Johnson, G. C.; Lumpkin, R.; Alexander, Michael A.; Amaya, Dillon J.; Beckley, Brian; Boyer, Tim; Bringas, Francis; Carter, Brendan R.; Cetinić, Ivona; Chambers, Don P.; Chan, Duo; Cheng, Lijing; Dong, Shenfu; Elipot, Shane; Feely, Richard A.; Franz, Bryan A.; Fu, Yao; Gao, Meng; Garg, Jay; Giglio, Donata; Gilson, John; Goes, Marlos; Graham, Garrett; Hamlington, Benjamin D.; Hobbs, Will; Hu, Zeng-Zhen; Huang, Boyin; Ishii, Masayoshi; Jacox, Michael G.; Jersild, Annika; Jevrejeva, Svetlana; Johns, William E.; Killick, Rachel E.; Kuusela, Mikael; Landschützer, Peter; Leuliette, Eric; Liu, Chao; Locarnini, Ricardo; Lozier, Susan M.; Lyman, John M.; Merrifield, Mark A.; Mishonov, Alexey; Mitchum, Gary T.; Moat, Ben I.; Nerem, R. Steven; Oe, Mitsuho; Perez, Renellys C.; Pita, Ivenis; Purkey, Sarah G.; Reagan, James; Sato, Kanako; Schmid, Claudia; Smeed, David A.; Smith, Ryan H.; Stackhouse, Paul W.; Sukianto, Thea; Sweet, William; Thompson, Philip R.; Triñanes, Joaquin A.; Volkov, Denis L.; Wanninkhof, Rik; Weller, Robert A.; Westberry, Toby K.; Widlansky, Matthew J.; Willis, Josh K.; Yin, Xungang; Yu, Lisan; Zhang, Huai-minJohnson, G. C., R. Lumpkin, M. A. Alexander, D. J. Amaya, B. Beckley, T. Boyer, F. Bringas, B. R. Carter, I. Cetinić, D. P. Chambers, D. Chan, L. Cheng, S. Dong, S. Elipot, R. A. Feely, B. A. Franz, Y. Fu, M. Gao, J. Garg, D. Giglio, J. Gilson, M. Goes, G. Graham, B. D. Hamlington, W. Hobbs, Z. Hu, B. Huang, M. Ishii, M. G. Jacox, A. Jersild, S. Jevrejeva, W. E. Johns, R. E. Killick, M. Kuusela, P. Landschützer, E. Leuliette, C. Liu, R. Locarnini, S. M. Lozier, J. M. Lyman, M. A. Merrifield, A. Mishonov, G. T. Mitchum, B. I. Moat, R. S. Nerem, M. Oe, R. C. Perez, I. Pita, S. G. Purkey, J. Reagan, K. Sato, C. Schmid, D. A. Smeed, R. H. Smith, P. W. Stackhouse, T. Sukianto, W. Sweet, P. R. Thompson, J. A. Triñanes, D. L. Volkov, R. Wanninkhof, R. A. Weller, T. K. Westberry, M. J. Widlansky, J. K. Willis, X. Yin, L. Yu, H. Zhang, 2024: Global Oceans. doi: 10.1175/BAMS-D-24-0100.1. "Global Oceans" published on 22 Aug 2024 by American Meteorological Society.
Zhang, Taiping; Stackhouse, Paul W.; Macpherson, Bradley; Colleen Mikovitz, J.Zhang, T., P. W. Stackhouse, B. Macpherson, J. Colleen Mikovitz, 2024: A CERES-based dataset of hourly DNI, DHI and global tilted irradiance (GTI) on equatorward tilted surfaces: Derivation and comparison with the ground-based BSRN data. Solar Energy, 274, 112538. doi: 10.1016/j.solener.2024.112538. The NASA CERES SYN1deg(Ed4.1) satellite-based products include hourly global horizontal irradiance (GHI), diffuse horizontal irradiance (DHI) and direct horizontal irradiance (DirHI) as well as hourly solar zenith angle (SZA), and the direct normal irradiance (DNI) can thus be calculated by dividing the DirHI by cos(SZA). The spatial resolution of the dataset is 1° latitude by 1° longitude, and the time span is from March 2000 to near present (October 2023 as of this writing). While the GHI of the dataset agrees well with the ground-based Baseline Surface Radiation Network (BSRN) data, the DHI and DirHI, and thus DNI, show appreciable biases against the BSRN data. Nevertheless, the uncertainty of the DHI and DNI, as exhibited in the standard deviations of their differences from the BSRN data, are smaller than results from the DirIndex model, a global-to-beam model, applied to the CERES data, albeit the model is one of the two best out of 140 models according to a study. This means that the original CERES hourly DNI, though biased, renders the spatiotemporal variability better than does the DirIndex model. For this reason, we decided to perform a bias correction on the hourly DHI and DNI. With the corrected hourly DHI and DNI, we are able to use the isotropic model to calculate the global tilted irradiance (GTI) and the global tracker irradiance (GTrI) on an hourly basis. The BSRN DHI and DNI, on the other hand, are available on near-instantaneous time scales (1-, 2-, 3, or 5-minute intervals) and thus are more conducive to the isotropic model, and for the first time, we use the BSRN data to validate the GTI and GTrI, as opposed to GHI and DHI that have previously been used for validation purpose. For comparison and validation, we also use the monthly-mean-based LJCR method, an independent method as used by RETScreen®, which requires monthly mean GHI and DHI, to directly calculate the monthly mean DNI, GTI and, to extend the model, GTrI, and the results agree well with the BSRN data, which proves the LJCR method itself and corroborates the corrected DHI and DNI as well as the derived GTI and GTrI. The monthly mean DHI and DNI from the Whitlock Method, also monthly-mean-based, are evaluated as well, and we find that minor modification can dramatically improve the method. BSRN; POWER; CERES SYN1deg; DHI; DNI; Global tilted irradiance; GTI
Johnson, G. C.; Lumpkin, R.; Atkinson, C.; Biló, Tiago; Boyer, Tim; Bringas, Francis; Carter, Brendan R.; Cetinić, Ivona; Chambers, Don P.; Chan, Duo; Cheng, Lijing; Chomiak, Leah; Cronin, Meghan F.; Dong, Shenfu; Feely, Richard A.; Franz, Bryan A.; Gao, Meng; Garg, Jay; Gilson, John; Goni, Gustavo; Hamlington, Benjamin D.; Hobbs, W.; Hu, Zeng-Zhen; Huang, Boyin; Ishii, Masayoshi; Jevrejeva, Svetlana; Johns, W.; Landschützer, Peter; Lankhorst, Matthias; Leuliette, Eric; Locarnini, Ricardo; Lyman, John M.; McPhaden, Michael J.; Merrifield, Mark A.; Mishonov, Alexey; Mitchum, Gary T.; Moat, Ben I.; Mrekaj, Ivan; Nerem, R. Steven; Purkey, Sarah G.; Qiu, Bo; Reagan, James; Sato, Katsunari; Schmid, Claudia; Sharp, Jonathan D.; Siegel, David A.; Smeed, David A.; Stackhouse, Paul W.; Sweet, William; Thompson, Philip R.; Triñanes, Joaquin A.; Volkov, Denis L.; Wanninkhof, Rik; Wen, Caihong; Westberry, Toby K.; Widlansky, Matthew J.; Willis, J.; Xie, Ping-Ping; Yin, Xungang; Zhang, Huai-min; Zhang, Li; Allen, Jessicca; Camper, Amy V.; Haley, Bridgette O.; Hammer, Gregory; Love-Brotak, S. Elizabeth; Ohlmann, Laura; Noguchi, Lukas; Riddle, Deborah B.; Veasey, Sara W.Johnson, G. C., R. Lumpkin, C. Atkinson, T. Biló, T. Boyer, F. Bringas, B. R. Carter, I. Cetinić, D. P. Chambers, D. Chan, L. Cheng, L. Chomiak, M. F. Cronin, S. Dong, R. A. Feely, B. A. Franz, M. Gao, J. Garg, J. Gilson, G. Goni, B. D. Hamlington, W. Hobbs, Z. Hu, B. Huang, M. Ishii, S. Jevrejeva, W. Johns, P. Landschützer, M. Lankhorst, E. Leuliette, R. Locarnini, J. M. Lyman, M. J. McPhaden, M. A. Merrifield, A. Mishonov, G. T. Mitchum, B. I. Moat, I. Mrekaj, R. S. Nerem, S. G. Purkey, B. Qiu, J. Reagan, K. Sato, C. Schmid, J. D. Sharp, D. A. Siegel, D. A. Smeed, P. W. Stackhouse, W. Sweet, P. R. Thompson, J. A. Triñanes, D. L. Volkov, R. Wanninkhof, C. Wen, T. K. Westberry, M. J. Widlansky, J. Willis, P. Xie, X. Yin, H. Zhang, L. Zhang, J. Allen, A. V. Camper, B. O. Haley, G. Hammer, S. E. Love-Brotak, L. Ohlmann, L. Noguchi, D. B. Riddle, S. W. Veasey, 2023: Global Oceans. Bull. Amer. Meteor. Soc., 104(9), S146-S206. doi: 10.1175/BAMS-D-23-0076.2. "Global Oceans" published on 06 Sep 2023 by American Meteorological Society.
