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Louis G Smith - One of the best experts on this subject based on the ideXlab platform.
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The Next Decade of Earth Radiation Budget Measurement
2015Co-Authors: Louis G Smith, Kory James Priestley, Bruce A WielickiAbstract:Measurements of the Earth’s Radiation Budget are necessary for understanding our climate and for monitoring its changes. Clouds and Earth Radiant Energy System (CERES) scanning radiometers have operated on the Terra spacecraft since 2000 and on the Aqua spacecraft since 2002. A CERES instrument, Flight Model 5, is now scheduled to fly on the NPOESS Preparatory Project spacecraft, with launch readiness in 2010. FM-5 has been vacuum-tested, calibrated and shipped for integration to the NPP spacecraft. Another CERES instrument, Flight Model 6, will be assembled and will fly on the NPOESS C1 platform, with launch readiness in 2013. The next step in the continuation of Earth Radiation Budget measurements is the development of a successor to the CERES instruments. The first model of that instrument is planned for flight on the NPOESS C3 platform with launch readiness in 2018. It is planned that each of these missions will overlap so that the climate data record of Radiation Budget will be seamless. By the flight of the NPP, the CERES and Earth Radiation Budget Experiment records will span a quarter of a century, enabling studies of climate variations with periods of decades
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diurnal variations of albedo retrieved from Earth Radiation Budget experiment measurements
Journal of Applied Meteorology and Climatology, 2014Co-Authors: David A Rutan, Louis G Smith, Takmeng WongAbstract:AbstractFive years of measurements from the Earth Radiation Budget Satellite (ERBS) have been analyzed to define the diurnal cycle of albedo from 55°N to 55°S. The ERBS precesses through all local times every 72 days so as to provide data regarding the diurnal cycles for Earth Radiation. Albedo together with insolation at the top of the atmosphere is used to compute the heating of the Earth–atmosphere system; thus its diurnal cycle is important in the energetics of the climate system. A principal component (PC) analysis of the diurnal variation of top-of-atmosphere albedo using these data is presented. The analysis is done separately for ocean and land because of the marked differences of cloud behavior over ocean and over land. For ocean, 90%–92% of the variance in the diurnal cycle is described by a single component; for land, the first PC accounts for 83%–89% of the variance. Some of the variation is due to the increase of albedo with increasing solar zenith angle, which is taken into account in the ER...
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unfiltering Earth Radiation Budget experiment erbe scanner radiances using the ceres algorithm and its evaluation with nonscanner observations
Journal of Atmospheric and Oceanic Technology, 2014Co-Authors: Alok K Shrestha, Louis G Smith, Patrick Minnis, Takmeng Wong, David A Rutan, Seiji Kato, Walter F Miller, Fred G Rose, Kristopher M Bedka, J R FernandezAbstract:AbstractThe NOAA-9 Earth Radiation Budget Experiment (ERBE) scanner measured broadband shortwave, longwave, and total radiances from February 1985 through January 1987. These scanner radiances are reprocessed using the more recent Clouds and the Earth’s Radiant Energy System (CERES) unfiltering algorithm. The scene information, including cloud properties, required for reprocessing is derived using Advanced Very High Resolution Radiometer (AVHRR) data on board NOAA-9, while no imager data were used in the original ERBE unfiltering. The reprocessing increases the NOAA-9 ERBE scanner unfiltered longwave radiances by 1.4%–2.0% during daytime and 0.2%–0.3% during nighttime relative to those derived from the ERBE unfiltering algorithm. Similarly, the scanner unfiltered shortwave radiances increase by ~1% for clear ocean and land and decrease for all-sky ocean, land, and snow/ice by ~1%. The resulting NOAA-9 ERBE scanner unfiltered radiances are then compared with NOAA-9 nonscanner irradiances by integrating the...
