A 10-yr Climatology of Tibetan plateau vortices with NCEP climate forecast system reanalysis

It is the major precipitation-producing weather system over the plateau, but the knowledge of its climatology and understanding of generation mechanisms are limited because of the lack of adequate observations in this harsh mountainous region. In this study, the high-resolution NCEP Climate Forecast System Reanalysis data have been used to perform a statistical survey of these vortices over 10 warm seasons (April⃛–October of 2000-09).

The purpose is to document their climatological features, including genesis, size, life cycle, propagation, and diurnal variation.Results show that ∼103 plateau vortices occur on average every year. Most are detected from May through August, with the maximum monthly count in July. The primary area of origin exhibits a west-east orientation in correspondence with a large-scale confluence zone, and the most concentrated source lies in the area of 33°-36°N, 84°-90°E in the high elevated central and western plateau.