Abstract

The precipitable water vapor (PW) data at 30-min intervals are analyzed and assimilated into the WRF model for the "7.10" Beijing heavy rainfall event that occurred in the period of 9-11 July, 2004. Observational results show that the temporal variation of the GPS/PW is an instructive factor for ... Show moreThe precipitable water vapor (PW) data at 30-min intervals are analyzed and assimilated into the WRF model for the "7.10" Beijing heavy rainfall event that occurred in the period of 9-11 July, 2004. Observational results show that the temporal variation of the GPS/PW is an instructive factor for the analysis and prediction of this heavy rainfall event. Using the WRF model and its 3D-Var system with two-way and two-nested grids of 12/4km, three 36h numerical experiments are conducted to investigate the impacts of PW with the variation analyses at 1200 UTC of July 9 as the initial fields. Numerical experimental results show that the assimilation of GPS/PW observations significantly helps to improve the moisture analysis at the initial time, then helps to improve forecasts of the location,intensity and evolution of this heavy rainfall event. Show less