Satellite Retrieval of Downwelling Shortwave Surface Flux and Diffuse Fraction under All Sky Conditions in the Framework of the LSA SAF Program (Part 1: Methodology)

Several studies have shown that changes in incoming solar radiation and variations of the diffuse fraction can significantly modify the vegetation carbon uptake. Hence, monitoring the incoming solar radiation at large scale and with high temporal frequency is crucial for this reason along with many others. The EUMETSAT Satellite Application Facility for Land Surface Analysis (LSA SAF) operationally disseminates in near real time estimates of the downwelling shortwave radiation at the surface since 2005. This product is derived from observations provided by the SEVIRI instrument onboard the Meteosat Second Generation series of geostationary satellites, which covers Europe, Africa, the Middle East, and part of South America. However, near real time generation of the diffuse fraction at the surface level has only recently been initiated. The main difficulty towards achieving this goal was the general lack of accurate information on the aerosol particles in the atmosphere. This limitation is nowadays less important thanks to the improvements in atmospheric numerical models. This study presents an upgrade of the LSA-SAF operational retrieval method, which provides the simultaneous estimation of the incoming solar radiation and its diffuse fraction from satellite every 15 minutes. The upgrade includes a comprehensive representation of the influence of aerosols based on physical approximations of the radiative transfer within an atmosphere-surface associated medium. This article explains the retrieval method, discusses its limitations and differences with the previous method, and details the characteristics of the output products. A companion article will focus on the evaluation of the products against independent measurements of solar radiation. Finally, the access to the source code is provided through an open access platform in order to share with the community the expertise on the satellite retrieval of this variable.

[1]  A. Ohmura,et al.  First global WCRP shortwave surface radiation budget dataset , 1995 .

[2]  Emilio Cuevas,et al.  Description of the Baseline Surface Radiation Network (BSRN) station at the Izaña Observatory (2009–2017): measurements and quality control/assurance procedures , 2019, Geoscientific Instrumentation, Methods and Data Systems.

[3]  Takashi Minemoto,et al.  Estimation of global tilted irradiance and output energy using meteorological data and performance of photovoltaic modules , 2013 .

[4]  E. Raschke,et al.  Incident Solar Radiation over Europe Estimated from METEOSAT Data. , 1984 .

[5]  Andreas Kazantzidis,et al.  Accuracy of ground surface broadband shortwave radiation monitoring , 2014 .

[6]  Flurin Babst,et al.  Verification of NCEP Reanalysis Shortwave Radiation With Mesoscale Remote Sensing Data , 2008, IEEE Geoscience and Remote Sensing Letters.

[7]  James K. B. Bishop,et al.  Spatial and temporal variability of global surface solar irradiance , 1991 .

[8]  Bin Zhao,et al.  The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2). , 2017, Journal of climate.

[9]  Xavier Ceamanos,et al.  An efficient approach to estimate the transmittance and reflectance of a mixture of aerosol components , 2014 .

[10]  W. Beckman,et al.  Diffuse fraction correlations , 1990 .

[11]  Jean-Louis Roujean,et al.  Near real‐time provision of downwelling shortwave radiation estimates derived from satellite observations , 2008 .

[12]  Rachel T. Pinker,et al.  Modeling Surface Solar Radiation: Model Formulation and Validation , 1985 .

[13]  Stanley G. Benjamin,et al.  Assessment of land-surface energy budgets from regional and global models , 1999 .

[14]  B. E. Psiloglou,et al.  Performance of the meteorological radiation model during the solar eclipse of 29 March 2006 , 2007 .

[15]  Bernhard Mayer,et al.  Atmospheric Chemistry and Physics Technical Note: the Libradtran Software Package for Radiative Transfer Calculations – Description and Examples of Use , 2022 .

[16]  Eleni Marinou,et al.  Dust impact on surface solar irradiance assessed with model simulations, satellite observations and ground-based measurements , 2017 .

[17]  K. T. Kriebel,et al.  The cloud analysis tool APOLLO: Improvements and validations , 2003 .

[18]  Martin Wild,et al.  Pollution trends over Europe constrain global aerosol forcing as simulated by climate models , 2014 .

[19]  W. L. Darnell,et al.  Estimation of surface insolation using sun-synchronous satellite data , 1988 .

[20]  Anu Sharma,et al.  Validation of the SARAH-E Satellite-Based Surface Solar Radiation Estimates over India , 2018, Remote. Sens..

[21]  Ina Mattis,et al.  Evaluation of ECMWF-IFS (version 41R1) operational model forecasts of aerosol transport by using ceilometer network measurements , 2018, Geoscientific Model Development.

[22]  W. Buermann,et al.  Small global effect on terrestrial net primary production due to increased fossil fuel aerosol emissions from East Asia since the turn of the century , 2016, Geophysical research letters.

[23]  Harry D. Kambezidis.  Current Trends in Solar Radiation Modeling: The Paradigm of MRM , 2016 .

