Version 2 total ozone mapping spectrometer ultraviolet algorithm: problems and enhancements

Satellite instruments provide global maps of surface UV irradiance by combining backscattered radiance measurements with radiative transfer models. The accuracy of the models is limited by uncertainties in input parameters representing the atmosphere and the Earth's surface. To reduce these uncertainties, we have made enhancements to the currently operational TOMS surface UV irradiance algorithm (Version 1) by including the effects of diurnal variations of cloudiness, an improved treatment of snow/ice, and a preliminary aerosol correction. We compare results of the version 1 TOMS UV algorithm and the proposed version. We evaluate different approaches for improved treatment for average cloud attenuation within a satellite pixel, with and without snow/ ice on the ground. In addition to treating cloud transmission based only on the measurements at the local time of the TOMS observations, the results from other satellites and weather assimilation models can be used to estimate atmospheric UV irradiance transmission throughout the day. A new method is proposed to obtain a more realistic treatment of the effects from snow-covered terrain. The method is based on an empirical relation between UV reflectivity and measured snow depth. The new method reduces the bias between the TOMS UV estimations and ground-based UV measurements for snow periods. We also briefly discuss the complex problem of estimating surface UV radiation in presence of UV-absorbing aerosols. The improved (Version 2) algorithm can be applied to reprocess the existing TOMS UV irradiance and exposure estimates (since November 1978) and to future satellite sensors (e.g., GOME-2, OMI on EOS/Aura, and Triana/EPIC).

[1]  John E. Frederick,et al.  Effects of aerosols on the wavelength dependence of atmospheric transmission in the ultraviolet and visible , 1998 .

[2]  R. McKenzie,et al.  Upwelling UV spectral irradiances and surface albedo measurements at Lauder, New Zealand , 1996 .

[3]  T. Eck,et al.  Optical Properties of Atmospheric Aerosol in Maritime Environments , 2002 .

[4]  James B. Kerr,et al.  Comparison of Brewer ultraviolet irradiance measurements with total ozone mapping spectrometer satellite retrievals , 2002 .

[5]  James B. Kerr,et al.  Satellite estimation of spectral surface UV irradiance in the presence of tropospheric aerosols , 1998 .

[6]  D. K. Prinz,et al.  Validation of the UARS solar ultraviolet irradiances: Comparison with the ATLAS 1 and 2 measurements , 1996 .

[7]  Jay R. Herman,et al.  Comparisons between ground measurements of UV irradiance 290 to 380nm and TOMS UV estimates over Moscow for 1979-2000 , 2002, SPIE Optics + Photonics.

[8]  H. Slaper,et al.  Reduction of solar UV by clouds: A comparison between satellite‐derived cloud effects and ground‐based radiation measurements , 2000 .

[9]  A. T. Green,et al.  A PORTABLE INSTRUMENT FOR MEASURING GROUND REFLECTANCE IN THE ULTRAVIOLET , 1995 .

[10]  Arve Kylling,et al.  Effect of aerosols on solar UV irradiances during the Photochemical Activity and Solar Ultraviolet Radiation campaign , 1998 .

[11]  A. Smirnov,et al.  AERONET-a federated instrument network and data archive for aerosol Characterization , 1998 .

[12]  Jay R. Herman,et al.  Distribution of UV radiation at the Earth's surface from TOMS-measured UV-backscattered radiances , 1999 .

[13]  A. J. Miller,et al.  Ultraviolet Index Forecasts Issued by the National Weather Service , 1996 .

[14]  Thomas F. Eck,et al.  Measurements of irradiance attenuation and estimation of aerosol single scattering albedo for biomass burning aerosols in Amazonia , 1998 .

[15]  T. Eck,et al.  Variability of Absorption and Optical Properties of Key Aerosol Types Observed in Worldwide Locations , 2002 .

[16]  Dan Lubin,et al.  The budget of biologically active ultraviolet radiation in the Earth‐atmosphere system , 1988 .

[17]  D. Lubin,et al.  Effects of clouds and stratospheric ozone depletion on ultraviolet radiation trends , 1995, Nature.