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the annual cycle of Earth Radiation Budget from clouds and the Earth s radiant energy system ceres data
Journal of Applied Meteorology and Climatology, 2011Co-Authors: Pamela E Mlynczak, Louis G Smith, David R DoellingAbstract:AbstractThe seasonal cycle of the Earth Radiation Budget is investigated by use of data from the Clouds and the Earth’s Radiant Energy System (CERES). Monthly mean maps of reflected solar flux and Earth-emitted flux on a 1° equal-angle grid are used for the study. The seasonal cycles of absorbed solar Radiation (ASR), outgoing longwave Radiation (OLR), and net Radiation are described by use of principal components for the time variations, for which the corresponding geographic variations are the empirical orthogonal functions. Earth’s surface is partitioned into land and ocean for the analysis. The first principal component describes more than 95% of the variance in the seasonal cycle of ASR and the net Radiation fluxes and nearly 90% of the variance of OLR over land. Because one term can express so much of the variance, principal component analysis is very useful to describe these seasonal cycles. The annual cycles of ASR are about 100 W m−2 over land and ocean, but the amplitudes of OLR are about 27 W m...
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radiometric performance of the ceres Earth Radiation Budget climate record sensors on the eos aqua and terra spacecraft through april 2007
Journal of Atmospheric and Oceanic Technology, 2011Co-Authors: Kory James Priestley, Louis G Smith, Denise Cooper, Dale R Walikainen, Phillip C Hess, Peter Z Szewczyk, Susan Thomas, Robert H WilsonAbstract:Abstract The Clouds and the Earth’s Radiant Energy System (CERES) flight models 1 through 4 instruments were launched aboard NASA’s Earth Observing System (EOS) Terra and Aqua spacecraft into 705-km sun-synchronous orbits with 10:30 p.m. and 1:30 a.m. local time equatorial crossing times. With these instruments CERES provides state-of-the-art observations and products related to the Earth’s Radiation Budget at the top of the atmosphere (TOA). The archived CERES science data products consist of geolocated and calibrated instantaneous filtered and unfiltered radiances through temporally and spatially averaged TOA, surface, and atmospheric fluxes. CERES-filtered radiance measurements cover three spectral bands: shortwave (0.3–5 μm), total (0.3>100 μm), and an atmospheric window channel (8–12 μm). CERES climate data products realize a factor of 2–4 improvement in calibration accuracy and stability over the previotus Earth Radiation Budget Experiment (ERBE) products. To achieve this improvement there are three...
Takmeng Wong - One of the best experts on this subject based on the ideXlab platform.
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diurnal variations of albedo retrieved from Earth Radiation Budget experiment measurements
Journal of Applied Meteorology and Climatology, 2014Co-Authors: David A Rutan, Louis G Smith, Takmeng WongAbstract:AbstractFive years of measurements from the Earth Radiation Budget Satellite (ERBS) have been analyzed to define the diurnal cycle of albedo from 55°N to 55°S. The ERBS precesses through all local times every 72 days so as to provide data regarding the diurnal cycles for Earth Radiation. Albedo together with insolation at the top of the atmosphere is used to compute the heating of the Earth–atmosphere system; thus its diurnal cycle is important in the energetics of the climate system. A principal component (PC) analysis of the diurnal variation of top-of-atmosphere albedo using these data is presented. The analysis is done separately for ocean and land because of the marked differences of cloud behavior over ocean and over land. For ocean, 90%–92% of the variance in the diurnal cycle is described by a single component; for land, the first PC accounts for 83%–89% of the variance. Some of the variation is due to the increase of albedo with increasing solar zenith angle, which is taken into account in the ER...
