Environmental Satellites (GOES), Polar Operational Environmental Satellites (POES), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra and Aqua spacecraft and the Defense Meteorological Satellite Program Operational Linescan System (OLS) sensor, (F14 and F15). Automated detection algorithms are employed for each of the satellites (except DMSP OLS) for the fire detects while smoke is annotated by a satellite analyst. Fire detects can also be added by the satellite analyst. Major customers for this product include the National Weather Service, Storm Prediction Center, US Forest Service, Environmental Protection Agency, research science teams, as well as numerous federal, state and local land and air quality managers. In 2004 the HMS was upgraded by adding the Canadian, Mexican, and Central American sectors for hotspot and smoke detection. These sectors can be easily turned off or on by changing flags in the system configuration file. This enables analysis in sectors only during their respective burning seasons. The Alaskan and Canadian sectors are typically turned off in the winter season and the Mexican sector is cut off after the March-May burning season. But sectors can also be easily added or restarted if, for instance, smoke from a region is affecting the United States. Various ancillary data sources are used in the HMS to aid the analysis. Stable Lights is a static product that identifies stable sources of light from the OLS sensor and is usually associated with cities and urban areas. It appears on the screen as a transparent overlay on the satellite imagery being displayed. This capability can assist the analyst by screening out heat sources where stable lights are present. Vegetation type and water overlays aid in the decision to add or delete a fire point. Water sources many times may cause false detects due to low sun zenith angles during sunrise and sunset or due to temperature contrast between land and water at night. This overlay aides in quickly finding these false detects. Vegetation overlays enable the analyst by showing what type of land is present near the hotspot in question. For example, fires are more likely in forest or grassland than desert or barren lands. The SSD fire team is currently assessing the feasibility of a descriptive smoke text product and would like to incorporate additional datasets for the monitoring of fires, smoke, dust, and air pollution. The HMS is a dynamic product that changes with the needs of our analysts and customers.
GPM Mission Overview and U.S. Science Status
NASA Technical Reports Server (NTRS)
Hou, Arthur Y.; Azarbarzin, Art; Skofronick, Gail; Carlisle, Candace
2012-01-01
The Global Precipitation Measurement (GPM) Mission is an international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide "next-generation" precipitation products [1-2]. Water is fundamental to life on Earth. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. Since rainfall and snowfall vary greatly from place to place and over time, satellites can provide more uniform observations of rain and snow around the globe than ground instruments, especially in areas where surface measurements are difficult. Relative to current global rainfall products, GPM data products will be characterized by: (l) more accurate instantaneous precipitation measurements (especially for light rain and cold-season solid precipitation), (2) more frequent sampling by an expanded constellation of domestic and international microwave radiometers including operational humidity sounders, (3) intercalibrated microwave brightness temperatures from constellation radiometers within a unified framework, and (4) physical-based precipitation retrievals from constellation radiometers using a common a priori cloud/hydrometeor database derived from GPM Core sensor measurements. The cornerstone of the GPM mission is the deployment of a Core Observatory in a unique 65 non-Sun-synchronous orbit to serve as a physics observatory and a reference standard to unify precipitation measurements by a constellation of dedicated and operational passive microwave sensors. The design of the GPM Core Observatory is an advancement of the Tropical Rainfall Measuring Mission (TRMM)'s highly successful rain-sensing package. The Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multichannel (l0-183 GHz) GPM Microwave Radiometer (GMI). Since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. The combined use of DPR and GMI measurements will place greater constraints on possible solutions to radiometer retrievals to improve the accuracy and consistency of precipitation retrievals from all constellation radiometers. The GMI uses 13 different microwave channels to observe energy from the different types of precipitation through clouds for estimating everything from heavy to light rain and for detecting falling snow. As the satellite passes over Earth, the GMI constantly scans a region 885 kilometers across. The Ball Aerospace and Technology Corporation built the GMI under contract with NASA Goddard Space Flight Center. The DPR provides three-dimensional information about precipitation particles derived from reflected energy by these particles at different heights within the cloud system. The two frequencies of the DPR also allow the radar to infer the sizes of precipitation particles and offer insights into a storm's physical characteristics. The Ka-band frequeny scans across a region of 125 kilometers and is nested within the wider scan of the Ku-band frequency of 245 kilometers. The Japan Aerospace and Exploration Agency (JAXA) and Japan's National Institute of Information and Communications Technology (NICT) built the DPR. The Core Observatory satellite will fly at an altitude of 253 miles (407 kilometers) in a non-Sun-synchronous orbit that covers the Earth from 65 S to 65 N - from about the Antarctic Circle to the Arctic Circle. The GPM Core Observatory is being developed and tested at NASA Goddard Space Flight Center. Once complete, a Japanese H-lIA rocket will carry thPM Core Observatory into orbit from Tanegashima Island, Japan in 2014. The GPM constellation is envisioned to comprise 8 or more microwave sensors provided by partners, including both conical imagers and cross-track sounders. GPM is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA). Additional partnerships are under development to include microwave radiometers on the French-Indian Megha-Tropiques satellite and U.S. Defense Meteorological Satellite Program (DMSP) satellites, as well as humidity sounders or precipitation sensors on operational satellites such as the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), NOAA-NASA Joint Polar Satellite System (JPSS) satellites, European MetOp satellites, and DMSP follow-on sensors. In addition, data from Chinese and Russian microwave radiometers may be available through international cooperation under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). GPM's next-generation global precipitation data will lead to scientific advances and societal benefits in the following areas: (1) Improved knowledge of the Earth's water cycle and its link to climate change (2) New insights into precipitation microphysics, storm structures and large-scale atmospheric processes (3) Better understanding of climate sensitivity and feedback processes (4) Extended capabilities in monitoring and predicting hurricanes and other extreme weather events (5) Improved forecasting capabilities for natural hazards, including floods, droughts and landslides. (6) Enhanced numerical prediction skills for weather and climate (7) Better agricultural crop forecasting and monitoring of freshwater resources. An overview of the GPM mission concept and science activities in the United States, together with an update on international collaborations in radiometer intercalibration and ground validation, will be presented.
Key Features of the Deployed NPP/NPOESS Ground System
NASA Astrophysics Data System (ADS)
Heckmann, G.; Grant, K. D.; Mulligan, J. E.
2010-12-01
The National Oceanic & Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics & Space Administration (NASA) are jointly acquiring the next-generation weather/environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current NOAA Polar-orbiting Operational Environmental Satellites (POES) and DoD Defense Meteorological Satellite Program (DMSP). NPOESS satellites carry sensors to collect meteorological, oceanographic, climatological, and solar-geophysical data of the earth, atmosphere, and space. The ground data processing segment is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence & Information Systems (IIS). The IDPS processes NPOESS Preparatory Project (NPP)/NPOESS satellite data to provide environmental data products/records (EDRs) to NOAA and DoD processing centers operated by the US government. The IDPS will process EDRs beginning with NPP and continuing through the lifetime of the NPOESS system. The command & telemetry segment is the Command, Control & Communications Segment (C3S), also developed by Raytheon IIS. C3S is responsible for managing the overall NPP/NPOESS missions from control & status of the space and ground assets to ensuring delivery of timely, high quality data from the Space Segment to IDPS for processing. In addition, the C3S provides the globally-distributed ground assets needed to collect and transport mission, telemetry, and command data between the satellites and processing locations. The C3S provides all functions required for day-to-day satellite commanding & state-of-health monitoring, and delivery of Stored Mission Data to each Central IDP for data products development and transfer to system subscribers. The C3S also monitors and reports system-wide health & status and data communications with external systems and between the segments. The C3S & IDPS segments were delivered & transitioned to operations for NPP. C3S transitioned to operations at the NOAA Satellite Operations Facility (NSOF) in Suitland Maryland in August 2007 and IDPS transitioned in July 2009. Both segments were involved with several compatibility tests with the NPP Satellite at the Ball Aerospace Technology Corporation (BATC) factory. The compatibility tests involved the spacecraft bus, the four sensors (VIIRS, ATMS, CrIS and OMPS), and both ground segments flowing data between the NSOF and BATC factory and flowing data from the polar ground station (Svalbard) over high-speed links back to the NSOF and the two IDP locations (NESDIS & AFWA). This presentation will describe the NPP/NPOESS ground architecture features & enhancements for the NPOESS era. These will include C3S-provided space-to-ground connectivity, reliable and secure data delivery and insight & oversight of the total operation. For NPOESS the ground architecture is extended to provide additional ground receptor sites to reduce data product delivery times to users and delivery of additional sensor data products from sensors similar to NPP and more NPOESS sensors. This architecture is also extended from two Centrals (NESDIS & AFWA) to two additional Centrals (FNMOC & NAVO). IDPS acts as a buffer minimizing changes in how users request and receive data products.
Real-time Monitoring of 2017 Hurricanes and Typhoons with Lightning
NASA Astrophysics Data System (ADS)
Solorzano, N. N.; Thomas, J. N.; Bracy, C.; Holzworth, R. H., II
2017-12-01
The 2017 Atlantic season had the highest number of major hurricanes since 2005. To tackle the demand of real-time tropical cyclone (TC) monitoring, our group has developed a unique "storm-following" satellite and ground-based lightning product known as WWLLN-TC (World Wide Lightning Location Network - Tropical Cyclones; http://wwlln.net/storms/). In the present study, we explore this tool and other datasets, combining lightning and microwave data to quantify areas of intense convection in 2017 TCs Harvey, Hato, Irma, Maria, Nate, Ophelia and others. For each storm, the temporal distribution of discharges outside and within the inner core is compared to the changes in TC intensity. The intensification processes, monitored in near real-time by WWLLN-TC, are quantified in terms of pressure and/or wind speed changes. A peak in lightning activity is often observed in the inner core of TCs before and during rapid weakening, such as in Hurricanes Irma and Maria and Typhoon Hato. The microwave frequencies investigated include the 37 to 183 GHz channels of the satellite sensors DMSP/SSMIS and GPM/GMI. We reconstruct brightness temperatures from lightning data, providing more detailed pictures of the evolution of TCs at moments when satellite passes are missing or incomplete. This study also compares lightning activity in the inner core with convective and environmental parameters. Examples of environmental parameters discussed are sea surface temperature, wind shear, and sea surface height anomalies. We conclude by considering possible implications of WWLLN-TC on forecasts of rapid intensity change and rainfall.
Ion temperature of low-latitude and mid-latitude topside ionosphere for high solar activity
NASA Astrophysics Data System (ADS)
Cai, Lei; Zhang, Donghe; Hao, Yongqiang; Xiao, Zuo
The International Reference Ionosphere (IRI) describes the day and night latitudinal variation of ion temperature at 430 km with two functions using AEROS satellite measurements. The ion temperature at this height as one of the boundary parameters is used to make the ion temperature profile represented by a Booker-function. Since the low-latitude and mid-latitude topside ionospheric ion temperature has been measured with the Ionopsheric Plasma and Elec-trodynamics Instrument (IPEI) onboard Rocsat-1 satellite at about 600 km during the high solar activity years from 2000 to 2002, a new boundary at 600 km can be set for the ion temperature modeling. The latitudinal variation of ion temperature could be approximated by Epstein family of functions for different local time sectors. Furthermore, the longitudinal and seasonal variations are also taken into account to decide the fitting parameters. Only the magnetic quiet time data (Kp <3) are used for the statistical study. The results are compared with IRI-2007 model. In addition, events when Kp >4 are also analyzed to feature the ion temperature characteristic during the magnetic disturbance time condition. Combined with the IPEI field-aligned ion flow velocities and the plasma temperatures measured by the Special Sensors-Ions, Electrons, and Scintillation (SSIES) thermal plasma analysis package on board the DMSP F13 and F15 satellites, several feasible ion heating and heat loss mechanisms are summarized to interpret the ion temperature crests and toughs for different local time sectors, seasonal and longitudinal variations.
Strategy of photo-protection in phytoplankton assemblages in the Kongsfjorden, Svalbard, Arctic
NASA Astrophysics Data System (ADS)
Ha, Sun-Yong; Lee, Doo Byoul; Kang, Sung-Ho; Shin, Kyung-Hoon
2016-01-01
Photo-protective functions were investigated in phytoplankton assemblages at Kongsfjorden, Svalbard in spring, using their UV-absorbing compounds (mycosporine-like amino acids (MAAs)), xanthophyll pigments (diadinoxanthin (DD) and diatoxanthin (DT)) and < beta >- dimethylsulphoniopropionate (< beta >-DMSP). The dominant phytoplankton species in the inner bay were dominated by Phaeocystis spp. and nanoflagellates, while the offshore waters were dominated by Thalassiosira spp. In the inner bay, UVabsorbing compounds and xanthophyll pigments exhibited higher ratios of MAA to chlorophyll a (MAA:chl a ratio), and both DD and DT to chlorophyll a (DD:chl a ratio and DT:chl a ratio), respectively. Thus, the photoprotective-pigments such as DD and DT appear to complement MAAs in the natural phytoplankton assemblage. However, the ratio of < beta >-DMSP to chlorophyll a (< beta >-DMSP:chl a ratio) did not show a distinct spatial distribution according to environmental factors or interspecies differences. In this study, we found that photoprotective compounds occurred in a manner dependent on the phytoplankton species composition in Kongsfjorden Bay, where Phaeocystis is the dominant species.
Strato-mesospheric carbon monoxide profiles above Kiruna, Sweden (67.8 ° N, 20.4 ° E), since 2008
NASA Astrophysics Data System (ADS)
Ryan, Niall J.; Palm, Mathias; Raffalski, Uwe; Larsson, Richard; Manney, Gloria; Millán, Luis; Notholt, Justus
2017-02-01
This paper presents the retrieval and validation of a self-consistent time series of carbon monoxide (CO) above Kiruna using measurements from the Kiruna Microwave Radiometer (KIMRA). The data set currently spans the years 2008-2015, and measurements are ongoing at Kiruna. The spectra are inverted using an optimal estimation method to retrieve altitude profiles of CO concentrations in the atmosphere within an average altitude range of 48-84 km. Atmospheric temperature data from the Special Sensor Microwave Imager/Sounder aboard the US Air Force meteorological satellite DMSP-F18, are used in the inversion of KIMRA spectra between January 2011 and May 2014. This KIMRA CO data set is compared with CO data from the Microwave Limb Sounder aboard the Aura satellite: there is a maximum bias for KIMRA of ˜ 0.65 ppmv at 68 km (corresponding to 14.7 % of the mean CO value at 68 km) and a maximum relative bias of 22 % (0.44 ppmv) at 60 km. Standard deviations of the differences between profiles are similar in magnitude to the estimated uncertainties in the profiles. Correlations between the instruments are within 0.87 and 0.94. These numbers indicate agreement between the instruments. To expand the CO data set outside of the lifetime of DMSP-F18, another inversion setup was used that incorporates modelled temperatures from the European Centre for Medium-Range Weather Forecasts. The effect on the retrieved CO profiles when using a different temperature data set in the inversion was assessed. A comparison of the two overlapping KIMRA CO data sets shows a positive bias of < 5 % in the extended data set and a correlation > 0.98 between the lower retrievable altitude limit and 82.5 km. The extended data set shows a larger range ( ≤ 6 %) of CO concentrations that is not explained by random error estimates. Measurements are continuing and the extended KIMRA CO time series currently spans 2008-2015, with gaps corresponding to non-operation and summer periods when CO concentrations below ˜ 90 km drop to very low values. The data can be accessed at doi:10.1594/PANGAEA.861730.
An Hour of Spectacular Visualization
NASA Technical Reports Server (NTRS)
Hasler, Arthur F.
2005-01-01
The NASA/NOAA Electronic Theater presents Earth science observations and visualizations from space in a historical perspective. Fly in from outer space to Athens and site of the 2004 Summer Olympics and the Far East using 1 m IKONOS "Spy Satellite" data. Contrast the 1972 Apollo 17 "Blue Marble" image of the Earth with the latest US and International global satellite images that allow us to view our Planet from any vantage point. See the latest spectacular images from NASA/NOAA/Commercial remote sensing missions like Terra, GOES, TRMM, SeaWiFS, & Landsat 7, QuickBird of the SE Asia Tsunami, devastation of Hurricane Katrina this year in New Orleans, and the LA/San Diego Fires of 2003. See how High Definition Television (HDTV) is revolutionizing the way we do science communication. Take the pulse of the planet on a daily, annual and 30-year time scale. See daily thunderstorms, the annual blooming of the northern hemisphere land masses and oceans, fires in Africa, dust storms in Iraq, and carbon monoxide exhaust from global burning. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. Spectacular new global visualizations of the observed and simulated atmosphere & oceans are shown. See the currents and vortexes in the oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fishermen. See the how the ocean blooms in response to El Nino/La Nina climate changes. The Etheater will be presented using the latest High Definition TV (HDTV) and video projection technology on a large screen. See city lights around the globe and in your area observed by the "night-vision" DMSP satellite, Also see how Keyhole and Google Maps are using satellite and aerial photography to help you find your house and plan your vacation.
Polar CAP Boundary Identification Using Redline Imaging Data
NASA Astrophysics Data System (ADS)
Spanswick, E.; Roy, E. A.; Gallardo-Lacourt, B.; Donovan, E.; Ridley, A. J.; Gou, D.
2017-12-01
The location of the polar cap boundary is typically detected using low-orbit satellite measurements in which the boundary is identified by its unique signature of a sharp decrease in energy and particle flux poleward of the auroral oval. A previous study based in optical data by Blanchard et al. [1995] suggested that a dramatic gradient in redline aurora may also be an indicator of the polar cap boundary. While this study has been heavily cited, it was only based on few events and its findings have largely gone uncontested. Since the Blanchard study, satellite instrumentation and available auroral data have improved significantly. Auroral imaging has moved well beyond the capabilities of the instrumentation in the previous study in terms of sensitivity and both spatial and temporal resolution. We now have access to decades of optical data from arrays spanning a huge spatial range; none of which was available previously. In this study we have used data from FAST and DMSP satellites in conjunction with the University of Calgary's Narrow-band All-sky Cameras for Auroral Monitoring (NASCAM) ground based auroral imaging array and the REdline Geospace Observatory (REGO) data to assess the viability of automated detection of the polar cap boundary. In our analysis we used redline (630nm) auroral signatures from the ground based imagers around the location of the polar cap boundary observed in satellite data. We have characterized the polar cap boundary luminosity and location using the redline auroral data during different geomagnetic conditions. Our results enable a new tool to automatically identify the polar cap boundary to reach a deeper understanding of the connection between polar cap location and auroral activity.
Comparisons of Monthly Oceanic Rainfall Derived from TMI and SSM/I
NASA Technical Reports Server (NTRS)
Chang, A. T. C.; Chiu, L. S.; Meng, J.; Wilheit, T. T.; Kummerow, C. D.
1999-01-01
A technique for estimating monthly oceanic rainfall rate using multi-channel microwave measurements has been developed. There are three prominent features of this algorithm. First, the knowledge of the form of the rainfall intensity probability density function used to augment the measurements. Second, utilizing a linear combination of the 19.35 and 22.235 GHz channels to de-emphasize the effect of water vapor. Third, an objective technique has been developed to estimate the rain layer thickness from the 19.35 and 22.235 GHz brightness temperature histograms. This technique is applied to the SSM/I data since 1987 to infer monthly rainfall for the Global Precipitation Climatology Project (GPCP). A modified version of this algorithm is now being applied to the TRMM Microwave Imager (TMI) data. TMI data with better spatial resolution and 24 hour sampling (vs. sun-synchronized sampling, which is limited to two narrow intervals of local solar time for DMSP satellites) prompt us to study the similarity and difference between these two rainfall estimates. Six months of rainfall data (January to June 1998) are used in this study. Means and standard deviations are calculated. Paired student t-tests are administrated to evaluate the differences between rainfall estimates from SSM/I and TMI data. Their differences are discussed in the context of global satellite rainfall estimation.
Ionospheric Irregularities Characterization by Ground and Space-based GPS Observations
NASA Astrophysics Data System (ADS)
Zakharenkova, I.; Cherniak, I.; Krankowski, A.
2017-12-01
We present new results on detection and investigation of the topside ionospheric irregularities using GPS measurements from Precise Orbit Determination (POD) GPS antenna onboard Low Earth Orbit satellites. Our investigation is based on the recent ESA's Swarm mission launched on 22 November 2013 and consisted of three identical satellites, two of them fly in a tandem at an orbit altitude of 460 km while the third satellite - at an orbit altitude of 510 km. Each satellite is equipped with a zenith-looking antenna and 8-channel dual-frequency GPS receiver that delivered 1 Hz data for POD purposes, as well as Langmuir Probe instrument for in situ electron density. Additionally, we have analyzed GPS measurements onboard GRACE and TerraSAR-X satellite, which have rather similar to Swarm orbit altitude of 500 km. GPS measurements onboard MetOP-A and MetOP-B satellites (altitude of 840 km) can complement these observations in order to estimate an altitudinal extent of the ionospheric irregularities penetrating to higher altitudes. We demonstrate that space-based GPS observations can be effectively used for monitoring of the topside ionospheric irregularities occurrence in both high-latitude and equatorial regions and may essentially contribute to the multi-instrumental analysis of the ground-based and in situ data. Climatological characteristics of the equatorial ionospheric irregularities occurrence probability are derived from POD GPS measurements for all longitudinal sectors for the years 2013-2016. Several examples of strong geomagnetic storms, including the 2015 St. Patrick's Day storm, were analyzed to demonstrate differences between the climatlogical characteristics in space-based GPS data and storm-induced equatorial irregularities observations (postsunset suppression, night/morning-time occurrence). To support our observations and conclusions, we involve into our analysis in situ plasma density provided by Swarm constellation, GRACE KBR, DMSP satellites, as well as ground-based GNSS and digisonde networks. New International GNSS Service (IGS) product - the Northern Hemisphere GPS-based ROTI (rate of the TEC index) maps - was analyzed to determine similarities and differences in ionospheric irregularities signatures in the ground and space-based GPS observations.
Variations in Upper-Tropospheric Humidity and Convective Processes as Seen from SSM/T-2
NASA Technical Reports Server (NTRS)
Robertson, Franklin R.; Fitzjarrald, Dan E.
2007-01-01
Water vapor feedback, particularly involving water vapor in the upper troposphere (UTH), is widely regarded as the process with the most potential to amplify anthropogenic greenhouse forcing. Yet, our ability to quantify observationally water vapor variations in the current climate and the relationships to convective processes remains rather crude. Remote sensing from polar orbiting instruments has played a major role in documenting UTH variability, supplementing highly undersampled and poorly calibrated rawinsonde measurements. Most of our observational understanding of UTH has come from the 6.7 micrometer channel measurements which are subject to cloud contamination uncertainties. In this work we examine UTH variations present in the Special Sensor Microwave Temperature Sounder 2 (SSM/T-2) sensors flying aboard Defense Military Satellite Program (DMSP) polar orbiting satellites during the period 1993 through 2001. We employ data from the the 183.3 +/- 1 GHz channel which is far less sensitive to cirrus than IR methods. Our primary focus is on obtaining more reliable statistics of interannual behavior; i.e. How close to constant RH are interannual variations in T2 UTH over the tropics? How do temperature and moisture variations contribute regionally? The 1997/1998 strong ENS0 warming event and adjacent cool periods provide a strong signal to study, albeit a perturbation of natural climate variability. Modeling the 183.3 GHz channel using reanalysis temperature data, but with climatological water vapor, allows us to infer the separate contribution by water vapor in the observations. In addition, frozen hydrometeors produced by deep convection are also captured in the 150 GHz oxygen channel, providing an opportUnity to relate the incidence of deep convection to water vapor variability. Our results indicate a much larger variation of 183.3 GHz brightness temperatures would be observed were it not for water vapor variations positively correlated with tropical SSTs. Comparisons are made with previous studies using both IR and microwave observations to characterize UTH response to tropical SSTs.
Interplanetary magnetic field control of mantle precipitation and associated field-aligned currents
NASA Technical Reports Server (NTRS)
Xu, Dingan; Kivelson, Margaret G.; Walker, Ray J.; Newell, Patrick T.; Meng, C.-I.
1995-01-01
Dayside reconnection, which is particularly effective for a southward interplanetary magnetic field (IMF), allows magnetosheath particles to enter the magnetosphere where they form the plasma mantle. The motions of the reconnected flux tube produce convective flows in the ionosphere. It is known that the convection patterns in the polar cap are skewed to the dawnside for a positive IMF B(sub y) (or duskside for a negative IMF B(sub y)) in the northern polar cap. Correspondingly, one would expect to find asymmetric distributions of mantle particle precipitation, but previous results have been unclear. In this paper the correlation between B(sub y) and the distribution of mantle particle precipitation is studied for steady IMF conditions with southward IMF. Ion and electron data from the Defense Meteorological Satellite Program (DMSP) F6 and F7 satellites are used to identify the mantle region and IMP 8 is used as a solar wind monitor to characterize the IMF. We study the local time extension of mantle precipitation in the prenoon and postnoon regions. We find that, in accordance with theoretical expectations for a positive (negative) IMF B(sub y), mantle particle precipitation mainly appears in the prenoon region of the northern (southern) hemisphere. The mantle particle precipitation can extend to as early as 0600 magnetic local time (MLT) in the prenoon region but extends over a smaller local time region in the postnoon sector (we did not find mantle plasma beyond 1600 MLT in our data set although coverage is scant in this area). Magnetometer data from F7 are used to determine whether part of the region 1 current flows on open field lines. We find that at times part of the region 1 sense current extends into the region of mantle particle precipitation, and is therefore on open field lines. In other cases, region 1 currents are absent on open field lines. Most of the observed features can be readily interpreted in terms of the open magnetosphere model.
NASA Astrophysics Data System (ADS)
Suffrian, K.; Posman, K.; Matrai, P.; Countway, P. D.; Archer, S. D.
