Application of RTTOV Scattering Module to FY-3 MWHS Data Assimilation
All the time, because of the limits of observation operator in assimilation system, microwave observation over cloud area from satellite is often made clear hypothesis, which usually brings an overestimated content of atmospheric moisture. To overcome that, this paper designs a scheme to run RTTOV microwave scattering module in WRF 3DVAR for taking the information of atmospheric hydrometeors into assimilating calculation. On this basis, four groups of assimilation contrast tests are carried out for brightness temperature of FY3 A meteorological satellite microwave humidity sounder and reflectivity of Doppler radar. The results show that the introduction of RTTOV microwave scattering module can effectively suppress the overestimate of atmospheric water vapor content. When radar reflectivity factor is assimilated before satellite data, atmospheric hydrometeors content is increased significantly in this region. As a result, the scattering effects is increased too. With the area coverage of radar data assimilation increasing, precipitation forecast effect is improved more and more obviously.