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unfiltering Earth Radiation Budget experiment erbe scanner radiances using the ceres algorithm and its evaluation with nonscanner observations
Journal of Atmospheric and Oceanic Technology, 2014Co-Authors: Alok K Shrestha, Louis G Smith, Patrick Minnis, Takmeng Wong, David A Rutan, Seiji Kato, Walter F Miller, Fred G Rose, Kristopher M Bedka, J R FernandezAbstract:AbstractThe NOAA-9 Earth Radiation Budget Experiment (ERBE) scanner measured broadband shortwave, longwave, and total radiances from February 1985 through January 1987. These scanner radiances are reprocessed using the more recent Clouds and the Earth’s Radiant Energy System (CERES) unfiltering algorithm. The scene information, including cloud properties, required for reprocessing is derived using Advanced Very High Resolution Radiometer (AVHRR) data on board NOAA-9, while no imager data were used in the original ERBE unfiltering. The reprocessing increases the NOAA-9 ERBE scanner unfiltered longwave radiances by 1.4%–2.0% during daytime and 0.2%–0.3% during nighttime relative to those derived from the ERBE unfiltering algorithm. Similarly, the scanner unfiltered shortwave radiances increase by ~1% for clear ocean and land and decrease for all-sky ocean, land, and snow/ice by ~1%. The resulting NOAA-9 ERBE scanner unfiltered radiances are then compared with NOAA-9 nonscanner irradiances by integrating the...
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1999 2003 shortwave characterizations of Earth Radiation Budget satellite erbs Earth Radiation Budget experiment erbe broadband active cavity radiometer sensors
Proceedings of SPIE, 2008Co-Authors: Robert B Lee, G L Smith, Takmeng Wong, Kathryn A BushAbstract:From October 1984 through May 2005, the NASA Earth Radiation Budget Satellite (ERBS/ )/Earth Radiation Budget Experiment (ERBE)ERBE nonscanning active cavity radiometers (ACR) were used to monitor long-term changes in the Earth Radiation Budget components of the incoming total solar irradiance (TSI), Earth-reflected TSI, and Earth-emitted outgoing longwave Radiation (OLR). From September1984 through September 1999, using on-board calibration systems, the ERBS/ERBE ACR sensor response changes, in gains and offsets, were determined from on-orbit calibration sources and from direct observations of the incoming TSI through calibration solar ports at measurement precision levels approaching 0.5 W/sq m , at satellite altitudes. On October 6, 1999, the onboard radiometer calibration system elevation drive failed. Thereafter, special spacecraft maneuvers were performed to observe cold space and the sun in order to define the post-September 1999 geometry of the radiometer measurements, and to determine the October 1999-September 2003 ERBS sensor response changes. Analyses of these special solar and cold space observations indicate that the radiometers were pointing approximately 16 degrees away from the spacecraft nadir and on the anti-solar side of the spacecraft. The special observations indicated that the radiometers responses were stable at precision levels approaching 0.5 W/sq m . In this paper, the measurement geometry determinations and the determinations of the radiometers gain and offset are presented, which will permit the accurate processing of the October 1999 through September 2003 ERBE data products at satellite and top-of-the-atmosphere altitudes.
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:Abstract This paper gives an update on the observed decadal variability of the Earth Radiation Budget (ERB) using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20°N to 20°S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1, −2.4, and −0.7 to 1.6, −3.0, and 1.4 W m−2, respectively. In addition, a small SW instrument drift over the 15-yr period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner-observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7, −2.1, and 1.4 W m−2, respectivel...
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:This paper gives an update on the observed decadal variability of Earth Radiation Budget using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20N to 20S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1/-2.4/-0.7 to 1.6/-3.0/1.4 Wm(sup -2) respectively. In addition, a small SW instrument drift over the 15-year period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7/-2.1/1.4 Wm(sup -2), respectively, which are similar to the observed decadal changes in the HIRS Pathfinder OLR and the ISCCP FD record; but disagree with the AVHRR Pathfinder ERB record. Furthermore, the observed interannual variability of near-global ERBS WFOV Edition3_Rev1 net Radiation is found to be remarkably consistent with the latest ocean heat storage record for the overlapping time period of 1993 to 1999. Both data sets show variations of roughly 1.5 Wm(sup -2) in planetary net heat balance during the 1990s.