2016-02-01
Marine dimethyl sulfide (DMS), a ubiquitous atmospheric trace gas, comprises the largest source of sulphur to the atmosphere. So far, temperate and high-latitude ocean acidification (OA) mesocosm experiments point to a decrease of this precursor for cloud condensation nuclei, leading to fewer clouds, and resulting in an increased radiative force. To our knowledge no experiments have yet been carried out which address multiple forcings (temperature and pCO2) in the subtropics. We thus joined the 55-day KOSMOS large mesocosm experiment on Gran Canaria to investigate if the observed decrease could be global. As subtropical and tropical oceans comprise a large proportion of the world's oceans, we were i.a. interested if 1) increasing ocean acidification in a subtropical environment would also decrease [DMS], and if 2) bacterial DMS production could explain a large part of potential decreases. Here we focus on the first phase (day 1-23), showing the impact of OA on [DMS] and [DMSP] (dimethylsulfoniopropionate). Bacteria are thought to be the main DMS producers, so we used 35S-DMSP as a tracer to investigate the impact of bacterial DMS production on observed [DMS] decreases correlated with increasing OA. [DMS] showed a strong inverse correlation with [H+] (-50% vs. ambient control). [DMSPp] (-37%) and [DMSPd] (-20%) also decreased with increasing [H+]. Our results support findings from higher latitude mesocosm experiments, thus suggesting the effect might be global. Bacterial DMS production rates, their rate constants, and yields during the peak in [DMS] were negatively correlated with [H+] on single days, while gross DMS-production was high enough to support observed [DMS] increases. Bacterial DMSP uptake rates and DMS production rates were not correlated with [H+] on any other day. Bacterial effects alone are thus not enough to explain observed changes in standing stocks. We will further explore the results by normalizing to bacterial protein production, cell abundance, and potential changes in gene expression, and finally link DMS/P metabolism to diversity (in progress).
Vernal distribution and turnover of dimethylsulfide (DMS) in the surface water of the Yellow Sea
NASA Astrophysics Data System (ADS)
Li, Cheng-Xuan; Yang, Gui-Peng; Wang, Bao-Dong; Xu, Zong-Jun
2016-10-01
The spatial and interannual variations of dimethylsulfide (DMS) and its precursors, dissolved and particulate dimethylsulfoniopropionate (DMSP), were discussed on the basis of field observations in the surface waters of the Yellow Sea during spring 2007. Maxima of dimethylated sulfur compounds and low chlorophyll a concentrations were found in the central southern Yellow Sea, whereas low concentrations of DMS and DMSP were detected at the boundary between the northern and southern parts of the Yellow Sea. This frontal region is influenced by active water currents, air-sea interface exchanges, and biological turnover. The horizontal variations in DMS production and consumption rates showed a decreasing tendency from the coastal to offshore areas mainly due to the complicated biological features. DMS positively correlated with dissolved CH4 and CO2 but negatively correlated with nutrients (nitrite and phosphate). Particulate DMSP concentrations and DMS production rates positively correlated with dinoflagellate abundances but negatively correlated with diatom cell densities. DMS and DMSP concentrations, as well as DMS production and consumption rates, exhibited approximately 2.0-2.8 fold increases from 2005 to 2012. This finding was likely caused by shifts in the phytoplankton communities from diatoms to dinoflagellates and the increases in abundances of zooplankton and bacteria. Average sea-to-air DMS fluxes were estimated to be 8.12 ± 1.24 µmol·(m-2·d-1), and DMS microbial consumption was approximately 1.68 times faster than the DMS sea-air exchange. These findings imply that biological consumption, relative to ventilation, is a predominant mechanism in DMS removal from the surface water.
Iyadomi, Satoshi; Ezoe, Kentaro; Ohira, Shin-Ichi; Toda, Kei
2016-04-01
To monitor the fluctuations of dimethyl sulfur compounds at the seawater/atmosphere interface, an automated system was developed based on sequential injection analysis coupled with vapor generation-ion molecule reaction mass spectrometry (SIA-VG-IMRMS). Using this analytical system, dissolved dimethyl sulfide (DMS(aq)) and dimethylsulfoniopropionate (DMSP), a precursor to DMS in seawater, were monitored together sequentially with atmospheric dimethyl sulfide (DMS(g)). A shift from the equilibrium point between DMS(aq) and DMS(g) results in the emission of DMS to the atmosphere. Atmospheric DMS emitted from seawater plays an important role as a source of cloud condensation nuclei, which influences the oceanic climate. Water samples were taken periodically and dissolved DMS(aq) was vaporized for analysis by IMRMS. After that, DMSP was hydrolyzed to DMS and acrylic acid, and analyzed in the same manner as DMS(aq). The vaporization behavior and hydrolysis of DMSP to DMS were investigated to optimize these conditions. Frequent (every 30 min) determination of the three components, DMS(aq)/DMSP (nanomolar) and DMS(g) (ppbv), was carried out by SIA-VG-IMRMS. Field analysis of the dimethyl sulfur compounds was undertaken at a coastal station, which succeeded in showing detailed variations of the compounds in a natural setting. Observed concentrations of the dimethyl sulfur compounds both in the atmosphere and seawater largely changed with time and similar variations were repeatedly observed over several days, suggesting diurnal variations in the DMS flux at the seawater/atmosphere interface.
Rhodes, D.; Gage, D. A.; Cooper, AJL.; Hanson, A. D.
1997-01-01
Leaves of Wollastonia biflora (L.) DC. synthesize the osmoprotectant 3-dimethylsulfoniopropionate (DMSP) from methionine via S-methylmethionine (SMM) and 3-dimethylsulfoniopropionaldehyde (DMSP-ald); no other intermediates have been detected. To test whether the amino group of SMM is lost by transamination or deamination, [methyl-2H3,15N]SMM was supplied to leaf discs, and 15N-labeling of amino acids was monitored, along with synthesis of [2H3]DMSP. After short incubations more 15N was incorporated into glutamate than into other amino acids, and the 15N abundance in glutamate exceeded that in the amide group of glutamine (Gln). This is more consistent with transamination than deamination, because deamination would be predicted to give greater labeling of Gln amide N due to reassimilation, via Gln synthetase, of the 15NH4+ released. This prediction was borne out by control experiments with 15NH4Cl. The transamination product of SMM, 4-dimethylsulfonio-2-oxobutyrate (DMSOB), is expected to be extremely unstable. This was confirmed by attempting to synthesize it enzymatically from SMM using L-amino acid oxidase or Gln transaminase K and from 4-methylthio-2-oxobutyrate using methionine S-methyltransferase. In each case, the reaction product decomposed rapidly, releasing dimethylsulfide. The conversion of SMM to DMSP-ald is therefore unlikely to involve a simple transamination that generates free DMSOB. Plausible alternatives are that DMSOB is channeled within a specialized transaminase-decarboxylase complex or that it exists only as the bound intermediate of a single enzyme catalyzing an unusual transamination-decarboxylation reaction. PMID:12223879
NASA Astrophysics Data System (ADS)
Kim, J.; Yu, J.; Wang, L.; Liu, H.
2017-12-01
Changes in Antarctic ice sheet are caused by various reasons such as changes in Holocene climate, precipitation, and ocean temperature. Such issues of changes in ice sheet has been mainly focused on the Antarctic peninsula, and it is known that ice retreat of the area is caused by changes in atmospheric and ocean temperatures. For the case of West Antarctica, ice front change research is relatively rarely conducted except the Pine island glacier area. This study has monitored ice front changes of West Antarctica and compared the patterns with the changes in brightness temperature based on remote sensing techniques. We used 2000 Radarsat-1 and 2008 Rasarsat-2 SAR data to delineate coastlines of whole West Antarctica based on the locally thresholding adaptive algorithm. The delineated coast lines are analyzed to figure out ice front change patterns between the duration. The variations in brightness temperature for the same duration are calculated based on Defense Meteorological Satellite Program (DMSP)'s Special Sensor Microwave/Images-Special Sensor Microwave Imager/Sounder (SSM/I-SSMIS) passive microwave data. The results show ice front of West Antarctica shows advancing trend except the pine island glacier area. The brightness temperature had decreasing trend during the study period. It infers that changes in ice front and brightness temperature of West Antarctica have considerable relationships. It is expected that a long term monitoring of the relationship would contribute understanding ice dynamics of West Antarctica significantly.
A global fingerprint of macro-scale changes in urban structure from 1999 to 2009
NASA Astrophysics Data System (ADS)
Frolking, Steve; Milliman, Tom; Seto, Karen C.; Friedl, Mark A.
2013-06-01
Urban population now exceeds rural population globally, and 60-80% of global energy consumption by households, businesses, transportation, and industry occurs in urban areas. There is growing evidence that built-up infrastructure contributes to carbon emissions inertia, and that investments in infrastructure today have delayed climate cost in the future. Although the United Nations statistics include data on urban population by country and select urban agglomerations, there are no empirical data on built-up infrastructure for a large sample of cities. Here we present the first study to examine changes in the structure of the world’s largest cities from 1999 to 2009. Combining data from two space-borne sensors—backscatter power (PR) from NASA’s SeaWinds microwave scatterometer, and nighttime lights (NL) from NOAA’s defense meteorological satellite program/operational linescan system (DMSP/OLS)—we report large increases in built-up infrastructure stock worldwide and show that cities are expanding both outward and upward. Our results reveal previously undocumented recent and rapid changes in urban areas worldwide that reflect pronounced shifts in the form and structure of cities. Increases in built-up infrastructure are highest in East Asian cities, with Chinese cities rapidly expanding their material infrastructure stock in both height and extent. In contrast, Indian cities are primarily building out and not increasing in verticality. This new dataset will help characterize the structure and form of cities, and ultimately improve our understanding of how cities affect regional-to-global energy use and greenhouse gas emissions.
Characteristics of spacecraft charging in low Earth orbit
NASA Astrophysics Data System (ADS)
Anderson, Phillip C.
2012-07-01
It has been found that the DMSP spacecraft at 840 km can charge to very large negative voltages (up to -2000 V) when encountering intense precipitating electron events (auroral arcs). We present an 11-year study of over 1600 charging events, defined as when the spacecraft charged to levels exceeding 100 V negative during an auroral crossing. The occurrence frequency of events was highly correlated with the 11-year solar cycle with the largest number of events occurring during solar minimum. This was due to the requirement that the background thermal plasma density be low, at most 104 cm-3. During solar maximum, the plasma density is typically well above that level due to the solar EUV ionizing radiation, and although the occurrence frequency of auroral arcs is considerably greater than at solar minimum, the occurrence of high-level charging is minimal. As a result of this study, we produced a model spectrum for precipitating electrons that can be used as a specification for the low-altitude auroral charging environment. There are implications from this study on a number of LEO satellite programs, including the International Space Station, which does enter the auroral zone, particularly during geomagnetic activity when the auroral boundary can penetrate to very low latitudes. The plasma density in the ISS orbit is usually well above the minimum required density for charging. However, in the wake of the ISS, the plasma density can be 2 orders of magnitude or more lower than the background density and thus conditions are ripe for charging.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhou, Yuyu; Smith, Steven J.; Zhao, Kaiguang
Urbanization, one of the major human induced land-cover and land-use changes, has a profound impact on the Earth system including biodiversity, the cycling of water and carbon and exchange of energy and water between Earth’s surface and atmosphere, all affecting weather and climate. Accurate information on urban areas and their spatial distribution at the regional and global scales is important for scientific understanding of their contribution to the changing Earth system, and for practical management and policy decisions. We developed a method to map the urban extent from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime stable-light data atmore » the global level and derived a new global map of 1-km urban extent for year 2000. Based on this map, we found that globally, urban land area is about 0.5% of total land area but ranges widely at regional level from 0.1% in Oceania to 2.3% in Europe. At the country level, urban land area varies from lower than 0.01% to higher than 10%, but is lower than 1% for most (70%) countries. Urbanization follows land mass distribution, as anticipated, with the highest concentration found between 30°N to 45°N latitude and the largest longitudinal peak around 80°W. Based on a sensitivity analysis and comparison with other global urban area products, we found that our global product of urban area provides a reliable estimate of global urban areas and offer the potential of capturing more accurately their spatial and temporal dynamics.« less
Synchronized Regulation of Different Zwitterionic Metabolites in the Osmoadaption of Phytoplankton
Gebser, Björn; Pohnert, Georg
2013-01-01
The ability to adapt to different seawater salinities is essential for cosmopolitan marine phytoplankton living in very diverse habitats. In this study, we examined the role of small zwitterionic metabolites in the osmoadaption of two common microalgae species Emiliania huxleyi and Prorocentrum minimum. By cultivation of the algae under salinities between 16‰ and 38‰ and subsequent analysis of dimethylsulfoniopropionate (DMSP), glycine betaine (GBT), gonyol, homarine, trigonelline, dimethylsulfonioacetate, trimethylammonium propionate, and trimethylammonium butyrate using HPLC-MS, we could reveal two fundamentally different osmoadaption mechanisms. While E. huxleyi responded with cell size reduction and a nearly constant ratio between the major metabolites DMSP, GBT and homarine to increasing salinity, osmolyte composition of P. minimum changed dramatically. In this alga DMSP concentration remained nearly constant at 18.6 mM between 20‰ and 32‰ but the amount of GBT and dimethylsulfonioacetate increased from 4% to 30% of total investigated osmolytes. Direct quantification of zwitterionic metabolites via LC-MS is a powerful tool to unravel the complex osmoadaption and regulation mechanisms of marine phytoplankton. PMID:23774888
Current Development of Global Precipitation Mission (GPM)
NASA Technical Reports Server (NTRS)
Smith, Eric A.; Starr, David (Technical Monitor)
2001-01-01
The scientific success of the Tropical Rainfall Measuring Mission (TRMM) and additional satellite-focused precipitation retrieval projects, particularly those based on use of passive microwave radiometer measurements, have paved the way for a more advanced global precipitation mission. The new mission is motivated by a number of scientific questions that TRMM research has posed over a range of space-time scales and within a variety of scientific disciplines that are becoming more integrated into earth system science modeling. Added to this success is the realization that satellite rainfall datasets are now a foremost tool in understanding global climate variability out to decadal scales and beyond. This progress has motivated a comprehensive global measuring strategy -- leading to the "Global Precipitation Mission" (GPM). GPM is planning to expand the scope of rainfall measurement through use of a satellite constellation. The intent is to address looming scientific questions arising in the context of global climate-water cycle interactions, hydrometeorology, weather prediction & prediction of fresh water resources, the global carbon budget, and biogeochemical cycles. This talk overviews the status and scientific agenda of this mission currently planned for launch in the 2007-2008 time frame. The GPM notional design involves a 10-member satellite constellation, one of which will be an advanced TRMM-like "core" satellite carrying a dual-frequency Ku-Ka band radar (DFPR) and a TMI-like radiometer. The other nine members of the constellation will be considered daughters of the core satellite, each carrying some type of passive microwave radiometer measuring across the 10.7-85 GHz frequency range -- likely to include a combination of lightweight satellites and co-existing operational/experimental satellites carrying passive microwave radiometers (i.e., 2 DMSP/SSMISs, GCOM-B1/AMSR-J, & Megha Tropiques/MADRAS). The goal behind the constellation is to achieve no worse than 3-hour sampling at any spot on the globe. The constellation's orbit architecture will consist of a mix of sun-synchronous and non- sun-synchronous daughter satellites, with the core satellite providing relevant measurements on internal cloud-precipitation microphysical processes plus "training-calibrating" information to be used with the retrieval algorithms for the daughter satellite measurements. The GPM is organized internationally, currently involving a partnership between NASA in the US, NASDA in Japan, and ESA in Europe (representing the European community nations). The mission is expected to involve additional international participants, sister agencies to the mainstream space agencies, and a diverse collection scientists from academia, government, and the private sector.
JPSS Common Ground System Multimission Support
NASA Astrophysics Data System (ADS)
Jamilkowski, M. L.; Miller, S. W.; Grant, K. D.
2013-12-01
NOAA & NASA jointly acquire the next-generation civilian operational weather satellite: Joint Polar Satellite System (JPSS). JPSS contributes the afternoon orbit & restructured NPOESS ground system (GS) to replace the current Polar-orbiting Operational Environmental Satellite (POES) system run by NOAA. JPSS sensors will collect meteorological, oceanographic, climatological & solar-geophysical observations of the earth, atmosphere & space. The JPSS GS is the Common Ground System (CGS), consisting of Command, Control, & Communications (C3S) and Interface Data Processing (IDPS) segments, both developed by Raytheon Intelligence, Information & Services (IIS). CGS now flies the Suomi National Polar-orbiting Partnership (S-NPP) satellite, transfers its mission data between ground facilities and processes its data into Environmental Data Records for NOAA & Defense (DoD) weather centers. CGS will expand to support JPSS-1 in 2017. The JPSS CGS currently does data processing (DP) for S-NPP, creating multiple TBs/day across over two dozen environmental data products (EDPs). The workload doubles after JPSS-1 launch. But CGS goes well beyond S-NPP & JPSS mission management & DP by providing data routing support to operational centers & missions worldwide. The CGS supports several other missions: It also provides raw data acquisition, routing & some DP for GCOM-W1. The CGS does data routing for numerous other missions & systems, including USN's Coriolis/Windsat, NASA's SCaN network (including EOS), NSF's McMurdo Station communications, Defense Meteorological Satellite Program (DMSP), and NOAA's POES & EUMETSAT's MetOp satellites. Each of these satellite systems orbits the Earth 14 times/day, downlinking data once or twice/orbit at up to 100s of MBs/second, to support the creation of 10s of TBs of data/day across 100s of EDPs. Raytheon and the US government invested much in Raytheon's mission-management, command & control and data-processing products & capabilities. CGS's flexible, multimission capabilities offer major chances for cost reduction & improved information integration across missions. Raytheon has a unique ability to provide complex, highly-secure, multi-mission GSs. As disaggregation, hosted CGS multimission payloads, and other space-architecture trades are implemented and new sensors come on line that collect orders of magnitude more data, the importance of a flexible, expandable and virtualized modern GS architecture increases. The CGS offers that solution support. JPSS CGS supports 5 global ground stations that can receive S-NPP & JPSS-1 mission data. These, linked with high-bandwidth commercial fiber, quickly transport data to the IDPS for EDP creation & delivery. CGS will process & deliver JPSS-1 data to US operational users in < 80 minutes from time of collection. And CGS leverages this fiber network to provide added data routing for a wide array of global missions. The JPSS CGS is a mature, tested solution for support to operational weather forecasting for civil, military and international partners and climate research. It features a flexible design handling order-of-magnitude increases in data over legacy satellite GSs and meets demanding science accuracy needs. The Raytheon-built JPSS CGS gives the full GS capability, from design & development through operations & sustainment. This lays the foundation for CGS future evolution to support additional missions like Polar Free Flyers.
Multi-instrument observations of the ionospheric and plasmaspheric density structure
NASA Astrophysics Data System (ADS)
Yizengaw, E.; Moldwin, M. B.
2008-05-01
: The density within the ionosphere and plasmasphere can be monitored using a combination of techniques that use both ground- and space-based instruments. We are combining diagnostic observations of everything, but the kitchen sink. These include observations of GPS TEC, TOPEX and JASON TEC, IMAGE EUV and FUV, GUVI composition data, ULF resonances, and many other multi-satellite data sets such as DMSP in situ observations. The dramatically growing number of GPS receivers on the ground and onboard Low-Earth-Orbit (LEO) satellites offers an excellent opportunity for remote sensing and monitoring of the ionospheric and plasmaspheric density structure using GPS TEC tomographic reconstruction technique. This allows us to clearly quantify magnetosphere-ionosphere (M-I) coupling dynamics, as well as confirm the long-standing conjecture that the mid-latitude trough and plasmapause are on the same field line. This has been demonstrated globally, for the first time, using a combination of data from IMAGE EUV and ground- and space-based GPS receivers. The two dimensional tomographic image of the ionosphere and plasmasphere, using data from the GPS receiver onboard LEO satellites, such as FedSat, CHAMP, COSMIC, etc, also provides a new ability to image the flux tube structure of ionospheric ion outflows, tracking flux tube structure up to 3.17Re (20,200 km) altitude for the first time. The combination of data from the altimeter on JASON and ground-based GPS network also provides an excellent opportunity to experimentally estimate the plasmaspheric density contribution to the ground-based GPS TEC and thus to the degradation of navigation and communication accuracy.
NASA/NOAA Electronic Theater: 90 Minutes of Spectacular Visualization
NASA Technical Reports Server (NTRS)
Hasler, A. F.
2004-01-01
The NASA/NOAA Electronic Theater presents Earth science observations and visualizations from space in a historical perspective. Fly in from outer space to Ashville and the Conference Auditorium. Zoom through the Cosmos to SLC and site of the 2002 Winter Olympics using 1 m IKONOS 'Spy Satellite' data. Contrast the 1972 Apollo 17 'Blue Marble' image of the Earth with the latest US and International global satellite images that allow us to view our Planet from any vantage point. See the latest spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, & Landsat 7, of storms & fires like Hurricane Isabel and the LA/San Diego Fire Storms of 2003. See how High Definition Television (HDTV) is revolutionizing the way we do science communication. Take the pulse of the planet on a daily, annual and 30-year time scale. See daily thunderstorms, the annual blooming of the northern hemisphere land masses and oceans, fires in Africa, dust storms in Iraq, and carbon monoxide exhaust from global burning. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. Spectacular new global visualizations of the observed and simulated atmosphere and Oceans are shown. See the currents and vortexes in the Oceans that bring up the nutrients blooms in response to El Nino/La Nina climate changes. The Etheater will be presented using the latest High Definition TV (HDTV) and video projection technology on a large screen. See the global city lights, and the great NE US blackout of August 2003 observed by the 'night-vision' DMSP satellite.
The NASA/NOAA Electronic Theater
NASA Technical Reports Server (NTRS)
Hasler, A. F.
2003-01-01
The NASA/NOAA Electronic Theater presents Earth science observations and visualizations from space in a historical perspective. Fly in from outer space to Cambridge and Harvard University. Zoom through the Cosmos to SLC and site of the 2002 Winter Olympics using 1 m IKONOS "Spy Satellite" data. Contrast the 1972 Apollo 17 "Blue Marble" image of the Earth with the latest US and International global satellite images that allow us to view our Planet from any vantage point. See the latest spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, & Landsat 7, of storms & fires like Hurricane Isabel and the LNSan Diego firestorms of 2003. See how High Definition Television (HDTV) is revolutionizing the way we do science communication. Take the pulse of the planet on a daily, annual and 30-year time scale. See daily thunderstorms, the annual blooming of the northern hemisphere landmasses and oceans, fires in Africa, dust storms in Iraq, and carbon monoxide exhaust from global burning. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. Spectacular new global visualizations of the observed and simulated atmosphere & oceans are shown. See the currents and vortexes in the oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fishermen. See the how the ocean blooms in response to El Niiioh Niiia climate changes. The Etheater will be presented using the latest High Definition TV (HDTV) and video projection technology on a large screen. See the global city lights, and the great NE US blackout of August 2003 observed by the "night-vision" DMSP satellite.
Linking Plasma Conditions in the Magnetosphere with Ionospheric Signatures
NASA Technical Reports Server (NTRS)
Rastaetter, Lutz; Kozyra, Janet; Kuznetsova, Maria M.; Berrios, David H.
2012-01-01
Modeling of the full magnetosphere, ring current and ionosphere system has become an indispensable tool in analyzing the series of events that occur during geomagnetic storms. The CCMC has a full model suite available for the magnetosphere, together with visualization tools that allow a user to perform a large variety of analyses. The January, 21, 2005 storm was a moderate-size storm that has been found to feature a large penetration electric field and unusually large polar caps (low-latitude precipitation patterns) that are otherwise found in super storms. Based on simulations runs at CCMC we can outline the likely causes of this behavior. Using visualization tools available to the online user we compare results from different magnetosphere models and present connections found between features in the magnetosphere and the ionosphere that are connected magnetically. The range of magnetic mappings found with different models can be compared with statistical models (Tsyganenko) and the model's fidelity can be verified with observations from low earth orbiting satellites such as DMSP and TIMED.
Parameterization and scaling of Arctic ice conditions in the context of ice-atmosphere processes
NASA Technical Reports Server (NTRS)
Barry, R. G.; Heinrichs, J.; Steffen, K.; Maslanik, J. A.; Key, J.; Serreze, M. C.; Weaver, R. W.
1994-01-01
This report summarizes achievements during year three of our project to investigate the use of ERS-1 SAR data to study Arctic ice and ice/atmosphere processes. The project was granted a one year extension, and goals for the final year are outlined. The specific objects of the project are to determine how the development and evolution of open water/thin ice areas within the interior ice pack vary under different atmospheric synoptic regimes; compare how open water/thin ice fractions estimated from large-area divergence measurements differ from fractions determined by summing localized openings in the pack; relate these questions of scale and process to methods of observation, modeling, and averaging over time and space; determine whether SAR data might be used to calibrate ice concentration estimates from medium and low-rate bit sensors (AVHRR and DMSP-OLS) and the special sensor microwave imager (SSM/I); and investigate methods to integrate SAR data for turbulent heat flux parametrization at the atmosphere interface with other satellite data.
