Radiation budgetSlide 2ProblemsSatellites/sensorsSlide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Solar zenith angleSlide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29ERB climatologiesSlide 31Cloud forcingSlide 33Cloud ForcingSlide 35Radiation budgetRadiation budgetMETR280METR280Satellite Meteorology/ClimatologySatellite Meteorology/ClimatologyProfessor Menglin JinProfessor Menglin JinRadiation budgetRadiation budgetBasic definitionsBasic definitionsSome problems with measuring radiation Some problems with measuring radiation budget using satellitesbudget using satellitesSatellites/sensors which have been used to Satellites/sensors which have been used to measure radiation budgetmeasure radiation budgetSolar constantSolar constantTop of atmosphere radiation budgetTop of atmosphere radiation budgetSurface Radiation BudgetSurface Radiation BudgetGlobal-scale ERB climatologiesGlobal-scale ERB climatologiesProblemsProblemsProblems with measuring radiation Problems with measuring radiation budget componentsbudget components•Inverse problemInverse problem•Diurnal problemDiurnal problem•Spectral correction problemSpectral correction problem•Angular dependence problemAngular dependence problemSatellites/sensorsSatellites/sensorsSatellites/sensorsSatellites/sensors•NOAA polar orbitersNOAA polar orbiters–Reflected SWR (0.5-0.7 Reflected SWR (0.5-0.7 m)m)–LWR (TIR) (10.5-12.5 LWR (TIR) (10.5-12.5 m)m)•Nimbus 6 and 7 (‘75-’78 and ‘78-’87)Nimbus 6 and 7 (‘75-’78 and ‘78-’87)–Earth Radiation Budget instrumentEarth Radiation Budget instrument–0.2-3.8 0.2-3.8 m (SWR) and 0.2-50 m (SWR) and 0.2-50 m (broadl)m (broadl)–LWR = Broad - SWRLWR = Broad - SWR•Earth Radiation Budget Experiment (ERBE)Earth Radiation Budget Experiment (ERBE)–ERBS and NOAA 9 and 10ERBS and NOAA 9 and 10EOS program (NASA)EOS program (NASA)•TERRA (EOS AM)TERRA (EOS AM)–Clouds and Earth’s Radiant Energy System Clouds and Earth’s Radiant Energy System (CERES)(CERES)–ToA radiation budgetToA radiation budget–Cloud height, amount, particle sizeCloud height, amount, particle size–Next generation ERBENext generation ERBE–Multiangle Imaging SpectroRadiometer (MISR)Multiangle Imaging SpectroRadiometer (MISR)–Surface planetary albedo measurementsSurface planetary albedo measurements–Multiangle measurementsMultiangle measurementsSatellites/sensorsSatellites/sensorsSatellites/sensorsSatellites/sensorsTerraTerra•Moderate Resolution Imaging Spectroradiometer Moderate Resolution Imaging Spectroradiometer ((MODISMODIS))–Surface temperature*Surface temperature*–Snow cover and reflectance*Snow cover and reflectance*–Cloud cover with 250m resolution by day and Cloud cover with 250m resolution by day and 1,000m resolution at night*1,000m resolution at night*–Cloud properties*Cloud properties*–Aerosol properties* Aerosol properties* –Fire occurrence, size, and temperatureFire occurrence, size, and temperature–Cirrus cloud cover*Cirrus cloud cover*Multifrequency Imaging Microwave Multifrequency Imaging Microwave Radiometer (MIMR)Radiometer (MIMR)•Similar to ESMR, SMMR, SSM/ISimilar to ESMR, SMMR, SSM/I–ProductsProducts–Precipitation, soil moisture*Precipitation, soil moisture*–Ice and snow cover*Ice and snow cover*–SST*SST*–Oceanic wind speedOceanic wind speed–Atmospheric cloud water content and water vapor*Atmospheric cloud water content and water vapor**Significant to radiation budget*Significant to radiation budgetRadiation budgetRadiation budgetSolar constantSolar constant•The average annual irradiance received outside The average annual irradiance received outside the Earth’s atmosphere on a surface normal to the Earth’s atmosphere on a surface normal to the incident radiation and at the Earth’s mean the incident radiation and at the Earth’s mean distance from Sun.distance from Sun.•Roughly 1370 WmRoughly 1370 Wm-2-2•Interannual variation of 0.2 WmInterannual variation of 0.2 Wm-2-2, but annual , but annual variation of 3 Wm-2variation of 3 Wm-2Top of atmosphere radiation budgetTop of atmosphere radiation budget•We want to know the SW radiate exitance (MSW) We want to know the SW radiate exitance (MSW) and LW radiant exitance (MLW), a.k.a. Outgoing and LW radiant exitance (MLW), a.k.a. Outgoing Longwave RadiationLongwave RadiationActive Cavity Radiometer Irradiance MonitorsIncident solar radiaiton? http://climate.gsfc.nasa.gov/static/cahalan/Radiation/NoCloud.htmlClass ParticipationIf solar constant is 1370W/m2What isRadiation budgetRadiation budgetSurface radiation budgetSurface radiation budget•Must make corrections for the atmosphereMust make corrections for the atmosphere•ComponentsComponents–Downwelling SWR (insolation)Downwelling SWR (insolation)–Upwelling SWR (reflected)Upwelling SWR (reflected)–Downwelling LWR (atmospheric emission)Downwelling LWR (atmospheric emission)–Upwelling LWR (terrestrial emission)Upwelling LWR (terrestrial emission)•Net radiation is the sum of the componentsNet radiation is the sum of the componentsSatellites detect the radiation emitted by the Earth + reflected solar radiation, modified by the atmosphereInstantaneous Fluxes at TOA and Angular Distribution ModelsCERES Radiance Measurement TOA Flux Estimate SWLWWNfqoqSatelliteSun•θo: Solar zenith angle. (radiance direction)θ: Zenith angle of the radiance. Range: 0-180.; 0 for straight-up; 90 for horizon; and 180 for straight-down. φ: Relative azimuth angle of radiance. Range: 0-360.; 0 as forward scattering; 180 as back scattering. Z NadirSolar zenith angle Solar zenith angle•Downwelling SWRDownwelling SWR–Three possible fatesThree possible fatesToA insolation = reflected at top of atm. + absorbed by atm. + downwelling ToA insolation = reflected at top of atm. + absorbed by atm. + downwelling SWR at surfaceSWR at surface•cos(cos(qq)): cosine of the solar zenith angle: cosine of the solar zenith angle•irradianceirradiance: A radiant flux density incident on some area (Wm: A radiant flux density incident on some area (Wm-2-2))•We’re interested in EWe’re interested in Esfcsfc•Assuming isotropic reflection (same amount of reflection in every Assuming isotropic reflection (same amount of reflection in every direction)...direction)...sunEsunsunEsunA