江西省区域霾天气过程典型个例分析

利用2011—2017年江西省基本气象观测资料,统计分析了江西省区域霾天气过程的时空分布特征,并选取典型个例进行天气学分析及模拟。结果表明:江西省区域霾天气过程的月、季变化特征明显,呈北多南少的空间分布特征。区域霾天气过程的天气形势可分为高压类、低压类和均压类,其中高压底部类出现次数最多。3个典型个例中江西地面分别处于高压底部、冷锋锋区和均压场,配合500 hPa高度层的平直西风气流、西北气流或西南气流控制,925 hPa高度层的反气旋控制,整层大气处于非常稳定的状态。江西中北部上空为弱的气流下沉区,相对湿度非常低,为逆温或中性层结。后向轨迹模拟显示,高压底部与冷锋锋区个例过程输送带均为西北路径,均压场个例过程污染物气团为西南气流输送。

Typical case analysis of regional haze weather processes in Jiangxi province

Based on the meteorological observation data of Jiangxi from 2011 to 2017, the temporal and spatial distribution characteristics of regional haze weather processes in Jiangxi were discussed, and typical cases were analyzed and simulated. The results showed that the monthly and seasonal variations of regional haze in Jiangxi were obvious, and the haze occurred more frequently in northern Jiangxi than in southern part. The weather conditions of regional haze mainly included high pressure, low pressure and pressure equalization types, and the high pressure bottom type appeared most frequently. In the three typical cases, Jiangxi were located at the high surface pressure bottom, cold front, and pressure equalization field respectively, and controlled by the straight westerly air flow, northwest air flow or southwest air flow at 500 hPa and anticyclone at 925 hPa, and the entire atmosphere was in a very stable state. The weaker air flow sinking area over the north central part of Jiangxi presented very low relative humidity, with a inversion or neutral stratification structure; The simulation of backward trajectory showed that both the high pressure bottom and the cold front types were transported by the northwest path, and the equal pressure field type was transported by the southerly air flow.