All-sky Data Assimilation of MWTS-2 and MWHS-2 in the Met Office Global NWP System.  

作　　者：Fabien CARMINATI Stefano MIGLIORINI 

机构地区：[1]Met Office,Exeter EX13PB,UK

出　　处：《Advances in Atmospheric Sciences》2021年第10期1682-1694,共13页大气科学进展（英文版）

基　　金：This work was supported by the UK-China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund.

摘　　要：Microwave radiances from passive polar-orbiting radiometers have been,until recently,assimilated in the Met Office global numerical weather prediction system after the scenes significantly affected by atmospheric scattering are discarded.Recent system upgrades have seen the introduction of a scattering-permitting observation operator and the development of a variable observation error using both liquid and ice water paths as proxies of scattering-induced bias.Applied to the Fengyun 3 Microwave Temperature Sounder 2(MWTS-2)and the Microwave Humidity Sounder 2(MWHS-2),this methodology increases the data usage by up to 8%at 183 GHz.It also allows for the investigation into the assimilation of MWHS-2118 GHz channels,sensitive to temperature and lower tropospheric humidity,but whose large sensitivity to ice cloud have prevented their use thus far.While the impact on the forecast is mostly neutral with small but significant short-range improvements,0.3%in terms of root mean square error,for southern winds and low-level temperature,balanced by 0.2%degradations of short-range northern and tropical low-level temperature,benefits are observed in the background fit of independent instruments used in the system.The lower tropospheric temperature sounding Infrared Atmospheric Sounding Interferometer(IASI)channels see a reduction of the standard deviation in the background departure of up to 1.2%.The Advanced Microwave Sounding Unit A(AMSU-A)stratospheric sounding channels improve by up to 0.5%and the Microwave Humidity Sounder(MHS)humidity sounding channels improve by up to 0.4%.

关 键 词：microwave remote sensing numerical weather prediction data assimilation Fengyun 3 

分 类 号：P456.7[天文地球—大气科学及气象学]