资源环境科技发展态势分析平台

Central Asian vortices (CAVs) are synoptic-scale systems affecting the weather over Central Asia and downstream regions. We established an historical dataset of CAVs for the time period 1980–2017 based on an improved objective identification and tracking method and the ERA-Interim reanalysis dataset. Based on the CAV and 6-h precipitation datasets, we analyzed the climatological features of 389 CAVs and carried out a composite analysis of the CAVs influencing precipitation in Xinjiang. The CAVs tended to move eastward and had two main high-frequency centers over the Central Asia. The occurrence of CAVs peaks in summer and there is a considerable interannual variability. Most CAVs have a lifetime of two to three days and a spatial size of about 1100 km. The CAV-related precipitation in Xinjiang is mainly located in the Tianshan mountains. The precipitation in the western part of southern Xinjiang in the warm seasons is more sensitive to CAVs. There is a significant convergence of moisture in the southeast quadrant of the CAVs influencing Xinjiang, along with strong divergence in the upper level and associated ascending motion, which both favor precipitation.