Auroras over North America as Seen from Space
2017-12-08
Overnight on October 4-5, 2012, a mass of energetic particles from the atmosphere of the Sun were flung out into space, a phenomenon known as a coronal mass ejection. Three days later, the storm from the Sun stirred up the magnetic field around Earth and produced gorgeous displays of northern lights. NASA satellites track such storms from their origin to their crossing of interplanetary space to their arrival in the atmosphere of Earth. Using the “day-night band” (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS), the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite acquired this view of the aurora borealis early on the morning of October 8, 2012. The northern lights stretch across Canada’s Quebec and Ontario provinces in the image, and are part of the auroral oval that expanded to middle latitudes because of a geomagnetic storm. The DNB sensor detects dim light signals such as auroras, airglow, gas flares, city lights, and reflected moonlight. In the case of the image above, the sensor detected the visible light emissions as energetic particles rained down from Earth’s magnetosphere and into the gases of the upper atmosphere. The images are similar to those collected by the Operational Linescan System flown on U.S. Defense Meteorological Satellite Program (DMSP) satellites for the past three decades. “When I first saw images like this as a graduate student, I was immediately struck by the fluid dynamic characteristics of the aurora,” said Tom Moore, a space physicist at NASA's Goddard Space Flight Center. “Viewing the aurora in this way makes it immediately clear that space weather is an interaction of fluids from the Sun with those of the Earth's upper atmosphere. The electrodynamics make for important differences between plasmas and ordinary fluids, but familiar behaviors (for example, waves and vortices) are still very apparent. It makes me wonder at the ability of apparently empty space to behave like a fluid.” Auroras typically occur when solar flares and coronal mass ejections—or even an active solar wind stream—disturb and distort the magnetosphere, the cocoon of space protected by Earth’s magnetic field. The collision of solar particles and pressure into our planet’s magnetosphere accelerates particles trapped in the space around Earth (such as in the radiation belts). Those particles are sent crashing down into Earth’s upper atmosphere—at altitudes of 100 to 400 kilometers (60 to 250 miles)—where they excite oxygen and nitrogen molecules and release photons of light. The results are rays, sheets, and curtains of dancing light in the sky. Auroras are a beautiful expression of the connection between Sun and Earth, but not all of the connections are benign. Auroras are connected to geomagnetic storms, which can distort radio communications (particularly high frequencies), disrupt electric power systems on the ground, and give slight but detectable doses of radiation to flight crews and passengers on high-latitude airplane flights and on spacecraft. The advantage of images like those from VIIRS and DMSP is resolution, according to space physicist Patrick Newell of the Johns Hopkins University Applied Physics Laboratory. “You can see very fine detail in the aurora because of the low altitude and the high resolution of the camera,” he said. Most aurora scientists prefer to use images from missions dedicated to aurora studies (such as Polar, IMAGE, and ground-based imagers), which can offer many more images of a storm (rather than one per orbit) and can allow researchers to calculate the energy moving through the atmosphere. There are no science satellites flying right now that provide such a view, though astronauts regularly photograph and film auroras from the International Space Station. NASA Earth Observatory image by Jesse Allen and Robert Simmon, using VIIRS Day-Night Band data from the Suomi National Polar-orbiting Partnership (Suomi NPP) and the University of Wisconsin's Community Satellite Processing Package. Suomi NPP is the result of a partnership between NASA, the National Oceanic and Atmospheric Administration, and the Department of Defense. Caption by Mike Carlowicz. Instrument: Suomi NPP - VIIRS Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Garcia-Jimenez, Pilar; Brito-Romano, Olegario; Robaina, Rafael R
2013-08-01
The effects of different light conditions and exogenous ethylene on the emission of volatile compounds from the alga Gelidium arbuscula Bory de Saint-Vincent were studied. Special emphasis was placed on the possibility that the emission of ethylene and dimethyl sulfide (DMS) are related through the action of dimethylsulfoniopropionate (DMSP) lyase. The conversion of DMSP to DMS and acrylate, which is catalyzed by DMSP lyase, can indirectly support the synthesis of ethylene through the transformation of acrylate to ethylene. After mimicking the desiccation of G. arbuscula thalli experienced during low tides, the volatile compounds emitted were trapped in the headspace of 2 mL glass vials for 1 h. Two methods based on gas chromatography/mass spectrometry revealed that the range of organic volatile compounds released was affected by abiotic factors, such as the availability and spectral quality of light, salinity, and exogenous ethylene. Amines and methyl alkyl compounds were produced after exposure to white light and darkness but not after exposure to exogenous ethylene or red light. Volatiles potentially associated with the oxidation of fatty acids, such as alkenes and low-molecular-weight oxygenated compounds, accumu-lated after exposure to exogenous ethylene and red light. Ethylene was produced in all treatments, especially after exposure to exogenous ethylene. Levels of DMS, the most abundant sulfur-compound that was emitted in all of the conditions tested, did not increase after incubation with ethylene. Thus, although DMSP lyase is active in G. arbuscula, it is unlikely to contribute to ethylene synthesis. The generation of ethylene and DMS do not appear to be coordinated in G. arbuscula. © 2013 Phycological Society of America.
NASA Technical Reports Server (NTRS)
Blonski, Slawomir; Peterson, Craig
2006-01-01
Observations of icebergs are identified as one of the requirements for the GEOSS (Global Earth Observation System of Systems) in the area of reducing loss of life and property from natural and human-induced disasters. However, iceberg observations are not included among targets in the GEOSS 10-Year Implementation Plan, and thus there is an unfulfilled need for iceberg detection and tracking in the near future. Large Antarctic icebergs have been tracked by the National Ice Center and by the academic community using a variety of satellite sensors including both passive and active microwave imagers, such as SSM/I (Special Sensor Microwave/Imager) deployed on the DMSP (Defense Meteorological Satellite Program) spacecraft. Improvements provided in recent years by NASA and non-NASA satellite radars, scatterometers, and radiometers resulted in an increased number of observed icebergs and even prompted a question: Is The Number of Antarctic Icebergs Really Increasing? [D.G. Long, J. Ballantyne, and C. Bertoia, Eos, Transactions of the American Geophysical Union 83 (42): 469 & 474, 15 October 2002]. AMSR-E (Advanced Microwave Scanning Radiometer for the Earth Observing System) represents an improvement over SSM/I, its predecessor. AMSR-E has more measurement channels and higher spatial resolution than SSM/I. For example, the instantaneous field of view of the AMSR-E s 89-GHz channels is 6 km by 4 km versus 16 km by 14 km for SSM/I s comparable 85-GHz channels. AMSR-E, deployed on the Aqua satellite, scans across a 1450-km swath and provides brightness temperature measurements with nearglobal coverage every one or two days. In polar regions, overlapping swaths generate coverage up to multiple times per day and allow for creation of image time series with high temporal resolution. Despite these advantages, only incidental usage of AMSR-E data for iceberg tracking has been reported so far, none in an operational environment. Therefore, an experiment was undertaken in the RPC (Rapid Prototyping Capability) of NASA s (National Aeronautics and Space Administration) Applied Science Program to demonstrate that passive microwave brightness temperature measurements acquired by AMSR-E can be effectively used to track iceberg movement around Antarctica. The RPC s robust computation environment enabled processing of terabytes of data products available from the NASA Distributed Active Archive Center at the National Snow and Ice Data Center. Iceberg tracking based on the AMSR-E Level 2A data product was compared with records from the National Ice Center for currently existing icebergs. Some icebergs as small as roughly 10 km in size were easily observed, but tracking of many others, even larger ones, was obscured by presence of sea ice surrounding the icebergs. The best results, such as for the large iceberg A22A, were achieved when an iceberg was in open ocean.
2015-03-23
Using the “day-night band” (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS), the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite acquired this view of the aurora borealis on March 18, 2015. The northern lights stretch across Canada’s Quebec, Ontario, Manitoba, Nunavut, and Newfoundland provinces in the image, and are part of the auroral oval that expanded to middle latitudes because of a geomagnetic storm on March 17, 2015. The DNB sensor detects dim light signals such as auroras, airglow, gas flares, city lights, and reflected moonlight. In the case of the image above, the sensor detected the visible light emissions as energetic particles rained down from Earth’s magnetosphere and into the gases of the upper atmosphere. The images are similar to those collected by the Operational Linescan System flown on U.S. Defense Meteorological Satellite Program (DMSP) satellites for the past three decades. Auroras typically occur when solar flares and coronal mass ejections—or even an active solar wind stream—disturb and distort the magnetosphere, the cocoon of space protected by Earth’s magnetic field. The collision of solar particles and pressure into our planet’s magnetosphere accelerates particles trapped in the space around Earth (such as in the radiation belts). Those particles are sent crashing down into Earth’s upper atmosphere—at altitudes of 100 to 400 kilometers (60 to 250 miles)—where they excite oxygen and nitrogen molecules and release photons of light. The results are rays, sheets, and curtains of dancing light in the sky. Read more: earthobservatory.nasa.gov/NaturalHazards/view.php?id=8555... NASA Earth Observatory image by Jesse Allen, using VIIRS day-night band data from the Suomi National Polar-orbiting Partnership. Suomi NPP is the result of a partnership between NASA, the National Oceanic and Atmospheric Administration, and the Department of Defense. Caption by Mike Carlowicz and Adam Voiland. Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Validation of NASCAP-2K Spacecraft-Environment Interactions Calculations
NASA Technical Reports Server (NTRS)
Davis, V. A.; Mandell, M. J.; Gardner, B. M.; Mikellides, I. G.; Neergaard, L. F.; Cooke, D. L.; Minor, J.
2004-01-01
The recently released Nascap-2k, version 2.0, three-dimensional computer code models interactions between spacecraft surfaces and low-earth-orbit, geosynchronous, auroral, and interplanetary plasma environments. It replaces the earlier three-dimensional spacecraft interactions codes NASCAP/GEO, NASCAP/LEO, POLAR, and DynaPAC. Nascap-2k has improved numeric techniques, a modern user interface, and a simple, interactive satellite surface definition module (Object ToolKit). We establish the accuracy of Nascap-2k both by comparing computed currents and potentials with analytic results and by comparing Nascap-2k results with published calculations using the earlier codes. Nascap-2k predicts Langmuir-Blodgett or Parker-Murphy current collection for a nearly spherical (100 surfaces) satellite in a short Debye length plasma depending on the absence or presence of a magnetic field. A low fidelity (in geometry and time) Nascap-2k geosynchronous charging calculation gives the same results as the corresponding low fidelity NASCAP/GEO calculation. A high fidelity calculation (using the Nascap-2k improved geometry and time stepping capabilities) gives higher potentials, which are more consistent with typical observations. Nascap-2k predicts the same current as a function of applied potential as was observed and calculated by NASCAP/LEO for the SPEAR I rocket with a bipolar sheath. A Nascap-2k DMSP charging calculation gives results similar to those obtained using POLAR and consistent with observation.
Extreme changes in the dayside ionosphere during a Carrington-type magnetic storm
NASA Astrophysics Data System (ADS)
Tsurutani, Bruce T.; Verkhoglyadova, Olga P.; Mannucci, Anthony J.; Lakhina, Gurbax S.; Huba, Joseph D.
2012-06-01
It is shown that during the 30 October 2003 superstorm, dayside O+ ions were uplifted to DMSP altitudes (~850 km). Peak densities were ~9 × 105 cm-3 during the magnetic storm main phase (peak Dst = -390 nT). By comparison the 1-2 September 1859 Carrington magnetic storm (peak Dst estimated at -1760 nT) was considerably stronger. We investigate the impact of this storm on the low- to mid-latitude ionosphere using a modified version of the NRL SAMI2 ionospheric code. It is found that the equatorial region (LAT = 0° ± 15°) is swept free of plasma within 15 min (or less) of storm onset. The plasma is swept to higher altitudes and higher latitudes due to E × B convection associated with the prompt penetration electric field. Equatorial Ionization Anomaly (EIA) O+ density enhancements are found to be located within the broad range of latitudes ~ ± (25°-40°) at ~500-900 km altitudes. Densities within these peaks are ~6 × 106 oxygen ions-cm-3 at ~700 km altitude, approximately +600% quiet time values. The oxygen ions at the top portions (850-1000 km) of uplifted EIAs will cause strong low-altitude satellite drag. Calculations are currently being performed on possible uplift of oxygen neutrals by ion-neutral coupling to understand if there might be further significant satellite drag forces present.
NASA Astrophysics Data System (ADS)
Zhao, Q.; Zhan, S.; Kuai, X.; Zhan, Q.
2015-12-01
The goal of this research is to combine DMSP-OLS nighttime light data with Landsat imagery and use spatio-temporal analysis methods to evaluate the relationships between urbanization processes and temperature variation in Phoenix metropolitan area. The urbanization process is a combination of both land use change within the existing urban environment as well as urban sprawl that enlarges the urban area through the transformation of rural areas to urban structures. These transformations modify the overall urban climate environment, resulting in higher nighttime temperatures in urban areas compared to the surrounding rural environment. This is a well-known and well-studied phenomenon referred to as the urban heat island effect (UHI). What is unknown is the direct relationship between the urbanization process and the mechanisms of the UHI. To better understand this interaction, this research focuses on using nighttime light satellite imagery to delineate and detect urban extent changes and utilizing existing land use/land cover map or newly classified imagery from Landsat to analyze the internal urban land use variations. These data are combined with summer and winter land surface temperature data extracted from Landsat. We developed a time series of these combined data for Phoenix, AZ from 1992 to 2013 to analyze the relationships among land use change, land surface temperature and urban growth.
NASA Technical Reports Server (NTRS)
Hasler, A. F.; Starr, David (Technical Monitor)
2002-01-01
Spectacular Visualizations of our Blue Marble The NASA/NOAA Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to the 2002 Winter Olympic Stadium Site of the Olympic Opening and Closing Ceremonies in Salt Lake City. Fly in and through Olympic Alpine Venues using 1 m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and international global satellite weather movies including hurricanes & "tornadoes". See the latest visualizations of spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, Landsat 7 including new 1 - min GOES rapid scan image sequences of Nov 9th 2001 Midwest tornadic thunderstorms and have them explained. See how High-Definition Television (HDTV) is revolutionizing the way we communicate science. (In cooperation with the American Museum of Natural History in NYC). See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on the covers of Newsweek, TIME, National Geographic, Popular Science & on National & International Network TV. New computer software tools allow us to roam & zoom through massive global images e.g. Landsat tours of the US, and Africa, showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See vertexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nicola Nina climate changes. See the city lights, fishing fleets, gas flares and biomass burning of the Earth at night observed by the "night-vision" DMSP military satellite.
Electronic-Theater 2001: Visions of Our Planet's Atmosphere, Land and Oceans
NASA Technical Reports Server (NTRS)
Hasler, Authur; Starr, David OC. (Technical Monitor)
2001-01-01
The NASA/NOAA/AMS Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to Wisconsin, Madison and the Monona Terrace Center. Drop in on the Kennedy Space Center and Park City Utah, site of the 2002 Olympics using I m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s pioneered by UW. Scientists and see them contrasted with the latest US and International global satellite weather movies including hurricanes & tornadoes. See the latest spectacular images from NASA/NOAA remote sensing missions like Terra GOES, TRMM, SeaWiFS, Landsat 7 that are visualized & explained. See how High Definition Television (HDTV) is revolutionizing the way we communicate science in cooperation with the American Museum of Natural History in NYC. See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. New visualization tools allow us to roam & zoom through massive global images eg Landsat tours of the US, Africa, & New Zealand showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See massive dust storms sweeping across Africa. See vortices and currents in the global oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nina/La Nina climate changes. The demonstration is interactively driven by a SGI Onyx 11 Graphics Supercomputer with four CPUs, 8 Gigabytes of RAM and Terabyte of disk. With five projectors on a giant IMAX sized 18 x 72 ft screen. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "nightvision" DMSP military satellite.
Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA Electronic Theater 2002
NASA Technical Reports Server (NTRS)
Haser, Fritz; Starr, David (Technical Monitor)
2002-01-01
The NASA/NOAA Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to the 2002 Winter Olympic Stadium Site of the Olympic Opening and Closing Ceremonies in Salt Lake City. Fly in and through Olympic Alpine Venues using 1 m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and international global satellite weather movies including hurricanes and "tornadoes". See the latest visualizations of spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, Landsat 7 including new 1 - min GOES rapid scan image sequences of Nov 9th 2001 Midwest tornadic thunderstorms and have them explained. See how High-Definition Television (HDTV) is revolutionizing the way we communicate science. (In cooperation with the American Museum of Natural History in NYC) See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on the covers of Newsweek, TIME, National Geographic, Popular Science and on National and International Network TV. New computer software tools allow us to roam and zoom through massive global images e.g. Landsat tours of the US, and Africa, showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds. data. Spectacular new visualizations of the global atmosphere and oceans are shown. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP military satellite.
Visions of Our Planet's Atmosphere, Land and Oceans Electronic-Theater 2001
NASA Technical Reports Server (NTRS)
Hasler, A. F.; Einaudi, Franco (Technical Monitor)
2001-01-01
The NASA/NOAA/AMS Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to Fredericton New Brunswick. Drop in on the Kennedy Space Center and Park City Utah, site of the 2002 Olympics using 1 m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and International global satellite weather movies including hurricanes & tornadoes. See the latest spectacular images from NASA/NOAA and Canadian remote sensing missions like Terra GOES, TRMM, SeaWiFS, Landsat 7, and Radarsat that are visualized & explained. See how High Definition Television (HDTV) is revolutionizing the way we communicate science in cooperation with the American Museum of Natural History in NYC. See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. New visualization tools allow us to roam & zoom through massive global images eg Landsat tours of the US, Africa, & New Zealand showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See massive dust storms sweeping across Africa. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. The demonstration is interactively driven by a SGI Onyx II Graphics Supercomputer with four CPUs, 8 Gigabytes of RAM and Terabyte of disk. With multiple projectors on a giant screen. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP military satellite.
A global analysis of the urban heat island effect based on multisensor satellite data
NASA Astrophysics Data System (ADS)
Xiao, J.; Frolking, S. E.; Milliman, T. E.; Schneider, A.; Friedl, M. A.
2017-12-01
Human population is rapidly urbanizing. In much of the world, cities are prone to hotter weather than surrounding rural areas - so-called `urban heat islands' - and this effect can have mortal consequences during heat waves. During the daytime, when the surface energy balance is driven by incoming solar radiation, the magnitude of urban warming is strongly influenced by surface albedo and the capacity to evaporate water (i.e., there is a strong relationship between vegetated land fraction and the ratio of sensible to latent heat loss or Bowen ratio). At nighttime, urban cooling is often inhibited by the thermal inertia of the built environment and anthropogenic heat exhaust from building and transportation energy use. We evaluated a suite of global remote sensing data sets representing a range of urban characteristics against MODIS-derived land-surface temperature differences between urban and surrounding rural areas. We included two new urban datasets in this analysis - MODIS-derived change in global urban extent and global urban microwave backscatter - along with several MODIS standard products and DMSP/OLS nighttime lights time series data. The global analysis spanned a range of urban characteristics that likely influence the magnitude of daytime and/or nighttime urban heat islands - urban size, population density, building density, state of development, impervious fraction, eco-climatic setting. Specifically, we developed new satellite datasets and synthesizing these with existing satellite data into a global database of urban land surface parameters, used two MODIS land surface temperature products to generate time series of daytime and nighttime urban heat island effects for 30 large cities across the globe, and empirically analyzed these data to determine specifically which remote sensing-based characterizations of global urban areas have explanatory power with regard to both daytime and nighttime urban heat islands.
An Hour of Spectacular Visualization
NASA Technical Reports Server (NTRS)
Hasler, Arthur F.
2004-01-01
The NASA/NOAA Electronic Theater presents Earth science observations and visualizations from space in a historical perspective. Fly in from outer space to the Far East and down to Beijing and Bangkok. Zooms through the Cosmos to the site of the 2004 Summer Olympic games in Athens using 1 m IKONOS "Spy Satellite" data. Contrast the 1972 Apollo 17 "Blue Marble" image of the Earth with the latest US and International global satellite images that allow us to view our Planet from any vantage point. See the latest spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, & Landsat 7, of typhoons/hurricanes and fires in California and around the planet. See how High Definition Television (HDTV) is revolutionizing the way we do science communication. Take the pulse of the planet on a daily, annual and 30-year time scale. See daily thunderstorms, the annual greening of the northern hemisphere land masses and Oceans, fires in Africa, dust storms in Iraq, and carbon monoxide exhaust from global burning. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. Spectacular new global visualizations of the observed and simulated atmosphere & Oceans are shown. See the currents and vortexes in the Oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fishermen. See the how the ocean blooms in response to El Nino/La Nina climate changes. The Etheater will be presented using the latest High Definition TV (HDTV) and video projection technology on a large screen. See the global city lights, showing population concentrations in the US, Africa, and Asia observed by the "night-vision" DMSP satellite.
NASA/NOAA Electronic Theater: An Hour of Spectacular Visualization
NASA Technical Reports Server (NTRS)
Hasier, A. F.
2004-01-01
The NASA/NOAA Electronic Theater presents Earth science observations and visualizations from space in a historical perspective. Fly in from outer space to Utah, Logan and the USU Agriculture Station. Compare zooms through the Cosmos to the sites of the 2004 Summer and 2002 Winter Olympic games using 1 m IKONOS "Spy Satellite" data. Contrast the 1972 Apollo 17 "Blue Marble" image of the Earth with the latest US and International global satellite images that allow us to view our Planet from any vantage point. See the latest spectacular images h m NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiF!3,& Landsat 7, of storms & fires like Hurricanes Charlie & Isabel and the LA/San Diego Fire Storms of 2003. See how High Definition Television (HDTV) is revolutionizing the way we do science communication. Take the pulse of the planet on a daily, annual and 30-year time scale. See daily thunderstorms, the annual greening of the northern hemisphere land masses and oceans, fires in Africa, dust storms in Iraq, and carbon monoxide exhaust from global burning. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. Spectacular new global visualizations of the observed and simulated atmosphere & oceans are shown. See the currents and vortexes in the oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fishermen. See the how the Ocean blooms in response to El Nino/La Nina climate changes. The E-theater will be presented using the latest High Definition TV and video projection technology on a large screen. See the global city lights, and the great NE US blackout of August 2003 observed by the "night-vision" DMSP satellite.
Longitudinal Variations in the Variability of Spread F Occurrence
NASA Astrophysics Data System (ADS)
Groves, K. M.; Bridgwood, C.; Carrano, C. S.
2017-12-01
The complex dynamics of the equatorial ionosphere have attracted the interest and attention of researchers for many decades. The relatively local processes that give rise to large meridional gradients have been well documented and the associated terminology has entered the common lexicon of ionospheric research (e.g., fountain effect, equatorial anomaly, bubbles, Spread F). Zonal variations have also been noted, principally at the level of determining longitudinal differences in seasonal activity patterns. Due to a historical lack of high resolution ground-based observations at low latitudes, the primary source of data for such analyses has been space-based observations from satellites such as ROCSAT, DMSP, C/NOFS that measure in situ electron density variations. An important longitudinal variation in electron density structure associated with non-migrating diurnal tides was discovered by Immel et al. in 2006 using data from the FUV sensor aboard the NASA IMAGE satellite. These satellite observations have been very helpful in identifying the structural characteristics of the equatorial ionosphere and the occurrence of Spread F, but they provide little insight into variations in scintillation features and potential differences in bubble development characteristics. Moreover space-based studies tend towards the statistics of occurrence frequency over periods of weeks to months. A recent analysis of daily spread F occurrence as determined by low latitude VHF scintillation activity shows that statistical results that are consistent with previous space-based observations, but the level of variability in the occurrence data show marked variations with longitude. For example, the American sector shows very low in-season variability while the African and Asian sectors exhibit true day-to-day variability regardless of seasonal variations. The results have significant implications for space weather as they suggest that long-term forecasts of equatorial scintillation may be meaningful within specific longitude boundaries.
NASA Astrophysics Data System (ADS)
Lin, M.; Yang, Z.; Park, H.; Qian, S.; Chen, J.; Fan, P.
2017-12-01
Impervious surface area (ISA) has become an important indicator for studying urban environments, but mapping ISA at the regional or global scale is still challenging due to the complexity of impervious surface features. The Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) nighttime light data is (NTL) and Resolution Imaging Spectroradiometer (MODIS) are the major remote sensing data source for regional ISA mapping. A single regression relationship between fractional ISA and NTL or various index derived based on NTL and MODIS vegetation index (NDVI) data was established in many previous studies for regional ISA mapping. However, due to the varying geographical, climatic, and socio-economic characteristics of different cities, the same regression relationship may vary significantly across different cities in the same region in terms of both fitting performance (i.e. R2) and the rate of change (Slope). In this study, we examined the regression relationship between fractional ISA and Vegetation Adjusted Nighttime light Urban Index (VANUI) for 120 randomly selected cities around the world with a multilevel regression model. We found that indeed there is substantial variability of both the R2 (0.68±0.29) and slopes (0.64±0.40) among individual regressions, which suggests that multilevel/hierarchical models are needed for accuracy improvement of future regional ISA mapping .Further analysis also let us find the this substantial variability are affected by climate conditions, socio-economic status, and urban spatial structures. However, all these effects are nonlinear rather than linear, thus could not modeled explicitly in multilevel linear regression models.
Ohayon, Maurice M; Milesi, Cristina
2016-06-01
Our study aims to explore the associations between outdoor nighttime lights (ONL) and sleep patterns in the human population. Cross-sectional telephone study of a representative sample of the general US population age 18 y or older. 19,136 noninstitutionalized individuals (participation rate: 83.2%) were interviewed by telephone. The Sleep-EVAL expert system administered questions on life and sleeping habits; health; sleep, mental and organic disorders (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; International Classification of Sleep Disorders, Second Edition; International Classification of Diseases, 10(th) Edition). Individuals were geolocated by longitude and latitude. Outdoor nighttime light measurements were obtained from the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS), with nighttime passes taking place between 19:30 and 22:30 local time. Light data were correlated precisely to the geolocation of each participant of the general population sample. Living in areas with greater ONL was associated with delayed bedtime (P < 0.0001) and wake up time (P < 0.0001), shorter sleep duration (P < 0.01), and increased daytime sleepiness (P < 0.0001). Living in areas with greater ONL also increased the dissatisfaction with sleep quantity and quality (P < 0.0001) and the likelihood of having a diagnostic profile congruent with a circadian rhythm disorder (P < 0.0001). Although they improve the overall safety of people and traffic, nighttime lights in our streets and cities are clearly linked with modifications in human sleep behaviors and also impinge on the daytime functioning of individuals living in areas with greater ONL. © 2016 Associated Professional Sleep Societies, LLC.
A global map of urban extent from nightlights
Zhou, Yuyu; Smith, Steven J.; Zhao, Kaiguang; ...
