A New Advection Scheme for Calculating the Long Distance Transport of Water Vapor

Many scientists have struggled for improving the forecast skill of precipitation fields of numerical for more than 50 years , however, the forecasting score for rainfall is much worse than other products of numerical forecasting models. In our opinion, one of the reasons is that water vapor field in real atmosphere is discontinuously distributed, however, our modeler treated water vapor field continuous because our main-stream scientists get used to solve problems basing on some quantitatively data by some known mathematical formula or methods. In this paper, we show a new way to improve the forecasting of precipitation by using the PTPR advection scheme, which is put forward by the first author for the purpose of calculating the advection item for the long distance transport of hazard materials in 2001 & 2002 when he worked in MRI,JMA. By comparison of the numerical simulation results between the traditional advection scheme and the new advection scheme of water vapor, we find that the PTPR advection scheme has a bright future to improve the forecasting skill of precipitation field for numerical weather forecasting models.