P-24

Assimilation Experiments of MTSAT Rapid Scan Data

M. Otsuka (Metorological Research Institute / RIKEN), M. Kunii (Metorological Research Institute), H. Seko (Meteorological Research Institute), K. Shimoji (Meteorological Satellite Center), M. Hayashi (Meteorological Satellite Center), T. Imai (Meteorological Satellite Center)

MTSAT-1R has been providing images of Japan and the neighboring area as frequently as every 5 min during the daytime in summer for the purpose of monitoring severe convective weather, volcanic ash plumes, and other phenomena that might affect air traffic. Because of the high frequency of observations, the rapid scan observations increase the amount of data available, and they are also expected to capture atmospheric changes that are too short-lived to be depicted by routine images obtained at 30-min intervals. The utilization of rapid scan products such as AMVs and cloud properties including effective cloud fraction and cloud top height in mesoscale data assimilation systems is being planned. As a first attempt, assimilation experiments of AMVs using JMA's operational non-hydrostatic model with 4-dimensional variational data assimilation (JNoVA) covering a heavy rainfall event were conducted. The results showed slight improvement in the verification scores of precipitation forecast in the early forecast hours.