2015-05-13
Urbanization, one of the major human induced land-cover and land-use changes, has a profound impact on the Earth system including biodiversity, the cycling of water and carbon and exchange of energy and water between Earth’s surface and atmosphere, all affecting weather and climate. Accurate information on urban areas and their spatial distribution at the regional and global scales is important for scientific understanding of their contribution to the changing Earth system, and for practical management and policy decisions. We developed a method to map the urban extent from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime stable-light data atmore » the global level and derived a new global map of 1-km urban extent for year 2000. Based on this map, we found that globally, urban land area is about 0.5% of total land area but ranges widely at regional level from 0.1% in Oceania to 2.3% in Europe. At the country level, urban land area varies from lower than 0.01% to higher than 10%, but is lower than 1% for most (70%) countries. Urbanization follows land mass distribution, as anticipated, with the highest concentration found between 30°N to 45°N latitude and the largest longitudinal peak around 80°W. Based on a sensitivity analysis and comparison with other global urban area products, we found that our global product of urban area provides a reliable estimate of global urban areas and offer the potential of capturing more accurately their spatial and temporal dynamics.« less
NASA Astrophysics Data System (ADS)
Hayashida, Hakase; Steiner, Nadja; Monahan, Adam; Galindo, Virginie; Lizotte, Martine; Levasseur, Maurice
2017-06-01
Sea ice represents an additional oceanic source of the climatically active gas dimethyl sulfide (DMS) for the Arctic atmosphere. To what extent this source contributes to the dynamics of summertime Arctic clouds is, however, not known due to scarcity of field measurements. In this study, we developed a coupled sea ice-ocean ecosystem-sulfur cycle model to investigate the potential impact of bottom-ice DMS and its precursor dimethylsulfoniopropionate (DMSP) on the oceanic production and emissions of DMS in the Arctic. The results of the 1-D model simulation were compared with field data collected during May and June of 2010 in Resolute Passage. Our results reproduced the accumulation of DMS and DMSP in the bottom ice during the development of an ice algal bloom. The release of these sulfur species took place predominantly during the earlier phase of the melt period, resulting in an increase of DMS and DMSP in the underlying water column prior to the onset of an under-ice phytoplankton bloom. Production and removal rates of processes considered in the model are analyzed to identify the processes dominating the budgets of DMS and DMSP both in the bottom ice and the underlying water column. When openings in the ice were taken into account, the simulated sea-air DMS flux during the melt period was dominated by episodic spikes of up to 8.1 µmol m-2 d-1. Further model simulations were conducted to assess the effects of the incorporation of sea-ice biogeochemistry on DMS production and emissions, as well as the sensitivity of our results to changes of uncertain model parameters of the sea-ice sulfur cycle. The results highlight the importance of taking into account both the sea-ice sulfur cycle and ecosystem in the flux estimates of oceanic DMS near the ice margins and identify key uncertainties in processes and rates that should be better constrained by new observations.
NASA Astrophysics Data System (ADS)
Maynard, N. C.; Savin, S.; Erickson, G. M.; Kawano, H.; Němeček, Z.; Peterson, W. K.; Šafránoková, J.; Sandahl, I.; Scudder, J. D.; Siscoe, G. L.; Sonnerup, B. U. Ö.; Weimer, D. R.; White, W. W.; Wilson, G. R.
2001-04-01
Using a unique data set from the Wind, Polar, Interball 1, Magion 4, and Defense Meteorological Satellite Program (DMSP) F11 satellites, comparisons with the Integrated Space Weather Model (ISM) have provided validation of the global structure predicted by the ISM model, which in turn has allowed us to use the model to interpret the data to further understand boundary layers and magnetospheric processes. The comparisons have shown that the magnetospheric ``sash'' [White et al., 1998], a region of low magnetic field discovered by the MHD modeling which extends along the high-latitude flank of the magnetopause, is related to the turbulent boundary layer on the high-latitude magnetopause, recently mapped by Interball 1. The sash in the data and in the model has rotational discontinuity properties, expected for a reconnection site. At some point near or behind the terminator, the sash becomes a site for reconnection of open field lines, which were previously opened by merging on the dayside. This indicates that significant reconnection in the magnetotail occurs on the flanks. Polar mapped to the high-density extension of the sash into the tilted plasma sheet. The source of the magnetosheath plasma observed by Polar on closed field lines behind the terminator was plasma entry through the low field connection of the sash to the central plasma sheet. The Polar magnetic field line footprints in each hemisphere are moving in different directions. Above and below the tilted plasma sheet the flows in the model are consistent with the corresponding flows in the ionosphere. The turbulence in the plasma sheet allows the convection patterns from each hemisphere to adjust. The boundary layer in the equatorial plane on the flank for this interplanetary magnetic field BY condition, which is below the tilted central plasma sheet, is several RE thick and is on tailward flowing open field lines. This thick boundary layer shields the magnetopause from viscous forces and must be driven by magnetic tension. Above the plasma sheet the boundary layer is dominated by the sash, and the model indicates that the open region inside the sash is considerably thinner.
NASA Astrophysics Data System (ADS)
Redmon, Robert J.
The mechanisms by which thermal O+ escapes from the top of the ionosphere and into the magnetosphere are not fully understood even with 30 years of active research. This thesis introduces a new database, builds a simulation framework around a thermospheric model and exploits these tools to gain new insights into the study of O+ ion outflows. A dynamic auroral boundary identification system is developed using Defense Meteorological Satellite Program (DMSP) spacecraft observations at 850 km to build a database characterizing the oxygen source region. This database resolves the ambiguity of the expansion and contraction of the auroral zone. Mining this new dataset, new understanding is revealed. We describe the statistical trajectory of the cleft ion fountain return flows over the polar cap as a function of activity and the orientation of the interplanetary magnetic field y-component. A substantial peak in upward moving O+ in the morning hours is discovered. Using published high altitude data we demonstrate that between 850 and 6000 km altitude, O+ is energized predominantly through transverse heating; and acceleration in this altitude region is relatively more important in the cusp than at midnight. We compare data with a thermospheric model to study the effects of solar irradiance, electron precipitation and neutral wind on the distribution of upward O+ at auroral latitudes. EUV irradiance is shown to play a dominant role in establishing a dawn-focused source population of upwelling O+ that is responsible for a pre-noon feature in escaping O+ fluxes. This feature has been corroborated by observations on platforms including the Dynamics Explorer 1 (DE-1), Polar, and Fast Auroral Snapshot SnapshoT (FAST) spacecraft. During quiet times our analysis shows that the neutral wind is more important than electron precipitation in establishing the dayside O+ upwelling distribution. Electron precipitation is found to play a relatively modest role in controlling dayside, and a critical role in controlling nightside, upwelling O+. This thesis provides a new database, and insights into the study of oxygen ion outflows during quiet times. These results and tools will be essential for researchers working on topics involving magnetosphere-ionosphere interactions.
Operational Space Weather Models: Trials, Tribulations and Rewards
NASA Astrophysics Data System (ADS)
Schunk, R. W.; Scherliess, L.; Sojka, J. J.; Thompson, D. C.; Zhu, L.
2009-12-01
There are many empirical, physics-based, and data assimilation models that can probably be used for space weather applications and the models cover the entire domain from the surface of the Sun to the Earth’s surface. At Utah State University we developed two physics-based data assimilation models of the terrestrial ionosphere as part of a program called Global Assimilation of Ionospheric Measurements (GAIM). One of the data assimilation models is now in operational use at the Air Force Weather Agency (AFWA) in Omaha, Nebraska. This model is a Gauss-Markov Kalman Filter (GAIM-GM) model, and it uses a physics-based model of the ionosphere and a Kalman filter as a basis for assimilating a diverse set of real-time (or near real-time) measurements. The physics-based model is the Ionosphere Forecast Model (IFM), which is global and covers the E-region, F-region, and topside ionosphere from 90 to 1400 km. It takes account of five ion species (NO+, O2+, N2+, O+, H+), but the main output of the model is a 3-dimensional electron density distribution at user specified times. The second data assimilation model uses a physics-based Ionosphere-Plasmasphere Model (IPM) and an ensemble Kalman filter technique as a basis for assimilating a diverse set of real-time (or near real-time) measurements. This Full Physics model (GAIM-FP) is global, covers the altitude range from 90 to 30,000 km, includes six ions (NO+, O2+, N2+, O+, H+, He+), and calculates the self-consistent ionospheric drivers (electric fields and neutral winds). The GAIM-FP model is scheduled for delivery in 2012. Both of these GAIM models assimilate bottom-side Ne profiles from a variable number of ionosondes, slant TEC from a variable number of ground GPS/TEC stations, in situ Ne from four DMSP satellites, line-of-sight UV emissions measured by satellites, and occultation data. Quality control algorithms for all of the data types are provided as an integral part of the GAIM models and these models take account of latent data (up to 3 hours). The trials, tribulations and rewards of constructing and maintaining operational data assimilation models will be discussed.
1979-12-30
42.22 122.52 Cloudy Green Bay 0253 Z Wisconsin (WI) 23 Nov 79 44.29 88.08 Cloudy Monterrey 0429 Z Mexico (MEX) 23 Nov 79 25.52 100.12 Cloudy Dodge City...230 250 270 290 - 35 35 Ii 30 30 / 25 / MONTERREY, MEXICO 25 GREEN DAY. WISCONSIN 23 NOV. 79,OOZ,0429Z 23 NOV. 79,OOZ,02 53Z - RAOS i -- RAO 20...bINDOW/ UP1NG2.INT)eDW(NG2.INT)eTHETA(t4),NU(INT)eLv(INT~e ICK~IINT).CK2(lNT).6UVERT(INI).CDVERT(INT) COMMON /MADATA/ PINIINGvINT) .PTIINT) . SEXT (INT
NASA Astrophysics Data System (ADS)
Li, Mao; Li, Lel-in
2018-03-01
For the sake of curbing the spreading of Changsha-Zhuzhou-Xiangtan urban agglomeration and spatial disorder in the process of urbanization development on the regional bearing capacity of land resources and ecological environment and assisting to plan the integration process of ChangZhuTan,this paper uses the DMSP/OLS night light data of Chang ZhuTan in 1992 to 2013 to invert the urbanization process index of ChangZhuTan urban agglomeration. Based on the two scales of time and space, this paper analyzes the average index of lights, the speed of urban expansion and urban compactness index et al and studies the temporal and spatial characteristics of ChangZhuTan urban agglomeration in this period.
DMSP F7 observations of a substorm field-aligned current
NASA Technical Reports Server (NTRS)
Lopez, R. E.; Spence, H. E.; Meng, C.-I.
1991-01-01
Observations are described of a substorm field-aligned current (FAC) system traversed by the DMSP F7 spacecraft just after 0300 UT on April 25, 1985. It is shown that the substorm FAC portion of the current system was located equatorward of the boundary between open and closed field lines. The equatorward boundary of the substorm FAC into the magnetotail was mapped using the Tsyganenko (1987) model, showing that the boundary corresponds to 6.9 earth radii. The result is consistent with the suggestion of Akasofu (1972) and Lopez and Lui (1990) that the region of substorm initiation lies relatively close to the earth and the concept that an essential feature of substorms is the disruption and diversion of the near-earth current sheet.
Topside ionospheric irregularities as seen from multisatellite observations
NASA Astrophysics Data System (ADS)
Zakharenkova, Irina; Astafyeva, Elvira
2015-01-01
use in situ data from CHAMP and DMSP satellites, along with data of GPS receiver onboard CHAMP satellite and ground-based GPS receivers to study the occurrence and global distribution of ionospheric irregularities during the main phase of the geomagnetic storm of 29-31 August 2004 (minimum Dst excursion of -128 nT). Using the CHAMP GPS measurements, we created maps of GPS phase fluctuation activity and found two specific zones of the most intense irregularities: (1) the region of the auroral oval at high latitudes of both hemispheres and (2) the low latitudes/equatorial region between Africa and South America. At high latitudes, the topside ionospheric irregularities appeared to be more intensive in the southern hemisphere, which is, most likely, due to seasonal variations in the interhemispheric field-aligned currents system. An analysis of multi-instrumental observations reveals reinforcement of the equatorial ionization anomaly after sunset in Atlantic sector on 30 August and formation of the significant plasma depletions and irregularities over a large longitudinal range. Equatorial irregularities were also found in the morning sector at the recovery phase of the storm. In addition to low Earth orbit (LEO) GPS measurements, we analyze the LEO in situ measurements, and we show that these two techniques cannot be interchangeable in all cases because of the altitudinal extent of plasma irregularities. Overall, we demonstrate that the LEO GPS technique can serve a useful tool for detection of the topside ionospheric irregularities during space weather events and may essentially contribute to other methods based on various instruments.
Source of the dayside cusp aurora.
Mende, S B; Frey, H U; Angelopoulos, V
2016-08-01
Monochromatic all-sky imagers at South Pole and other Antarctic stations of the Automatic Geophysical Observatory chain recorded the aurora in the region where the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites crossed the dayside magnetopause. In several cases the magnetic field lines threading the satellites when mapped to the atmosphere were inside the imagers' field of view. From the THEMIS magnetic field and the plasma density measurements, we were able to locate the position of the magnetopause crossings and map it to the ionosphere using the Tsyganenko-96 field model. Field line mapping is reasonably accurate on the dayside subsolar region where the field is strong, almost dipolar even though compressed. From these coordinated observations, we were able to prove that the dayside cusp aurora of high 630 nm brightness is on open field lines, and it is therefore direct precipitation from the magnetosheath. The cusp aurora contained significant highly structured N 2 + 427.8 nm emission. The THEMIS measurements of the magnetosheath particle energy and density taken just outside the magnetopause compared to the intensity of the structured N 2 + 427.8 nm emissions showed that the precipitating magnetosheath particles had to be accelerated. The most likely electron acceleration mechanism is by dispersive Alfvén waves propagating along the field line. Wave-accelerated suprathermal electrons were seen by FAST and DMSP. The 427.8 nm wavelength channel also shows the presence of a lower latitude hard-electron precipitation zone originating inside the magnetosphere.
NASA Astrophysics Data System (ADS)
Raev, M. D.; Sharkov, E. A.; Tikhonov, V. V.; Repina, I. A.; Komarova, N. Yu.
2015-12-01
The GLOBAL-RT database (DB) is composed of long-term radio heat multichannel observation data received from DMSP F08-F17 satellites; it is permanently supplemented with new data on the Earth's exploration from the space department of the Space Research Institute, Russian Academy of Sciences. Arctic ice-cover areas for regions higher than 60° N latitude were calculated using the DB polar version and NASA Team 2 algorithm, which is widely used in foreign scientific literature. According to the analysis of variability of Arctic ice cover during 1987-2014, 2 months were selected when the Arctic ice cover was maximal (February) and minimal (September), and the average ice cover area was calculated for these months. Confidence intervals of the average values are in the 95-98% limits. Several approximations are derived for the time dependences of the ice-cover maximum and minimum over the period under study. Regression dependences were calculated for polynomials from the first degree (linear) to sextic. It was ascertained that the minimal root-mean-square error of deviation from the approximated curve sharply decreased for the biquadratic polynomial and then varied insignificantly: from 0.5593 for the polynomial of third degree to 0.4560 for the biquadratic polynomial. Hence, the commonly used strictly linear regression with a negative time gradient for the September Arctic ice cover minimum over 30 years should be considered incorrect.
Source of the dayside cusp aurora
Frey, H. U.; Angelopoulos, V.
2016-01-01
Abstract Monochromatic all‐sky imagers at South Pole and other Antarctic stations of the Automatic Geophysical Observatory chain recorded the aurora in the region where the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites crossed the dayside magnetopause. In several cases the magnetic field lines threading the satellites when mapped to the atmosphere were inside the imagers' field of view. From the THEMIS magnetic field and the plasma density measurements, we were able to locate the position of the magnetopause crossings and map it to the ionosphere using the Tsyganenko‐96 field model. Field line mapping is reasonably accurate on the dayside subsolar region where the field is strong, almost dipolar even though compressed. From these coordinated observations, we were able to prove that the dayside cusp aurora of high 630 nm brightness is on open field lines, and it is therefore direct precipitation from the magnetosheath. The cusp aurora contained significant highly structured N2 + 427.8 nm emission. The THEMIS measurements of the magnetosheath particle energy and density taken just outside the magnetopause compared to the intensity of the structured N2 + 427.8 nm emissions showed that the precipitating magnetosheath particles had to be accelerated. The most likely electron acceleration mechanism is by dispersive Alfvén waves propagating along the field line. Wave‐accelerated suprathermal electrons were seen by FAST and DMSP. The 427.8 nm wavelength channel also shows the presence of a lower latitude hard‐electron precipitation zone originating inside the magnetosphere. PMID:27867797
47 CFR 76.1002 - Specific unfair practices prohibited.
Code of Federal Regulations, 2013 CFR
2013-10-01
... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Competitive Access to Cable Programming § 76.1002 Specific... interest in a satellite cable programming vendor or in a satellite broadcast programming vendor shall... such vendor's prices, terms and conditions for the sale of, satellite cable programming or satellite...
47 CFR 76.1002 - Specific unfair practices prohibited.
Code of Federal Regulations, 2011 CFR
2011-10-01
... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Competitive Access to Cable Programming § 76.1002 Specific... interest in a satellite cable programming vendor or in a satellite broadcast programming vendor shall... such vendor's prices, terms and conditions for the sale of, satellite cable programming or satellite...
Nakamura, R.; Sergeev, V. A.; Baumjohann, W.; Owen, C. J.; Petrukovich, A. A.; Yao, Z.; Nakamura, T. K. M.; Kubyshkina, M. V.; Sotirelis, T.; Burch, J. L.; Genestreti, K. J.; Vörös, Z.; Andriopoulou, M.; Gershman, D. J.; Avanov, L. A.; Magnes, W.; Russell, C. T.; Plaschke, F.; Khotyaintsev, Y. V.; Giles, B. L.; Coffey, V. N.; Dorelli, J. C.; Strangeway, R. J.; Torbert, R. B.; Lindqvist, P.‐A.; Ergun, R.
2017-01-01
Abstract During a magnetic storm on 23 June 2015, several very intense substorms took place, with signatures observed by multiple spacecraft including DMSP and Magnetospheric Multiscale (MMS). At the time of interest, DMSP F18 crossed inbound through a poleward expanding auroral bulge boundary at 23.5 h magnetic local time (MLT), while MMS was located duskward of 22 h MLT during an inward crossing of the expanding plasma sheet boundary. The two spacecraft observed a consistent set of signatures as they simultaneously crossed the reconnection separatrix layer during this very intense reconnection event. These include (1) energy dispersion of the energetic ions and electrons traveling earthward, accompanied with high electron energies in the vicinity of the separatrix; (2) energy dispersion of polar rain electrons, with a high‐energy cutoff; and (3) intense inward convection of the magnetic field lines at the MMS location. The high temporal resolution measurements by MMS provide unprecedented observations of the outermost electron boundary layer. We discuss the relevance of the energy dispersion of the electrons, and their pitch angle distribution, to the spatial and temporal evolution of the boundary layer. The results indicate that the underlying magnetotail magnetic reconnection process was an intrinsically impulsive and the active X‐line was located relatively close to the Earth, approximately at 16–18 RE. PMID:29399431
NASA Astrophysics Data System (ADS)
Varsani, A.; Nakamura, R.; Sergeev, V. A.; Baumjohann, W.; Owen, C. J.; Petrukovich, A. A.; Yao, Z.; Nakamura, T. K. M.; Kubyshkina, M. V.; Sotirelis, T.; Burch, J. L.; Genestreti, K. J.; Vörös, Z.; Andriopoulou, M.; Gershman, D. J.; Avanov, L. A.; Magnes, W.; Russell, C. T.; Plaschke, F.; Khotyaintsev, Y. V.; Giles, B. L.; Coffey, V. N.; Dorelli, J. C.; Strangeway, R. J.; Torbert, R. B.; Lindqvist, P.-A.; Ergun, R.
2017-11-01
During a magnetic storm on 23 June 2015, several very intense substorms took place, with signatures observed by multiple spacecraft including DMSP and Magnetospheric Multiscale (MMS). At the time of interest, DMSP F18 crossed inbound through a poleward expanding auroral bulge boundary at 23.5 h magnetic local time (MLT), while MMS was located duskward of 22 h MLT during an inward crossing of the expanding plasma sheet boundary. The two spacecraft observed a consistent set of signatures as they simultaneously crossed the reconnection separatrix layer during this very intense reconnection event. These include (1) energy dispersion of the energetic ions and electrons traveling earthward, accompanied with high electron energies in the vicinity of the separatrix; (2) energy dispersion of polar rain electrons, with a high-energy cutoff; and (3) intense inward convection of the magnetic field lines at the MMS location. The high temporal resolution measurements by MMS provide unprecedented observations of the outermost electron boundary layer. We discuss the relevance of the energy dispersion of the electrons, and their pitch angle distribution, to the spatial and temporal evolution of the boundary layer. The results indicate that the underlying magnetotail magnetic reconnection process was an intrinsically impulsive and the active X-line was located relatively close to the Earth, approximately at 16-18 RE.
Sub-Auroral Polarization Stream (SAPS) Events Under Non-storm Conditions
NASA Astrophysics Data System (ADS)
Sazykin, S. Y.; Coster, A. J.; Huba, J.; Spiro, R. W.; Baker, J. B.; Kunduri, B.; Ruohoniemi, J. M.; Erickson, P. J.; Wolf, R.
2017-12-01
The occurrence of Sub-Auroral Polarization Stream, or SAPS, structures, defined here as latitudinally narrow channels of enhanced westward plasma convection in the evening ionosphere equatorward of the auroral electron precipitation boundary, is most dramatic during geomagnetic storms. However, SAPS-like structures known as Polarization Jets or SAIDs (Sub-Auroral Ion Drift events) are also frequently observed during non-storm conditions, typically during periods of isolated substorm activity or during bursts of enhanced convection associated with southward IMF Bz component. This paper presents results from data analysis and numerical simulations of several SAPS/SAID events observed during non-storm conditions. We use convection velocity measurements from the mid-latitude chain of SuperDARN radars and cross-track drift meter data from DMSP spacecraft to identify SAPS/SAID and to characterize their structure and temporal evolution. DMSP topside ion density data and high-resolution ground-based GPS total electron content (TEC) maps are used to determine the ionospheric and plasmaspheric morphology of SAPS regions. DMSP electron precipitation data are used to determine auroral boundaries. We also present simulation results of the chosen event intervals obtained with the SAMI3-RCM ionosphere-magnetosphere coupled model. Observational results are analyzed to identify systematic differences between non-storm SAPS/SAID and the picture that has emerged based on previous storm time studies. Simulation results are used to provide physical interpretation of these differences.
NASA Technical Reports Server (NTRS)
Smith, Eric A.
2004-01-01
This study presents results from a multi-satellite/multi-sensor retrieval system designed to obtain the atmospheric water budget over the open ocean. A combination of 3ourly-sampled monthly datasets derived from the GOES-8 5-channel Imager, the TRMM TMI radiometer, and the DMSP 7-channel passive microwave radiometers (SSM/I) have been acquired for the combined Gulf of Mexico-Caribbean Sea basin. Whereas the methodology has been tested over this basin, the retrieval system is designed for portability to any open-ocean region. Algorithm modules using the different datasets to retrieve individual geophysical parameters needed in the water budget equation are designed in a manner that takes advantage of the high temporal resolution of the GOES-8 measurements, as well as the physical relationships inherent to the TRMM and SSM/I passive microwave measurements in conjunction with water vapor, cloud liquid water, and rainfall. The methodology consists of retrieving the precipitation, surface evaporation, and vapor-cloud water storage terms in the atmospheric water balance equation from satellite techniques, with the water vapor advection term being obtained as the residue needed for balance. Thus, the intent is to develop a purely satellite-based method for obtaining the full set of terms in the atmospheric water budget equation without requiring in situ sounding information on the wind profile. The algorithm is validated by cross-checking all the algorithm components through multiple- algorithm retrieval intercomparisons. A further check on the validation is obtained by directly comparing water vapor transports into the targeted basin diagnosed from the satellite algorithms to those obtained observationally from a network of land-based upper air stations that nearly uniformly surround the basin, although it is fair to say that these checks are more effective m identifying problems in estimating vapor transports from a leaky operational radiosonde network than in verifying the transport estimates determined from the satellite algorithm system Total columnar atmospheric water budget results are presented for an extended annual cycle consisting of the months of October-97, January-98, April-98, July-98,October-98, and January 1999. These results are used to emphasize the changing relationship in E-P, as well as in the varying roles of storage and advection in balancing E-P both on daily and monthly time scales and on localized and basin space scales. Results from the algorithm-to-algorithm intercomparisons are also presented in the context of sensitivity testing to help understand the intrinsic uncertainties in evaluating the water budget terms by an all-satellite algorithm approach.
NASA Technical Reports Server (NTRS)
Smith, E. A.; Santos, P.
2006-01-01
This study presents results from a multi-satellite/multi-sensor retrieval system design d to obtain the atmospheric water budget over the open ocean. A combination of hourly-sampled monthly datasets derived from the GOES-8 5-channel Imager, the TRMM TMI radiometer, and the DMSP 7-channel passive microwave radiometers (SSM/I) have been acquired for the combined Gulf of Mexico-Caribbean Sea basin. Whereas the methodology has been tested over this basin, the retrieval system is designed for portability to any open-ocean region. Algorithm modules using the different datasets to retrieve individual geophysical parameters needed in the water budget equation are designed in a manner that takes advantage of the high temporal resolution of the GOES-8 measurements, as well as the physical relationships inherent to the TRMM and SSM/I passive microwave measurements in conjunction with water vapor, cloud liquid water, and rainfall. The methodology consists of retrieving the precipitation, surface evaporation, and vapor-cloud water storage terms in the atmospheric water balance equation from satellite techniques, with the water vapor advection term being obtained as the residue needed for balance. Thus, the intent is to develop a purely satellite-based method for obtaining the full set of terms in the atmospheric water budget equation without requiring in situ sounding information on the wind profile. The algorithm is validated by cross-checking all the algorithm components through multiple-algorithm retrieval intercomparisons. A further check on the validation is obtained by directly comparing water vapor transports into the targeted basin diagnosed from the satellite algorithms to those obtained observationally from a network of land-based upper air stations that nearly uniformly surround the basin, although it is fair to say that these checks are more effective in identifying problems in estimating vapor transports from a "leaky" operational radiosonde network than in verifying the transport estimates determined from the satellite algorithm system. Total columnar atmospheric water budget results are presented for an extended annual cycle consisting of the months of October-97, January-98, April-98, July-98,October-98, and January- 1999. These results are used to emphasize the changing relationship in E-P, as well as in the varying roles of storage and advection in balancing E-P both on daily and monthly time scales and on localized and basin space scales. Results from the algorithm-to-algorithm intercomparisons are also presented in the context of sensitivity testing to help understand the intrinsic uncertainties in evaluating the water budget terms by an all-satellite algorithm approach.
NASA Technical Reports Server (NTRS)
Wray, S. T., Jr.