Scott, Ryan C.; Rose, Fred G.; Stackhouse, Paul W.; Loeb, Norman G.; Kato, Seiji; Doelling, David R.; Rutan, David A.; Taylor, Patrick C.; Smith, William L.Scott, R. C., F. G. Rose, P. W. Stackhouse, N. G. Loeb, S. Kato, D. R. Doelling, D. A. Rutan, P. C. Taylor, W. L. Smith, 2022: Clouds and the Earth’s Radiant Energy System (CERES) Cloud Radiative Swath (CRS) Edition 4 Data Product. J. Atmos. Oceanic Technol., 39(11), 1781-1797. doi: 10.1175/JTECH-D-22-0021.1. Abstract Satellite observations from Clouds and the Earth’s Radiant Energy System (CERES) radiometers have produced over two decades of world-class data documenting time–space variations in Earth’s top-of-atmosphere (TOA) radiation budget. In addition to energy exchanges among Earth and space, climate studies require accurate information on radiant energy exchanges at the surface and within the atmosphere. The CERES Cloud Radiative Swath (CRS) data product extends the standard Single Scanner Footprint (SSF) data product by calculating a suite of radiative fluxes from the surface to TOA at the instantaneous CERES footprint scale using the NASA Langley Fu–Liou radiative transfer model. Here, we describe the CRS flux algorithm and evaluate its performance against a network of ground-based measurements and CERES TOA observations. CRS all-sky downwelling broadband fluxes show significant improvements in surface validation statistics relative to the parameterized fluxes on the SSF product, including a ∼30%–40% (∼20%) reduction in SW↓ (LW↓) root-mean-square error (RMSΔ), improved correlation coefficients, and the lowest SW↓ bias over most surface types. RMSΔ and correlation statistics improve over five different surface types under both overcast and clear-sky conditions. The global mean computed TOA outgoing LW radiation (OLR) remains within
Stackhouse, P. W., T. Wong, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, D. P. Kratz, and N. G. LoebStackhouse, P. W., T. Wong, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, D. P. Kratz, and N. G. Loeb, 2021: Earth Radiation Budget at Top-of-atmosphere [in "State of the Climate in 2020"]. Bull. Amer. Meteor. Soc., 102(8). doi: 10.1175/2021BAMSStateoftheClimate.1.
Zhang, Taiping; Stackhouse, Paul W.; Cox, Stephen J.; Mikovitz, J. Colleen; Long, Charles N.Zhang, T., P. W. Stackhouse, S. J. Cox, J. C. Mikovitz, C. N. Long, 2021: Addendum to figs. 10 and 11 in “Clear-sky shortwave downward flux at the earth's surface: Ground-based data vs. satellite-based data” [J. Quant. Spec. and Rad. Tran. 224 (2019) 247-260]. Journal of Quantitative Spectroscopy and Radiative Transfer, 261, 107487. doi: 10.1016/j.jqsrt.2020.107487. While the CERES input aerosol optical depth and precipitable water data are continuously available, the same parameters derived from BSRN site measurements are available only intermittently. Cloudiness disrupts the aerosol optical depth (AOD) retrieval and precipitable water (w) observation sampling. Irregularly sampled records, such as these, can cause systematic biases if the averages of the continuous data are not sampled at the same times as the observed data, as shown by high biases in Fig. 10 in our original paper. This, however, does not suggest that the CERES input aerosol optical depth and precipitable water are systematically significantly higher than ground-based observations. In this addendum, we show that when the monthly means are computed from only those CERES hourly means that have a BSRN match, then the resulting monthly means differ from BSRN-derived parameters to a much lesser extent. To be precise, the biases in the original Fig. 10 decrease 82%, 69% and 52%, respectively; the magnitudes of slopes in the original Fig. 11 decrease by 69% and 65%, respectively. Imposing a cloud fraction less than or equal to 5% further reduces AOD and w mean values but not biases. Nevertheless, the flux bias reduces from -16.9 W m−2 to -4.2 W m−2 after imposing the cloud fraction restraint relative to the RADFlux clear-sky fluxes which appear to represent the driest and clearest conditions. CERES; Solar radiation; Satellite; GEWEX SRB; RadFlux
Bosilovich, Michael G.; Robertson, Franklin R.; Stackhouse, Paul W.Bosilovich, M. G., F. R. Robertson, P. W. Stackhouse, 2020: El Niño–Related Tropical Land Surface Water and Energy Response in MERRA-2. J. Climate, 33(3), 1155-1176. doi: 10.1175/JCLI-D-19-0231.1. Although El Niño events each have distinct evolutionary character, they typically provide systematic large-scale forcing for warming and increased drought frequency across the tropical continents. We assess this response in the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), reanalysis and in a 10-member-model Atmospheric Model Intercomparison Project (AMIP) ensemble. The lagged response (3–4 months) of mean tropical land temperature to El Niño warming in the Pacific Ocean is well represented. MERRA-2 reproduces the patterns of precipitation in the tropical regions, and the AMIP ensemble reproduces some regional responses that are similar to those observed and some regions that are not simulating the response well. Model skill is dependent on event forcing strength and temporal proximity to the peak of the sea surface warming. A composite approach centered on maximum Niño-3.4 SSTs and lag relationships to energy fluxes and transports is used to identify mechanisms supporting tropical land warming. The composite necessarily moderates weather-scale variability of the individual events while retaining the systematic features across all events. We find that reduced continental upward motions lead to reduced cloudiness and more shortwave radiation at the surface, as well as reduced precipitation. The increased shortwave heating at the land surface, along with reduced soil moisture, leads to warmer surface temperature, more sensible heating, and warming of the lower troposphere. The composite provides a broad picture of the mechanisms governing the hydrologic response to El Niño forcing, but the regional and temporal responses can vary substantially for any given event. The 2015/16 El Niño, one of the strongest events, demonstrates some of the forced response noted in the composite, but with shifts in the evolution that depart from the composite, demonstrating the limitations of the composite and individuality of El Niño.
Wong, T.; Stackhouse, P. W.; Kratz, D. P.; Sawaengphokhai, Parnchai; Wilber, A. C.; Gupta, S. K.; Loeb, N. GWong, T., P. W. Stackhouse, D. P. Kratz, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, N. G. Loeb, 2020: Earth Radiation Budget at Top-Of-Atmosphere [in “State of the Climate in 2019”].. Bull. Amer. Meteor. Soc, 101(8), S68-69. doi: 10.1175/BAMS-D-20-0104.1.
Yu, Lisan; Stackhouse, P. W.; Wilber, A. C.; Weller, R.Yu, L., P. W. Stackhouse, A. C. Wilber, R. Weller, 2020: Global ocean heat, freshwater, and momentum fluxes.[in "State of the Climate in 2019"]. Bull. Amer. Meteor. Soc, 101(8), S149-152. doi: 10.1175/BAMS-D-20-0105.1.
