Assimilation of precipitation radars on TRMM and GPM Core satellites
An ensemble-based variational assimilation (EnVA) scheme has been developed to address the nonlinearity issue and effectively utilize precipitation-affected satellite data. The EnVA scheme uses a cloud-resolving model of the non-hydrostatic model of JMA (JMA-NHM) to explicitly treat with precipitation variables. It was developed to assimilate microwave imagers and has been expanded for precipitation radars. We investigated how well JMA-NHM reproduced TRMM/PR in the radar reflectivity space. It was found that JMA-NHM overestimated the reflectivity from ice particles and was not able to simulate bright bands. These results will help us to develop quality control procedures and specify observation error statistics that are used in the radar assimilation. Preliminary results of the model comparison and assimilation of PR and DPR will be presented.