[18]  A. Green,et al.  Influence of clouds, haze, and smog on the middle ultraviolet reaching the ground. , 1974, Applied optics.

[19]  Gary J. Rottman,et al.  Solar‐Stellar Irradiance Comparison Experiment 1: 1. Instrument design and operation , 1993 .

[20]  Paul Ginoux,et al.  A Long-Term Record of Aerosol Optical Depth from TOMS Observations and Comparison to AERONET Measurements , 2002 .

[21]  Jean Verdebout,et al.  A method to generate surface UV radiation maps over Europe using GOME, Meteosat, and ancillary geophysical data , 2000 .

[22]  P. Bhartia,et al.  Derivation of aerosol properties from satellite measurements of backscattered ultraviolet radiation , 1998 .

[23]  D. Wardle,et al.  The relationship between total ozone and spectral UV irradiance from Brewer observations and its use for derivation of total ozone from UV measurements , 1997 .

[24]  Alexander Smirnov,et al.  Characterization of the optical properties of biomass burning aerosols in Zambia during the 1997 ZIBBEE field campaign , 2001 .

[25]  M. Jacobson.  Isolating nitrated and aromatic aerosols and nitrated aromatic gases as sources of ultraviolet light absorption , 1999 .

[26]  K. Arrigo,et al.  Global mapping of underwater UV irradiances and DNA‐weighted exposures using Total Ozone Mapping Spectrometer and Sea‐viewing Wide Field‐of‐view Sensor data products , 2001 .

[27]  G. Seckmeyer,et al.  Surface UV from ERS‐2/GOME and NOAA/AVHRR data: A case study , 1997 .

[28]  Ziauddin Ahmad,et al.  Satellite estimation of spectral surface UV irradiance: 2. Effects of homogeneous clouds and snow , 2001 .

[29]  Jay R. Herman,et al.  Earth surface reflectivity climatology at 340–380 nm from TOMS data , 1997 .

[30]  Zhanqing Li,et al.  A simple and efficient method for retrieving surface UV radiation dose rate from satellite , 2000 .

[31]  G. Stenchikov,et al.  The impact of aerosols on solar ultraviolet radiation and photochemical smog. , 1997, Science.

[32]  Ernest Hilsenrath,et al.  Observations of the solar irradiance in the 200-350 nm interval during the ATLAS-1 Mission: A comparison among three sets of measurements-SSBUV, SOLSPEC, and SUSIM , 1996 .

[33]  Lawrence E. Flynn,et al.  Long‐term ozone trends derived from the 16‐year combined Nimbus 7/Meteor 3 TOMS Version 7 record , 1996 .

[34]  Glen Jaross,et al.  Earth probe total ozone mapping spectrometer (TOMS): data products user's guide , 1998 .

[35]  J. R. Herman,et al.  UV 380 NM Reflectivity of the Earth's Surface , 2001 .

[36]  Stuart A. McKeen,et al.  Effect of anthropogenic aerosols on biologically active ultraviolet radiation , 1991 .

[37]  Christos Zerefos,et al.  Spectral measurements of solar UVB radiation and its relations to total ozone, SO2, and clouds , 1993 .

[38]  V. K. Saxena,et al.  Atmospheric transmission in the ultraviolet and visible: Aerosols in cloudy atmospheres , 1998 .

[39]  Dan Lubin,et al.  Global surface ultraviolet radiation climatology from TOMS and ERBE data , 1998 .

[40]  N. Chubarova.  ULTRAVIOLET RADIATION UNDER BROKEN CLOUD CONDITIONS AS INFERRED FROM MANY-YEAR GROUND-BASED OBSERVATIONS , 1998 .

[41]  J. Lenoble,et al.  Modeling of the influence of snow reflectance on ultraviolet irradiance for cloudless sky. , 1998, Applied optics.

[42]  S. Madronich.  Implications of recent total atmospheric ozone measurements for biologically active ultraviolet radiation reaching the Earth's surface , 1992 .

