P-34

Observation system simulation experiments of the meso-scale convergence that causes the local heavy rainfall

H. Seko (MRI, AICS, JST, JAMSTEC), O. Suzuki (JMA), A. Adachi (MRI)

In the local heavy rainfalls that occurred in Osaka urban area, convection cells are generated by convergence of the southerly flow from Osaka-Bay and the northeasterly flow. If the large-scale convergence that generate thunderstorms are reproduced before their generation, the forecast with long leading time (a time from the forecast to the occurrence of heavy rainfalls) is expected to be obtained. In this study, the observation system simulation experiments (OSSE) were conducted with the data of Doppler Lidars and temperature profilers that are deployed around Osaka urban area. The observation data of Doppler Lidars and temperature profilers were produced from the truth data of 15 JST, 2 hour before the development of the thunderstorm. The truth data was obtained by the data assimilation of GPS PWV data and conventional data. The impact of these data was investigated by adding the data of Doppler Lidars and temperature profilers into the conventional data. In this study, the rainfall distribution of thunderstorms was improved by the data assimilation of the Doppler Lidar and temperature profiler data. This result shows that observation data surrounding the thunderstorms can improve their rainfall forecast even if the direct observation data of the thunderstorms cannot be used.