[24]  L. Wald,et al.  McClear: a new model estimating downwelling solar radiation at ground level in clear-sky conditions , 2013 .

[25]  Nicholas C. Coops,et al.  Validation of Solar Radiation Surfaces from MODIS and Reanalysis Data over Topographically Complex Terrain , 2009 .

[26]  Zhanqing Li,et al.  A New Parameterization for the Determination of Solar Flux Absorbed at the Surface from Satellite Measurements , 1995 .

[27]  Xavier Ceamanos,et al.  Improved retrieval of direct and diffuse downwelling surface shortwave flux in cloudless atmosphere using dynamic estimates of aerosol content and type: application to the LSA-SAF project , 2014 .

[28]  Y. Kerr,et al.  Satellite Estimation of Solar Irradiance at the Surface of the Earth and of Surface Albedo Using a Physical Model Applied to Metcosat Data , 1987 .

[29]  Zhanqing Li,et al.  Global climatologies of solar radiation budgets at the surface and in the atmosphere from 5 years of ERBE data , 1993 .

[30]  J. A. Ruiz-Arias,et al.  Extensive worldwide validation and climate sensitivity analysis of direct irradiance predictions from 1-min global irradiance , 2016 .

[31]  Robert Pitz-Paal,et al.  Direct normal irradiance related definitions and applications: The circumsolar issue , 2014 .

[32]  M. Pinar Mengüç,et al.  Comparison of radiative transfer approximations for a highly forward scattering planar medium. , 1983 .

[33]  Jerald A. Brotzge,et al.  A Two-Year Comparison of the Surface Water and Energy Budgets between Two OASIS Sites and NCEP–NCAR Reanalysis Data , 2004 .

[34]  B. Barkstrom,et al.  Cloud-Radiative Forcing and Climate: Results from the Earth Radiation Budget Experiment , 1989, Science.

[35]  B. E. Psiloglou,et al.  Comparison between MRM simulations, CAMS and PVGIS databases with measured solar radiation components at the Methoni station, Greece , 2020 .

[36]  Lucien Wald,et al.  Decoupling the effects of clear atmosphere and clouds to simplify calculations of the broadband solar irradiance at ground level , 2014 .

[37]  Song-You Hong,et al.  Comparison of NCEP-NCAR Reanalysis with 1987 FIFE Data , 1996 .

[38]  P. Poggi,et al.  Correlations for direct normal and global horizontal irradiation on a French Mediterranean site , 1991 .

[39]  S. Dewitte,et al.  SOVAP/Picard, a Spaceborne Radiometer to Measure the Total Solar Irradiance , 2014 .

[40]  B. Psiloglou,et al.  On broadband Rayleigh scattering in the atmosphere for solar radiation modelling , 1995 .

[41]  J. D. Tarpley.  Estimating Incident Solar Radiation at the Surface from Geostationary Satellite Data , 1979 .

[42]  P. Cox,et al.  Impact of changes in diffuse radiation on the global land carbon sink , 2009, Nature.

[43]  K. T. Kriebel,et al.  Optical Properties of Clouds Derived from Fully Cloudy AVHRR Pixels , 1989 .

[44]  Pedro Viterbo,et al.  The European Summer of 2003: Sensitivity to Soil Water Initial Conditions , 2006 .

[45]  S. N. Tiwari,et al.  Bidirectional Reflectance Functions for Application to Earth Radiation Budget Studies , 1997 .

[46]  Lucas Alados-Arboledas,et al.  Short-wave radiative forcing at the surface for cloudy systems at a midlatitude site , 2013 .

[47]  B. E. Psiloglou,et al.  Meteorological Radiation Model (MRM v6.1): Improvements in diffuse radiation estimates and a new approach for implementation of cloud products , 2017 .

[48]  Domenico Cimini,et al.  Improvement in Surface Solar Irradiance Estimation Using HRV/MSG Data , 2018, Remote. Sens..

[49]  J. Duffie,et al.  Estimation of the diffuse radiation fraction for hourly, daily and monthly-average global radiation , 1982 .

[50]  J. Schmetz,et al.  Supplement to An Introduction to Meteosat Second Generation (MSG): SEVIRI CALIBRATION , 2002 .

[51]  V. Ramanathan,et al.  Direct observations of aerosol radiative forcing over the tropical Indian Ocean during the January-F , 1998 .

[52]  C. Gautier,et al.  A Simple Physical Model to Estimate Incident Solar Radiation at the Surface from GOES Satellite Data , 1980 .

[53]  M. Wild,et al.  Spatial representativeness of ground‐based solar radiation measurements , 2013 .

[54]  H. Guillard,et al.  A method for the determination of the global solar radiation from meteorological satellite data , 1986 .

[55]  B. Psiloglou,et al.  Predicting the broadband transmittance of the uniformly mixed gases (CO2, CO, N2O, CH4 and O2) in the atmosphere, for solar radiation models , 1995 .