Zhang, Taiping; Stackhouse, Paul W.; Cox, Stephen J.; Mikovitz, J. ColleenZhang, T., P. W. Stackhouse, S. J. Cox, J. C. Mikovitz, 2020: The uncertainty of the BSRN monthly mean Global 1 and Global 2 fluxes due to missing hourly means with and without quality-control and an examination through validation of the NASA GEWEX SRB datasets. Journal of Quantitative Spectroscopy and Radiative Transfer, 255, 107272. doi: 10.1016/j.jqsrt.2020.107272. The Baseline Surface Radiation Network (BSRN) is a project of the Data and Assessments Panel from the Global Energy and Water Exchanges (GEWEX) under the umbrella of the World Climate Research Programme (WCRP). Currently in the archive there are data from 67 sites located in all seven continents spanning from 1992 to the present. The original BSRN records are at 1-, 2-, 3- or 5-minute intervals, and sophisticated quality-control procedures have been developed to eliminate erroneous records before hourly, daily and monthly means are computed. The resulting gaps from quality-control, however, give rise to uncertainties in computed temporal averages on various scales. There are two types of total shortwave downward fluxes: The Global 1 which is the sum of direct horizontal and diffuse irradiances, observed using the pyrheliometer and radiometer, respectively, and is recommended by the BSRN committee for its higher precision, and the Global 2 which is observed using the pyranometer. It has been found that, compared to Global 2, Global 1 is more susceptible to errors, thus resulting in more gaps in the original records. Here we examine the effect of quality-control on the monthly mean Global 1 and Global 2 and attempt to quantify the resulting uncertainties through analysis of the quality-control procedure and averaging algorithm and comparison with the NASA GEWEX Surface Radiation Budget (SRB) dataset. The SRB project is now making progress toward its Release 4.0 Integrated Products (Rel. 4.0-IP or V4.0-IP) with changes in both algorithm and inputs on the basis of its Release 3.0 (Rel. 3.0 or V3.0) products. The preliminary results from Rel. 4.0-IP span 34 years continuously from July 1983 to June 2017 on a 1° by 1° quasi-equal-area grid system in the form of 3-hourly, daily and monthly means. It is found that Global 2 generally has fewer missing records and is less affected by the quality-check procedure; on average, the monthly mean Global 1 and Global 2 differ by less than 1 W m−2; the GEWEX SRB preliminary GSW(V4.0-IP) monthly mean shortwave downward fluxes agree the best with the BSRN Global 1 monthly means computed from observational records that are nearly complete and that survive the quality-check nearly completely. BSRN; GEWEX SRB; Global 1; Global 2; Uncertainty
Cronin, Meghan F.; Gentemann, Chelle L.; Edson, James; Ueki, Iwao; Bourassa, Mark; Brown, Shannon; Clayson, Carol Anne; Fairall, Chris W.; Farrar, J. Thomas; Gille, Sarah T.; Gulev, Sergey; Josey, Simon A.; Kato, Seiji; Katsumata, Masaki; Kent, Elizabeth; Krug, Marjolaine; Minnett, Peter J.; Parfitt, Rhys; Pinker, Rachel T.; Stackhouse, Paul W.; Swart, Sebastiaan; Tomita, Hiroyuki; Vandemark, Douglas; Weller, A. Robert; Yoneyama, Kunio; Yu, Lisan; Zhang, DongxiaoCronin, M. F., C. L. Gentemann, J. Edson, I. Ueki, M. Bourassa, S. Brown, C. A. Clayson, C. W. Fairall, J. T. Farrar, S. T. Gille, S. Gulev, S. A. Josey, S. Kato, M. Katsumata, E. Kent, M. Krug, P. J. Minnett, R. Parfitt, R. T. Pinker, P. W. Stackhouse, S. Swart, H. Tomita, D. Vandemark, A. R. Weller, K. Yoneyama, L. Yu, D. Zhang, 2019: Air-Sea Fluxes With a Focus on Heat and Momentum. Frontiers in Marine Science, 6, 430. doi: 10.3389/fmars.2019.00430. Turbulent and radiative exchanges of heat between the ocean and atmosphere (hereafter heat fluxes), ocean surface wind stress, and state variables used to estimate them, are Essential Ocean Variables (EOVs) and Essential Climate Variables (ECVs) influencing weather and climate. This paper describes an observational strategy for producing 3-hourly, 25-km (and an aspirational goal of hourly at 10-km) heat flux and wind stress fields over the global, ice-free ocean with breakthrough 1-day random uncertainty of 15 W m–2 and a bias of less than 5 W m–2. At present this accuracy target is met only for OceanSITES reference station moorings and research vessels (RVs) that follow best practices. To meet these targets globally, in the next decade, satellite-based observations must be optimized for boundary layer measurements of air temperature, humidity, sea surface temperature, and ocean wind stress. In order to tune and validate these satellite measurements, a complementary global in situ flux array, built around an expanded OceanSITES network of time series reference station moorings, is also needed. The array would include 500–1000 measurement platforms, including autonomous surface vehicles, moored and drifting buoys, RVs, the existing OceanSITES network of 22 flux sites, and new OceanSITES expanded in 19 key regions. This array would be globally distributed, with 1–3 measurement platforms in each nominal 10° by 10° box. These improved moisture and temperature profiles and surface data, if assimilated into Numerical Weather Prediction (NWP) models, would lead to better representation of cloud formation processes, improving state variables and surface radiative and turbulent fluxes from these models. The in situ flux array provides globally distributed measurements and metrics for satellite algorithm development, product validation, and for improving satellite-based, NWP and blended flux products. In addition, some of these flux platforms will also measure direct turbulent fluxes, which can be used to improve algorithms for computation of air-sea exchange of heat and momentum in flux products and models. With these improved air-sea fluxes, the ocean’s influence on the atmosphere will be better quantified and lead to improved long-term weather forecasts, seasonal-interannual-decadal climate predictions, and regional climate projections.
Shrestha, A. K.; Kato, S.; Wong, T.; Stackhouse, P.; Loughman, R. P.Shrestha, A. K., S. Kato, T. Wong, P. Stackhouse, R. P. Loughman, 2019: New Temporal and Spectral Unfiltering Technique for ERBE/ERBS WFOV Nonscanner Instrument Observations. IEEE Transactions on Geoscience and Remote Sensing, 1-12. doi: 10.1109/TGRS.2019.2891748. Earth Radiation Budget Experiment (ERBE) Wide-Field-of-View (WFOV) nonscanner instrument onboard Earth Radiation Budget Satellite (ERBS) provided critical 15-year outgoing broadband irradiances at the top of atmosphere (TOA) from 1985 to 1999 for studying Earth's climate. However, earlier studies show that the uncertainty in this radiation data set (Ed3) is significantly higher after the Mt. Pinatubo eruption in 1991 and satellite battery issue in 1993. Furthermore, Lee et al. showed that the transmission of ERBS WFOV shortwave dome degraded due to exposure to direct sunlight. To account for this degradation, a simple time-dependent but spectral-independent correction model was implemented in the past. This simple spectral-independent model did not completely remove the shortwave sensor artifact as seen in the temporal growth of the tropical mean day-minus-night longwave irradiance. A new temporal-spectral-dependent correction model of shortwave dome transmissivity loss similar to that used in the Clouds and the Earth's Radiant Energy System (CERES) project is developed and applied to the 15-year ERBS WFOV data. This model is constrained by the solar transmission obtained from ERBS WFOV shortwave nonscanner instrument observations of the Sun during biweekly in-flight solar calibration events. This new model is able to reduce the reported tropical day-minus-night longwave irradiance trend by ≈34%. In addition, the slope of this new trend is observed to be consistent over different regions. The remaining trend is accounted using a postprocess Ed3Rev1 correction. Furthermore, the time series analysis of these data over the Libya-4 desert site showed that the shortwave data are stable to within 0.7%. Earth; Instruments; Meteorology; Satellite broadcasting; Radiometry; Data models; Calibration; Data conversion; earth; energy measurements.
Stackhouse, P. W.; Wong, T.; Kratz, D. P.; Sawaengphokhai, Parnchai; Wilber, A. C.; Gupta, S. K.; Loeb, N. GStackhouse, P. W., T. Wong, D. P. Kratz, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, N. G. Loeb, 2019: Earth Radiation Budget at Top-Of-Atmosphere [in “State of the Climate in 2018”].. Bull. Amer. Meteor. Soc, 100(9), S46-48. doi: 10.1175/2019BAMSStateoftheClimate.1.
Stackhouse, P. W.; Wong, T.; Kratz, D. P.; Sawaengphokhai, Parnchai; Wilber, A. C.; Gupta, S. K.; Loeb, N. GStackhouse, P. W., T. Wong, D. P. Kratz, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, N. G. Loeb, 2019: Earth Radiation Budget at Top-Of-Atmosphere [in “State of the Climate in 2018”].. Bull. Amer. Meteor. Soc, 100(9), S46-48. doi: 10.1175/2019BAMSStateoftheClimate.1.
Yu, Lisan; Jin, X.; Stackhouse, P. W.; Wilber, A. C.; Kato, S.; Loeb, N. G; Weller, R.Yu, L., X. Jin, P. W. Stackhouse, A. C. Wilber, S. Kato, N. G. Loeb, R. Weller, 2019: Global ocean heat, freshwater, and momentum fluxes.[in "State of the Climate in 2018"]. Bull. Amer. Meteor. Soc, 100(9), S81-84. doi: 10.1175/2019BAMSStateoftheClimate.1.
Zhang, Taiping; Stackhouse, Paul W.; Cox, Stephen J.; Mikovitz, J. Colleen; Long, Charles N.Zhang, T., P. W. Stackhouse, S. J. Cox, J. C. Mikovitz, C. N. Long, 2019: Clear-sky shortwave downward flux at the Earth's surface: Ground-based data vs. satellite-based data. Journal of Quantitative Spectroscopy and Radiative Transfer, 224, 247-260. doi: 10.1016/j.jqsrt.2018.11.015. The radiative flux data and other meteorological data in the BSRN archive start in 1992, but the RadFlux data, the clear-sky radiative fluxes at the BSRN sites empirically inferred through regression analyses of actually observed clear-sky fluxes, did not come into existence until the early 2000s, and at first, they were limited to the 7 NOAA SURFRAD and 4 DOE ARM sites, a subset of the BSRN sites. Recently, the RadFlux algorithm was applied more extensively to the BSRN sites for the production of clear-sky ground-based fluxes. At the time of this writing, there are 7119 site-months of clear-sky fluxes at 42 BSRN sites spanning from 1992 to late 2017. These data provide an unprecedented opportunity to validate the satellite-based clear-sky fluxes. In this paper, the GEWEX SRB GSW(V3.0) clear-sky shortwave downward fluxes spanning 24.5 years from July 1983 to December 2007, the CERES SYN1deg(Ed4A) and EBAF(Ed4.0) clear-sky shortwave fluxes spanning March 2000 to mid-2017 are compared with their RadFlux counterparts on the hourly, 3-hourly, daily and monthly time scales. All the three datasets show reasonable agreement with their ground-based counterparts. Comparison of the satellite-based surface shortwave clear-sky radiative fluxes to the BSRN RadFlux analysis shows negative biases (satellite-based minus RadFlux). Further analysis shows that the satellite-based atmosphere contains greater aerosol loading as well as more precipitable water than RadFlux analysis estimates. CERES; Solar radiation; Satellite; GEWEX SRB; RadFlux
Chen, Xiuhong; Huang, Xianglei; Dong, Xiquan; Xi, Baike; Dolinar, Erica K.; Loeb, Norman G.; Kato, Seiji; Stackhouse, Paul W.; Bosilovich, Michael G.Chen, X., X. Huang, X. Dong, B. Xi, E. K. Dolinar, N. G. Loeb, S. Kato, P. W. Stackhouse, M. G. Bosilovich, 2018: Using AIRS and ARM SGP Clear-Sky Observations to Evaluate Meteorological Reanalyses: A Hyperspectral Radiance Closure Approach. Journal of Geophysical Research: Atmospheres, 123(20), 11,720-11,734. doi: 10.1029/2018JD028850. Using the ground-based measurements from the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site and spectral radiance from the Atmospheric Infrared Sounder (AIRS) on National Aeronautics and Space Administration Aqua, we evaluate the temperature and humidity profiles from European Center for Medium Range Weather Forecasting ERA-Interim and Modern-Era Retrospective analysis for Research and Applications Version 2 reanalyses. Four sets of synthetic AIRS spectra are calculated using 51 clear-sky sounding profiles from the ARM SGP observations, the collocated AIRS L2 retrievals and the two reanalyses, respectively. A subset of AIRS channels sensitive to temperature, CO2, or H2O but not to other trace gases is chosen and further categorized into different groups according to the peak altitudes of their weighting functions. Synthetic radiances are then compared to the observed AIRS radiances for each group. For all groups, the observed AIRS radiances agree well with the synthetic ones based on the ARM SGP soundings or the AIRS L2 retrievals. The brightness temperature (BT) differences are within ±0.5 K. For two reanalyses, BT differences in all temperature-sensitive groups are generally within ±0.5 K; but the mean BT differences in all groups sensitive to both T and H2O are negative. Together, they suggest a wet bias in the free troposphere in both reanalyses. Moreover, such BT differences can be seen in the analysis of AIRS clear-sky radiances over the entire 30–40°N zone. A grid-search retrieval suggests that 9–30% reduction for reanalysis humidity between 200 and 800 hPa is needed to correct such wet bias. AIRS radiances; ARM soundings; reanalysis bias correction
Wong, T.; Kratz, D. P.; Stackhouse, P. W.; Sawaengphokhai, Parnchai; Wilber, A. C.; Gupta, S. K.; Loeb, N. GWong, T., D. P. Kratz, P. W. Stackhouse, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, N. G. Loeb, 2018: Earth Radiation Budget at Top-Of-Atmosphere [in “State of the Climate in 2017”].. Bull. Amer. Meteor. Soc, 99(8), S45-46. doi: 10.1175/2018BAMSStateoftheClimate.1.
