Institution
Goddard Space Flight Center
Facility•Greenbelt, Maryland, United States•
About: Goddard Space Flight Center is a facility organization based out in Greenbelt, Maryland, United States. It is known for research contribution in the topics: Galaxy & Solar wind. The organization has 19058 authors who have published 63344 publications receiving 2786037 citations. The organization is also known as: GSFC & Space Flight Center.
Topics: Galaxy, Solar wind, Magnetosphere, Stars, Population
Papers published on a yearly basis
Papers
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TL;DR: The MSIS-86 empirical model of thermospheric temperature, density and composition as discussed by the authors uses new temperature and composition data from the Dynamics Explorer satellite to improve the representation of polar region morphology over that in theMSIS-83 model.
Abstract: The MSIS-86 empirical model of thermospheric temperature, density and composition uses new temperature and composition data from the Dynamics Explorer satellite to improve the representation of polar region morphology over that in the MSIS-83 model. Terms were added or changed to better represent seasonal variations in the polar regions under both quiet and magnetically disturbed conditions. Local time variations in the magnetic activity effect were added. In addition a new species, atomic nitrogen, was added to the previous list of N2, O2, He, O, H, and Ar covered by the model.
1,699 citations
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South Dakota State University1, Natural Resources Canada2, United States Geological Survey3, Boston University4, University of Idaho5, United States Department of Agriculture6, Goddard Space Flight Center7, University of Colorado Boulder8, University of Massachusetts Boston9, Rochester Institute of Technology10, University of California, Los Angeles11, United States Forest Service12, Agricultural Research Service13, Humboldt University of Berlin14, Desert Research Institute15, University of Maryland, College Park16, University of Nebraska–Lincoln17, Geoscience Australia18, Virginia Tech19
TL;DR: Landsat 8, a NASA and USGS collaboration, acquires global moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave, and thermal infrared as mentioned in this paper.
1,697 citations
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University of California, Los Angeles1, Institut d'Astrophysique de Paris2, University of Porto3, Columbia University4, Carnegie Institution for Science5, Johns Hopkins University6, California Institute of Technology7, Goddard Space Flight Center8, Yonsei University9, University of California, Berkeley10
TL;DR: In this article, the authors measured star formation rates (SFRs) of 50,000 optically selected galaxies in the local universe (z ≈ 0.1) by fitting the GALEX (ultraviolet) and SDSS photometry to a library of dustattenuated population synthesis models.
Abstract: We measure star formation rates (SFRs) of ≈50,000 optically selected galaxies in the local universe (z ≈ 0.1)—from gas-rich dwarfs to massive ellipticals. We obtain dust-corrected SFRs by fitting the GALEX (ultraviolet) and SDSS photometry to a library of dust-attenuated population synthesis models. For star-forming galaxies, our UV-based SFRs compare remarkably well with those from SDSS-measured emission lines (Hα). Deviations from perfect agreement are shown to be due to differences in the dust attenuation estimates. In contrast to Hα measurements, UV provides reliable SFRs for galaxies with weak Hα, and where Hα is contaminated with AGN emission (1/2 of the sample). Using full-SED SFRs, we calibrate a simple prescription that uses GALEX far- and near-UV magnitudes to produce dust-corrected SFRs for normal star-forming galaxies. The specific SFR is considered as a function of stellar mass for (1) star-forming galaxies with no AGNs, (2) those hosting an AGN, and (3) galaxies without Hα emission. We find that the three have distinct star formation histories, with AGNs lying intermediate between the star-forming and the quiescent galaxies. Star-forming galaxies without an AGN lie on a relatively narrow linear sequence. Remarkably, galaxies hosting a strong AGN appear to represent the massive continuation of this sequence. On the other hand, weak AGNs, while also massive, have lower SFRs, sometimes extending to the realm of quiescent galaxies. We propose an evolutionary sequence for massive galaxies that smoothly connects normal star-forming galaxies to quiescent galaxies via strong and weak AGNs. We confirm that some galaxies with no Hα show signs of star formation in the UV. We derive a cosmic star formation density at z = 0.1 with significantly smaller total error than previous measurements.
