Eddy current introduction

A low-pressure vortex that appears in the middle and lower atmosphere and has a small horizontal and vertical range. In the northern hemisphere, the airflow in the vortex rotates counterclockwise, similar to a cyclone. The vortices that have a great influence on the weather in China can be divided into two categories: one is the sub-synoptic vortex generated by the special topography of the Qinghai-Tibet Plateau, such as the southwest vortex generated in southwest Sichuan and the northwest vortex near Qinghai Lake; The other is the cold vortex cut off by the high-altitude westerly trough. Such as the North China Cold Vortex and the Northeast Cold Vortex.