kozo Okamoto, JMA/MRI, RIKEN/AICS
Towards the assimilation of all-sky infrared radiances of Himawari-8
CoauthorsHiroshi Ishimoto, Masaru Kunii, Michiko Otsuka, Sho Yokota, and Hiromu Seko
Abstract: Assimilation of space-borne infrared radiances have substantial impact on analysis and forecast accuracy in NWP despite their limited use mainly in clear-sky regions. Development of all-sky infrared radiance assimilation is expected to bring greater impacts and is highly required now that we can utilize the third generation of geostationary satellite such as Himawari-8.
As the first step of the development, we compared observation with simulation from JMA’s nonhydrostatic model (JMA-NHM) and RTTOV, and then investigated the Gaussianity of their difference dependent on cloud effect. We extended a JMA-NHM-based LETKF assimilation system to include procedures for the radiance assimilation, such as pre-processing of radiances, and are testing its performance. Preliminary results will be presented in the symposium.