广西霾天气系统分型

利用2009—2013年NCEP再分析资料和广西14个地级市的历史气象资料,通过天气学方法对广西233个霾日对应的天气系统进行了分类,将形成广西霾日的天气系统分成冷高压脊控制型、入海高压后部型、低压槽型、均压场型、冷锋前部型、副高控制型、静止锋暖区型和热带气旋外围型共8种类型,研究了各类型天气系统的特点及其在广西霾形成中的作用。结果表明:冷高压脊控制型、入海高压后部型、均压场型和低压槽型是4种主要的环流型,造成的广西霾日较多,静止锋暖区型和热带气旋外围型造成的霾日较少;冷高压脊控制型和副高控制型的霾过程持续时间比较长,冷锋前部型的霾过程持续时间最短;地面风速较小,中低空为下沉气流是出现霾日时各类天气型的共同特征。

Weather Types of Haze Days in Guangxi

By using the reanalysis data of NCEP/NCAR and the historical meteorological data of 14 cities in Guangxi, the corresponding weather systems of 233 haze days from 2009 to 2013 in Guangxi are classified by the synoptic method. The weather systems of Guangxi haze days are divided into 8 types: the cold high pressure ridge control, the rear of high pressure moving to the sea, the low pressure trough, the uniform pattern of pressure, the front of cold front, the subtropical high control, the warm area of stationary front, and the peripheral of tropical cyclone. The characteristics of each type and their role in the haze formation in Guangxi are studied. Results indicate that the cold high pressure ridge control, the rear of high pressure moving to the sea, the low pressure trough, and the uniform pattern of pressure types are the four main circulation types which induce more haze days in Guangxi while the warm area of stationary front and the peripheral of tropical cyclone types induce less haze days. The haze processes resulted from the cold high pressure ridge control and the subtropical high control types lasts longer, and those from the front of cold front type have the shortest duration. The small ground wind speed and the sinking airflow at the low and medium altitudes are the common characteristics of all kinds of weather types for haze days.