Analysis of Water Vapor Change and Precipitation Conversion Efficiency Based on HYSPLIT Backward Trajectory Model over the Three-River Headwaters Region

Abstract

Qiang, A.; Wang, N.; Xie, J., and Wei, J., 2020. Analysis of water vapor change and precipitation conversion efficiency based on HYSPLIT backward trajectory model over the three-river headwaters region. In: Hu, C. and Cai, M. (eds.), Geo-informatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 6–11. Coconut Creek (Florida), ISSN 0749-0208.The paper traced the moisture transport path for –240 h of the Three-River Headwaters Region (TRHR) and calculated atmospheric water vapor content and Precipitation Conversion Efficiency (PCE) by introducing Hybrid Single Particle Lagrangian Integrated Trajectory backward trajectory model based on Lagrangian integral propagation diffusion model using the Global Data Assimilation System assimilation data provided by National Centers for Environmental Prediction and the ERA-Interim data of the European Centre for Medium-Range Weather Forecasts, they were compared and analyzed PCE with precipitation contribution rate. The results were as follows: first, the PWV and P had been increasing trend from 1979 to 2017 in the TRHR, but the seasonal difference was obvious. They gradually decreased in space from southeast to northwest. Second, a height of 1000 m becomes the water vapor source boundary layer in TRHR, the southern flow (45.5%), and the northern flow (54.5%) appear below 1000 m; however, the western water vapor (75%) and eastern water vapor (25%) above 1000 m. Third, the water vapor mainly come from the west-oriented airflow brought by the westerly belt in the TRHR, but the backward trajectory variation is different at different altitudes and moments. Fourth, The precipitation contribution rate isn't consistent with the results reflected by PCE in the TRHR.