1975-01-01
The LOVES computer code developed to investigate the concept of space servicing operational satellites as an alternative to replacing expendable satellites or returning satellites to earth for ground refurbishment is presented. In addition to having the capability to simulate the expendable satellite operation and the ground refurbished satellite operation, the program is designed to simulate the logistics of space servicing satellites using an upper stage vehicle and/or the earth to orbit shuttle. The program not only provides for the initial deployment of the satellite but also simulates the random failure and subsequent replacement of various equipment modules comprising the satellite. The program has been used primarily to conduct trade studies and/or parametric studies of various space program operational philosophies.
An overview of the Office of Space Flight satellite servicing program plan
NASA Technical Reports Server (NTRS)
Levin, George M.; Erwin, Harry O., Jr.
1987-01-01
A comprehensive program for the development of satellite servicing tools and techniques is being currently carried out by the Office of Space Flight. The program is based on a satellite servicing infrastructure formulated by analyzing satellite servicing requirements; the program is Shuttle-based and compatible with the Orbital Maneuvering Vehicle and Space Station. The content of the satellite servicing program is reviewed with reference to the tools, techniques, and procedures being developed for refueling (or consumables resupply), repairing, and retrieving.
Ohayon, Maurice M.; Milesi, Cristina
2016-01-01
Study Objectives: Our study aims to explore the associations between outdoor nighttime lights (ONL) and sleep patterns in the human population. Methods: Cross-sectional telephone study of a representative sample of the general US population age 18 y or older. 19,136 noninstitutionalized individuals (participation rate: 83.2%) were interviewed by telephone. The Sleep-EVAL expert system administered questions on life and sleeping habits; health; sleep, mental and organic disorders (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; International Classification of Sleep Disorders, Second Edition; International Classification of Diseases, 10th Edition). Individuals were geolocated by longitude and latitude. Outdoor nighttime light measurements were obtained from the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS), with nighttime passes taking place between 19:30 and 22:30 local time. Light data were correlated precisely to the geolocation of each participant of the general population sample. Results: Living in areas with greater ONL was associated with delayed bedtime (P < 0.0001) and wake up time (P < 0.0001), shorter sleep duration (P < 0.01), and increased daytime sleepiness (P < 0.0001). Living in areas with greater ONL also increased the dissatisfaction with sleep quantity and quality (P < 0.0001) and the likelihood of having a diagnostic profile congruent with a circadian rhythm disorder (P < 0.0001). Conclusions: Although they improve the overall safety of people and traffic, nighttime lights in our streets and cities are clearly linked with modifications in human sleep behaviors and also impinge on the daytime functioning of individuals living in areas with greater ONL. Citation: Ohayon MM, Milesi C. Artificial outdoor nighttime lights associate with altered sleep behavior in the american general population. SLEEP 2016;39(6):1311–1320. PMID:27091523
NASA Technical Reports Server (NTRS)
1972-01-01
Satellite tracking and earth dynamics research programs are discussed. Geodetic and geophysical investigations are reported along with atmospheric research using satellite drag data. Satellite tracking network functions and support groups which are discussed include: network operations, communications, data-services division, moonwatch, and programming group.
NASA Astrophysics Data System (ADS)
Archer, S. D.; Safi, K.; Hall, A.; Cummings, D. G.; Harvey, M.
2011-03-01
The impact of in situ iron fertilisation on the production of particulate dimethylsulphoniopropionate (DMSPp) and its breakdown product dimethyl sulphide (DMS) was monitored during the SOLAS air-sea gas exchange experiment (SAGE). The experiment was conducted in the high nitrate, low chlorophyll (HNLC) waters of the sub-Antarctic Southern Ocean (46.7°S 172.5°E) to the south-east of New Zealand, during March-April, 2004. In addition to monitoring net changes in the standing stocks of DMSPp and DMS, a series of dilution experiments were used to determine the DMSPp production and consumption rates in relation to increased iron availability. In contrast to previous experiments in the Southern Ocean, DMS concentrations decreased over the course of the 15-d iron-fertilisation experiment, from an integrated volume-specific concentration in the mixed layer on day 0 of 0.78 nM (measured values 0.65-0.91 nM) to 0.46 nM (measured values 0.42-0.47 nM) by day 15, in parallel with the surrounding waters. DMSPp, chlorophyll a and the abundance of photosynthetic picoeukaryotes exhibited indiscernible or only moderate increases in response to the raised iron availability, despite an obvious physiological response by the phytoplankton. High specific growth rates of DMSPp, equivalent to 0.8-1.2 doublings d -1, occurred at the simulated 60% light level of the dilution experiments. Despite the high production rates, DMSPp accumulation was suppressed in part by microzooplankton grazers who consumed between 61% d -1 and 126% d -1 of the DMSPp production. Temporal trends in the rates of production and consumption illustrated a close coupling between the DMSP-producing phytoplankton and their microzooplankton grazers. Similar grazing and production rates were observed for the eukaryotic picophytoplankton that dominated the phytoplankton biomass, partial evidence that picoeukaryotes contributed a substantial proportion of the DMSP synthesis. These rates for DMSPp and picoeukaryotes were considerably higher than for chlorophyll a, indicating higher cycling rates of the DMSP-producing taxa than for the bulk phytoplankton community. When compared to the total phytoplankton community, there was no evidence of selection against the DMSP-containing phytoplankton by the microzooplankton grazers; the opposite appeared to be the case. SAGE demonstrated that increased iron availability in the HNLC waters of the Southern Ocean does not invariably lead to enhanced DMS sea-air flux. The potential suppression of DMSPp accumulation by grazers needs to be taken into account in future attempts to elevate DMS emission through in situ iron fertilisation and in understanding the hypothesised link between levels of Aeolian iron deposition in the Southern Ocean, DMS emission and global albedo.
High-speed and supersonic upward plasma drifts: multi-instrumental study
NASA Astrophysics Data System (ADS)
Astafyeva, E.; Zakharenkova, I.; Hairston, M. R.; Huba, J.; Coley, W. R.
2017-12-01
Since the pioneering observations by Aggson et al. (1992, JGR, doi: 10.1002/92JA00644), there have been several reports of the occurrence of high-speed (Vz>800 m/s) and supersonic plasma flows in the post-sunset (e.g., Hysell et al., 1994, JGR, doi: 10.1029/94JA00476; Hanson et al., 1997, JGR, doi: 10.1029/96JA03376) and the pre-dawn sector (Astafyeva and Zakharenkova, 2015, GRL, doi:10.1002/2015GL066369). However, despite this observational evidence, these events remain rare and are not well understood. The main issue is to determine the background conditions leading to the occurrence of these high-speed plasma drifts. In this work, we perform a multi-instrumental study of high-speed and supersonic upward plasma drift events/structures. For this purpose, we analyze data from several ground-based and space-borne instruments, including data from the DMSP, Swarm and C/NOFS (IVM instrument) satellites. In addition to the space-borne instruments, we use data from ground-based GPS-receivers and ionosondes to further investigate the background ionosphere conditions, as well as the effects produced by the plasma bubbles and ionospheric irregularities. Besides the observations, we add the SAMI3/ESF modeling results on plasma bubble simulations and high-speed drifts inside plasma bubbles. TIE-GCM runs (from the CCMC, https://ccmc.gsfc.nasa.gov) are used to define the background atmospheric/ionospheric and electrodynamical conditions leading to the occurrence of the high-speed and supersonic plasma drift events. Our search of events with upward plasma drift exceeding 800 m/s in the data of DMSP for the years 2002-2016 shows that such high-speed events are extremely rare. During this period of time, only 6 events were found, two of them occurred during the recovery phase of a geomagnetic storm, while the other four were detected during geomagnetically quiet conditions. Concerning the generation of such events, our preliminary results show that enhanced electric fields are required and that horizontal thermospheric winds play an important role in the occurrence of high-speed plasma flows.
ERIC Educational Resources Information Center
Swistock, Bryan R.; Sharpe, William E.; Dickison, John
2001-01-01
A safe drinking water program was delivered by satellite as well as the live speaker program. Responses from 230 traditional and 161 satellite participants showed the satellite program met objectives, was cheaper, and required less specialist time although it attracted a smaller audience and allowed limited interaction. The cost per attendee for…
NASA Astrophysics Data System (ADS)
May, J. C.; Rowley, C. D.; Meyer, H.
2017-12-01
The Naval Research Laboratory (NRL) Ocean Surface Flux System (NFLUX) is an end-to-end data processing and assimilation system used to provide near-real-time satellite-based surface heat flux fields over the global ocean. The first component of NFLUX produces near-real-time swath-level estimates of surface state parameters and downwelling radiative fluxes. The focus here will be on the satellite swath-level state parameter retrievals, namely surface air temperature, surface specific humidity, and surface scalar wind speed over the ocean. Swath-level state parameter retrievals are produced from satellite sensor data records (SDRs) from four passive microwave sensors onboard 10 platforms: the Special Sensor Microwave Imager/Sounder (SSMIS) sensor onboard the DMSP F16, F17, and F18 platforms; the Advanced Microwave Sounding Unit-A (AMSU-A) sensor onboard the NOAA-15, NOAA-18, NOAA-19, Metop-A, and Metop-B platforms; the Advanced Technology Microwave Sounder (ATMS) sensor onboard the S-NPP platform; and the Advanced Microwave Scannin Radiometer 2 (AMSR2) sensor onboard the GCOM-W1 platform. The satellite SDRs are translated into state parameter estimates using multiple polynomial regression algorithms. The coefficients to the algorithms are obtained using a bootstrapping technique with all available brightness temperature channels for a given sensor, in addition to a SST field. For each retrieved parameter for each sensor-platform combination, unique algorithms are developed for ascending and descending orbits, as well as clear vs cloudy conditions. Each of the sensors produces surface air temperature and surface specific humidity retrievals. The SSMIS and AMSR2 sensors also produce surface scalar wind speed retrievals. Improvement is seen in the SSMIS retrievals when separate algorithms are used for the even and odd scans, with the odd scans performing better than the even scans. Currently, NFLUX treats all SSMIS scans as even scans. Additional improvement in all of the surface retrievals comes from using a 3-hourly SST field, as opposed to a daily SST field.
A High Fidelity Approach to Data Simulation for Space Situational Awareness Missions
NASA Astrophysics Data System (ADS)
Hagerty, S.; Ellis, H., Jr.
2016-09-01
Space Situational Awareness (SSA) is vital to maintaining our Space Superiority. A high fidelity, time-based simulation tool, PROXOR™ (Proximity Operations and Rendering), supports SSA by generating realistic mission scenarios including sensor frame data with corresponding truth. This is a unique and critical tool for supporting mission architecture studies, new capability (algorithm) development, current/future capability performance analysis, and mission performance prediction. PROXOR™ provides a flexible architecture for sensor and resident space object (RSO) orbital motion and attitude control that simulates SSA, rendezvous and proximity operations scenarios. The major elements of interest are based on the ability to accurately simulate all aspects of the RSO model, viewing geometry, imaging optics, sensor detector, and environmental conditions. These capabilities enhance the realism of mission scenario models and generated mission image data. As an input, PROXOR™ uses a library of 3-D satellite models containing 10+ satellites, including low-earth orbit (e.g., DMSP) and geostationary (e.g., Intelsat) spacecraft, where the spacecraft surface properties are those of actual materials and include Phong and Maxwell-Beard bidirectional reflectance distribution function (BRDF) coefficients for accurate radiometric modeling. We calculate the inertial attitude, the changing solar and Earth illumination angles of the satellite, and the viewing angles from the sensor as we propagate the RSO in its orbit. The synthetic satellite image is rendered at high resolution and aggregated to the focal plane resolution resulting in accurate radiometry even when the RSO is a point source. The sensor model includes optical effects from the imaging system [point spread function (PSF) includes aberrations, obscurations, support structures, defocus], detector effects (CCD blooming, left/right bias, fixed pattern noise, image persistence, shot noise, read noise, and quantization noise), and environmental effects (radiation hits with selectable angular distributions and 4-layer atmospheric turbulence model for ground based sensors). We have developed an accurate flash Light Detection and Ranging (LIDAR) model that supports reconstruction of 3-dimensional information on the RSO. PROXOR™ contains many important imaging effects such as intra-frame smear, realized by oversampling the image in time and capturing target motion and jitter during the integration time.
Visions of our Planet's Atmosphere, Land & Oceans
NASA Technical Reports Server (NTRS)
Hasler, Arthur F.
2002-01-01
The NASA/NOAA Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to South Africa, Cape Town and Johannesburg using NASA Terra MODIS data, Landsat data and 1m IKONOS "Spy Satellite" data. Zoom in to any place South Africa using Earth Viewer 3D from Keyhole Inc. and Landsat data at 30 m resolution. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and international global satellite weather movies including hurricanes & "tornadoes". See the latest visualizations of spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, Landsat 7 including 1 - min GOES rapid scan image sequences of Nov 9th 2001 Midwest tornadic thunderstorms and have them explained. See how High-Definition Television (HDTV) is revolutionizing the way we present science to the public. See dust storms and flooding in Africa and smoke plumes from fires in Mexico. See visualizations featured on the covers of Newsweek, TIME, National Geographic, Popular Science & on National & International Network TV. New computer software tools allow us to roam & zoom through massive global images e.g. Landsat tours of the US, and Africa, showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the north and south polar ice packs and with icebergs on the coasts of Greenland and off the coast of Antarctica. Spectacular new visualizations of the global land, atmosphere & oceans are shown. Listen to the pulse of our planet. See how land vegetation, ocean plankton, clouds and temperatures respond to the sun & seasons. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and biomass burning of the Earth at night observed by the "night-vision" DMSP military satellite. The presentation will be made using the latest HDTV and video projection technology that is now done from a laptop computer through an entirely digital path.
Ground and satellite observations of multiple sun-aligned auroral arcs on the duskside
NASA Astrophysics Data System (ADS)
Hosokawa, K.; Maggiolo, R.; Zhang, Y.; Fear, R. C.; Fontaine, D.; Cumnock, J. A.; Kullen, A.; Milan, S. E.; Kozlovsky, A.; Echim, M.; Shiokawa, K.
2014-12-01
Sun-aligned auroral arcs (SAAs) are one of the outstanding phenomena in the high-latitude region during periods of northward interplanetary magnetic field (IMF). Smaller scale SAAs tend to occur either in the duskside or dawnside of the polar cap and are known to drift in the dawn-dusk direction depending on the sign of the IMF By. Studies of SAAs are of particular importance because they represent dynamical characteristics of their source plasma in the magnetosphere, for example in the interaction region between the solar wind and magnetosphere or in the boundary between the plasma sheet and tail lobe. To date, however, very little has been known about the spatial structure and/or temporal evolution of the magnetospheric counterpart of SAAs. In order to gain more comprehensive understanding of the field-aligned plasma transport in the vicinity of SAAs, we have investigated an event of SAAs on November 10, 2005, during which multiple SAAs were detected by a ground-based all-sky camera at Resolute Bay, Canada. During this interval, several SAAs were detached from the duskside oval and moved poleward. The large-scale structure of these arcs was visualized by space-based imagers of TIMED/GUVI and DMSP/SSUSI. In addition to these optical observations, we employ the Cluster satellites to reveal the high-altitude particle signature corresponding to the small-scale SAAs. The ionospheric footprints of the 4 Cluster satellites encountered the SAAs sequentially and observed well correlated enhancements of electron fluxes at weak energies (< 1 keV). The Cluster satellites also detected signatures of upflowing beams of ions and electrons in the vicinity of the SAAs. This implies that these ions and electrons were accelerated upward by a quasi-stationary electric field existing in the vicinity of the SAAs and constitute a current system in the magnetosphere-ionosphere coupling system. Ionospheric convection measurement from one of the SuperDARN radars shows an indication that the SAAs are embedded in the lobe cell during northward IMF conditions. In the presentation, we will show the results of detailed comparison between the ground-based radio and optical signatures of the SAAs and those obtained by the Cluster spacecraft at magnetospheric altitudes.
NASA Astrophysics Data System (ADS)
Turk, F. J.; Miller, S. D.
2007-12-01
One of the main challenges facing current and future environmental satellite systems (e.g, the future National Polar Orbiting Environmental Satellite System (NPOESS)) is reaching and entraining the diverse user community via communication of how these systems address their particular needs. A necessary element to meeting this challenge is effective data visualization: facilitating the display, animation and layering of multiple satellite imaging and sounding sensors (providing complementary information) in a user-friendly and intuitive fashion. In light of the fact that these data are rapidly making their way into the classroom owing to efficient and timely data archival systems and dissemination over the Internet, there is a golden opportunity to leverage existing technology to introduce environmental science to wide spectrum of users. Google Earth's simplified interface and underlying markup language enables access to detailed global geographic information, and contains features which are both desirable and advantageous for geo-referencing and combining a wide range of environmental satellite data types. Since these satellite data are available with a variety of horizontal spatial resolutions (tens of km down to hundreds of meters), the imagery can be sub-setted (tiled) at a very small size. This allows low-bandwidth users to efficiently view and animate a sequence of imagery while zoomed out from the surface, whereas high-bandwidth users can efficiently zoom into the finest image resolution when viewing fine-scale phenomena such as fires, volcanic activity, as well as the details of meteorological phenomena such as hurricanes, rainfall, lightning, winds, etc. Dynamically updated network links allow for near real-time updates such that these data can be integrated with other Earth-hosted applications and exploited not only in the teaching environment, but also for operational users in the government and private industry sectors. To conceptualize how environmental satellite data would be utilized within a geobrowser in a near real-time setting, we present a demonstration from the 2007 hurricane season, developed within the Google Earth framework. A menu of imagery based sequential satellite overpasses (GOES and other geostationary satellites, TRMM, CloudSat, Terra, Aqua, DMSP, NOAA, QuikScat) during the storm lifecycle, are presented to the Earth client in an structured folder format. The remapping of these satellite data follows the hurricane track, enabling the user to view, animate, zoom, overlay and combine visible, infrared and passive microwave imagery and combine with other data (surface reports, forecasts, surface winds, ground and spaceborne radars, etc.) at various stages of the hurricane lifecycle. Pop-up balloons provide training that explains the properties and capabilities of the satellite datasets and what components of the underlying weather are represented. Future satellite overpass tracks are provided so that the user can anticipate imagery updates several days in advance (e.g., as a hurricane approaches landfall). This combination of geo-navigable data provides a convenient framework for efficiently demonstrating meteorological, oceanographic and weather and climate concepts to students, planners, and the public at large.
NASA Astrophysics Data System (ADS)
Feher, K.
Topics discussed include highlights of Canadian and US communication-satellite developments, video teleconferencing, modulation/system studies, organization/interface tradeoffs, Canadian satellite programs, performance monitoring techniques, spread spectrum satcom systems, social and educational satellite services, atmospheric/navigational satcom systems, TDMA systems, and Teleglobe/Intelsat and Inmarsat programs. Consideration is also given to SCPC developments, TV and program reception, earth station components, European satcom systems, TCTS/CNCP satellite communications services, satellite designs, coding techniques, Japanese satellite systems, network developments, the ANIK user workshop, industrial/business systems, and satellite antenna technology.
NASA Technical Reports Server (NTRS)
Smith, Eric A.; Santos, Pablo; Einaudi, Franco (Technical Monitor)
2001-01-01
This study presents results from a multi-satellite/multi-sensor retrieval system designed to obtain the atmospheric water budget over the open ocean. A combination of hourly-sampled monthly datasets derived from the GOES-8 5 Imager and the DMSP 7-channel passive microwave radiometer (SSM/I) have been acquired for the Gulf of Mexico-Caribbean Sea basin. Whereas the methodology is being tested over this basin, the retrieval system is designed for portability to any open-ocean region. Algorithm modules using the different datasets to retrieve individual geophysical parameters needed in the water budget equation are designed in a manner that takes advantage of the high temporal resolution of the GOES-8 measurements, as well as the physical relationships inherent to the SSM/I passive microwave signals in conjunction with water vapor, cloud liquid water, and rainfall. The methodology consists of retrieving the precipitation, surface evaporation, and vapor-cloud water storage terms in the atmospheric water balance equation from satellite techniques, with the water vapor advection term being obtained as the residue needed for balance. Thus, we have sought to develop a purely satellite-based method for obtaining the full set of terms in the atmospheric water budget equation without requiring in situ sounding information on the wind profile. The algorithm is partly validated by first cross-checking all the algorithm components through multiple-algorithm retrieval intercomparisons. More fundamental validation is obtained by directly comparing water vapor transports into the targeted basin diagnosed from the satellite algorithm to those obtained observationally from a network of land-based upper air stations that nearly uniformly surround the basin. Total columnar atmospheric water budget results will be presented for an extended annual cycle consisting of the months of October-97, January-98, April-98, July-98, October-98, and January-1999. These results are used to emphasize the changing relationship in E-P, as well as in the varying roles of storage and advection in balancing E-P both on daily and monthly time scales and on localized and basin space scales. Results from the algorithm-to-algorithm intercomparisons will also be presented in the context of sensitivity testing to help understand the intrinsic uncertainties in the water budget terms.
NASA Astrophysics Data System (ADS)
Bazell, D.; Sotirelis, T.; Nair, H.; Roelof, E. C.; Brandt, P. C.
2009-12-01
The brightest source of energetic neutral atoms (ENAs) at energies >1keV is low altitude emission (LAE) from ~200-400km near auroral latitudes where precipitating energetic ions undergo multiple atomic collisions with the monatomic (O) exosphere. This emission is many times brighter than that from the high-altitude ring current region where the energetic ions interact only weakly with the much less dense monatomic (H) hydrogen geocorona. The recently selected NSF CubeSat mission CINEMA [Lin et al., this special session] has, as part of its science payload (STEIN), an ENA imager covering energies 4-100keV. From a high-inclination ~800km orbit, STEIN will view the LAE four times during every 90 minutes. The NASA TWINS stereo ENA imagers (2-40keV) will also view the LAE from their Molniya orbits (apogee radius~7Re). We have been analyzing the TWINS ENA images of LAE and comparing them with in situ ion measurements (1-40keV) from DMSP spacecraft when their tracks take them under the ion precipitation regions imaged by TWINS. We have developed an ENA emissivity function that relates the directionally-dependent emergent ENA spectrum to that of the precipitating ions. The TWINS/DMSP direct comparisons show good agreement. We offer suggestions on joint observing strategies for CINEMA, TWINS and DMSP after the CINEMA launch in the second half of 2011.
NASA Astrophysics Data System (ADS)
Lee, C.-C.; Chen, W. S.; Chu, F. D.
2013-06-01
For solar minimum, the spread F, GPS phase fluctuations, and plasma bubbles near the crest of equatorial ionization anomaly (EIA) are simultaneously analyzed to investigate F region irregularities for the first time. The data were observed using the Chungli ionosonde, YMSM GPS receiver, and DMSP satellites during 1996. It is found that in the observed ionograms, the frequency spread F (FSF) usually comes after the range spread F (RSF) in a series of nighttime spread F events. This results in that the maximum occurrence of RSF appears before that of FSF in the nighttime variations in occurrence probabilities. Moreover, the seasonal variation for RSF is close to that for FSF. Both have a board maximum in the J-months and a secondary maximum in December. These indicate that RSF and FSF should be regarded as one type of spread F, which is the all spread F (ASF) in this study. Because the equatorial plasma bubbles occur infrequently during solar minimum, the F region irregularities forming ASF are not related to the equatorial spread F. On the other hand, the similarity in seasonal occurrence between ASF and medium-scale traveling ionospheric disturbances (MSTIDs) demonstrates that the F region irregularities near the EIA crest are mainly generated by the gradient drift instability driven by MSTIDs. The irregularities, generated by MSTIDs, mostly occur in the bottom side of the F region. Consequently, the events of significant GPS phase fluctuations and plasma bubble near the EIA crest are rare during 1996.
Validation of the AMSU-B Bias Corrections Based on Satellite Measurements from SSM/T-2
NASA Technical Reports Server (NTRS)
Kolodner, Marc A.
1999-01-01
The NOAA-15 Advanced Microwave Sounding Unit-B (AMSU-B) was designed in the same spirit as the Special Sensor Microwave Water Vapor Profiler (SSM/T-2) on board the DMSP F11-14 satellites, to perform remote sensing of spatial and temporal variations in mid and upper troposphere humidity. While the SSM/T-2 instruments have a 48 km spatial resolution at nadir and 28 beam positions per scan, AMSU-B provides an improvement with a 16 km spatial resolution at nadir and 90 beam positions per scan. The AMSU-B instrument, though, has been experiencing radio frequency interference (RFI) contamination from the NOAA-15 transmitters whose effect is dependent upon channel, geographic location, and current spacecraft antenna configuration. This has lead to large cross-track biases reaching as high as 100 Kelvin for channel 17 (150 GHz) and 50 Kelvin for channel 19 (183 +/-3 GHz). NOAA-NESDIS has recently provided a series of bias corrections for AMSU-B data starting from March, 1999. These corrections are available for each of the five channels, for every third field of view, and for three cycles within an eight second period. There is also a quality indicator in each data record to indicate whether or not the bias corrections should be applied. As a precursor to performing retrievals of mid and upper troposphere humidity, a validation study is performed by statistically analyzing the differences between the F14 SSM/T-2 and the bias corrected AMSU-B brightness temperatures for three months in the spring of 1999.
MAMI: Modeling of the Magnetosphere-Ionosphere-Atmosphere System
NASA Technical Reports Server (NTRS)
1998-01-01
Major emphasis of the investigation was the development of theoretical and numerical models of the aurora and of high latitude ionospheric processes. In particular: (1) the NCAR TIGCM (Thermosphere-Ionosphere Global Circulation Model) was updated to include mid and low latitude electrodynamics (this version is called TIE-GCM); (2) the NCAR TIE-GCM was modified to include a more realistic representation of the aurora; (3) the UAF auroral electron transport model was modified to include local acceleration processes; (4) a local ionospheric and auroral model (AURORA) was developed to allow detailed studies of the aurora; (5) a proton-hydrogen transport code has been developed to model proton aurora; and (6) a theory for the production of suprathermal atoms and ions in the upper atmosphere was developed and applied to studies of atomic nitrogen transport and helium escape on open field lines. These models enable us to devise schemes for tile interpretation and quantitative analysis of data obtained by the POLAR spacecraft. Parameterizations were formulated and are available to the GGS investigators. The UVI and VIS teams have adopted these parameterizations and include them in their data analysis. We have developed software for the quantitative interpretation of UVI and VIS images. After the launch of the POLAR satellite we used the image data from UVI and VIS in combination with ground based data from SuperDARN and incoherent scatter radars, magnetometers, and in situ observations from DMSP and NOAA satellites to characterize the state of the ionosphere. A number of event studies have been carried out in cooperation with other CGS theory teams.