[43]  G. E. Brueckner,et al.  The solar ultraviolet spectral irradiance monitor (SUSIM) experiment on board the Upper Atmosphere Research Satellite (UARS) , 1993 .

[44]  Jay R. Herman,et al.  Problems in assessment of the UV penetration into natural waters from space-based measurements , 2002, SPIE Optics + Photonics.

[45]  James B. Kerr,et al.  Satellite retrievals of erythemal UV dose compared with ground-based measurements at northern and southern , 2001 .

[46]  D. Deirmendjian.  Electromagnetic scattering on spherical polydispersions , 1969 .

[47]  P. Bhartia,et al.  Global distribution of UV-absorbing aerosols from Nimbus 7/TOMS data , 1997 .

[48]  J. Herman,et al.  Low ozone amounts during 1992–1993 from Nimbus 7 and Meteor 3 total ozone mapping spectrometers , 1994 .

[49]  S. Madronich.  The Atmosphere and UV-B Radiation at Ground Level , 1993 .

[50]  James B. Kerr,et al.  Comparison of Brewer UV irradiance measurements with TOMS satellite retrievals , 2002, SPIE Optics + Photonics.

[51]  A. J. Miller,et al.  Interannual variability of the North Polar Vortex in the lower stratosphere during the UARS Mission , 1996 .

[52]  K. Baker,et al.  Ozone depletion: ultraviolet radiation and phytoplankton biology in antarctic waters. , 1992, Science.

[53]  James B. Kerr,et al.  Satellite estimation of spectral UVB irradiance using TOMS derived total ozone and UV reflectivity , 1995 .

[54]  T. Eck,et al.  An emerging ground-based aerosol climatology: Aerosol optical depth from AERONET , 2001 .

[55]  S. Warren,et al.  A Model for the Spectral Albedo of Snow. I: Pure Snow , 1980 .

[56]  M. Blumthaler,et al.  SOLAR UVB‐ALBEDO OF VARIOUS SURFACES , 1988, Photochemistry and photobiology.

[57]  Jay R. Herman,et al.  Total ozone trends deduced from Nimbus 7 TOMS data , 1991 .

[58]  S. Warren,et al.  Reflection of solar radiation by the Antarctic snow surface at ultraviolet, visible, and near‐infrared wavelengths , 1994 .

[59]  P. Forster,et al.  Changes in ultraviolet radiation due to stratospheric and tropospheric ozone changes since preindustrial times , 1998 .

[60]  Kåre Edvardsen,et al.  Assessment of four methods to estimate surface UV radiation using satellite data, by comparison with ground measurements from four stations in Europe , 2002 .

[61]  Jay R. Herman,et al.  Comparisons between ground measurements of broadband ultraviolet irradiance (300 to 380 nm) and total ozone mapping spectrometer ultraviolet estimates at Moscow from 1979 to 2000 , 2002 .

[62]  K. Arrigo,et al.  Global Mapping of Underwater UV Irradiances and DNA-Weighted Exposures using TOMS and SeaWiFS Data Products , 1999 .

[63]  Teruyuki Nakajima,et al.  Tropospheric aerosol optical thickness from the GOCART model and comparisons with satellite and sun photometer measurements , 2002 .

[64]  Jay R. Herman,et al.  Comparison of daily UV doses estimated from Nimbus 7/TOMS measurements and ground‐based spectroradiometric data , 2000 .

[65]  Wei Gao,et al.  Comparisons of USDA UV shadow-band irradiance measurements with TOMS satellite and DISORT model retrievels under all sky conditions , 2002, SPIE Optics + Photonics.

[66]  B. Mayer,et al.  Estimation of surface actinic flux from satellite (TOMS) ozone and cloud reflectivity measurements , 1998 .

[67]  P. Bhartia,et al.  UV‐B increases (1979–1992) from decreases in total ozone , 1996 .

[68]  D. Leffell,et al.  Sunlight and skin cancer. , 1996, Scientific American.

[69]  W. Rossow,et al.  ISCCP Cloud Data Products , 1991 .