[56]  R. Pinker,et al.  Modeling Surface Solar Irradiance for Satellite Applications on a Global Scale , 1992 .

[57]  Domenico Cimini,et al.  Nowcasting Surface Solar Irradiance with AMESIS via Motion Vector Fields of MSG-SEVIRI Data , 2018, Remote. Sens..

[58]  Lucien Wald,et al.  Fast radiative transfer parameterisation for assessing the surface solar irradiance: The Heliosat-4 method , 2017 .

[59]  L. Wald,et al.  Improving the McClear model estimating the downwelling solar radiation at ground level in cloud-free conditions – McClear‑v3 , 2019, Meteorologische Zeitschrift.

[60]  Isabel F. Trigo,et al.  Incoming Solar and Infrared Radiation Derived from METEOSAT: Impact on the Modeled Land Water and Energy Budget over France , 2012 .

[61]  S. K. Satheesh,et al.  Large differences in tropical aerosol forcing at the top of the atmosphere and Earth's surface , 2000, Nature.

[62]  Jean-Louis Roujean,et al.  Comparing Operational MSG/SEVIRI Land Surface Albedo Products From Land SAF With Ground Measurements and MODIS , 2010, IEEE Transactions on Geoscience and Remote Sensing.

[63]  R. Dickinson.  Land Surface Processes and Climate—Surface Albedos and Energy Balance , 1983 .

[64]  Sandra C. Freitas,et al.  The Satellite Application Facility for Land Surface Analysis , 2011 .

[65]  Ana M. Gracia-Amillo,et al.  Evaluation of global horizontal irradiance estimates from ERA5 and COSMO-REA6 reanalyses using ground and satellite-based data , 2018 .

[66]  Herman Eerens,et al.  Evaluation of MSG-derived global radiation estimates for application in a regional crop model , 2012 .

[67]  Xavier Ceamanos,et al.  AERUS‐GEO: A newly available satellite‐derived aerosol optical depth product over Europe and Africa , 2014 .

[68]  M. R. van den Broeke,et al.  Clouds enhance Greenland ice sheet meltwater runoff , 2016, Nature Communications.

[69]  Yong Xue,et al.  Can satellite-derived aerosol optical depth quantify the surface aerosol radiative forcing? , 2014 .

[70]  Pierre Ineichen.  High Turbidity Solis Clear Sky Model: Development and Validation , 2018, Remote. Sens..

[71]  N. C. Strugnell,et al.  First operational BRDF, albedo nadir reflectance products from MODIS , 2002 .

[72]  L. Wald,et al.  The method Heliosat-2 for deriving shortwave solar radiation from satellite images , 2004 .

[73]  Jean-Philippe Gastellu-Etchegorry,et al.  A canopy radiative transfer scheme with explicit FAPAR for the interactive vegetation model ISBA‐A‐gs: Impact on carbon fluxes , 2013 .

[74]  A. T. Young,et al.  Revised optical air mass tables and approximation formula. , 1989, Applied optics.

[75]  Thomas Carlund,et al.  Validation of CM SAF Surface Solar Radiation Datasets over Finland and Sweden , 2015, Remote. Sens..

[76]  Bernhard Geiger,et al.  Satellite Application Facilities irradiance products: hourly time step comparison and validation over Europe , 2009 .

[77]  M. Derrien,et al.  MSG/SEVIRI cloud mask and type from SAFNWC , 2005 .

[78]  J. D. Tarpley,et al.  The multi‐institution North American Land Data Assimilation System (NLDAS): Utilizing multiple GCIP products and partners in a continental distributed hydrological modeling system , 2004 .

[79]  J. A. Ruiz-Arias,et al.  Proposal of a regressive model for the hourly diffuse solar radiation under all sky conditions , 2010 .

[80]  J. Hansen,et al.  A parameterization for the absorption of solar radiation in the earth's atmosphere , 1974 .

[81]  Catherine Gautier,et al.  Surface Solar Radiation Flux and Cloud Radiative Forcing for the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP): A Satellite, Surface Observations, and Radiative Transfer Model Study , 1997 .

[82]  J. Orgill,et al.  Correlation equation for hourly diffuse radiation on a horizontal surface , 1976 .

[83]  O. Boucher,et al.  Description and evaluation of the tropospheric aerosol scheme in the Integrated Forecasting System (IFS-AER, cycle 45R1) of ECMWF , 2019 .

[84]  Xavier Ceamanos,et al.  On the Importance of Aerosol Composition for Estimating Incoming Solar Radiation: Focus on the Western African Stations of Dakar and Niamey during the Dry Season , 2015, ATMOS 2015.

[85]  María Amparo Gilabert,et al.  Validation of daily global solar irradiation images from MSG over Spain , 2013 .

[86]  Sietse O. Los,et al.  A global dataset of atmospheric aerosol optical depth and surface reflectance from AATSR , 2012 .