Kathryn A Bush - One of the best experts on this subject based on the ideXlab platform.
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1999 2003 shortwave characterizations of Earth Radiation Budget satellite erbs Earth Radiation Budget experiment erbe broadband active cavity radiometer sensors
Proceedings of SPIE, 2008Co-Authors: Robert B Lee, G L Smith, Takmeng Wong, Kathryn A BushAbstract:From October 1984 through May 2005, the NASA Earth Radiation Budget Satellite (ERBS/ )/Earth Radiation Budget Experiment (ERBE)ERBE nonscanning active cavity radiometers (ACR) were used to monitor long-term changes in the Earth Radiation Budget components of the incoming total solar irradiance (TSI), Earth-reflected TSI, and Earth-emitted outgoing longwave Radiation (OLR). From September1984 through September 1999, using on-board calibration systems, the ERBS/ERBE ACR sensor response changes, in gains and offsets, were determined from on-orbit calibration sources and from direct observations of the incoming TSI through calibration solar ports at measurement precision levels approaching 0.5 W/sq m , at satellite altitudes. On October 6, 1999, the onboard radiometer calibration system elevation drive failed. Thereafter, special spacecraft maneuvers were performed to observe cold space and the sun in order to define the post-September 1999 geometry of the radiometer measurements, and to determine the October 1999-September 2003 ERBS sensor response changes. Analyses of these special solar and cold space observations indicate that the radiometers were pointing approximately 16 degrees away from the spacecraft nadir and on the anti-solar side of the spacecraft. The special observations indicated that the radiometers responses were stable at precision levels approaching 0.5 W/sq m . In this paper, the measurement geometry determinations and the determinations of the radiometers gain and offset are presented, which will permit the accurate processing of the October 1999 through September 2003 ERBE data products at satellite and top-of-the-atmosphere altitudes.
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:Abstract This paper gives an update on the observed decadal variability of the Earth Radiation Budget (ERB) using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20°N to 20°S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1, −2.4, and −0.7 to 1.6, −3.0, and 1.4 W m−2, respectively. In addition, a small SW instrument drift over the 15-yr period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner-observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7, −2.1, and 1.4 W m−2, respectivel...
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:This paper gives an update on the observed decadal variability of Earth Radiation Budget using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20N to 20S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1/-2.4/-0.7 to 1.6/-3.0/1.4 Wm(sup -2) respectively. In addition, a small SW instrument drift over the 15-year period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7/-2.1/1.4 Wm(sup -2), respectively, which are similar to the observed decadal changes in the HIRS Pathfinder OLR and the ISCCP FD record; but disagree with the AVHRR Pathfinder ERB record. Furthermore, the observed interannual variability of near-global ERBS WFOV Edition3_Rev1 net Radiation is found to be remarkably consistent with the latest ocean heat storage record for the overlapping time period of 1993 to 1999. Both data sets show variations of roughly 1.5 Wm(sup -2) in planetary net heat balance during the 1990s.
