The accuracy of the cloud-aerosol lidar with orthogonal polarization (CALIOP), moderate resolution imaging spectroradiometer (MODIS), Multi-Angle Implementation of Atmospheric Correction (MAIAC), and Geostationary Ope...The accuracy of the cloud-aerosol lidar with orthogonal polarization (CALIOP), moderate resolution imaging spectroradiometer (MODIS), Multi-Angle Implementation of Atmospheric Correction (MAIAC), and Geostationary Operational Environmental Satellite (GOES) aerosol optical depth (AOD) products for the Arctic north of 59.75°N was examined by means of 35 aerosol robotic network (AERONET) AOD sites. The assessment for June to October 2006 to 2020 showed MAIAC AOD agreed the best with AERONET AOD;CALIOP AOD differed the strongest from the AERONET AOD. Cross-correlations of CALIOP AOD along the satellite path indicated that AOD-values 40 km up-and-down the path often failed to represent the AERONET AOD-values within ±30 min of the overpass in this region dominated by easterly winds. Typically, CALIOP AOD was lower than AERONET AOD and MAIAC AOD at the sites, especially, at sites with mean AOD below 0.1. Generally, MODIS AOD values exceeded those of MAIAC. Comparison of CALIOP, MAIAC, and MODIS products resampled on a 0.25° × 0.25° grid revealed differences among the products caused by their temporal and spatial resolution, sample habit and size. Typically, the MODIS AOD-product showed the most details in AOD distribution. Despite differences in AOD-values, all products provided similar temporal evolution of elevated and lower AOD.展开更多
首次将MSG-2(Meteosat Second Generation-2)卫星上的旋转增强可见光及红外成像仪(Spinning Enhanced Visible and Infrared Imager,SEVIRI)的观测资料同化到美国国家环境预报中心(National Centers for Environmental Prediction,NCEP...首次将MSG-2(Meteosat Second Generation-2)卫星上的旋转增强可见光及红外成像仪(Spinning Enhanced Visible and Infrared Imager,SEVIRI)的观测资料同化到美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)全球资料同化系统(global data assimilation system,GDAS)中。对当前的地球静止业务环境卫星(Geostationary Operational Environmental Satellite,GOES)成像仪资料的同化问题也进行了进一步探讨。利用CRTM(The Community Radiative Transfer Model)模式,对SEVIRI辐射率观测资料进行了模拟。为了对红外辐射率资料进行模拟,CRTM模式中的几个关键部分得到改进,例如:动态更新地面发射率资料以及采用了快速精确的气体吸收模块。为了改进对SEVIRI和GOES成像仪辐射率资料的模拟效果,采用了GSICS(The Global Space-Based Inter-Calibration System)标定订正。初步研究结果表明,包含对SEVIRI辐射率资料的水汽通道(6.25和7.35μm)和二氧化碳通道(13.40μm)的同化对GFS(Global Forecast System)6d预报具有显著的正影响;而对其他5个SEVIRI红外窗口通道资料的同化则减小了这种正影响。通过应用GSICS标定算法,订正了SEVIRI和GOES-12成像仪观测资料的偏差,提高了对GFS预报的影响。此外,还需作进一步研究来提高对SEVIRI红外窗口通道辐射率资料同化的有效性。展开更多
The intensification of a low-level jet off the Somali coast, as observed through GOES (I-O) satellite during Indian summer monsoon 1979 has been studied. Excitation of Low-level cross-equatorial flow in the western In...The intensification of a low-level jet off the Somali coast, as observed through GOES (I-O) satellite during Indian summer monsoon 1979 has been studied. Excitation of Low-level cross-equatorial flow in the western Indian ocean results from an interaction between extratropical perturbations moving eastward across the South African-Malgassy region of the Southern Hemisphere. This excitation occurs 2-3 days after the first appearance of a northward propagation cold front across the South African-Malgassy region. Inten-sification of cross-equatorial flow is followed by an increase in rainfall activity along the west coast of India after 3-4 days. The study reveals that this association can be used to forecast an increase in rainfall activity along the west coast of India 5-7 days in advance.展开更多
文摘The accuracy of the cloud-aerosol lidar with orthogonal polarization (CALIOP), moderate resolution imaging spectroradiometer (MODIS), Multi-Angle Implementation of Atmospheric Correction (MAIAC), and Geostationary Operational Environmental Satellite (GOES) aerosol optical depth (AOD) products for the Arctic north of 59.75°N was examined by means of 35 aerosol robotic network (AERONET) AOD sites. The assessment for June to October 2006 to 2020 showed MAIAC AOD agreed the best with AERONET AOD;CALIOP AOD differed the strongest from the AERONET AOD. Cross-correlations of CALIOP AOD along the satellite path indicated that AOD-values 40 km up-and-down the path often failed to represent the AERONET AOD-values within ±30 min of the overpass in this region dominated by easterly winds. Typically, CALIOP AOD was lower than AERONET AOD and MAIAC AOD at the sites, especially, at sites with mean AOD below 0.1. Generally, MODIS AOD values exceeded those of MAIAC. Comparison of CALIOP, MAIAC, and MODIS products resampled on a 0.25° × 0.25° grid revealed differences among the products caused by their temporal and spatial resolution, sample habit and size. Typically, the MODIS AOD-product showed the most details in AOD distribution. Despite differences in AOD-values, all products provided similar temporal evolution of elevated and lower AOD.
基金美国NOAA和NASA GOES-R Algorithm Working Group和GOES-R Risk Reduction关于地球静止卫星资料模拟和同化项目
文摘首次将MSG-2(Meteosat Second Generation-2)卫星上的旋转增强可见光及红外成像仪(Spinning Enhanced Visible and Infrared Imager,SEVIRI)的观测资料同化到美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)全球资料同化系统(global data assimilation system,GDAS)中。对当前的地球静止业务环境卫星(Geostationary Operational Environmental Satellite,GOES)成像仪资料的同化问题也进行了进一步探讨。利用CRTM(The Community Radiative Transfer Model)模式,对SEVIRI辐射率观测资料进行了模拟。为了对红外辐射率资料进行模拟,CRTM模式中的几个关键部分得到改进,例如:动态更新地面发射率资料以及采用了快速精确的气体吸收模块。为了改进对SEVIRI和GOES成像仪辐射率资料的模拟效果,采用了GSICS(The Global Space-Based Inter-Calibration System)标定订正。初步研究结果表明,包含对SEVIRI辐射率资料的水汽通道(6.25和7.35μm)和二氧化碳通道(13.40μm)的同化对GFS(Global Forecast System)6d预报具有显著的正影响;而对其他5个SEVIRI红外窗口通道资料的同化则减小了这种正影响。通过应用GSICS标定算法,订正了SEVIRI和GOES-12成像仪观测资料的偏差,提高了对GFS预报的影响。此外,还需作进一步研究来提高对SEVIRI红外窗口通道辐射率资料同化的有效性。
文摘The intensification of a low-level jet off the Somali coast, as observed through GOES (I-O) satellite during Indian summer monsoon 1979 has been studied. Excitation of Low-level cross-equatorial flow in the western Indian ocean results from an interaction between extratropical perturbations moving eastward across the South African-Malgassy region of the Southern Hemisphere. This excitation occurs 2-3 days after the first appearance of a northward propagation cold front across the South African-Malgassy region. Inten-sification of cross-equatorial flow is followed by an increase in rainfall activity along the west coast of India after 3-4 days. The study reveals that this association can be used to forecast an increase in rainfall activity along the west coast of India 5-7 days in advance.