Yu, L.; Jin, X; Kato, S.; Loeb, N. G; Stackhouse, P. W.; Weller, R. A.; Wilber, A. C.Yu, L., X. Jin, S. Kato, N. G. Loeb, P. W. Stackhouse, R. A. Weller, A. C. Wilber, 2018: Global ocean heat, freshwater, and momentum fluxes [in “State of the Climate in 2017”].. Bull. Amer. Meteor. Soc, 99(8), S81-84. doi: 10.1175/2018BAMSStateoftheClimate.1.
Kratz, D. P.; Stackhouse, P.W.; Wong, T; Sawaengphokhai, P.; Wilber, A. C.; Gupta, S. K.; Loeb, N. G.Kratz, D. P., P. Stackhouse, T. Wong, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, N. G. Loeb, 2017: Earth radiation Budget at Top-of-Atmosphere [in “State of the Climate in 2016"]. Bull. Amer. Meteor. Soc., 97(8), S41-S42. doi: 10.1175/2017BAMSStateoftheClimate.1.
Smith, William L.; Hansen, Christy; Bucholtz, Anthony; Anderson, Bruce E.; Beckley, Matthew; Corbett, Joseph G.; Cullather, Richard I.; Hines, Keith M.; Hofton, Michelle; Kato, Seiji; Lubin, Dan; Moore, Richard H.; Segal Rosenhaimer, Michal; Redemann, Jens; Schmidt, Sebastian; Scott, Ryan; Song, Shi; Barrick, John D.; Blair, J. Bryan; Bromwich, David H.; Brooks, Colleen; Chen, Gao; Cornejo, Helen; Corr, Chelsea A.; Ham, Seung-Hee; Kittelman, A. Scott; Knappmiller, Scott; LeBlanc, Samuel; Loeb, Norman G.; Miller, Colin; Nguyen, Louis; Palikonda, Rabindra; Rabine, David; Reid, Elizabeth A.; Richter-Menge, Jacqueline A.; Pilewskie, Peter; Shinozuka, Yohei; Spangenberg, Douglas; Stackhouse, Paul; Taylor, Patrick; Thornhill, K. Lee; van Gilst, David; Winstead, EdwardSmith, W. L., C. Hansen, A. Bucholtz, B. E. Anderson, M. Beckley, J. G. Corbett, R. I. Cullather, K. M. Hines, M. Hofton, S. Kato, D. Lubin, R. H. Moore, M. Segal Rosenhaimer, J. Redemann, S. Schmidt, R. Scott, S. Song, J. D. Barrick, J. B. Blair, D. H. Bromwich, C. Brooks, G. Chen, H. Cornejo, C. A. Corr, S. Ham, A. S. Kittelman, S. Knappmiller, S. LeBlanc, N. G. Loeb, C. Miller, L. Nguyen, R. Palikonda, D. Rabine, E. A. Reid, J. A. Richter-Menge, P. Pilewskie, Y. Shinozuka, D. Spangenberg, P. Stackhouse, P. Taylor, K. L. Thornhill, D. van Gilst, E. Winstead, 2017: Arctic Radiation-IceBridge Sea and Ice Experiment: The Arctic Radiant Energy System during the Critical Seasonal Ice Transition. Bull. Amer. Meteor. Soc., 98(7), 1399-1426. doi: 10.1175/BAMS-D-14-00277.1. AbstractThe National Aeronautics and Space Administration (NASA)?s Arctic Radiation-IceBridge Sea and Ice Experiment (ARISE) acquired unique aircraft data on atmospheric radiation and sea ice properties during the critical late summer to autumn sea ice minimum and commencement of refreezing. The C-130 aircraft flew 15 missions over the Beaufort Sea between 4 and 24 September 2014. ARISE deployed a shortwave and longwave broadband radiometer (BBR) system from the Naval Research Laboratory; a Solar Spectral Flux Radiometer (SSFR) from the University of Colorado Boulder; the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) from the NASA Ames Research Center; cloud microprobes from the NASA Langley Research Center; and the Land, Vegetation and Ice Sensor (LVIS) laser altimeter system from the NASA Goddard Space Flight Center. These instruments sampled the radiant energy exchange between clouds and a variety of sea ice scenarios, including prior to and after refreezing began. The most critical and unique aspect of ARISE mission planning was to coordinate the flight tracks with NASA Cloud and the Earth?s Radiant Energy System (CERES) satellite sensor observations in such a way that satellite sensor angular dependence models and derived top-of-atmosphere fluxes could be validated against the aircraft data over large gridbox domains of order 100?200 km. This was accomplished over open ocean, over the marginal ice zone (MIZ), and over a region of heavy sea ice concentration, in cloudy and clear skies. ARISE data will be valuable to the community for providing better interpretation of satellite energy budget measurements in the Arctic and for process studies involving ice?cloud?atmosphere energy exchange during the sea ice transition period.
Yu, L.; Adler, R.; Huffman, G.; Jin, X.; Kato, S.; Loeb, N.; Stackhouse, P.; Weller, R.; Wilber, A.Yu, L., R. Adler, G. Huffman, X. Jin, S. Kato, N. Loeb, P. Stackhouse, R. Weller, A. Wilber, 2017: Ocean surface heat and momentum fluxes [In "State of the Climate in 2016"]. Bull. Amer. Meteor. Soc., 97(8), S75-S79. doi: 10.1175/2017BAMSStateoftheClimate.1.
Raschke, Ehrhard; Kinne, Stefan; Rossow, William B.; Stackhouse, Paul W.; Wild, MartinRaschke, E., S. Kinne, W. B. Rossow, P. W. Stackhouse, M. Wild, 2016: Comparison of Radiative Energy Flows in Observational Datasets and Climate Modeling. J. Appl. Meteor. Climatol., 55(1), 93-117. doi: 10.1175/JAMC-D-14-0281.1. This study examines radiative flux distributions and local spread of values from three major observational datasets (CERES, ISCCP, and SRB) and compares them with results from climate modeling (CMIP3). Examinations of the spread and differences also differentiate among contributions from cloudy and clear-sky conditions. The spread among observational datasets is in large part caused by noncloud ancillary data. Average differences of at least 10 W m−2 each for clear-sky downward solar, upward solar, and upward infrared fluxes at the surface demonstrate via spatial difference patterns major differences in assumptions for atmospheric aerosol, solar surface albedo and surface temperature, and/or emittance in observational datasets. At the top of the atmosphere (TOA), observational datasets are less influenced by the ancillary data errors than at the surface. Comparisons of spatial radiative flux distributions at the TOA between observations and climate modeling indicate large deficiencies in the strength and distribution of model-simulated cloud radiative effects. Differences are largest for lower-altitude clouds over low-latitude oceans. Global modeling simulates stronger cloud radiative effects (CRE) by +30 W m−2 over trade wind cumulus regions, yet smaller CRE by about −30 W m−2 over (smaller in area) stratocumulus regions. At the surface, climate modeling simulates on average about 15 W m−2 smaller radiative net flux imbalances, as if climate modeling underestimates latent heat release (and precipitation). Relative to observational datasets, simulated surface net fluxes are particularly lower over oceanic trade wind regions (where global modeling tends to overestimate the radiative impact of clouds). Still, with the uncertainty in noncloud ancillary data, observational data do not establish a reliable reference. aerosols; albedo; Radiative fluxes; Radiation budgets; Climatology; Cloud radiative effects
Stackhouse, P., D. P. Kratz, T. Wong, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, and N. G. LoebStackhouse, P., D. P. Kratz, T. Wong, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, and N. G. Loeb, 2016: Earth radiation Budget at Top-of-Atmosphere [in “State of the Climate in 2015"]. Bull. Amer. Meteor. Soc., 97(S41-S43). doi: 10.1175/2016BAMSStateoftheClimate.1.