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on orbit calibrations of the erbe active cavity radiometers on the Earth Radiation Budget satellite erbs 1984 2002
Remote Sensing, 2004Co-Authors: Robert Benjamin Lee, G L Smith, Kathryn A Bush, Jack Paden, Dhirendra K Pandey, Robert S Wilson, Kory J PriestleyAbstract:From October 1984 until September 30, 1999, on-orbit, the Earth Radiation Budget Satellite (ERBS)/Earth Radiation Budget Experiment (ERBE) nonscanning, active cavity radiometers (ACR) were calibrated using observations of the incoming total solar irradiance, and of reference irradiances from an on-board tungsten lamp and blackbodies in order to determine drifts and shifts in the ACR responses. On October 7, 1999, the ERBE elevation drive system failed near the Earth nadir viewing configuration. Thereafter, the elevation failure prevented observations of the on-board, built-in calibration systems. On July 23, August 8, and December 10, 2002, the ERBS was pitched 180 degrees to observe cold space, representative of a 3 Kelvin blackbody, in order to determine the ACR's zero-irradiance offsets. On December 4, 2002, the ERBS was pitched 180 degrees away from the Earth in order to observe the sun, and to determine the ACR's gains. In this paper, the 2002, 180-degree pitch calibrations are compared with the earlier 1984-1999, calibrations which were obtained using the on-orbit, built-in calibration systems. In addition, the 2002 calibrations are compared with earlier scheduled November 21, 1984, and October 20, 1985, 180-degree pitch calibrations, as well as with deep space calibrations from unscheduled July 2, 1987, January 16, 1999, and November 16, 2000, ERBS spacecraft tumbles. The 2002 ACR offsets were found to be consistent with 1984-2000 offsets at the 1.0 Wm -2 . 1984-1999, ERBE top-of-the-atmosphere (TOA), and satellite altitude (SA) Earth irradiances are presented. Analyses of the TOA ERBE Earth irradiances indicate that the TOA irradiance time series exhibited a 1.7 Wm -2 increase as a result of 1988-1992, and 1998-2002 satellite altitudinal decreases during periods of maximum solar magnetic activity.
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on orbit radiometric calibrations of the Earth Radiation Budget experiment erbe active cavity radiometers on the Earth Radiation Budget satellite erbs
International Symposium on Optical Science and Technology, 2002Co-Authors: Robert Benjamin Lee, Kathryn A Bush, Jack Paden, Dhirendra K Pandey, Robert S Wilson, Louis G SmithAbstract:Between November 1984 and July 2002, the Earth Radiation Budget Satellite (ERBS)/Earth Radiation Budget Experiment (ERBE) nonscanning, active cavity radiometers (ACR) were used to measure incoming total solar irradiance, Earth-reflected solar irradiance, and Earth-emitted outgoing longwave Radiation (OLR) irradiance. The ERBE shortwave wide field-of view (SWFOV) and toal wide field-of-view (TWFOV) ACR's measured irradiances from the entire Earth disc in the shortwave (0.2-5.0 μm) and total (0.2-100 μm) broadband spectral regions. On-orbit, the ACR's observations of the incoming total solar irradiance, and of reference irradiance from on-board tungsten lamp and blackbodies were used to determine drifts and shifts in the ACR responses/gains. In the cases of the SWFOV ACR, its response/gain changed as much as 8.8% while the TWFOV response was stable at levels better than 0.1%. The precise measurements of gain and offset variations have permitted the generations of ERBE level 1 data products [Earth-reflected solar (≈240 Wm -2 )and Earth-emitted (≈100 Wm -2 ) irradiances] at the precision levels better than 0.3 Wm -2 . In this paper, the ACR radiometric on-orbit calibration approaches and systems are outlined.
Josh K Willis - One of the best experts on this subject based on the ideXlab platform.
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:Abstract This paper gives an update on the observed decadal variability of the Earth Radiation Budget (ERB) using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20°N to 20°S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1, −2.4, and −0.7 to 1.6, −3.0, and 1.4 W m−2, respectively. In addition, a small SW instrument drift over the 15-yr period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner-observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7, −2.1, and 1.4 W m−2, respectivel...
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:This paper gives an update on the observed decadal variability of Earth Radiation Budget using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20N to 20S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1/-2.4/-0.7 to 1.6/-3.0/1.4 Wm(sup -2) respectively. In addition, a small SW instrument drift over the 15-year period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7/-2.1/1.4 Wm(sup -2), respectively, which are similar to the observed decadal changes in the HIRS Pathfinder OLR and the ISCCP FD record; but disagree with the AVHRR Pathfinder ERB record. Furthermore, the observed interannual variability of near-global ERBS WFOV Edition3_Rev1 net Radiation is found to be remarkably consistent with the latest ocean heat storage record for the overlapping time period of 1993 to 1999. Both data sets show variations of roughly 1.5 Wm(sup -2) in planetary net heat balance during the 1990s.