Ramdani, Fatwa; Setiani, Putri
2017-06-01
Availability of electricity can be used as an indicator to proximate parameters related to human well-being. Overall, the electrification process in Indonesia has been accelerating in the past two decades. Unfortunately, monitoring the country's progress on its effort to provide wider access to electricity poses challenges due to inconsistency of data provided by each national bureau, and limited availability of information. This study attempts to provide a reliable measure by employing nighttime satellite imagery to observe and to map the progress of electrification within a duration of 20 years, from 1993 to 2013. Brightness of 67,021 settlement-size points in 1993, 2003, and 2013 was assessed using data from DMSP/OLS instruments to study the electrification progress in the three service regions (Sumatera, Java-Bali, and East Indonesia) of the country's public electricity company, PLN. Observation of all service areas shows that the increase in brightness, which correspond with higher electricity development and consumption, has positive correlation with both population density (R 2 = 0.70) and urban change (R 2 = 0.79). Moreover, urban change has a stronger correlation with brightness, which is probably due to the high energy consumption in urban area per capita. This study also found that the brightness in Java-Bali region is very dominant, while the brightness in other areas has been lagging during the period of analysis. The slow development of electricity infrastructure, particularly in major parts of East Indonesia region, affects the low economic growth in some areas and formed vicious cycle.
Uncloaking the Scientific Process
NASA Astrophysics Data System (ADS)
Leitzell, K.; Meier, W.
2009-12-01
Since April 2008, NSIDC has offered daily updates of sea ice data on our Arctic Sea Ice News & Analysis Web page (http://nsidc.org/arcticseaicenews). The images provide near-real-time data to the general public and policy makers, accompanied by monthly or more frequent analysis updates. In February 2009, a crucial channel of the Special Sensor Microwave/Imager (SSM/I) sensor on the Defense Meteorological Satellite Program (DMSP) F15 satellite, from which NSIDC was obtaining near-real-time Arctic sea ice data, suddenly failed. The daily image, which is automatically updated, showed a sudden drop in ice extent of over 50,000 square kilometers. Even after taking the images down, skeptical blogs jumped on the event, posting headlines such as “Errors in publicly presented data - Worth blogging about?” and “NSIDC pulls the plug on sea ice data.” In fact, NSIDC data managers and scientists were well aware that the F15 satellite sensor would eventually fail. NSIDC switched to a previously used back-up sensor, F13, and work to transition to a newer sensor on the F17 satellite had been underway for several weeks. While the deluge of questions from readers and bloggers were frustrating to NSIDC communications staff and scientists, they also presented a chance to give readers a window into the scientific process, and specifically into the collection of satellite data. We decided to publish a clear account of the process used to transition between sensors, as well as a basic explanation of the satellites used to measure sea ice data. While most scientists are familiar with the limitations of near-real-time data, the concept is unfamiliar to many in the general public. The Web page includes links to information on near-real-time data, including notes that images sometimes contain missing or erroneous data, and that delays can occur. However, to a skeptical person, the words that scientists use to describe the processing of final data, including “adjustment,” “bias,” and “correction,” can convey a sinister or political motive. How much information is really necessary for the general public? How much should we share about our processes and motives? This poster/presentation will address some of the dangers and opportunities of presenting near-real-time data to the public, and share some of strategies we used to respond to attacks on our data quality. In order to develop effective responses to climate change, it is important for policymakers to focus on complete data records and not short-term variability in near-real-time data, which may not be indicative of long-term trends or, as in the case presented here, may have errors that need to be corrected. NSIDC clearly states that its near-real-time images and data should not be used for significant conclusions about the long-term state of the climate, but are an initial snapshot for informational purposes. Nonetheless, NSIDC did hear from some policymakers that our data was regularly being used in various briefs within governmental agencies. This has led to greater attention to how our data may be used. However, we hope that our transparency and clear explanations will be valuable in guiding how policymakers employ our data and images in the future.
NASA Technical Reports Server (NTRS)
Lin, Xin; Zhang, Sara Q.; Hou, Arthur Y.
2006-01-01
Global microwave rainfall retrievals from a 5-satellite constellation, including TMI from TRMM, SSWI from DMSP F13, F14 and F15, and AMSR-E from EOS-AQUA, are assimilated into the NASA Goddard Earth Observing System (GEOS) Data Assimilation System (DAS) using a 1-D variational continuous assimilation (VCA) algorithm. The physical and dynamical impact of rainfall assimilation on GEOS analyses and forecasts is examined at various temporal and spatial scales. This study demonstrates that the 1-D VCA algorithm, which was originally developed and evaluated for rainfall assimilations over tropical oceans, can effectively assimilate satellite microwave rainfall retrievals and improve GEOS analyses over both the Tropics and the extratropics where the atmospheric processes are dominated by different large-scale dynamics and moist physics, and also over the land, where rainfall estimates from passive microwave radiometers are believed to be less accurate. Results show that rainfall assimilation renders the GEOS analysis physically and dynamically more consistent with the observed precipitation at the monthly-mean and 6-hour time scales. Over regions where the model precipitation tends to misbehave in distinctly different rainy regimes, the 1-D VCA algorithm, by compensating for errors in the model s moist time-tendency in a 6-h analysis window, is able to bring the rainfall analysis closer to the observed. The radiation and cloud fields also tend to be in better agreement with independent satellite observations in the rainfall-assimilation m especially over regions where rainfall analyses indicate large improvements. Assimilation experiments with and without rainfall data for a midlatitude frontal system clearly indicates that the GEOS analysis is improved through changes in the thermodynamic and dynamic fields that respond to the rainfall assimilation. The synoptic structures of temperature, moisture, winds, divergence, and vertical motion, as well as vorticity are more realistically captured across the front. Short-term forecasts using initial conditions assimilated with rainfall data also show slight improvements. 1
GIS Tool for Real-time Decision Making and Analysis of Multidisciplinary Cryosphere Datasets.
NASA Astrophysics Data System (ADS)
Roberts, S. D.; Moore, J. A.
2004-12-01
In support of the Western Arctic Shelf-Basin Interaction Project(SBI) a web-based interactive mapping server was installed on the USCGC Healy's on-board science computer network during its 2004 spring(HLY-04-02) and summer cruises (HLY-04-03) in the Chukchi and Beaufort Seas. SBI is a National Science Foundation sponsored multi-year and multidisciplinary project studying the biological productivity in the region. The mapping server was developed by the UCAR Joint Office of Science Support(JOSS) using OpenSource GIS tools(University of Minnesota Mapserver and USGS MapSurfer). Additional OpenSource tools such as GMT and MB-Systems were also utilized. The key layers in this system are the current ship track, station locations, multibeam bottom bathymetry, IBCAO bathymetry, DMSP satellite imagery , NOAA AVHRR Sea Surface temperature and all past SBI Project ship tracks and station locations. The ship track and multibeam layers are updated in real-time and the satellite layers are updated daily only during clear weather. In addition to using current high resolution multibeam bathymetry data, a composite high resolution bathymetry layer was created using multibeam data from past cruises in the SBI region. The server provides click-and-drag zooms, pan, feature query, distance measure and lat/lon/depth querys on a polar projection map of the arctic ocean. The main use of the system on the ship was for cruise track and station position planning by the scientists utilizing all available historical data and high resolution bathymetry. It was also the main source of information to all the scientist on board as to the cruise progress and plans. The system permitted on-board scientists to integrate historical cruise information for comparative purposes. A mirror web site was set up on land and the current ship track/station information was copied once a day to this site via a satellite link so people interested SBI research could follow the cruise progress.
Satellite communication for public services
NASA Technical Reports Server (NTRS)
Cooper, R. S.; Redisch, W. N.
1977-01-01
Public service programs using NASA's ATS-6 and CTS satellites are discussed. Examples include the ATS-6 Health and Education Telecommunications experimental program and the use of CTS to enable students in one university to take courses presented at another distant university. Possible applications of satellite communication systems to several areas of public service are described, and economic and political obstacles hindering the implementation of these programs are considered. It is suggested that a federally sponsored program demonstrating the utility of satellites accomodating a large number of small terminals is needed to encourage commercial satellite operations.
NASA compendium of satellite communications programs
NASA Technical Reports Server (NTRS)
1975-01-01
A comprehensive review is given of worldwide satellite communication programs that range in time from the inception of satellite communications to mid-1974. Particular emphasis is placed on program results, including experiments conducted, communications system operational performance, and technology employed. The background for understanding these results is established through brief summaries of the program organization, system configuration, and satellite and ground terminal characteristics. Major consideration is given to the communications system aspects of each program, but general spacecraft technology and other experiments conducted as part of the same program are mentioned summarily.
U.S. Aeronautical L-Band Satellite Technology Test Program : Interim Tests Results
DOT National Transportation Integrated Search
1975-06-01
The U.S. Aeronautical L-Band satellite test program was performed between September 1974 and April 1975 as part of an international ATS-6 L-Band satellite test program. The U.S. program consisted of both technology and ATC communications demonstratio...
NORAD LOOK ANGLES AND PIO SATELLITE PACKAGE
NASA Technical Reports Server (NTRS)
ANONYMOUS
1994-01-01
This program package consists of two programs. First is the NORAD Look Angles Program, which computes satellite look angles (azimuth, elevation, and range) as well as the subsatellite points (latitude, longitude, and height). The second program in this package is the PIO Satellite Program, which computes sighting directions, visibility times, and the maximum elevation angle attained during each pass of an earth-orbiting satellite. Computations take into consideration the observing location and the effect of the earth's shadow on the satellite visibility. Input consists of a magnetic tape prepared by the NORAD Look Angles Program and punched cards containing reference Julian date, right ascension, declination, mean sidereal time at zero hours universal time of the reference date, and daily changes of these quantities. Output consists of a tabulated listing of the satellite's rise and set times, direction, and the maximum elevation angle visible from each observing location. This program has been implemented on the GE 635. The program Assembler code can easily be replaced by FORTRAN statements.
BOREAS Landsat MSS Imagery: Digital Counts
NASA Technical Reports Server (NTRS)
Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Strub, Richard; Newcomer, Jeffrey A.
2000-01-01
The Boreal Ecosystem-Atmospheric Study (BOREAS) Staff Science Satellite Data Acquisition Program focused on providing the research teams with the remotely sensed satellite data products they needed to compare and spatially extend point results. The Earth Resources Technology Satellite (ERTS) Program launched the first of a series of satellites (ERTS-1) in 1972. Part of the NASA Earth Resources Survey Program, the ERTS Program and the ERTS satellites were later renamed Landsat to better represent the civil satellite program's prime emphasis on remote sensing of land resources. Landsat satellites 1 through 5 carry the Multispectral Scanner (MSS) sensor. Canada for Remote Sensing (CCRS) and BOREAS personnel gathered a set of MSS images of the BOREAS region from Landsat satellites 1, 2, 4, and 5 covering the dates of 21 Aug 1972 to 05 Sep 1988. The data are provided in binary image format files of various formats. The Landsat MSS imagery is available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).
The American mobile satellite system
NASA Technical Reports Server (NTRS)
Garner, William B.
1990-01-01
During 1989, the American Mobile Satellite Corporation (AMSC) was authorized to construct, launch, and operate satellites to provide mobile satellite services (MSS) to the U.S. and Puerto Rico. The AMSC has undertaken three major development programs to bring a full range of MSS services to the U.S. The first program is the space segment program that will result in the construction and launch of the satellites as well as the construction and installation of the supporting ground telemetry and command system. The second segment will result in the specification, design, development, construction, and installation of the Network Control System necessary for managing communications access to the satellites, and the specification and development of ground equipment for standard circuit switched and packet switched communications services. The third program is the Phase 1 program to provide low speed data services within the U.S. prior to availability of the AMSC satellites and ground segment. Described here are the present status and plans for these three programs as well as an update on related business arrangements and regulatory matters.
Evaluation of Q-band instrumentation requirements for Strategic Satellite System (SSS) program
NASA Astrophysics Data System (ADS)
Raponi, D. J.
1981-12-01
Q-band instrumentation appropriate for testing the Strategic Satellite System (SSS) satellite terminal is evaluated in terms of current and projected availability; desired and practical measurement capabilities; required development; and schedule/cost impacts to the program. The Air Force is considering several approaches to increasing the strategic communications capability now provided by the recently deployed ultra high frequency (UHF) Air Force Satellite Communications (AFSATCOM) system. The Strategic Satellite System (SSS) was proposed to improve antijam (AJ) characteristics through the use of advanced modulation techniques and higher frequencies (8 and 44 GHz) on links between ground and airborne terminals and the satellites. This report is an assessment of Q-band (44 GHz) test instrumentation requirements, availability, and accuracy as these factors affect cost and schedule for the SSS satellite terminal development program. Though the SSS program has been cancelled, information presented in the report has applicability to the EHF MILSTAR program.
NASA Astrophysics Data System (ADS)
Verkhoglyadova, O. P.; Komjathy, A.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Paxton, L. J.
2017-12-01
We revisit three complex superstorms of 19-20 November 2003, 7-8 November 2004 and 9-11 November 2004 to analyze ionosphere-thermosphere (IT) effects driven by different solar wind structures. We distinguish structures associated with ICMEs and their upstream sheaths. The efficiencies of the solar wind-magnetosphere connection throughout the storms are estimated by coupling functions. The daytime IT responses to the complex driving are characterized by combining measurements of characteristic IT parameters. We focus on low- and middle-latitude TEC, global thermospheric infrared nitric oxide emission, composition ratio and locations of the auroral boundary obtained from multiple satellite platforms and ground-based measurements (GPS, TIMED/SABER, TIMED/GUVI, DMSP/SSUSI). A variety of metrics are utilized to examine IT phenomena at 1 hour time scales. It is well-known that the November storm periods featured TEC responses that did not fit a typical pattern. The role of direct driving of IT dynamics by solar wind structures and the role of IT pre-conditioning in these storms are examined to explain the complex unusual ionospheric responses. We identify IT feedback effects that can be important for long-lasting strong storms.
Assessment of a demonstration project to supply near real-time sea ice information to end users
NASA Astrophysics Data System (ADS)
Blackford, C.; Howes, Sally; Whitelaw, Alan S.; Laxon, S.; Mantripp, D.
1994-12-01
Sea ice maps are required by a diverse range of users for scientific research and operational activities. Satellite remote sensing provides opportunities for monitoring and producing sea ice maps at a range of scales, in near real time. During March 1994 ESYS Limited and the University College London Mullard Space Science Laboratory (MSSL) operated a sea ice demonstration project to supply near real time sea ice maps in the southern ocean. The sea ice information was derived from a number of data sources: DMSP SSM/I data; ERS-1 SAR and Radar Altimeter fast delivery data; NOAA AVHRR data; and PoSAT-1 imagery. The maps were supplied to three users, two involved in yacht races in the southern ocean and a ship on an oceanographic research cruise in the waters of the Princess Elizabeth Trough region of Antarctica. The demonstration was successful, supplying the users with sea ice information which they had previously not received and combining data from various sources to produce sea ice maps. The demonstration also developed operational skills within ESYS and enabled the transfer of knowledge from MSSL to ESYS.
Real Time Monitoring of Flooding from Microwave Satellite Observations
NASA Technical Reports Server (NTRS)
Galantowicz, John F.; Frey, Herb (Technical Monitor)
2002-01-01
We have developed a new method for making high-resolution flood extent maps (e.g., at the 30-100 m scale of digital elevation models) in real-time from low-resolution (20-70 km) passive microwave observations. The method builds a "flood-potential" database from elevations and historic flood imagery and uses it to create a flood-extent map consistent with the observed open water fraction. Microwave radiometric measurements are useful for flood monitoring because they sense surface water in clear-or-cloudy conditions and can provide more timely data (e.g., compared to radars) from relatively wide swath widths and an increasing number of available platforms (DMSP, ADEOS-II, Terra, NPOESS, GPM). The chief disadvantages for flood mapping are the radiometers' low resolution and the need for local calibration of the relationship between radiances and open-water fraction. We present our method for transforming microwave sensor-scale open water fraction estimates into high-resolution flood extent maps and describe 30-day flood map sequences generated during a retrospective study of the 1993 Great Midwest Flood. We discuss the method's potential improvement through as yet unimplemented algorithm enhancements and expected advancements in microwave radiometry (e.g., improved resolution and atmospheric correction).
Direct Broadcast Satellite: Radio Program
NASA Astrophysics Data System (ADS)
Hollansworth, James E.
1992-10-01
NASA is committed to providing technology development that leads to the introduction of new commercial applications for communications satellites. The Direct Broadcast Satellite-Radio (DBS-R) Program is a joint effort between The National Aeronautics and Space Administration (NASA) and The United States Information Agency/Voice of America (USIA/VOA) directed at this objective. The purpose of this program is to define the service and develop the technology for a direct-to-listener satellite sound broadcasting system. The DBS-R Program, as structured by NASA and VOA, is now a three-phase program designed to help the U.S. commercial communications satellite and receiver industry bring about this new communications service. Major efforts are being directed towards frequency planning hardware and service development, service demonstration, and experimentation with new satellite and receiver technology.
Self-Organized Service Negotiation for Collaborative Decision Making
Zhang, Bo; Zheng, Ziming
2014-01-01
This paper proposes a self-organized service negotiation method for CDM in intelligent and automatic manners. It mainly includes three phases: semantic-based capacity evaluation for the CDM sponsor, trust computation of the CDM organization, and negotiation selection of the decision-making service provider (DMSP). In the first phase, the CDM sponsor produces the formal semantic description of the complex decision task for DMSP and computes the capacity evaluation values according to participator instructions from different DMSPs. In the second phase, a novel trust computation approach is presented to compute the subjective belief value, the objective reputation value, and the recommended trust value. And in the third phase, based on the capacity evaluation and trust computation, a negotiation mechanism is given to efficiently implement the service selection. The simulation experiment results show that our self-organized service negotiation method is feasible and effective for CDM. PMID:25243228
Self-organized service negotiation for collaborative decision making.
Zhang, Bo; Huang, Zhenhua; Zheng, Ziming
2014-01-01
This paper proposes a self-organized service negotiation method for CDM in intelligent and automatic manners. It mainly includes three phases: semantic-based capacity evaluation for the CDM sponsor, trust computation of the CDM organization, and negotiation selection of the decision-making service provider (DMSP). In the first phase, the CDM sponsor produces the formal semantic description of the complex decision task for DMSP and computes the capacity evaluation values according to participator instructions from different DMSPs. In the second phase, a novel trust computation approach is presented to compute the subjective belief value, the objective reputation value, and the recommended trust value. And in the third phase, based on the capacity evaluation and trust computation, a negotiation mechanism is given to efficiently implement the service selection. The simulation experiment results show that our self-organized service negotiation method is feasible and effective for CDM.
NASA Technical Reports Server (NTRS)
Steffen, K.; Schweiger, A. J.
1990-01-01
The validation of sea ice products derived from the Special Sensor Microwave Imager (SSM/I) on board a DMSP platform is examined using data from the Landsat MSS and NOAA-AVHRR sensors. Image processing techniques for retrieving ice concentrations from each type of imagery are developed and results are intercompared to determine the ice parameter retrieval accuracy of the SSM/I NASA-Team algorithm. For case studies in the Beaufort Sea and East Greenland Sea, average retrieval errors of the SSM/I algorithm are between 1.7 percent for spring conditions and 4.3 percent during freeze up in comparison with Landsat derived ice concentrations. For a case study in the East Greenland Sea, SSM/I derived ice concentration in comparison with AVHRR imagery display a mean error of 9.6 percent.
NASA compendium of satellite communications programs
NASA Technical Reports Server (NTRS)
1971-01-01
A comprehensive review of worldwide satellite communication programs is reported that ranges in time from the inception of satellite communications to mid-1971. Particular emphasis is placed on program results, including experiments conducted, communications system operational performance, and technology employed.
Alternative mathematical programming formulations for FSS synthesis
NASA Technical Reports Server (NTRS)
Reilly, C. H.; Mount-Campbell, C. A.; Gonsalvez, D. J. A.; Levis, C. A.
1986-01-01
A variety of mathematical programming models and two solution strategies are suggested for the problem of allocating orbital positions to (synthesizing) satellites in the Fixed Satellite Service. Mixed integer programming and almost linear programming formulations are presented in detail for each of two objectives: (1) positioning satellites as closely as possible to specified desired locations, and (2) minimizing the total length of the geostationary arc allocated to the satellites whose positions are to be determined. Computational results for mixed integer and almost linear programming models, with the objective of positioning satellites as closely as possible to their desired locations, are reported for three six-administration test problems and a thirteen-administration test problem.
Satellite-tracking and earth-dynamics research programs
NASA Technical Reports Server (NTRS)
1975-01-01
The activities and progress in the satellite tracking and earth dynamics research during the first half of calendar year 1975 are described. Satellite tracking network operations, satellite geodesy and geophysics programs, GEOS 3 project support, and atmospheric research are covered.
Saha, Mahasweta; Rempt, Martin; Stratil, Stephanie B.; Wahl, Martin; Pohnert, Georg; Weinberger, Florian
2014-01-01
The goals of this study were (1) to investigate whether Fucus vesiculosus regulates the production of its antifouling defence chemicals against epibacteria in response to light limitation and temperature shifts and (2) to investigate if different surface concentrations of defence compounds shape epibacterial communities. F. vesiculosus was incubated in indoor mesocosms at five different temperature conditions (5 to 25°C) and in outdoor mesocosms under six differently reduced sunlight conditions (0 to 100%), respectively. Algal surface concentrations of previously identified antifouling compounds - dimethylsulphopropionate (DMSP), fucoxanthin and proline – were determined and the bacterial community composition was characterized by in-depth sequencing of the 16S-rRNA gene. Altogether, the effect of different treatment levels upon defence compound concentrations was limited. Under all conditions DMSP alone appeared to be sufficiently concentrated to warrant for at least a partial inhibitory action against epibiotic bacteria of F. vesiculosus. In contrast, proline and fucoxanthin rarely reached the necessary concentration ranges for self-contained inhibition. Nonetheless, in both experiments along with the direct influence of temperature and light, all three compounds apparently affected the overall bacterial community composition associated with F. vesiculosus since tendencies for insensitivity towards all three compounds were observed among bacterial taxa that typically dominate those communities. Given that the concentrations of at least one of the compounds (in most cases DMSP) were always high enough to inhibit bacterial settlement, we conclude that the capacity of F. vesiculosus for such defence will hardly be compromised by shading or warming to temperatures up to 25°C. PMID:25360717
Saha, Mahasweta; Rempt, Martin; Stratil, Stephanie B; Wahl, Martin; Pohnert, Georg; Weinberger, Florian
2014-01-01
The goals of this study were (1) to investigate whether Fucus vesiculosus regulates the production of its antifouling defence chemicals against epibacteria in response to light limitation and temperature shifts and (2) to investigate if different surface concentrations of defence compounds shape epibacterial communities. F. vesiculosus was incubated in indoor mesocosms at five different temperature conditions (5 to 25°C) and in outdoor mesocosms under six differently reduced sunlight conditions (0 to 100%), respectively. Algal surface concentrations of previously identified antifouling compounds--dimethylsulphopropionate (DMSP), fucoxanthin and proline--were determined and the bacterial community composition was characterized by in-depth sequencing of the 16S-rRNA gene. Altogether, the effect of different treatment levels upon defence compound concentrations was limited. Under all conditions DMSP alone appeared to be sufficiently concentrated to warrant for at least a partial inhibitory action against epibiotic bacteria of F. vesiculosus. In contrast, proline and fucoxanthin rarely reached the necessary concentration ranges for self-contained inhibition. Nonetheless, in both experiments along with the direct influence of temperature and light, all three compounds apparently affected the overall bacterial community composition associated with F. vesiculosus since tendencies for insensitivity towards all three compounds were observed among bacterial taxa that typically dominate those communities. Given that the concentrations of at least one of the compounds (in most cases DMSP) were always high enough to inhibit bacterial settlement, we conclude that the capacity of F. vesiculosus for such defence will hardly be compromised by shading or warming to temperatures up to 25°C.
Yi, Kunpeng; Tani, Hiroshi; Li, Qiang; Zhang, Jiquan; Guo, Meng; Bao, Yulong; Wang, Xiufeng; Li, Jing
2014-01-01
In this paper, an Urban Light Index (ULI) is constructed to facilitate analysis and quantitative evaluation of the process of urbanization and expansion rate by using DMSP/OLS Nighttime Light Data during the years from 1992 to 2010. A unit circle urbanization evaluation model is established to perform a comprehensive analysis of the urbanization process of 34 prefecture-level cities in Northeast China. Furthermore, the concept of urban light space is put forward. In this study, urban light space is divided into four types: the core urban area, the transition zone between urban and suburban areas, suburban area and fluorescent space. Proceeding from the temporal and spatial variation of the four types of light space, the pattern of morphologic change and space-time evolution of the four principal cities in Northeast China (Harbin, Changchun, Shenyang, Dalian) is analyzed and given particular attention. Through a correlation analysis between ULI and the traditional urbanization indexes (urban population, proportion of the secondary and tertiary industries in the regional GDP and the built-up area), the advantages and disadvantages as well as the feasibility of using the ULI in the study of urbanization are evaluated. The research results show that ULI has a strong correlation with urban built-up area (R2 = 0.8277). The morphologic change and history of the evolving urban light space can truly reflect the characteristics of urban sprawl. The results also indicate that DMSP/OLS Nighttime Light Data is applicable for extracting urban space information and has strong potential to urbanization research. PMID:24553086
NASA Compendium of Satellite Communications Programs
NASA Technical Reports Server (NTRS)
1973-01-01
A comprehensive review is presented of worldwide communication programs that range in time from the inception of satellite communications to August 1971. The programs included are: Echo, Courier, West Ford, Telstar, Relay, Syncom, Lincoln experimental satellites, Intelsat, Tacsat, Skynet, Nato system, and Telesat.