Stackhouse, P.; Kratz, D. P.; Wong, T.; Sawaengphokhai, P.; Wilber, A. C.; Gupta, SK; Loeb, N. G.Stackhouse, P., D. P. Kratz, T. Wong, P. Sawaengphokhai, A. C. Wilber, S. Gupta, N. G. Loeb, 2016: Earth radiation Budget at Top-of-Atmosphere [in “State of the Climate in 2015"]. Bull. Amer. Meteor. Soc., 97(8), S41-S43. doi: 10.1175/2016BAMSStateoftheClimate.1.
Chiacchio, Marc; Solmon, Fabien; Giorgi, Filippo; Stackhouse, Paul; Wild, MartinChiacchio, M., F. Solmon, F. Giorgi, P. Stackhouse, M. Wild, 2015: Evaluation of the radiation budget with a regional climate model over Europe and inspection of dimming and brightening. Journal of Geophysical Research: Atmospheres, 120(5), 1951–1971. doi: 10.1002/2014JD022497. Shortwave (SW) and longwave (LW) components of the radiation budget at the surface and top of atmosphere (TOA) are evaluated in the regional climate model RegCM version 4 driven by European Centre for Medium-Range Weather Forecasts Reanalysis over Europe. The simulated radiative components were evaluated with those from satellite-based products and reanalysis. At the surface the model overestimated the absorbed solar radiation but was compensated by a greater loss of thermal energy while both SW and LW TOA net fluxes were underestimated representing too little solar energy absorbed and too little outgoing thermal energy. Averaged biases in radiative parameters were generally within 25 W m−2, were dependent on differences by as much as 0.2 in cloud fraction, surface, and planetary albedo and less dependent on surface temperature associated with the surface longwave parameters, and are in line with other studies. Clear-sky fluxes showed better results when cloud cover differences had no influence. We also found a clear distinction between land versus water with smaller biases over land at the surface and over water at the TOA due to differences in cloud fraction and albedo. Finally, we inspected dimming and brightening for the period 1979–2010 with an indication for dimming early in the time series (i.e., 1979–1987) and brightening after, which agrees with surface-based observations. After 2000, however, a decrease in the brightening by more than 1 order of magnitude was evident which is in contrast to the continued brightening found in surface records and satellite-derived estimates. 0360 Radiation: transmission and scattering; 0321 Cloud/radiation interaction; 3311 Clouds and aerosols; 1637 Regional climate change; radiation budget; dimming and brightening; regional modeling
Wong, T; Kratz, D. P.; Stackhouse, P.W.; Sawaengphokhai, P.; Wilber, A. C.; Gupta, S. K.; Loeb, N. G.Wong, T., D. P. Kratz, P. Stackhouse, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, N. G. Loeb, 2015: Earth radiation Budget at Top-of-Atmosphere [in “State of the Climate in 2014"]. Bull. Amer. Meteor. Soc., 96(7), S37-38. doi: 10.1175/2015BAMSStateoftheClimate.1.
Yu, L.; Jin, X.; Stackhouse, P.; Wilber, A.; Josey, S.; Xue, Y.; Kumar, A.Yu, L., X. Jin, P. Stackhouse, A. Wilber, S. Josey, Y. Xue, A. Kumar, 2015: Ocean surface heat and momentum fluxes [In "State of the Climate in 2014"]. Bull. Amer. Meteor. Soc., 96(7), S68-S71. doi: 10.1175/2015BAMSStateoftheClimate.1.
Kratz, David P.; Stackhouse, Paul W.; Gupta, Shashi K.; Wilber, Anne C.; Sawaengphokhai, Parnchai; McGarragh, Greg R.Kratz, D. P., P. W. Stackhouse, S. K. Gupta, A. C. Wilber, P. Sawaengphokhai, G. R. McGarragh, 2014: The Fast Longwave and Shortwave Flux (FLASHFlux) Data Product: Single-Scanner Footprint Fluxes. J. Appl. Meteor. Climatol., 53(4), 1059-1079. doi: 10.1175/JAMC-D-13-061.1. AbstractThe Clouds and the Earth’s Radiant Energy Systems (CERES) project utilizes radiometric measurements taken aboard the Terra and Aqua spacecrafts to derive the world-class data products needed for climate research. Achieving the exceptional fidelity of the CERES data products, however, requires a considerable amount of processing to assure quality and to verify accuracy and precision, which results in the CERES data being released more than 6 months after the satellite observations. For most climate studies such delays are of little consequence; however, there are a significant number of near–real time uses for CERES data products. The Fast Longwave and Shortwave Radiative Flux (FLASHFlux) data product was therefore developed to provide a rapid release version of the CERES results, which could be made available to the research and applications communities within 1 week of the satellite observations by exchanging some accuracy for speed. FLASHFlux has both achieved this 1-week processing objective and demonstrated the ability to provide remarkably good agreement when compared with the CERES data products for both the instantaneous single-scanner footprint (SSF) fluxes and the time- and space-averaged (TISA) fluxes. This paper describes the methods used to expedite the production of the FLASHFlux SSF fluxes by utilizing data from the CERES and Moderate Resolution Imaging Spectroradiometer instruments, as well as other meteorological sources. This paper also reports on the validation of the FLASHFlux SSF results against ground-truth measurements and the intercomparison of FLASHFlux and CERES SSF results. A complementary paper will discuss the production and validation of the FLASHFlux TISA fluxes. satellite observations; longwave radiation; Shortwave radiation; Surface observations; Surface fluxes
Rosenzweig, Cynthia; Horton, Radley M.; Bader, Daniel A.; Brown, Molly E.; DeYoung, Russell; Dominguez, Olga; Fellows, Merrilee; Friedl, Lawrence; Graham, William; Hall, Carlton; Higuchi, Sam; Iraci, Laura; Jedlovec, Gary; Kaye, Jack; Loewenstein, Max; Mace, Thomas; Milesi, Cristina; Patzert, William; Stackhouse, Paul W.; Toufectis, KimRosenzweig, C., R. M. Horton, D. A. Bader, M. E. Brown, R. DeYoung, O. Dominguez, M. Fellows, L. Friedl, W. Graham, C. Hall, S. Higuchi, L. Iraci, G. Jedlovec, J. Kaye, M. Loewenstein, T. Mace, C. Milesi, W. Patzert, P. W. Stackhouse, K. Toufectis, 2014: Enhancing Climate Resilience at NASA Centers: A Collaboration between Science and Stewardship. Bull. Amer. Meteor. Soc., 95(9), 1351-1363. doi: 10.1175/BAMS-D-12-00169.1. A partnership between Earth scientists and institutional stewards is helping the National Aeronautics and Space Administration (NASA) prepare for a changing climate and growing climate-related vulnerabilities. An important part of this partnership is an agency-wide Climate Adaptation Science Investigator (CASI) Workgroup. CASI has thus far initiated 1) local workshops to introduce and improve planning for climate risks, 2) analysis of climate data and projections for each NASA Center, 3) climate impact and adaptation toolsets, and 4) Center-specific research and engagement. Partnering scientists with managers aligns climate expertise with operations, leveraging research capabilities to improve decision-making and to tailor risk assessment at the local level. NASA has begun to institutionalize this ongoing process for climate risk management across the entire agency, and specific adaptation strategies are already being implemented. A case study from Kennedy Space Center illustrates the CASI and workshop process, highlighting the need to protect launch infrastructure of strategic importance to the United States, as well as critical natural habitat. Unique research capabilities and a culture of risk management at NASA may offer a pathway for other organizations facing climate risks, promoting their resilience as part of community, regional, and national strategies.
Stackhouse, P.W.; Wong, T; Kratz, D. P.; Sawaengphokhai, P.; Wilber, A. C.; Gupta, S. K.; Loeb, N. G.Stackhouse, P., T. Wong, D. P. Kratz, P. Sawaengphokhai, A. C. Wilber, S. K. Gupta, N. G. Loeb, 2013: Earth radiation Budget at Top-of-Atmosphere [in “State of the Climate in 2012"]. Bull. Amer. Meteor. Soc., 94(8), S41-S43. doi: 10.1175/2013BAMSStateoftheClimate.1.
