The objective of this study is to evaluate the accuracy of the daily nadir total column ozone products derived from the nadir mapper instrument on the Ozone Mapping and Profiler Suite （OMPS） flying onboard the Suomi...The objective of this study is to evaluate the accuracy of the daily nadir total column ozone products derived from the nadir mapper instrument on the Ozone Mapping and Profiler Suite （OMPS） flying onboard the Suomi National Polar-orbiting Partnership satellite （S- NPP） launched as a part of the Joint Polar Satellite System （JPSS） program between NOAA and NASA. Since NOAA is already operationally processing OMPS nadir total ozone products, evaluations were made in this study on the total column ozone research products generated by NASA＇s science team, utilizing the latest version of their Backscatter Ultraviolet （BUV） retrieval algorithms, to provide insight into the performance of the operation system. Comparisons were made with globally distributed ground-based Brewer and Dobson spectrophotometer total column ozone measurements. Linear regressions show fair agreement between OMPS and ground-based total column ozone measurements with a root-mean-square error （RMSE） of approximately 3% （10 DU）. The comparison results indicate that the OMPS total column ozone data are 0.59% higher than the Brewer measurements with a standard deviation of 2.82% while 1.09% higher than the Dobson measurements with a standard deviation of 3.27%. Additionally, the variability of relative differences between OMPS and ground total column ozone were analyzed as a function of latitude, time, viewing geometry, and total column ozone value. Results show a 2% bias over most latitudes and viewing conditions when total column ozone value varies between 220 DU and 450 DU.展开更多
A Bayesian optimal estimation （OE） retrieval technique was used to retreive aerosol optical depth （AOD）, aerosol single scattering albedo （SSA）, and an asymmetry factor （g） at seven ultraviolet wavelengths, al...A Bayesian optimal estimation （OE） retrieval technique was used to retreive aerosol optical depth （AOD）, aerosol single scattering albedo （SSA）, and an asymmetry factor （g） at seven ultraviolet wavelengths, along with total column ozone （TOC）, from the measurements of the UltraViolet Multifilter Rotating Shadowband Radiometer （UV-MFRSR） deployed at the Southern Great Plains （SGP） site during March through November in 2009. The OE technique specifies appropriate error covariance matrices and optimizes a forward model （Tropospheric ultraviolet radiative transfer model, TUV）, and thus provides a supplemental method for use across the network of the Department of Agriculture UV-B Monitoring and Research Program （USDA UVMRP） for the retrieval of aerosol properties and TOC with reasonable accuracy in the UV spectral range under various atmo- spheric conditions. In order to assess the accuracy of the OE technique, we compared the AOD retreivals from this method with those from Beer＇s Law and the AErosol RObotic Network （AERONET） AOD product. We also examine the OE retrieved TOC in comparison with the TOC from the U.S. Department of Agriculture UV-B Monitoring and Research Program （USDA UVMRP） and the Ozone Monitoring Instrument （OMI） satellite data. The scatterplots of the estimated AOD from the OE method agree well with those derived from Beer＇s law and the collocated AERONET AOD product, showing high values of correlation coefficients, generally 0.98 and 0.99, and large slopes, ranging from 0.95 to 1.0, as well as small offsets, less than 0.02 especially at 368 nm. The comparison of TOC retrievals also indicates the promising accuracy of the OE method in that the standard deviations of the difference between the OE derived TOC and other TOC products are about 5 to 6 Dobson Units （DU）. Validation of the OE retrievals on these selected dates suggested that the OE technique has its merits and can serve as a supplemental tool in further analyzing UVMRP data.展开更多
文摘The objective of this study is to evaluate the accuracy of the daily nadir total column ozone products derived from the nadir mapper instrument on the Ozone Mapping and Profiler Suite （OMPS） flying onboard the Suomi National Polar-orbiting Partnership satellite （S- NPP） launched as a part of the Joint Polar Satellite System （JPSS） program between NOAA and NASA. Since NOAA is already operationally processing OMPS nadir total ozone products, evaluations were made in this study on the total column ozone research products generated by NASA＇s science team, utilizing the latest version of their Backscatter Ultraviolet （BUV） retrieval algorithms, to provide insight into the performance of the operation system. Comparisons were made with globally distributed ground-based Brewer and Dobson spectrophotometer total column ozone measurements. Linear regressions show fair agreement between OMPS and ground-based total column ozone measurements with a root-mean-square error （RMSE） of approximately 3% （10 DU）. The comparison results indicate that the OMPS total column ozone data are 0.59% higher than the Brewer measurements with a standard deviation of 2.82% while 1.09% higher than the Dobson measurements with a standard deviation of 3.27%. Additionally, the variability of relative differences between OMPS and ground total column ozone were analyzed as a function of latitude, time, viewing geometry, and total column ozone value. Results show a 2% bias over most latitudes and viewing conditions when total column ozone value varies between 220 DU and 450 DU.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant No. 41101037）, the National Basic Research Program of China （No. 2010CB951603）, USDA NIFA project （2011-34263-30654）, the Research Fund for the Doctoral Program of Higher Education （20100076120024）, and the Fundamental Research Funds for the Central Universities （East China Normal University）. We would also like to thank the PI investigators and their staff for establishing and maintaining the AERONET site used in this investigation.
文摘A Bayesian optimal estimation （OE） retrieval technique was used to retreive aerosol optical depth （AOD）, aerosol single scattering albedo （SSA）, and an asymmetry factor （g） at seven ultraviolet wavelengths, along with total column ozone （TOC）, from the measurements of the UltraViolet Multifilter Rotating Shadowband Radiometer （UV-MFRSR） deployed at the Southern Great Plains （SGP） site during March through November in 2009. The OE technique specifies appropriate error covariance matrices and optimizes a forward model （Tropospheric ultraviolet radiative transfer model, TUV）, and thus provides a supplemental method for use across the network of the Department of Agriculture UV-B Monitoring and Research Program （USDA UVMRP） for the retrieval of aerosol properties and TOC with reasonable accuracy in the UV spectral range under various atmo- spheric conditions. In order to assess the accuracy of the OE technique, we compared the AOD retreivals from this method with those from Beer＇s Law and the AErosol RObotic Network （AERONET） AOD product. We also examine the OE retrieved TOC in comparison with the TOC from the U.S. Department of Agriculture UV-B Monitoring and Research Program （USDA UVMRP） and the Ozone Monitoring Instrument （OMI） satellite data. The scatterplots of the estimated AOD from the OE method agree well with those derived from Beer＇s law and the collocated AERONET AOD product, showing high values of correlation coefficients, generally 0.98 and 0.99, and large slopes, ranging from 0.95 to 1.0, as well as small offsets, less than 0.02 especially at 368 nm. The comparison of TOC retrievals also indicates the promising accuracy of the OE method in that the standard deviations of the difference between the OE derived TOC and other TOC products are about 5 to 6 Dobson Units （DU）. Validation of the OE retrievals on these selected dates suggested that the OE technique has its merits and can serve as a supplemental tool in further analyzing UVMRP data.