NASA Technical Reports Server (NTRS)
Scofield, Rod; Vicente, Gilberto; Hodges, Mike
2000-01-01
This Tech Report summarizes years of study and experiences on using GOES Water vapor (6.7 micron and precipitable water) and Special Sensor Microwave Imager (SSM/1) from the Defense Meteorological Satellite Program (DMSP) derived Precipitable Water (PNAI) for detecting environments favorable for convectively produced flash floods. An emphasis is on the moisture. upper air flow, and equivalent potential temperature (Theta(sub e)) patterns that lead to devastating flood events. The 15 minute 6.7 micron water vapor imagery is essential for tracking middle to upper tropospheric disturbances that produce upward vertical motion and initiate flash flood producing systems. Water vapor imagery at 6.7 micron is also used to detect surges of upper level moisture (called tropical water vapor plumes) that have been associated with extremely heavy rainfall. Since the water vapor readily depicts lifting mechanisms and upper level moisture, water vapor imagery is often an excellent source of data for recognizing patterns of heavy precipitation and flash floods. In order to analyze the depth of the moisture, the PW aspects of the troposphere must be measured. The collocation (or nearby location) of high values ofP\\V and instability are antecedent conditions prior to the flash flood or heavy rainfall events. Knowledge of PW magnitudes have been used as thresholds for impending flash flood events, PW trends are essential in flash flood prediction. Conceptual models and water vapor products are used to study some of the characteristics of convective systems that occurred over the United States of America (USA) during the summer of 1997 and the 1997-1998 El Nino. P\\V plumes were associated with most of the \\vest coast heavy precipitation events examined during the winter season of 1997 - 1998, In another study, conducted during the summer season of 1997. results showed that the collocation of water vapor (6.7 micron) and P\\N' plumes possessed higher correlations with predicted rainfall amounts than when PW plumes occurred by themselves (i.e.. without the presence of 6.7 micron water vapor plumes). Satellite Analysis Branch (SAB) meteorologists use the 6.7 micron water and P\\V products for their QPE's (interactive Flash Flood Analyzer (IFFA) and Auto-Estimator precipitation estimates), Outlooks, and heavy precipitation briefings with the Hydrometeorological Prediction Center/National Center for Environmental Prediction.
Mustang Complex Fires in Idaho
2017-12-08
On August 29, 2012, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this nighttime view of wildfires burning in Idaho and Montana. The image was captured by the VIIRS “day-night band,” which detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe signals such as gas flares, auroras, wildfires, city lights, and reflected moonlight. When the image was acquired, the moon was in its waxing gibbous phase, meaning it was more than half-lit, but less than full. Numerous hot spots from the Mustang Complex Fire are visible in northern Idaho. A plume of thick, billowing smoke streams west from the brightest fires near the Idaho-Montana border. The Halstead and Trinity Ridge fires are visible to the south. In addition to the fires, city lights from Boise and other smaller cities appear throughout the image. A bank of clouds is located west of the Mustang Complex, over southeastern Washington and northeastern Oregon. The Operational Line System (OLS)—an earlier generation of night-viewing sensors on the U.S. Defense Meteorological Satellite Program (DMSP) satellites—was also capable of detecting fires at night. But the VIIRS “day-night band” is far better than OLS at resolving them. Each pixel of an VIIRS image shows roughly 740 meters (0.46 miles), compared to the 3-kilometer footprint (1.86 miles) on the OLS system. NASA Earth Observatory image by Jesse Allen and Robert Simmon, using VIIRS Day-Night Band data from the Suomi National Polar-orbiting Partnership. Suomi NPP is the result of a partnership between NASA, the National Oceanic and Atmospheric Administration, and the Department of Defense. Caption by Adam Voiland. Instrument: Suomi NPP - VIIRS Credit: NASA Earth Observatory Click here to view all of the Earth at Night 2012 images Click here to read more about this image NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
NASA Astrophysics Data System (ADS)
Luton, J.-M.
1992-02-01
Successful European Space Agency (ESA) programs include the Ariane launcher development, the Meteosat meteorological satellites and the Intelsat 6, ECS (European Communications Satellite) series of communications satellites. The ESA's policy of placing contracts with industrial companies in its 13 member countries has contributed to the strategic development of European high technology in the world market. The ESA's long-term programs, in addition to the Ariane launcher and Columbus/Hermes space-station/spaceplane programs, include participation in the International Space Station program, the Data Relay Satellite system and a variety of space applications programs. Two high-performance satellites to be placed in polar orbits will contribute to European environmental and climate variation studies and, together with the Polar Platform sector of the Columbus program, will drive the establishment and development of new institutions, industrial structures and infrastructure.
The DMSP/MFR total ozone and radiance data base
NASA Technical Reports Server (NTRS)
Ellis, J. S.; Lovill, J. E.; Luther, F. M.; Sullivan, T. J.; Taylor, S. S.; Weichel, R. L.
1983-01-01
This report describes the entries in sufficient detail so that the data base might be useful to others. The characteristics of the MFR sensor are briefly discussed and a complete index to the data base tapes is given.
NASA Technical Reports Server (NTRS)
1974-01-01
Observations and research progress of the Smithsonian Astrophysical Observatory are reported. Satellite tracking networks (ground stations) are discussed and equipment (Baker-Nunn cameras) used to observe the satellites is described. The improvement of the accuracy of a laser ranging system of the ground stations is discussed. Also, research efforts in satellite geodesy (tides, gravity anomalies, plate tectonics) is discussed. The use of data processing for geophysical data is examined, and a data base for the Earth and Ocean Physics Applications Program is proposed. Analytical models of the earth's motion (computerized simulation) are described and the computation (numerical integration and algorithms) of satellite orbits affected by the earth's albedo, using computer techniques, is also considered. Research efforts in the study of the atmosphere are examined (the effect of drag on satellite motion), and models of the atmosphere based on satellite data are described.
ERIC Educational Resources Information Center
Lonsdale, Helen C.; O'Neill, Donald W.
To implement a career education program for junior high school students in the rural, isolated areas of the Rocky Mountain States, Satellite Technology Demonstration (STD) tested the use of a satellite-assisted communications system for the delivery of social services. A magazine was designed to promote acceptance of the television programing and…
Building technological capability within satellite programs in developing countries
NASA Astrophysics Data System (ADS)
Wood, Danielle; Weigel, Annalisa
2011-12-01
This paper explores the process of building technological capability in government-led satellite programs within developing countries. The key message is that these satellite programs can learn useful lessons from literature in the international development community. These lessons are relevant to emerging satellite programs that leverage international partnerships in order to establish local capability to design, build and operate satellites. Countries with such programs include Algeria, Nigeria, Turkey, Malaysia and the United Arab Emirates. The paper first provides background knowledge about space activity in developing countries, and then explores the nuances of the lessons coming from the international development literature. Developing countries are concerned with satellite technology because satellites provide useful services in the areas of earth observation, communication, navigation and science. Most developing countries access satellite services through indirect means such as sharing data with foreign organizations. More countries, however, are seeking opportunities to develop satellite technology locally. There are objective, technically driven motivations for developing countries to invest in satellite technology, despite rich debate on this topic. The paper provides a framework to understand technical motivations for investment in satellite services, hardware, expertise and infrastructure in both short and long term. If a country decides to pursue such investments they face a common set of strategic decisions at the levels of their satellite program, their national context and their international relationships. Analysis of past projects shows that countries have chosen diverse strategies to address these strategic decisions and grow in technological capability. What is similar about the historical examples is that many countries choose to leverage international partnerships as part of their growth process. There are also historical examples from outside the space arena in which organizations have pursued technological capability. Scholars have analyzed these examples and developed insightful frameworks. The paper draws key concepts from this literature about the nature of development, technology, knowledge and organizational learning. These concepts are relevant to learning in new satellite programs, but the ideas must be applied cautiously because of the nature of satellite technology. The paper draws three major lessons from the international development literature regarding absorptive capacity, tacit knowledge and organizational learning; it synthesizes these lessons into a cohesive, original framework. The closing section proposes future work on a detailed study of technological learning in specific government satellite programs.
NASA Technical Reports Server (NTRS)
Greenburg, J. S.; Gaelick, C.; Kaplan, M.; Fishman, J.; Hopkins, C.
1985-01-01
Commercial organizations as well as government agencies invest in spacecraft (S/C) technology programs that are aimed at increasing the performance of communications satellites. The value of these programs must be measured in terms of their impacts on the financial performane of the business ventures that may ultimately utilize the communications satellites. An economic evaluation and planning capability was developed and used to assess the impact of NASA on-orbit propulsion and space power programs on typical fixed satellite service (FSS) and direct broadcast service (DBS) communications satellite business ventures. Typical FSS and DBS spin and three-axis stabilized spacecraft were configured in the absence of NASA technology programs. These spacecraft were reconfigured taking into account the anticipated results of NASA specified on-orbit propulsion and space power programs. In general, the NASA technology programs resulted in spacecraft with increased capability. The developed methodology for assessing the value of spacecraft technology programs in terms of their impact on the financial performance of communication satellite business ventures is described. Results of the assessment of NASA specified on-orbit propulsion and space power technology programs are presented for typical FSS and DBS business ventures.
NASA Astrophysics Data System (ADS)
Greenburg, J. S.; Gaelick, C.; Kaplan, M.; Fishman, J.; Hopkins, C.
1985-09-01
Commercial organizations as well as government agencies invest in spacecraft (S/C) technology programs that are aimed at increasing the performance of communications satellites. The value of these programs must be measured in terms of their impacts on the financial performane of the business ventures that may ultimately utilize the communications satellites. An economic evaluation and planning capability was developed and used to assess the impact of NASA on-orbit propulsion and space power programs on typical fixed satellite service (FSS) and direct broadcast service (DBS) communications satellite business ventures. Typical FSS and DBS spin and three-axis stabilized spacecraft were configured in the absence of NASA technology programs. These spacecraft were reconfigured taking into account the anticipated results of NASA specified on-orbit propulsion and space power programs. In general, the NASA technology programs resulted in spacecraft with increased capability. The developed methodology for assessing the value of spacecraft technology programs in terms of their impact on the financial performance of communication satellite business ventures is described. Results of the assessment of NASA specified on-orbit propulsion and space power technology programs are presented for typical FSS and DBS business ventures.
Extremely Low Passive Microwave Brightness Temperatures Due to Thunderstorms
NASA Technical Reports Server (NTRS)
Cecil, Daniel J.
2015-01-01
Extreme events by their nature fall outside the bounds of routine experience. With imperfect or ambiguous measuring systems, it is appropriate to question whether an unusual measurement represents an extreme event or is the result of instrument errors or other sources of noise. About three weeks after the Tropical Rainfall Measuring Mission (TRMM) satellite began collecting data in Dec 1997, a thunderstorm was observed over northern Argentina with 85 GHz brightness temperatures below 50 K and 37 GHz brightness temperatures below 70 K (Zipser et al. 2006). These values are well below what had previously been observed from satellite sensors with lower resolution. The 37 GHz brightness temperatures are also well below those measured by TRMM for any other storm in the subsequent 16 years. Without corroborating evidence, it would be natural to suspect a problem with the instrument, or perhaps an irregularity with the platform during the first weeks of the satellite mission. Automated quality control flags or other procedures in retrieval algorithms could treat these measurements as errors, because they fall outside the expected bounds. But the TRMM satellite also carries a radar and a lightning sensor, both confirming the presence of an intense thunderstorm. The radar recorded 40+ dBZ reflectivity up to about 19 km altitude. More than 200 lightning flashes per minute were recorded. That same storm's 19 GHz brightness temperatures below 150 K would normally be interpreted as the result of a low-emissivity water surface (e.g., a lake, or flood waters) if not for the simultaneous measurements of such intense convection. This paper will examine records from TRMM and related satellite sensors including SSMI, AMSR-E, and the new GMI to find the strongest signatures resulting from thunderstorms, and distinguishing those from sources of noise. The lowest brightness temperatures resulting from thunderstorms as seen by TRMM have been in Argentina in November and December. For SSMI sensors carried on five DMSP satellites examined so far, the lowest thunderstorm-related brightness temperatures have been from Argentina in November - December and from Minnesota in June-July. The Minnesota cases were associated with spotter reports of large hail, significant severe wind, and tornadoes. Those locations have the record-holders for each satellite. The lowest AMSR-E 36.5 GHz brightness temperatures associated with deep convection have been in Argentina; the lowest 89.0 GHz brightness temperatures were from Typhoon Bolaven in the Philippine Sea. This paper will show examples of cases with the lowest brightness temperatures, and map the locations of these and other storms with brightness temperatures nearly as low. The study is largely motivated by the new GMI sensor on the Global Precipitation Mission core satellite, launched in February 2014, with its high resolution expected to reveal unprecedented low brightness temperatures when extreme events are encountered.
Public Service Communication Satellite Program
NASA Technical Reports Server (NTRS)
Brown, J. P.
1977-01-01
The proposed NASA Public Service Communication Satellite Program consists of four different activities designed to fulfill the needs of public service sector. These are: interaction with the users, experimentation with existing satellites, development of a limited capability satellite for the earliest possible launch, and initiation of an R&D program to develop the greatly increased capability that future systems will require. This paper will discuss NASA efforts in each of these areas.
ERIC Educational Resources Information Center
Arnall, Gail C.
1987-01-01
Discusses the application of satellite information delivery to training. Describes a new trend, horizontal programming. Also discusses vertical programming and in-house production of training materials. Lists vendors of satellite-based training. (CH)
Computer-Aided Communication Satellite System Analysis and Optimization.
ERIC Educational Resources Information Center
Stagl, Thomas W.; And Others
Various published computer programs for fixed/broadcast communication satellite system synthesis and optimization are discussed. The rationale for selecting General Dynamics/Convair's Satellite Telecommunication Analysis and Modeling Program (STAMP) in modified form to aid in the system costing and sensitivity analysis work in the Program on…
The 1973 Smithsonian standard earth (3). [for the satellite geodesy program
NASA Technical Reports Server (NTRS)
Garoschkin, E. M. (Editor)
1973-01-01
The origins of the satellite geodesy program are described, starting with the International Geophysical Year, continuing through a number of international programs, and culminating with the National Geodetic Satellite Program. The philosophical basis for the Baker-Nunn camera and the laser ranging system, the evolution of international scientific cooperation, and the significance of the results are discussed.
Proceedings of the International Meteorological Satellite Workshop
NASA Technical Reports Server (NTRS)
1962-01-01
International Meteorological Satellite Workshop, November 13-22, 1961, presented the results of the meteorological satellite program of the United States and the possibilities for the future, so that-- the weather services of other nations may acquire a working knowledge of meteorological satellite data for assistance in their future analysis programs both in research and in daily synoptic application and guidance in their national observational support efforts; the world meteorological community may become more familiar with the TIROS program.; and the present activity may be put in proper perspective relative to future operational programs.
NASA Astrophysics Data System (ADS)
Bernardes, S.; Cotten, D. L.
2016-12-01
University-based satellite programs have been successfully used as a platform for teaching STEM related fields, bringing tremendous benefits to graduate and undergraduate education. Considering their infrastructure and curricula, tech schools have traditionally been considered logical candidates for hosting such programs. More recently, with the dissemination of small satellites initiatives, non-tech schools have been presented the opportunity of developing satellite design and implementation programs. This work reports on the experiences and challenges associated with implementing a satellite program at the University of Georgia (UGA), a non-tech university. With funding from the Air Force Research Laboratory's (AFRL) University Nanosat Program (UNP) and NASA's Undergraduate Student Instrument Project (USIP) a team of undergraduates at UGA has recently been tasked with building two small satellites and helping to create a Small Satellite Research Laboratory (SSRL) at the university. Unique features of the satellite program at UGA include its team of students from a broad range of backgrounds and departments (Engineering, Computer Science, Art, Business, and Geography) and the previous exposure of many of these students to synergistic technologies, including arduino and unmanned aerial systems. We show how informal exposure to those technologies and willingness of students to focus on areas outside of their field of study can benefit from the implementation of satellite programs. In this regard, we report on methods and techniques used to find and recruit driven and knowledgeable students to work in a high paced field such as satellite system integration. We show how students and faculty from multiple departments have collaborated to reach a common, far reaching goal and describe our proposed methods to evaluate and measure educational goals based around SSRL and its projects. We also present the challenges associated with the lack of a developed engineering program, including our solutions to a shortage of equipment and expertise regarding building satellite systems and a satellite laboratory. Finally, we our outreach methods, including K-12, and share our experience and successes finding industry partners, considering an absence of background in the field and prior collaborations.
Cloud cover determination in polar regions from satellite imagery
NASA Technical Reports Server (NTRS)
Barry, R. G.; Key, J.
1989-01-01
The objectives are to develop a suitable validation data set for evaluating the effectiveness of the International Satellite Cloud Climatology Project (ISCCP) algorithm for cloud retrieval in polar regions, to identify limitations of current procedures and to explore potential means to remedy them using textural classifiers, and to compare synoptic cloud data from model runs with observations. Toward the first goal, a polar data set consisting of visible, thermal, and passive microwave data was developed. The AVHRR and SMMR data were digitally merged to a polar stereographic projection with an effective pixel size of 5 sq km. With this data set, two unconventional methods of classifying the imagery for the analysis of polar clouds and surfaces were examined: one based on fuzzy sets theory and another based on a trained neural network. An algorithm for cloud detection was developed from an early test version of the ISCCP algorithm. This algorithm includes the identification of surface types with passive microwave, then temporal tests at each pixel location in the cloud detection phase. Cloud maps and clear sky radiance composites for 5 day periods are produced. Algorithm testing and validation was done with both actural AVHRR/SMMR data, and simulated imagery. From this point in the algorithm, groups of cloud pixels are examined for their spectral and textural characteristics, and a procedure is developed for the analysis of cloud patterns utilizing albedo, IR temperature, and texture. In a completion of earlier work, empirical analyses of arctic cloud cover were explored through manual interpretations of DMSP imagery and compared to U.S. Air Force 3D-nephanalysis. Comparisons of observed cloudiness from existing climatologies to patterns computed by the GISS climate model were also made.
NASA Technical Reports Server (NTRS)
Neale, Christopher M. U.; Mcdonnell, Jeffrey J.; Ramsey, Douglas; Hipps, Lawrence; Tarboton, David
1993-01-01
Since the launch of the DMSP Special Sensor Microwave/Imager (SSM/I), several algorithms have been developed to retrieve overland parameters. These include the present operational algorithms resulting from the Navy calibration/validation effort such as land surface type (Neale et al. 1990), land surface temperature (McFarland et al. 1990), surface moisture (McFarland and Neale, 1991) and snow parameters (McFarland and Neale, 1991). In addition, other work has been done including the classification of snow cover and precipitation using the SSM/I (Grody, 1991). Due to the empirical nature of most of the above mentioned algorithms, further research is warranted and improvements can probably be obtained through a combination of radiative transfer modelling to study the physical processes governing the microwave emissions at the SSM/I frequencies, and the incorporation of additional ground truth data and special cases into the regression data sets. We have proposed specifically to improve the retrieval of surface moisture and snow parameters using the WetNet SSM/I data sets along with ground truth information namely climatic variables from the NOAA cooperative network of weather stations as well as imagery from other satellite sensors such as the AVHRR and Thematic Mapper. In the case of surface moisture retrievals the characterization of vegetation density is of primary concern. The higher spatial resolution satellite imagery collected at concurrent periods will be used to characterize vegetation types and amounts which, along with radiative transfer modelling should lead to more physically based retrievals. Snow parameter retrieval algorithm improvement will initially concentrate on the classification of snowpacks (dry snow, wet snow, refrozen snow) and later on specific products such as snow water equivalent. Significant accomplishments in the past year are presented.
NASA as a Catalyst: Use of Satellite Data in the States
NASA Technical Reports Server (NTRS)
Warnecke, Lisa
1997-01-01
NASA revolutionized our view of the world in 1972 with the launch of the first satellite to monitor the Earth. Recognizing the importance of states in governing the United States, NASA then established a program in the late 1970s to educate and assist states in using satellite data products. This report reviews this brief, but beneficial program that laid a foundation and catalyzed satellite data work that continues today in several states. More recently, outreach efforts as part of NASAs Mission to Planet Earth program and growing state government roles, responsibilities, and initiatives led NASA to begin a new effort in 1994 to understand and work effectively with states. This effort included an investigation and synthesis of current satellite data conditions in each of the 50 states that are included in this report. It provided strong evidence that some state governments are applying satellite data to an increasing array of government needs, while other states have very limited applications to date. A wide range of satellite data applications in executive branch agencies are described, as well as the recent status of the Gap Analysis Program in each of the states with this program. The report also reviews the status of satellite data and geographic information coordination efforts in each of the 50 states. In addition to this investigation, NASA convened a meeting of representatives of 12 states experienced with satellite data to identify future satellite data uses and needs, as well as NASA opportunities to enhance the utility of satellite data products. The findings and recommendations from this meeting, the 50 state investigations, and NASAs past state programs are also included in the report; they provide the rationale for NASA to establish a new outreach effort with state governments in the late 1990s.
ATS simultaneous and turnaround ranging experiments
NASA Technical Reports Server (NTRS)
Watson, J. S.; Putney, B. H.
1971-01-01
This report explains the data reduction and spacecraft position determination used in conjunction with two ATS experiments - Trilateration and Turnaround Ranging - and describes in detail a multilateration program that is used for part of the data reduction process. The process described is for the determination of the inertial position of the satellite, and for formating input for related programs. In the trilateration procedure, a geometric determination of satellite position is made from near simultaneous range measurements made by three different tracking stations. Turnaround ranging involves two stations; one, the master station, transmits the signal to the satellite and the satellite retransmits the signal to the slave station which turns the signal around to the satellite which in turn retransmits the signal to the master station. The results of the satellite position computations using the multilateration program are compared to results of other position determination programs used at Goddard. All programs give nearly the same results which indicates that because of its simplicity and computational speed the trilateration technique is useful in obtaining spacecraft positions for near synchronous satellites.
A space standards application to university-class microsatellites: The UNISAT experience
NASA Astrophysics Data System (ADS)
Graziani, Filippo; Piergentili, Fabrizio; Santoni, Fabio
2010-05-01
Hands-on education is recognized as an invaluable tool to improve students' skills, to stimulate their enthusiasm and to educate them to teamwork. University class satellite programs should be developed keeping in mind that education is the main goal and that university satellites are a unique opportunity to make involved students familiar with all the phases of space missions. Moreover university budgets for education programs are much lower than for industrial satellites programs. Therefore two main constraints must be respected: a time schedule fitting with the student course duration and a low economic budget. These have an impact on the standard which can be followed in university class satellite programs. In this paper university-class satellite standardization is discussed on the basis of UNISAT program experience, reporting successful project achievements and lessons learned through unsuccessful experiences. The UNISAT program was established at the Scuola di Ingegneria Aerospaziale by the Group of Astrodynamics of the University of Rome "La Sapienza" (GAUSS) as a research and education program in which Ph.D. and graduate students have the opportunity to gain hands-on experience on small space missions. Four university satellites (UNISAT, UNISAT-2, UNISAT-3, UNISAT-4), weighing about 10 kg, have been designed, manufactured, tested and launched every two years since 2000 in the framework of this program In the paper, after a brief overview of new GAUSS programs, an analysis of the UNISAT satellites ground test campaign is carried out, identifying the most critical procedures and requirements to be fulfilled. Moreover a device for low earth orbit low-cost satellite end-of-life disposal is presented; this system (SIRDARIA) complies with the international guidelines on space debris.
NASA Technical Reports Server (NTRS)
1991-01-01
The NASA-developed Artificial Satellite Analysis Program (ASAP), was purchased from COSMIC and used to enhance OPNET, a program for developing simulations of communications satellite networks. OPNET's developer, MIL3, applied ASAP to support predictions of low Earth orbit, enabling the company to offer satellite modeling capability to customers earlier than if they had to actually develop the program.
NASA Astrophysics Data System (ADS)
Jia, S.; Gillespie, T. W.
2016-12-01
Stable nighttime light, an indicator of persisting human activity and light pollution is a well-recognized disturbance to the wilderness of protected areas (PAs). Mostly supported by in situ observations, very limited studies of light pollution for PAs focused at a regional level and on a continuous time span to support policy making effectively. DMSP-OLS stable nighttime series provide continuous observation of nightlight and have been widely applied in studies focusing on human activities. In this study, we employed inter-calibrated DMSP-OLS nightlight series from 1992 to 2012 to evaluate the change of intensity and extension of stable nighttime light inside California PAs. We observed a decrease of stable nighttime light and a shrinkage in spatial extent in PAs located in all ecoregions from 1992 to 2012, especially before 2004. Such decrease and shrinkage occurred mostly in southern California and the Bay Area where mega metropolitan clusters locate. The successful application of protecting strategies in PAs and the improved technologies of lighting may contribute to the relieving of light pollution in PAs. However, the stable nighttime light slightly increased since 2004, when there was limited room for stricter protective regulations and the pressure from population growth persisted. Population density explained most spatial distribution of nightlight in years with census tract level demographic data available, except PAs with the highest wilderness such as Sierra Nevada Mts. We anticipate to improve the models with the newest remote sensing nighttime product from NASA Suomi-NPP and annually updated demographic data from American Community Survey at census tract level in the future to provide a cost-effective evaluation on protecting strategies. Such evaluation will support land managers of PAs and local policy-makers for modification and proposal of policies.
Dust in an acidified ocean: iron bioavailability, phytoplankton growth and DMS
NASA Astrophysics Data System (ADS)
Mélançon, J.; Levasseur, M.; Lizotte, M.; Scarratt, M. G.; Tremblay, J. E.; Tortell, P. D.; Yang, G.; Shi, G. Y.; Gao, H.; Semeniuk, D.; Robert, M.; Arychuk, M.; Johnson, K.; Sutherland, N.; Davelaar, M.; Nemcek, N.; Pena, A.; Richardson, W.