Stephens, Graeme L.; Wild, Martin; Stackhouse, Paul W.; L’Ecuyer, Tristan; Kato, Seiji; Henderson, David S.Stephens, G. L., M. Wild, P. W. Stackhouse, T. L’Ecuyer, S. Kato, D. S. Henderson, 2012: The Global Character of the Flux of Downward Longwave Radiation. J. Climate, 25(7), 2329-2340. doi: 10.1175/JCLI-D-11-00262.1. AbstractFour different types of estimates of the surface downwelling longwave radiative flux (DLR) are reviewed. One group of estimates synthesizes global cloud, aerosol, and other information in a radiation model that is used to calculate fluxes. Because these synthesis fluxes have been assessed against observations, the global-mean values of these fluxes are deemed to be the most credible of the four different categories reviewed. The global, annual mean DLR lies between approximately 344 and 350 W m−2 with an error of approximately ±10 W m−2 that arises mostly from the uncertainty in atmospheric state that governs the estimation of the clear-sky emission. The authors conclude that the DLR derived from global climate models are biased low by approximately 10 W m−2 and even larger differences are found with respect to reanalysis climate data. The DLR inferred from a surface energy balance closure is also substantially smaller that the range found from synthesis products suggesting that current depictions of surface energy balance also require revision. The effect of clouds on the DLR, largely facilitated by the new cloud base information from the CloudSat radar, is estimated to lie in the range from 24 to 34 W m−2 for the global cloud radiative effect (all-sky minus clear-sky DLR). This effect is strongly modulated by the underlying water vapor that gives rise to a maximum sensitivity of the DLR to cloud occurring in the colder drier regions of the planet. The bottom of atmosphere (BOA) cloud effect directly contrast the effect of clouds on the top of atmosphere (TOA) fluxes that is maximum in regions of deepest and coldest clouds in the moist tropics. Energy budget/balance; Hydrologic cycle; Climatology; Energy transport; Planetary atmospheres
Kato, Seiji; Rose, Fred G.; Sun-Mack, Sunny; Miller, Walter F.; Chen, Yan; Rutan, David A.; Stephens, Graeme L.; Loeb, Norman G.; Minnis, Patrick; Wielicki, Bruce A.; Winker, David M.; Charlock, Thomas P.; Stackhouse, Paul W.; Xu, Kuan-Man; Collins, William D.Kato, S., F. G. Rose, S. Sun-Mack, W. F. Miller, Y. Chen, D. A. Rutan, G. L. Stephens, N. G. Loeb, P. Minnis, B. A. Wielicki, D. M. Winker, T. P. Charlock, P. W. Stackhouse, K. Xu, W. D. Collins, 2011: Improvements of top-of-atmosphere and surface irradiance computations with CALIPSO-, CloudSat-, and MODIS-derived cloud and aerosol properties. Journal of Geophysical Research: Atmospheres, 116(D19), D19209. doi: 10.1029/2011JD016050. One year of instantaneous top-of-atmosphere (TOA) and surface shortwave and longwave irradiances are computed using cloud and aerosol properties derived from instruments on the A-Train Constellation: the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite, the CloudSat Cloud Profiling Radar (CPR), and the Aqua Moderate Resolution Imaging Spectrometer (MODIS). When modeled irradiances are compared with those computed with cloud properties derived from MODIS radiances by a Clouds and the Earth's Radiant Energy System (CERES) cloud algorithm, the global and annual mean of modeled instantaneous TOA irradiances decreases by 12.5 W m−2 (5.0%) for reflected shortwave and 2.5 W m−2 (1.1%) for longwave irradiances. As a result, the global annual mean of instantaneous TOA irradiances agrees better with CERES-derived irradiances to within 0.5W m−2 (out of 237.8 W m−2) for reflected shortwave and 2.6W m−2 (out of 240.1 W m−2) for longwave irradiances. In addition, the global annual mean of instantaneous surface downward longwave irradiances increases by 3.6 W m−2 (1.0%) when CALIOP- and CPR-derived cloud properties are used. The global annual mean of instantaneous surface downward shortwave irradiances also increases by 8.6 W m−2 (1.6%), indicating that the net surface irradiance increases when CALIOP- and CPR-derived cloud properties are used. Increasing the surface downward longwave irradiance is caused by larger cloud fractions (the global annual mean by 0.11, 0.04 excluding clouds with optical thickness less than 0.3) and lower cloud base heights (the global annual mean by 1.6 km). The increase of the surface downward longwave irradiance in the Arctic exceeds 10 W m−2 (∼4%) in winter because CALIOP and CPR detect more clouds in comparison with the cloud detection by the CERES cloud algorithm during polar night. The global annual mean surface downward longwave irradiance of 345.4 W m−2 is estimated by combining the modeled instantaneous surface longwave irradiance computed with CALIOP and CPR cloud profiles with the global annual mean longwave irradiance from the CERES product (AVG), which includes the diurnal variation of the irradiance. The estimated bias error is −1.5 W m−2 and the uncertainty is 6.9 W m−2. The uncertainty is predominately caused by the near-surface temperature and column water vapor amount uncertainties. clouds; 0360 Radiation: transmission and scattering; 1610 Atmosphere; 1640 Remote sensing; aerosols; radiation; surface energy budget
Kratz, D. P.; Stackhouse, P.W.; Wong, T; Sawaengphokhai, P.; Wilber, A. C.; Loeb, N. G.Kratz, D. P., P. Stackhouse, T. Wong, P. Sawaengphokhai, A. C. Wilber, N. G. Loeb, 2011: Earth Radiation Budget at top-of-atmosphere in 'State of the Climate 2010'. Bulletin of the American Meterological Society, 92(6). doi: 10.1175/1520-0477-92.6.S1.
Mlynczak, Pamela E.; Smith, G. Louis; Wilber, Anne C.; Stackhouse, Paul W.Mlynczak, P. E., G. L. Smith, A. C. Wilber, P. W. Stackhouse, 2011: Annual Cycle of Surface Longwave Radiation. J. Appl. Meteor. Climatol., 50(6), 1212-1224. doi: 10.1175/2011JAMC2663.1. AbstractThe annual cycles of upward and downward longwave fluxes at the earth’s surface are investigated by use of the NASA Global Energy and Water Cycle Experiment (GEWEX) Surface Radiation Budget Dataset. Principal component analysis is used to quantify the annual cycles. Because of the immense difference between the heat capacity of land and ocean, the surface of the earth is partitioned into these two categories. Over land, the first principal component describes over 95% of the variance of the annual cycle of the upward and downward longwave fluxes. Over ocean the first term describes more than 87% of these annual cycles. Empirical orthogonal functions show the corresponding geographical distributions of these cycles. Phase-plane diagrams of the annual cycles of upward longwave fluxes as a function of net shortwave flux show the thermal inertia of land and ocean. Radiative fluxes; longwave radiation; Surface fluxes; Annual variations; Principal components analysis
White, Jeffrey W.; Hoogenboom, Gerrit; Wilkens, Paul W.; Stackhouse, Paul W.; Hoel, James M.White, J. W., G. Hoogenboom, P. W. Wilkens, P. W. Stackhouse, J. M. Hoel, 2011: Evaluation of Satellite-Based, Modeled-Derived Daily Solar Radiation Data for the Continental United States. Agronomy Journal, 103(4), 1242. doi: 10.2134/agronj2011.0038.