Bruce A Wielicki - One of the best experts on this subject based on the ideXlab platform.
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The Next Decade of Earth Radiation Budget Measurement
2015Co-Authors: Louis G Smith, Kory James Priestley, Bruce A WielickiAbstract:Measurements of the Earth’s Radiation Budget are necessary for understanding our climate and for monitoring its changes. Clouds and Earth Radiant Energy System (CERES) scanning radiometers have operated on the Terra spacecraft since 2000 and on the Aqua spacecraft since 2002. A CERES instrument, Flight Model 5, is now scheduled to fly on the NPOESS Preparatory Project spacecraft, with launch readiness in 2010. FM-5 has been vacuum-tested, calibrated and shipped for integration to the NPP spacecraft. Another CERES instrument, Flight Model 6, will be assembled and will fly on the NPOESS C1 platform, with launch readiness in 2013. The next step in the continuation of Earth Radiation Budget measurements is the development of a successor to the CERES instruments. The first model of that instrument is planned for flight on the NPOESS C3 platform with launch readiness in 2018. It is planned that each of these missions will overlap so that the climate data record of Radiation Budget will be seamless. By the flight of the NPP, the CERES and Earth Radiation Budget Experiment records will span a quarter of a century, enabling studies of climate variations with periods of decades
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ceres fm 5 on the npp spacecraft continuing the Earth Radiation Budget climate data record
Sensors Systems and Next-Generation Satellites XIII, 2009Co-Authors: Kory J Priestley, Louis G Smith, Bruce A Wielicki, Norman G LoebAbstract:The Clouds and the Earth's Radiant Energy System (CERES) Flight Model-5 (FM-5) instrument will fly on the NPOESS Preparatory Project (NPP) spacecraft, which has a launch-readiness date in June, 2010. This mission will continue the critical Earth Radiation Budget Climate Data Record (CDR) begun by the Earth Radiation Budget Experiment (ERBE) instruments in the mid 1980 s and continued by the CERES instruments currently flying on the EOS Terra and Aqua spacecraft. Ground calibrations have been completed for FM-5 and the instrument has been delivered for integration to the spacecraft Rigorous pre-launch ground calibration is performed on each CERES unit to achieve an accuracy goal of 1% for SW flux and 0.5% for outgoing LW flux. Any ground to flight or in-flight changes in radiometer response is monitored using a protocol employing both onboard and vicarious calibration sources and experiments. Recent studies of FM-1 through FM-4 data have shown that the SW response of space based broadband radiometers can change dramatically due to optical contamination. With these changes having most impact on optical response to blue-to UV radiance, where tungsten lamps are largely devoid of output, such changes are hard to monitor accurately using existing on-board sources. This paper outlines the lessons learned on the existing CERES sensors from 30+ years of flight experience and presents a radiometric protocol to be implemented on the FM-5 instrument to ensure that its performance exceeds the stated calibration and stability goals.
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:Abstract This paper gives an update on the observed decadal variability of the Earth Radiation Budget (ERB) using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20°N to 20°S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1, −2.4, and −0.7 to 1.6, −3.0, and 1.4 W m−2, respectively. In addition, a small SW instrument drift over the 15-yr period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner-observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7, −2.1, and 1.4 W m−2, respectivel...
