2023年2月大气环流和天气分析

Analysis of the February 2023 Atmospheric Circulation and Weather

2023年2月,大气环流的主要特征为,北半球极涡呈偶极型,次中心位于鄂霍次克海,强度较常年偏强;欧亚中高纬地区由多槽型转变为“两槽一脊”型。我国中高纬度大部处于高压脊前锋区内,槽前为正距平,冷空气活动较多但强度偏弱,南支槽位置强度接近常年同期,导致我国北方地区多雨雪天气过程,南方地区出现阶段性阴雨寡照天气。全国平均气温为0.3℃,较常年同期偏高1.6℃,全国平均降水量为15.5 mm,较常年同期偏少5%。

The main characteristics of the general atmospheric circulation in February 2023 are as follows.Two polar vortex centers existed in the Northern Hemisphere,with the sub-center located along the Sea of Okhotsk and stronger than normal.The atmospheric circulation over mid-high latitudes of Eurasia changed from multi-wave type to“two-trough-and-one-ridge”type.Most of the mid-high latitude region of China was in the frontal zone ahead of ridge,with a positive anomaly before the trough range,so the associated cold air activities were more in number but weaker in intensity.The southern branch trough with regular position and intensity held a more frequency of rain and snow events in the northern China and phased continuously rainy weather in the southern China.The February average temperature over China was 0.3℃,1.6℃warmer than normal,and the monthly average precipitation was 15.5 mm,5%less than normal.