Characteristics of Circulation Structure Inducing Summer Heavy Rainfall in Kazakhstan
By using FNL1°×1°and CPC0.5°×0.5°reanalysis data,the circulation characteristics of three heavy rainfall processes in different regions of Kazakhstan during summer are compared and analyzed,the circulation structure that induced the heavy rainfall in Summer is revealed.The results show that when heavy rainfall occurs in various regions of Kazakhstan,the centers of heavy rainfall in the western and eastern regions are located on the right side of the entrance area of the high-altitude jet stream,while the northern region is located on the left side of the exit area.The radiative suction effect is conducive to the development of upward movement.The main impact system of heavy rainfall is the low vortex at 500 hPa,with the center of heavy rainfall located on the southwest airflow belt in front of the trough line.The middle level temperature advection promotes the occurrence of heavy rainfall,while the western and northern heavy rainfall centers are located in the low level cold advection high value area,and the eastern part is located in the cyclonic convergence area on the south side of the northeast cold advection.Except for heavy rainfall in eastern Kazakhstan,which is affected by terrain,the surface system scale is relatively small.During heavy rainfall in western and northern Kazakhstan,there are obvious cold fronts on the surface and cyclonic convergence shear.The convergence line formed by the convergence of cold and warm is the main mesoscale triggering system of heavy rainfall.The main sources of water vapor for heavy rainfall in Kazakhstan are the Mediterranean,Black Sea,Persian Gulf,and Arctic Ocean.Through long-distance transportation,strong water vapor convergence is formed in heavy rainfall areas,with convergence values over 40×10-6g·cm-1·s-1.
heavy rainfallcirculation characteristicsvertical structurewater vapor transportKazakhstan
万方数据
维普