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reexamination of the observed decadal variability of the Earth Radiation Budget using altitude corrected erbe erbs nonscanner wfov data
Journal of Climate, 2006Co-Authors: Takmeng Wong, Louis G Smith, Bruce A Wielicki, Robert Benjamin Lee, Kathryn A Bush, Josh K WillisAbstract:This paper gives an update on the observed decadal variability of Earth Radiation Budget using the latest altitude-corrected Earth Radiation Budget Experiment (ERBE)/Earth Radiation Budget Satellite (ERBS) Nonscanner Wide Field of View (WFOV) instrument Edition3 dataset. The effects of the altitude correction are to modify the original reported decadal changes in tropical mean (20N to 20S) longwave (LW), shortwave (SW), and net Radiation between the 1980s and the 1990s from 3.1/-2.4/-0.7 to 1.6/-3.0/1.4 Wm(sup -2) respectively. In addition, a small SW instrument drift over the 15-year period was discovered during the validation of the WFOV Edition3 dataset. A correction was developed and applied to the Edition3 dataset at the data user level to produce the WFOV Edition3_Rev1 dataset. With this final correction, the ERBS Nonscanner observed decadal changes in tropical mean LW, SW, and net Radiation between the 1980s and the 1990s now stand at 0.7/-2.1/1.4 Wm(sup -2), respectively, which are similar to the observed decadal changes in the HIRS Pathfinder OLR and the ISCCP FD record; but disagree with the AVHRR Pathfinder ERB record. Furthermore, the observed interannual variability of near-global ERBS WFOV Edition3_Rev1 net Radiation is found to be remarkably consistent with the latest ocean heat storage record for the overlapping time period of 1993 to 1999. Both data sets show variations of roughly 1.5 Wm(sup -2) in planetary net heat balance during the 1990s.
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defining top of the atmosphere flux reference level for Earth Radiation Budget studies
Journal of Climate, 2002Co-Authors: Norman G Loeb, Seiji Kato, Bruce A WielickiAbstract:To estimate the Earth's Radiation Budget at the top of the atmosphere (TOA) from satellite-measured radiances, it is necessary to account for the finite geometry of the Earth and recognize that the Earth is a solid body surrounded by a translucent atmosphere of finite thickness that attenuates solar Radiation differently at different heights. As a result, in order to account for all of the reflected solar and emitted thermal Radiation from the planet by direct integration of satellite-measured radiances, the measurement viewing geometry must be defined at a reference level well above the Earth s surface (e.g., 100 km). This ensures that all Radiation contributions, including Radiation escaping the planet along slant paths above the Earth s tangent point, are accounted for. By using a field-of- view (FOV) reference level that is too low (such as the surface reference level), TOA fluxes for most scene types are systematically underestimated by 1-2 W/sq m. In addition, since TOA flux represents a flow of radiant energy per unit area, and varies with distance from the Earth according to the inverse-square law, a reference level is also needed to define satellite-based TOA fluxes. From theoretical radiative transfer calculations using a model that accounts for spherical geometry, the optimal reference level for defining TOA fluxes in Radiation Budget studies for the Earth is estimated to be approximately 20 km. At this reference level, there is no need to explicitly account for horizontal transmission of solar Radiation through the atmosphere in the Earth Radiation Budget calculation. In this context, therefore, the 20-km reference level corresponds to the effective radiative top of atmosphere for the planet. Although the optimal flux reference level depends slightly on scene type due to differences in effective transmission of solar Radiation with cloud height, the difference in flux caused by neglecting the scene-type dependence is less than 0.1%. If an inappropriate TOA flux reference level is used to define satellite TOA fluxes, and horizontal transmission of solar Radiation through the planet is not accounted for in the Radiation Budget equation, systematic errors in net flux of up to 8 W/sq m can result. Since climate models generally use a plane-parallel model approximation to estimate TOA fluxes and the Earth Radiation Budget, they implicitly assume zero horizontal transmission of solar Radiation in the Radiation Budget equation, and do not need to specify a flux reference level. By defining satellite-based TOA flux estimates at a 20-km flux reference level, comparisons with plane-parallel climate model calculations are simplified since there is no need to explicitly correct plane-parallel climate model fluxes for horizontal transmission of solar Radiation through a finite Earth.
