Abstract:
The characteristics of surface weather pattern and high-altitude circulation pattern of heavily polluted weather at 08:00 were studied by using the data from 2013 to 2015 in Langfang City, and the configuration of high and low-altitude atmospheric circulation analyzed. The results showed that there were 8 types of surface weather circulation patterns, among which the bottom of high pressure accounted for the most, and the rear of high pressure, deformed high pressure and the front of high pressure appeared more. Whenever slight or severe haze occurred, the most surface weather circulation pattern was the bottom of high pressure, the backflow situation appeared the most in mild haze, while the rear of the high pressure field was the most in moderate haze. There were 7 types of 700 hPa circulation, with the northwest airflow before the ridge taking the largest proportion, followed by straight west airflow and southwest airflow before the trough. The slight haze and severe haze most controlled by the northwest airflow before the ridge, while the mild haze and moderate haze were dominated by the straight west wind. There were 9 types of high and low altitude atmospheric circulation configuration, with three main configuration situations being 700 hPa high-pressure ridge control with ground high-pressure field, 700 hPa straight west wind with ground high-pressure field, and 700 hPa high-air trough with ground high-pressure field. Whenever slight or severe haze occurred, the main configuration type was high-pressure ridge in 700 hPa with high-pressure field on surface. When mild haze and moderate haze occurred, the main configuration type was straight western airflow in 700 hPa with high-pressure field on surface. During 3-5 days of continuous haze process, high pressure bottom accounted for the most on the ground, and the proportion of the high altitude situation of the straight westerly circulation, ridge, high-altitude groove was 36.0%, 35.2% and 28.9%, respectively. The most typical circulation situation of high and low air configuration was controlled by high-pressure ridge at high altitude, and for the ground circulation the most typical situation was the bottom of high pressure.