In this study, the frequency and the intensity of localized heavy rainfall enhanced by climate change was quantified using the outputs from super high resolution regional climate model (resolutions of 5km and 30minutes) provided by KAKUSHIN program. Since we are concerned with the localized heavy rainfall caused when the Baiu front hangs in a specific region, it is not easy to identify based on simple criterion of a certain threshold rainfall. Therefore, through the experiences of radar-based severe storm analysis, we counted the number of events, checked their location, and quantified their intensity by watching the images of precipitation for several accumulation time steps and meteorological variables based on several criterions developed in this study. As results, it was found that the frequency of localized heavy rainfall events has a tendency to increase significantly in the end of the 21st century and that they might occurs on the Pacific Ocean side of East Japan with obvious spatial pattern.

No abstract

This study investigated the application of the successive correction method(SCM), a simple data assimilation method, for synthesizing the radar and rain gauge data. First, the number of iteration and influence radius for the SCM application were decided based on their sensitivity analysis. Also, for the evaluation of synthetic rainfall, the distributed rainfall field using the dense rainfall gauge network was assumed to be the true one. The synthetic rainfall field based on the SCM was also compared quantitatively with the one based on the co-Kriging frequently used nowadays. As the results, the SCM, a simple and economical data assimilation method, was found to secure the accuracy and statistical characteristics of the co-Kriging application.

No abstract