2015-12-01
Ocean acidification (OA) is likely to have an effect on the fertilizing potential of desert dust in high-nutrient, low-chlorophyll oceanic regions, either by modifying Fe speciation and bioavailability, or by altering phytoplankton Fe requirements and acquisition. To address this issue, short incubations (4 days) of northeast subarctic Pacific waters enriched with either FeSO4 or dust, and maintained at pH 8.0 (in situ) and 7.8 were conducted in August 2010. We assessed the impact of a decrease in pH on dissolved Fe concentration, phytoplankton biomass, taxonomy and productivity, and the production of dimethylsulfide (DMS) and its algal precursor dimethylsulfoniopropionate (DMSP). Chlorophyll a (chl a) remained unchanged in the controls and doubled in both the FeSO4-enriched and dust-enriched incubations, confirming the Fe-limited status of the plankton assemblage during the experiment. In the acidified treatments, a significant reduction (by 16-38%) of the final concentration of chl a was measured compared to their non-acidified counterparts, and a 15% reduction in particulate organic carbon (POC) concentration was measured in the dust-enriched acidified treatment compared to the dust-enriched non-acidified treatment. FeSO4 and dust additions had a fertilizing effect mainly on diatoms and cyanobacteria. Lowering the pH affected mostly the haptophytes, but pelagophyte concentrations were also reduced in some acidified treatments. Acidification did not significantly alter DMSP and DMS concentrations. These results show that dust deposition events in a low-pH iron-limited Northeast subarctic Pacific are likely to stimulate phytoplankton growth to a lesser extent than in today's ocean during the few days following fertilization and point to a low initial sensitivity of the DMSP and DMS dynamics to OA.
Proteomic Analysis of Stationary Phase in the Marine Bacterium "Candidatus Pelagibacter ubique"
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sowell, S. M.; Norbeck, A. D.; Lipton, M. S.
2008-05-09
The α-proteobacterium ‘Candidatus Pelagibacter ubique’ str. HTCC1062, and most other members of the SAR11 clade, lack genes for assimilatory sulfate reduction, making them dependent on organosulfur compounds that occur naturally in seawater. To investigate how these cells adapt to sulfur limitation, batch cultures were grown in defined media containing either limiting or non-limiting amounts of dimethylsulfoniopropionate (DMSP) as the sole sulfur source. Protein and mRNA expression were measured during exponential growth, immediately prior to stationary phase, and in late stationary phase. Two distinct responses were observed: one as DMSP became exhausted, and another as cells acclimated to a sulfur-limited environment.more » The first response was characterized by increased transcription and translation of all Ca. P. ubique genes downstream of previously confirmed S-adenosyl methionine (SAM) riboswitches: bhmT, mmuM, and metY. Proteins encoded by these genes were up to 33 times more abundant as DMSP became limiting. Their predicted function is to shunt all available sulfur to methionine. The secondary response, observed during sulfur-depleted stationary phase, was a 6-10 fold increase in transcription of the heme c shuttle ccmC and two small genes of unknown function (SAR11_1163 and SAR11_1164). This bacterium's strategy for coping with sulfur stress appears to be intracellular redistribution to support methionine biosynthesis, rather than increasing organosulfur import. Many of the genes and SAM riboswitches involved in this response are located in a hypervariable genome region (HVR). One of these HVR genes, ordL, is located downstream of a conserved motif that evidence suggests is a novel riboswitch.« less
Occurrence and Turnover of Biogenic Sulfur in the Bering Sea During Summer
NASA Astrophysics Data System (ADS)
Li, Cheng-Xuan; Wang, Bao-Dong; Yang, Gui-Peng; Wang, Zi-Cheng; Chen, Jian-Fang; Lyu, Yang
2017-11-01
The horizontal/geographical variations in dissolved dimethylsulfide (DMS), its precursor dimethylsulfoniopropionate (DMSPd and DMSPp), and chlorophyll a (Chl a), as well as the oceanographic parameters influencing the concentrations of dimethylated sulfur compounds, were investigated in the Bering Sea from July to August 2012. Similar to Chl a, the surface DMS and DMSPp levels, as well as DMS(P) production and consumption rates, exhibited a declining gradient from the central basin to the continental shelf, with high-value areas appearing in the central basin, the slope regions, and Anadyr Strait but a low-value area occurring on the outer-middle continental shelf. Considerably high values of DMS and DMSP were measured in the saline Bering Sea Basin Deep Water (>2,000 m) located at the southwest of the Bering Basin because of the release of resuspension in 2,000 m depth and the DMSP production from endogenous benthic bacteria and cyanobacteria population. Chl a was positively correlated with DMSPp and DMS in the surface waters and the upper water of the basin, whereas significant negative correlations were found between DMS and nutrients (dissolved inorganic nitrogen [DIN], phosphorus, and silicate) in the inner shelf of the Bering Sea. DMS microbial consumption was approximately 6.26 times faster than the DMS sea-air exchange, demonstrating that the major loss of DMS in the surface water occurred through biological consumption relative to evasion into the atmosphere. Average sea-to-air DMS fluxes were estimated to be 4.66 μmol/(m2·d), and consequently oceanic biogenic DMS emission had a dominant contribution to the sulfur budget over the observational area.
Inter-comparison of the EUMETSAT H-SAF and NASA PPS precipitation products over Western Europe.
NASA Astrophysics Data System (ADS)
Kidd, Chris; Panegrossi, Giulia; Ringerud, Sarah; Stocker, Erich
2017-04-01
The development of precipitation retrieval techniques utilising passive microwave satellite observations has achieved a good degree of maturity through the use of physically-based schemes. The DMSP Special Sensor Microwave Imager/Sounder (SSMIS) has been the mainstay of passive microwave observations over the last 13 years forming the basis of many satellite precipitation products, including NASA's Precipitation Processing System (PPS) and EUMETSAT's Hydrological Satellite Application Facility (H-SAF). The NASA PPS product utilises the Goddard Profiling (GPROF; currently 2014v2-0) retrieval scheme that provides a physically consistent retrieval scheme through the use of coincident active/passive microwave retrievals from the Global Precipitation Measurement (GPM) mission core satellite. The GPM combined algorithm retrieves hydrometeor profiles optimized for consistency with both Dual-frequency Precipitation Radar (DPR) and GPM Microwave Imager (GMI); these profiles form the basis of the GPROF database which can be utilized for any constellation radiometer within the framework a Bayesian retrieval scheme. The H-SAF product (PR-OBS-1 v1.7) is based on a physically-based Bayesian technique where the a priori information is provided by a Cloud Dynamic Radiation Database (CDRD). Meteorological parameter constraints, derived from synthetic dynamical-thermodynamical-hydrological meteorological profile variables, are used in conjunction with multi-hydrometeor microphysical profiles and multispectral PMW brightness temperature vectors into a specialized a priori knowledge database underpinning and guiding the algorithm's Bayesian retrieval solver. This paper will present the results of an inter-comparison of the NASA PPS GPROF and EUMETSAT H-SAF PR-OBS-1 products over Western Europe for the period from 1 January 2015 through 31 December 2016. Surface radar is derived from the UKMO-derived Nimrod European radar product, available at 15 minute/5 km resolution. Initial results show that overall the correlations between the two satellite precipitation products and surface radar precipitation estimates are similar, particularly for cases where there is extensive precipitation; however, the H-SAF tends to have poorer correlations in situations where rain is light or limited in extent. Similarly, RMSEs for the GPROF scheme tend to a smaller than those of the H-SAF retrievals. The difference in the performance can be traced to the identification of precipitation; the GPROF2014v2-0 scheme overestimates the occurrence and extent of the precipitation, generating a significant amount of light precipitation. The H-SAF scheme has a lower precipitation threshold of about 0.25 mmh-1 while overestimating moderate and higher precipitation intensities.
NASA Technical Reports Server (NTRS)
Mueller, I. I.; Kumar, M.; Reilly, J. P.; Saxena, N.; Soler, T.
1973-01-01
A multi-year study and analysis of data from satellites launched specifically for geodetic purposes and from other satellites useful in geodetic studies was conducted. The program of work included theoretical studies and analysis for the geometric determination of station positions derived from photographic observations of both passive and active satellites and from range observations. The current status of data analysis, processing and results are examined.
Estimation of polar low characteristics for the Nordic Seas for 1995-2008 using satellite data
NASA Astrophysics Data System (ADS)
Smirnova, Julia; Chapron, Bertrand; Zabolotskikh, Elizaveta; Leonid Bobylev, Mr
In recent years the scientific research confirmed the fact of the global warming. The Arctic climate is warming even more rapidly. Powerful storm polar lows having wind speeds of about 25 m/c are known to be the cause of hazardous weather. Polar lows present themselves as the atmospheric phenomena the horizontal dimensions of which do not exceed 1,000 km, appear and which exist from 12 to 24 hours. The wave fall and low temperatures can lead to increased probability of vessel icing the intensity of which increases with the high wind speed and large wave height. Study of the mesoscale processes, such as polar lows in the Arctic has become especially relevant due to the sharp sea ice decreasing in the Arctic Ocean and Arctic seas in recent years. Only the use of satellite data allows obtaining regular and spacious information about the polar lows. Early detection and evaluation of the characteristics of the polar lows is an extremely important task to ensure the safety of navigation, fishing and oil industry in the Arctic region. With new open areas dangerous polar lows can arise over them. So early detection of the polar lows, studying their characteristics, tracking their movement and prediction presents one the most important problems of the modern science. The present-day meteorological observational network has severe limitations in detecting all, especially small mesoscale cyclones, so there is a strong need for new and/or improved methods to detect and monitor polar lows. Satellite remote sensing seems to be the most feasible tool for early detection and monitoring of the polar lows. Several remote sensing sensors are capable to detect a polar low but each of them suffers from various deficiencies. In the work, satellite passive microwave data have been intensively exploited aiming at obtaining the fields of geophysical parameters inside the polar lows. DMSP Special Sensor Microwave/Imager - SSM/I data were used in the research. The polar lows have been identified on satellite passive microwave imagery by fields of means of analysis of atmospheric water vapour fields using a new approach. This approach consists of two stages. During the first stage the total atmospheric water vapor fields are calculated from passive microwave measurements using precise retrieval Neural Network Algorithms (Bobylev et al., 2010). During the second stage the vortex structures are detected in these fields, and polar lows are identified and tracked. Based on this approach, were estimated polar low characteristics in the Nordic seas for the period of 1995 - 2008. All polar lows have been identified for this period on SSM/I imagery. Other satellite data, such as QuikSCAT SeaWinds, NOAA AVHRR were used as additional information for polar low parameter retrieval and analysis.
NASA Astrophysics Data System (ADS)
Secan, James A.
1991-05-01
Modern military communication, navigation, and surveillance systems depend on reliable, noise-free transionospheric radio-frequency channels. They can be severely impacted by small-scale electron-density irregularities in the ionosphere, which cause both phase and amplitude scintillation. Basic tools used in planning and mitigation schemes are climatological in nature and thus may greatly over- and under-estimate the effects of scintillation in a given scenario. This report summarizes the results of the first year of a three-year investigation into the methods for updating ionospheric scintillation models using observations of ionospheric plasma-density irregularities measured by DMSP Scintillation Meter (SM) sensor. Results are reported from the analysis of data from a campaign conducted in January 1990 near Tromso, Norway, in which near coincident in-situ plasma-density and transionospheric scintillation measurements were made. Estimates for the level of intensity and phase scintillation on a transionospheric UHF radio link in the early-evening auroral zone were calculated from DMSP SM data and compared to the levels actually observed.
NASA Technical Reports Server (NTRS)
Le, G.; Luehr, H.; Anderson, B. J.; Strangeway, R. J.; Russell, C. T.; Singer, H.; Slavin, J. A.; Zhang, Y.; Huang, T.; Bromund, K.;
2016-01-01
We present multimission observations of field-aligned currents, auroral oval, and magnetopause crossings during the 17 March 2015 magnetic storm. Dayside reconnection is expected to transport magnetic flux, strengthen field-aligned currents, lead to polar cap expansion and magnetopause erosion. Our multimission observations assemble evidence for all these manifestations. After a prolonged period of strongly southward interplanetary magnetic field, Swarm and AMPERE observe significant intensification of field-aligned currents .The dayside auroral oval, as seen by DMSP, appears as a thin arc associated with ongoing dayside reconnection. Both the field-aligned currents and the auroral arc move equatorward reaching as low as approx. 60 deg. magnetic latitude. Strong magnetopause erosion is evident in the in situ measurements of the magnetopause crossings by GOES 13/15 and MMS. The coordinated Swarm, AMPERE, DMSP, MMS and GOES observations, with both global and in situ coverage of the key regions, provide a clear demonstration of the effects of dayside reconnection on the entire magnetosphere.
ERIC Educational Resources Information Center
Parkinson Norton, Susan; Pickus, Keith
2011-01-01
This essay will discuss the creation of adult-learner degree programs at Wichita State University's satellite campuses with a particular focus on how such programs complement the mission of a traditional urban-serving research institution. It will assess the decision-making process that led to the transformation of satellite campuses into…
Science opportunities from the Topex/Poseidon mission
NASA Technical Reports Server (NTRS)
Stewart, R.; Fu, L. L.; Lefebvre, M.
1986-01-01
The U.S. National Aeronautics and Space Administration (NASA) and the French Centre National d'Etudes Spatiales (CNES) propose to conduct a Topex/Poseidon Mission for studying the global ocean circulation from space. The mission will use the techniques of satellite altimetry to make precise and accurate measurements of sea level for several years. The measurements will then be used by Principal Investigators (selected by NASA and CNES) and by the wider oceanographic community working closely with large international programs for observing the Earth, on studies leading to an improved understanding of global ocean dynamics and the interaction of the ocean with other processes influencing life on Earth. The major elements of the mission include a satellite carrrying an altimetric system for measuring the height of the satellite above the sea surface; a precision orbit determination system for referring the altimetric measurements to geodetic coordinates; a data analysis and distribution system for processing the satellite data, verifying their accuracy, and making them available to the scientific community; and a principal investigator program for scientific studies based on the satellite observations. This document describes the satellite, its sensors, its orbit, the data analysis system, and plans for verifying and distributing the data. It then discusses the expected accuracy of the satellite's measurements and their usefulness to oceanographic, geophysical, and other scientific studies. Finally, it outlines the relationship of the Topex/Poseidon mission to other large programs, including the World Climate Research Program, the U.S. Navy's Remote Ocean Sensing System satellite program and the European Space Agency's ERS-1 satellite program.
A high-fidelity satellite ephemeris program for Earth satellites in eccentric orbits
NASA Technical Reports Server (NTRS)
Simmons, David R.
1990-01-01
A program for mission planning called the Analytic Satellite Ephemeris Program (ASEP), produces projected data for orbits that remain fairly close to the Earth. ASEP does not take into account lunar and solar perturbations. These perturbations are accounted for in another program called GRAVE, which incorporates more flexible means of input for initial data, provides additional kinds of output information, and makes use of structural programming techniques to make the program more understandable and reliable. GRAVE was revised, and a new program called ORBIT was developed. It is divided into three major phases: initialization, integration, and output. Results of the program development are presented.
A study program for geodetic satellite applications
NASA Technical Reports Server (NTRS)
Pearlman, M. R.
1972-01-01
The work is reported on support of the GEOS-C Program, National Geodetic Satellite program, and the Earth Physics Program. The statement of work, and a description of the GEOS-C are presented along with the trip reports, and the Earth and Ocean Physics Application program.
Exposure of tropical ecosystems to artificial light at night: Brazil as a case study
Bennie, Jon; Mantovani, Waldir; Gaston, Kevin J.
2017-01-01
Artificial nighttime lighting from streetlights and other sources has a broad range of biological effects. Understanding the spatial and temporal levels and patterns of this lighting is a key step in determining the severity of adverse effects on different ecosystems, vegetation, and habitat types. Few such analyses have been conducted, particularly for regions with high biodiversity, including the tropics. We used an intercalibrated version of the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS) images of stable nighttime lights to determine what proportion of original and current Brazilian vegetation types are experiencing measurable levels of artificial light and how this has changed in recent years. The percentage area affected by both detectable light and increases in brightness ranged between 0 and 35% for native vegetation types, and between 0 and 25% for current vegetation (i.e. including agriculture). The most heavily affected areas encompassed terrestrial coastal vegetation types (restingas and mangroves), Semideciduous Seasonal Forest, and Mixed Ombrophilous Forest. The existing small remnants of Lowland Deciduous and Semideciduous Seasonal Forests and of Campinarana had the lowest exposure levels to artificial light. Light pollution has not often been investigated in developing countries but our data show that it is an environmental concern. PMID:28178352
Extreme Magnetosphere-Ionosphere Coupling at the Plasmapause: a - In-A Bright SAR Arc
NASA Astrophysics Data System (ADS)
Baumgardner, J.; Wroten, J.; Semeter, J.; Mendillo, M.; Kozyra, J.
2007-05-01
Heat conduction from the ring current - plasmapause interaction region generates high electron temperature within the ionosphere that drive stable auroral red (SAR) arc emission at 6300 A. On the night of 29 October 1991, a SAR arc was observed using an all-sky imager and meridional imaging spectrograph at Millstone Hill. At xxxx UT, the SAR arc was south of Millstone at approximate L = 2 and reached emission levels of 13,000 rayleighs (R). Over two solar cycle of imaging observations have been made at Millstone Hill, and SAR arc brightness levels (excluding this event) averaged ~ 500 R. Simultaneous observations using the incoherent scatter radar (ISR), a DMSP satellite pass, the MSIS neutral atmosphere and SAR arc modeling using the Rees and Roble formalism succeeded in simulations of the observed emission. The reason for the unusual brightness was not the extreme temperatures achieved (and therefore heat conduction input), but the fact that the end of the plasmapause field line where the elevated Te values were measured did not occur in the ionospheric trough, but equatorward of it, thereby having far more ambient electrons to heat and subsequently collide with atomic oxygen. This unusual spatial geometry probably resulted from unusual convection patterns early in a superstorm scenario.
NASA Astrophysics Data System (ADS)
Yu, Y.; Jordanova, V. K.; McGranaghan, R. M.; Solomon, S. C.
2017-12-01
The ionospheric conductance, height-integrated electric conductivity, can regulate both the ionospheric electrodynamics and the magnetospheric dynamics because of its key role in determining the electric field within the coupled magnetosphere-ionosphere system. State-of-the-art global magnetosphere models commonly adopt empirical conductance calculators to obtain the auroral conductance. Such specification can bypass the complexity of the ionosphere-thermosphere chemistry but on the other hand breaks the self-consistent link within the coupled system. In this study, we couple a kinetic ring current model RAM-SCB-E that solves for anisotropic particle distributions with a two-stream electron transport code (GLOW) to more self-consistently compute the height-dependent electric conductivity, provided the auroral electron precipitation from the ring current model. Comparisons with the traditional empirical formula are carried out. It is found that the newly coupled modeling framework reveals smaller Hall and Pedersen conductance, resulting in a larger electric field. As a consequence, the subauroral polarization streams demonstrate a better agreement with observations from DMSP satellites. It is further found that the commonly assumed Maxwellian spectrum of the particle precipitation is not globally appropriate. Instead, a full precipitation spectrum resulted from wave particle interactions in the ring current accounts for a more comprehensive precipitation spectrum.
ERIC Educational Resources Information Center
Lonsdale, Helen C.
Because 16mm film programs for classroom use are expensive and distribution is unpredictable, the Satellite Technology Demonstration (STD) established a Materials Distribution Service (MDS) to transmit material via satellite to rural sites in the Rocky Mountains. The STD leased 300 programs from Encyclopedia Britannica Educational Corporation and…
NASA Astrophysics Data System (ADS)
Reddy, A.; Sonwalkar, V. S.; Huba, J. D.
2018-02-01
Knowledge of field-aligned electron and ion distributions is necessary for understanding the physical processes causing variations in field-aligned electron and ion densities. Using whistler mode sounding by Radio Plasma Imager/Imager for Magnetopause-to-Aurora Global Exploration (RPI/IMAGE), we determined the evolution of dayside electron and ion densities along L ˜ 2 and L ˜ 3 (90-4,000 km) during a 7 day (21-27 November 2005) geomagnetically quiet to moderately active period. Over this period the O+/H+ transition height was ˜880 ± 60 km and ˜1000 ± 100 km, respectively, at L ˜ 2 and L ˜ 3. The electron density varied in a complex manner; it was different at L ˜ 2 and L ˜ 3 and below and above the O+/H+ transition height. The measured electron and ion densities are consistent with those from Challenging Minisatellite Payload (CHAMP) and Defense Meteorological Satellite Program (DMSP) and other past measurements, but they deviated from bottomside sounding and International Reference Ionosphere (IRI) 2012 empirical model results. Using SAMI2 (Naval Research Laboratory (NRL) ionosphere model) with reasonably adjusted values of inputs (neutral densities, winds, electric fields, and photoelectron heating), we simulated the evolution of O+/H+ transition height and field-aligned electron and ion densities so that a fair agreement was obtained between the simulation results and observations. Simulation studies indicated that reduced neutral densities (H and/or O) with time limited O+-H charge exchange process. This reduction in neutral densities combined with changes in neutral winds and plasma temperature led to the observed variations in the electron and ion densities. The observation/simulation method presented here can be extended to investigate the role of neutral densities and composition, disturbed winds, and prompt penetration electric fields in the storm time ionosphere/plasmasphere dynamics.
Identification and observations of the plasma mantle at low altitude
DOE Office of Scientific and Technical Information (OSTI.GOV)
Newell, P.T.; Meng, Ching-I.; Sanchez, E.R.
1991-01-01
The direct injection of magnetosheath plasma into the cusp produces at low altitude a precipitation regime with an energy-latitude dispersion-the more poleward portion of which the authors herein term the cusp plume. An extensive survey of the Defense Meteorological Satellite Program (DMSP) F7 and F9 32 eV to 30 keV precipitating particle data shows that similar dispersive signatures exist over much of the dayside, just poleward of the auroral oval. Away from noon (or more precisely, anywhere not immediately poleward of the cusp) the fluxes are reduced by a factor of about 10 as compared to the cusp plume, butmore » other characteristics are quite similar. For example, the inferred temperatures and flow velocities, and the characteristic decline of energy and number flux with increasing latitude is essentially the same in a longitudinally broad ring of precipitation a few degrees thick in latitude over much of the dayside. They conclude that the field lines on which such precipitation occurs thread the magnetospheric plasma mantle over the entire longitudinally extended ring. Besides the location of occurence (i.e., immediately poleward of the dayside oval), the identification is based especially on the associated very soft ion spectra, which have densities from a few times 10{sup {minus}2} to a few times 10{sup {minus}1}/cm{sup 3}; on the temperature range, which is form from a few tens of eV up to about 200 eV; amd on the characteristic gradients with latitude. Further corroborating evidence that the precipitation is associated with field lines which thread the plasma mantle includes drift meter observations which show that regions so identified based on the particle data consistently lie on antisunward convecting field lines. The observations indicate that some dayside high-latitude auroral features just poleward of the auroral oval are embedded in the plasma mantle.« less
Recend advances of using VIIRS DNB for surface PM2.5 and fire monitoring
NASA Astrophysics Data System (ADS)
Wang, J.; Polivka, T. N.; Hyer, E. J.; Xu, X.; Ichoku, I.
2017-12-01
The launch of the Suomi National Polar-orbiting Partner- ship (S-NPP) satellite on 28 October 2011 has opened up unprecedented capabilities with the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument. With a heritage extending back over 40 years to the Defense Meteorological Satel- lite Program (DMSP) Sensor Aerospace Vehicle Electronics Package (SAP), first launched in 1970, Advanced Very High Resolution Radiometer (AVHRR, first launched 1978), and Moderate Resolution Imaging Spectroradiometer (MODIS, first launched in 1999), VIIRS boasts improved spatial resolution and a higher signal-to-noise ratio than these legacy sensors. In particular, at the spatial resolution of 750 m, the VIIRS' day-and-night band (DNB) can monitor the visible light reflected by the Earth and atmsophere in all conditions, from strong reflection of sun light by cloud to weak reflection of moon light by desert at night. While several studies have looked into the potential use of DNB for mapping city lights and for retrieving aerosol optical depth at night, there are still lots of learn about DNB. Here, we will present our recent work of using DNB together with other VIIRS data to improve detection of smaller and cooler fires, to characterize the smoldering vs. flamming phase of fires , and to derive surface PM2.5 at night. Quantiitve understanding of visible light trasnfer from surface to the top of atmospehre will be presented, along with the study to undertand the radiation of fires from visible to infrared spectrum. Varous case studies will be shown in which 30% more fire pixels were detected as comapred to tradiational infrared-mehod only. Cross validation of DNB-based regression model shows that the estimated surface PM2.5 concentration has nearly no bias and a linear correlation coefficient (R) of 0.67 with respect to the corresponding hourly observed surface PM2.5 concentration.
Hu, Zhiyong; Hu, Hongda; Huang, Yuxia
2018-08-01
Artificial lighting at night has becoming a new type of pollution posing an important anthropogenic environmental pressure on organisms. The objective of this research was to examine the potential association between nighttime artificial light pollution and nest densities of the three main sea turtle species along Florida beaches, including green turtles, loggerheads, and leatherbacks. Sea turtle survey data was obtained from the "Florida Statewide Nesting Beach Survey program". We used the new generation of satellite sensor "Visible Infrared Imaging Radiometer Suite (VIIRS)" (version 1 D/N Band) nighttime annual average radiance composite image data. We defined light pollution as artificial light brightness greater than 10% of the natural sky brightness above 45° of elevation (>1.14 × 10 -11 Wm -2 sr -1 ). We fitted a generalized linear model (GLM), a GLM with eigenvectors spatial filtering (GLM-ESF), and a generalized estimating equations (GEE) approach for each species to examine the potential correlation of nest density with light pollution. Our models are robust and reliable in terms of the ability to deal with data distribution and spatial autocorrelation (SA) issues violating model assumptions. All three models found that nest density is significantly negatively correlated with light pollution for each sea turtle species: the higher light pollution, the lower nest density. The two spatially extended models (GLM-ESF and GEE) show that light pollution influences nest density in a descending order from green turtles, to loggerheads, and then to leatherbacks. The research findings have an implication for sea turtle conservation policy and ordinance making. Near-coastal lights-out ordinances and other approaches to shield lights can protect sea turtles and their nests. The VIIRS DNB light data, having significant improvements over comparable data by its predecessor, the DMSP-OLS, shows promise for continued and improved research about ecological effects of artificial light pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.