Gupta, Shashi K.; Kratz, David P.; Stackhouse, Paul W.; Wilber, Anne C.; Zhang, Taiping; Sothcott, Victor E.Gupta, S. K., D. P. Kratz, P. W. Stackhouse, A. C. Wilber, T. Zhang, V. E. Sothcott, 2010: Improvement of Surface Longwave Flux Algorithms Used in CERES Processing. J. Appl. Meteor. Climatol., 49(7), 1579-1589. doi: 10.1175/2010JAMC2463.1. Abstract An improvement was developed and tested for surface longwave flux algorithms used in the Clouds and the Earth’s Radiant Energy System processing based on lessons learned during the validation of global results of those algorithms. The algorithms involved showed significant overestimation of downward longwave flux for certain regions, especially dry–arid regions during hot times of the day. The primary cause of this overestimation was identified and the algorithms were modified to (i) detect meteorological conditions that would produce an overestimation, and (ii) apply a correction when the overestimation occurred. The application of this correction largely eliminated the positive bias that was observed in earlier validation studies. Comparisons of validation results before and after the application of correction are presented. Fluxes; longwave radiation; Algorithms
Hinkelman, Laura M.; Stackhouse, Paul W.; Wielicki, Bruce A.; Zhang, Taiping; Wilson, Sara R.Hinkelman, L. M., P. W. Stackhouse, B. A. Wielicki, T. Zhang, S. R. Wilson, 2009: Surface insolation trends from satellite and ground measurements: Comparisons and challenges. Journal of Geophysical Research: Atmospheres, 114(D10), D00D20. doi: 10.1029/2008JD011004. Global “dimming” and “brightening,” the decrease and subsequent increase in solar downwelling flux reaching the surface observed in many locations over the past several decades, and related issues are examined using satellite data from the NASA/Global Energy and Water Cycle Experiment (GEWEX) Surface Radiation Budget (SRB) product, version 2.8. A 2.51 W m−2 decade−1 dimming is found between 1983 and 1991, followed by 3.17 W m−2 decade−1 brightening from 1991 to 1999, returning to 5.26 W m−2 decade−1 dimming over 1999–2004 in the SRB global mean. This results in an insignificant overall trend for the entire satellite period. However, patterns of variability for smaller regions (continents, land, and ocean) are found to differ significantly from the global signal. The significance of the computed linear trends is assessed using a statistical technique that accommodates the autocorrelation typically found in surface insolation time series. Satellite fluxes are compared to measurements from surface radiation stations on both a site-by-site and ensemble basis. Comparison of an ensemble of the most continuous Global Energy Balance Archive (GEBA) sites to SRB data yields a root-mean-square difference and correlation of 2.6 W m−2 and 0.822, respectively. However, the GEBA time series does not correspond well to the SRB global mean owing to its extremely limited distribution of sites. Simulations of the Baseline Surface Radiometer Network using SRB data suggest that the network is becoming more representative of the globe as it expands, but that the Southern Hemisphere and oceans remain seriously underrepresented in the surface networks. This study indicates that it is inappropriate to describe the variability of global surface insolation in the current satellite record using a single linear fit because major changes in slope have been observed over the last 20 years. Further efforts to improve the quality of satellite flux records and the spatial distribution of surface measurement sites are recommended, along with more rigorous analysis of the origins of observed insolation variations, in order to improve our understanding of both long- and short-term variability in the downwelling solar flux at the Earth's surface. 1640 Remote sensing; 3359 Radiative processes; 3305 Climate change and variability; Satellite; Shortwave radiation; 1814 Energy budgets; trend
L'Ecuyer, Tristan S.; Wood, Norman B.; Haladay, Taryn; Stephens, Graeme L.; Stackhouse, Paul W.L'Ecuyer, T. S., N. B. Wood, T. Haladay, G. L. Stephens, P. W. Stackhouse, 2008: Impact of clouds on atmospheric heating based on the R04 CloudSat fluxes and heating rates data set. Journal of Geophysical Research: Atmospheres, 113(D8), D00A15. doi: 10.1029/2008JD009951. Among the largest uncertainties in quantifying the radiative impacts of clouds are those that arise from the inherent difficulty in precisely specifying the vertical distribution of cloud optical properties using passive satellite measurements. Motivated by the need to address this problem, CloudSat was launched in April 2006 carrying into orbit the first millimeter wavelength cloud radar to be flown in space. Retrieved profiles of liquid and ice cloud microphysical properties from this Cloud Profiling Radar form the basis of the CloudSat's fluxes and heating rates algorithm, 2B-FLXHR, a standard product that provides high vertical resolution profiles of radiative fluxes and atmospheric heating rates on the global scale. This paper describes the physical basis of the 2B-FLXHR algorithm and documents the first year of 2B-FLXHR data in the context of assessing the radiative impact of clouds on global and regional scales. The analysis confirms that cloud contributions to atmospheric radiative heating are small on the global scale because of a cancelation of the much larger regional heating from high clouds in the tropics and cooling from low clouds at higher latitudes. Preliminary efforts to assess the accuracy of the 2B-FLXHR product using coincident CERES data demonstrate that outgoing longwave fluxes are better represented than those in the shortwave but both exhibit good agreement with CERES on scales longer than 5 days and larger than 5°. Colocated CALIPSO observations of clouds that are undetected by CloudSat further indicate that while thin cirrus can introduce modest uncertainty in the products, low clouds that are obscured by ground clutter represent a far more important source of error in the current 2B-FLXHR product that must be addressed in subsequent versions of the algorithm. clouds; 0321 Cloud/radiation interaction; 3359 Radiative processes; 3310 Clouds and cloud feedbacks; CloudSat; radiation; 0341 Middle atmosphere: constituent transport and chemistry
Lin, Bing; Stackhouse, Paul W.; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang; Hinkelman, Laura M.Lin, B., P. W. Stackhouse, P. Minnis, B. A. Wielicki, Y. Hu, W. Sun, T. Fan, L. M. Hinkelman, 2008: Assessment of global annual atmospheric energy balance from satellite observations. Journal of Geophysical Research: Atmospheres, 113(D16), D16114. doi: 10.1029/2008JD009869. Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface as well as latent and sensible heat over the oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimates. Global annual means of the TOA net radiation obtained from both satellite direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 W/m2, respectively. The estimated atmospheric and surface heat imbalances are about −8 and 9 W/m2, respectively, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and the likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget: the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements has significantly reduced the bias errors in the observed global energy budgets of the climate system. 3309 Climatology; radiation; 1814 Energy budgets; energy budget; latent and sensible heat
Yang, Kun; Pinker, Rachel T.; Ma, Yaoming; Koike, Toshio; Wonsick, Margaret M.; Cox, Stephen J.; Zhang, Yuanchong; Stackhouse, PaulYang, K., R. T. Pinker, Y. Ma, T. Koike, M. M. Wonsick, S. J. Cox, Y. Zhang, P. Stackhouse, 2008: Evaluation of satellite estimates of downward shortwave radiation over the Tibetan Plateau. Journal of Geophysical Research: Atmospheres, 113(D17), D17204. doi: 10.1029/2007JD009736. The state-of-the-art satellite products of downward shortwave radiation over the Tibetan Plateau against ground observations are evaluated in this study. The satellite products include the International Satellite Cloud Climatology Project-Flux Data (ISCCP-FD) as produced at the NASA Goddard Institute for Space Studies (GISS) from the ISCCP D1 data, the Global Energy and Water Cycle Experiment-Surface Radiation Budget (GEWEX-SRB) results as derived at the NASA Langley Research Center (LaRC) from the ISCCP DX data, and a University of Maryland product derived with a modified version of the University of Maryland Surface Radiation Budget (UMD-SRB) model as implemented with METEOSAT-5 observations. These products are at different spatial and temporal resolutions, and the evaluation is performed at their native resolutions. Comparisons indicate that, in this region of great variation in elevation, using hourly, spatially homogeneous, and high resolution satellite data (UMD-SRB) compares more favorably with surface measurements than products that use three hourly, sparse subsamples at coarse resolutions (ISCCP-FD and GEWEX-SRB). Discrepancies among the satellite products are usually larger in highly variable terrain (such as in the Himalayas region) and smaller for nonvariable terrain (such as in the central Plateau). This suggests that errors of satellite products are spatially dependent over the Tibet. Therefore caution needs to be exercised when extending comparison results based on limited in situ data from accessible sites to the entire Plateau. Attention should be also given to the quality of input parameters besides cloud properties, as there are large discrepancies among the satellite products for clear-sky radiation. satellite remote sensing; 3311 Clouds and aerosols; 3359 Radiative processes; Shortwave radiation; Tibetan Plateau; 3322 Land/atmosphere interactions; 3333 Model calibration
Zell, E.; Engel-Cox, J.; Eckman, R.; Stackhouse, P.Zell, E., J. Engel-Cox, R. Eckman, P. Stackhouse, 2008: Application of Satellite Sensor Data and Models for Energy Management. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 1(1), 5-17. doi: 10.1109/JSTARS.2008.2001142. Effective, environmentally sound development, production, and delivery of energy depend on Earth monitoring information. Satellite remote sensing data and products provide unique, objective information that has the additional advantage of yielding global, homogeneous, and repetitive coverage. Satellite remote sensing data and products have been used extensively in parts of the energy sector for applications ranging from climatology to identification of solar and wind energy sources, yet there is significant potential to expand energy applications. This paper discusses the key energy sector organizations and decision-support tools with the greatest potential to benefit from new applications of satellite remote sensing data, identifies relevant remote sensing data and products with a focus on NASA Earth science resources, and provides examples that show the added value of the Earth observations. These examples come from the application of NASA data to solar energy information needs. Although continued work for support of solar energy is warranted, this paper focuses on areas identified with the greatest demonstrated potential for new or expanded applications: renewable energy (specifically wind, biomass, and hydroelectric resources), load forecasting, and long-term energy modeling. This study also addresses the evolving context of the Global Earth Observation System of Systems (GEOSS), and the broader framework of integrating satellite remote sensing into energy sector decision-support tools. Remote sensing; Satellites; NASA; artificial satellites; solar energy; Acoustic sensors; biofuel; biomass resource; decision support tools; Earth monitoring information; ecology; energy delivery; energy development; Energy management; energy production; energy sector organizations; Geoscience; GEOSS; Global Earth Observation System of Systems; hydroelectric power; hydroelectric resource; load forecasting; long term energy modeling; NASA Earth science resources; Remote monitoring; renewable energy; satellite remote sensing data; satellite remote sensing products; satellite sensor data; solar power; sustainable development; wind energy; wind power; wind resource