1,694 citations
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TL;DR: In this paper, the authors describe the objectives of community efforts in improving the Noah land surface model (LSM), documents, through mathematical formulations, the augmented conceptual realism in biophysical and hydrological processes, and introduces a framework for multiple options to parameterize selected processes (Noah•MP).
Abstract: [1] This first paper of the two‐part series describes the objectives of the community efforts in improving the Noah land surface model (LSM), documents, through mathematical formulations, the augmented conceptual realism in biophysical and hydrological processes, and introduces a framework for multiple options to parameterize selected processes (Noah‐MP). The Noah‐MP’s performance is evaluated at various local sites using high temporal frequency data sets, and results show the advantages of using multiple optional schemes to interpret the differences in modeling simulations. The second paper focuses on ensemble evaluations with long‐term regional (basin) and global scale data sets. The enhanced conceptual realism includes (1) the vegetation canopy energy balance, (2) the layered snowpack, (3) frozen soil and infiltration, (4) soil moisture‐groundwater interaction and related runoff production, and (5) vegetation phenology. Sample local‐scale validations are conducted over the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) site, the W3 catchment of Sleepers River, Vermont, and a French snow observation site. Noah‐MP shows apparent improvements in reproducing surface fluxes, skin temperature over dry periods, snow water equivalent (SWE), snow depth, and runoff over Noah LSM version 3.0. Noah‐MP improves the SWE simulations due to more accurate simulations of the diurnal variations of the snow skin temperature, which is critical for computing available energy for melting. Noah‐MP also improves the simulation of runoff peaks and timing by introducing a more permeable frozen soil and more accurate simulation of snowmelt. We also demonstrate that Noah‐MP is an effective research tool by which modeling results for a given process can be interpreted through multiple optional parameterization schemes in the same model framework.
1,682 citations
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British Antarctic Survey1, University of Bristol2, Columbia University3, National Institute of Geophysics and Volcanology4, University of Aberdeen5, University of Texas at Austin6, Centro de Estudios Científicos7, Université libre de Bruxelles8, University of Washington9, Swansea University10, Institute for Geosciences and Natural Resources11, Technical University of Denmark12, National Institute of Polar Research13, California Institute of Technology14, University of Kansas15, Stockholm University16, St. Olaf College17, Norwegian Polar Institute18, Wallops Flight Facility19, University of Canterbury20, University of Oslo21, University of California, Santa Barbara22, University of California, Irvine23, University of York24, Australian Antarctic Division25, Newcastle University26, Goddard Space Flight Center27, Polar Research Institute of China28
TL;DR: Bedmap2 as discussed by the authors is a suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1.
Abstract: We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1) in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved data-coverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3) and its potential contribution to sea-level rise (58 m) are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6% greater, the mean depth of the bed beneath the grounded ice sheet is 72 m lower and the area of ice sheet grounded on bed below sea level is increased by 10%. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets.
1,678 citations
Authors
Showing all 19247 results
Name | H-index | Papers | Citations |
---|---|---|---|
Anton M. Koekemoer | 168 | 1127 | 106796 |
Alexander S. Szalay | 166 | 936 | 145745 |
David W. Johnson | 160 | 2714 | 140778 |
Donald G. York | 160 | 681 | 156579 |
Takeo Kanade | 147 | 799 | 103237 |
Gillian R. Knapp | 145 | 460 | 121477 |
Olaf Reimer | 144 | 716 | 74359 |
R. A. Sunyaev | 141 | 848 | 107966 |
Christopher T. Russell | 137 | 2378 | 97268 |
Hui Li | 135 | 2982 | 105903 |
Neil Gehrels | 134 | 727 | 80804 |
Christopher B. Field | 133 | 408 | 88930 |
Igor V. Moskalenko | 132 | 542 | 58182 |
William T. Reach | 131 | 535 | 90496 |
Adam Burrows | 130 | 623 | 55483 |