Yongxiang Hu; Wielicki, B. A.; Ping Yang; Stackhouse, P. W.; Lin, B.; Young, D. F.Yongxiang Hu, ., B. A. Wielicki, . Ping Yang, P. W. Stackhouse, B. Lin, D. F. Young, 2004: Application of deep convective cloud albedo observation to satellite-based study of the terrestrial atmosphere: monitoring the stability of spaceborne measurements and assessing absorption anomaly. IEEE Transactions on Geoscience and Remote Sensing, 42(11), 2594-2599. doi: 10.1109/TGRS.2004.834765. An objective method is developed to monitor the stability of spaceborne instruments, aimed at distinguishing climate trend from instrument drift in satellite-based climate observation records. This method is based on four-years of Clouds and the Earth's Radiant Energy System (CERES) broadband observations of deep convective cloud systems with cloud-top temperature lower than 205 K and with large optical depths. The implementation of this method to the CERES instrument stability analysis reveals that the monthly albedo distributions are practically the same for deep convective clouds with CERES measurements acquired from both the Tropical Rainfall Measuring Mission and Terra satellite platforms, indicating that CERES instruments are well calibrated and stable during both missions. Furthermore, with a nonlinear regression neural network narrowband-broadband conversion, this instrument-stability monitoring method can also be applied to narrowband instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible Infrared Scanner (VIRS). The results show that the drifts associated with both VIRS and MODIS instruments are less than 1% during a four-year period. Since the CERES albedo measurements are highly accurate, the absorptance of these opaque clouds can be reliably estimated. The absorptions of these clouds from observations are around 25%, whereas the absorptions from theory can be as low as 18%, depending on ice cloud microphysics. calibration; clouds; Earth; atmospheric techniques; Clouds and the Earth's Radiant Energy System; Instruments; Terrestrial atmosphere; atmospheric measuring apparatus; Tropical Rainfall Measuring Mission; Monitoring; albedo; Atmospheric measurements; radiative transfer; Absorption; artificial satellites; data acquisition; deep convective cloud; instrumentation; Moderate Resolution Imaging Spectroradiometer; MODIS; Stability; VIRS; climatology; remote sensing; Clouds; 4 yr; absorptance estimation; Absorption anomaly; absorption anomaly assessment; albedo distributions; CERES broadband observations; climate trend; cloud optical depths; cloud-top temperature; deep convective cloud albedo observation; deep convective cloud systems; ice cloud microphysics; instrument drift; instrument stability; narrowband instruments; nonlinear regression neural network narrowband-broadband conversion; objective method; opaque cloud absorptions; satellite-based climate observation; satellite-based study; s
Chiacchio, Marc; Francis, Jennifer; Stackhouse, PaulChiacchio, M., J. Francis, P. Stackhouse, 2002: Evaluation of Methods to Estimate the Surface Downwelling Longwave Flux during Arctic Winter. Journal of Applied Meteorology, 41(3), 306-318. doi: 10.1175/1520-0450(2002)041<0306:EOMTET>2.0.CO;2. Abstract Surface longwave radiation fluxes dominate the energy budget of nighttime polar regions, yet little is known about the relative accuracy of existing satellite-based techniques to estimate this parameter. We compare eight methods to estimate the downwelling longwave radiation flux and to validate their performance with measurements from two field programs in the Arctic: the Coordinated Eastern Arctic Experiment (CEAREX) conducted in the Barents Sea during the autumn and winter of 1988, and the Lead Experiment performed in the Beaufort Sea in the spring of 1992. Five of the eight methods were developed for satellite-derived quantities, and three are simple parameterizations based on surface observations. All of the algorithms require information about cloud fraction, which is provided from the NASA–NOAA Television and Infrared Observation Satellite (TIROS) Operational Vertical Sounder (TOVS) polar pathfinder dataset (Path-P); some techniques ingest temperature and moisture profiles (also from Path-P); one-half of the methods assume that clouds are opaque and have a constant geometric thickness of 50 hPa, and three include no thickness information whatsoever. With a somewhat limited validation dataset, the following primary conclusions result: 1) all methods exhibit approximately the same correlations with measurements and rms differences, but the biases range from −34 W m−2 (16% of the mean) to nearly 0; 2) the error analysis described here indicates that the assumption of a 50-hPa cloud thickness is too thin by a factor of 2 on average in polar nighttime conditions; 3) cloud-overlap techniques, which effectively increase mean cloud thickness, significantly improve the results; 4) simple Arctic-specific parameterizations performed poorly, probably because they were developed with surface-observed cloud fractions whereas the tests discussed here used satellite-derived effective cloud fractions; and 5) the single algorithm that includes an estimate of cloud thickness exhibits the smallest differences from observations.
Smith, G. Louis; Wilber, Anne C.; Gupta, Shashi K.; Stackhouse, Paul W.Smith, G. L., A. C. Wilber, S. K. Gupta, P. W. Stackhouse, 2002: Surface Radiation Budget and Climate Classification. J. Climate, 15(10), 1175-1188. doi: 10.1175/1520-0442(2002)015<1175:SRBACC>2.0.CO;2. Abstract The surface radiation budget of a region is strongly tied to its climate. An 8-yr climatology of surface radiation budget components for 2.5° regions over the earth is examined in order to learn how the regional climate and surface radiation are related. The yearly cycles of a few individual regions were studied by plotting monthly mean net longwave flux as a function of net shortwave flux at the surface. These plots show trajectories that are characteristic of the climate class. The behavior of the trajectories of surface radiation and their relation to the regional climate can be understood with simple conceptual models for many cases. From an examination of these trajectories, a set of parameters is developed, such as mean net longwave flux and range of net shortwave flux, which distinguish various climate classes on the basis of the surface radiation. These criteria are applied to produce a map of regional climate classes based on surface radiation, similar to those of Koeppen or Trewartha and Horn, which were based on vegetation, temperature, and precipitation. The current maps can be used to explore the relationships between surface radiation and regional climate.
Gupta, Shashi K.; Kratz, David P.; Stackhouse, Paul W.; Wilber, Anne C.Gupta, S. K., D. P. Kratz, P. W. Stackhouse, A. C. Wilber, 2001: The Langley Parameterized Shortwave Algorithm (LPSA) for Surface Radiation Budget Studies. 1.0. An efficient algorithm was developed during the late 1980's and early 1990's by W. F. Staylor at NASA/LaRC for the purpose of deriving shortwave surface radiation budget parameters on a global scale. While the algorithm produced results in good agreement with observations, the lack of proper documentation resulted in a weak acceptance by the science community. The primary purpose of this report is to develop detailed documentation of the algorithm. In the process, the algorithm was modified whenever discrepancies were found between the algorithm and its referenced literature sources. In some instances, assumptions made in the algorithm could not be justified and were replaced with those that were justifiable. The algorithm uses satellite and operational meteorological data for inputs. Most of the original data sources have been replaced by more recent, higher quality data sources, and fluxes are now computed on a higher spatial resolution. Many more changes to the basic radiation scheme and meteorological inputs have been proposed to improve the algorithm and make the product more useful for new research projects. Because of the many changes already in place and more planned for the future, the algorithm has been renamed the Langley Parameterized Shortwave Algorithm . energy budgets; atmospheric radiation; Algorithms; spatial resolution; meteorological parameters
Whitlock, C. H.; Brown, D. E.; Chandler, W. S.; DiPasquale, R. C.; Ritchey, Nancy A.; Gupta, Shashi K.; Wilber, Anne C.; Kratz, David P.; Stackhouse, Paul W.Whitlock, C. H., D. E. Brown, W. S. Chandler, R. C. DiPasquale, N. A. Ritchey, S. K. Gupta, A. C. Wilber, D. P. Kratz, P. W. Stackhouse, 2001: Global Surface Solar Energy Anomalies Including El Niño and La Niña Years*. Journal of Solar Energy Engineering, 123(3), 211-215. doi: 10.1115/1.1384570. Weather anomalies that increase clouds influence the reliability of both renewable energy and building environmental-control systems. Non-grid solar power systems may run out of capacity for such items as communications electronics, flood-warning stream gages, refrigerators, and small village power systems. This paper provides 1×1-degree resolution global maps that identify those regions which experienced large abnormal solar energy during a 10-year period. A source is identified where specific values for maximum year-to-year variability can be obtained in regions where ground-site measurements do not exist. The information may aid in the selection of safety factors for solar power systems.
Gupta, Shashi K.; Ritchey, Nancy A.; Wilber, Anne C.; Whitlock, Charles H.; Gibson, Gary G.; Stackhouse, Paul W.Gupta, S. K., N. A. Ritchey, A. C. Wilber, C. H. Whitlock, G. G. Gibson, P. W. Stackhouse, 1999: A Climatology of Surface Radiation Budget Derived from Satellite Data. J. Climate, 12(8), 2691-2710. doi: 10.1175/1520-0442(1999)012<2691:ACOSRB>2.0.CO;2. Abstract Climatological averages of surface radiation budget parameters, namely, the shortwave and longwave surface radiative fluxes, have been derived for each month of the year on a global scale. These climatological averages were derived from an 8-yr (96 month) time series of monthly average fluxes. The monthly averages were computed using fast radiation parameterizations and satellite data from the International Satellite Cloud Climatology Project and the Earth Radiation Budget Experiment. Results are presented as time series of hemispheric and global averages and as geographical distributions and time–latitude cross sections of climatological averages. The spatial/temporal variabilities of the results were found to be clearly related to the corresponding variabilities of meteorological and other inputs to the parameterizations. Numerous comparisons of the present results were made with available surface measurements for the purpose of validation. In most cases, the differences were found to be within the uncertainties of the measurements. In some cases, where they were large, the differences were attributable to identifiable deficiencies in the meteorological inputs and/or the surface measurements. However, large differences remained unexplained in a few cases. Anomalies of shortwave and longwave surface fluxes during the 1986/87 El Niño–Southern Oscillation episode show a strong relationship with corresponding top-of-atmosphere anomalies derived from an independent data source. Comparisons with results from several general circulation models showed large differences, but, in most cases, these were attributable to well-recognized deficiencies in model simulations. Global annual average downward and net shortwave fluxes were found to be about 185 and 161 W m−2, respectively. These values are 10–20 W m−2 lower than those obtained from the general circulation models, but they are in good agreement with other satellite-derived estimates. Global annual average downward and net longwave fluxes were found to be about 348 and −48 W m−2, respectively, which are about 10–15 W m−2 higher than corresponding values from general circulation models. Atmospheric shortwave absorption derived from the present results is 10–15 W m−2 larger than from the general circulation models, but it is in good agreement with another estimate based on satellite data.
