Characteristics of haze and the atmospheric boundary layer height during the periods with different category of haze over Suzhou observed by Micro-Pulse Lidar

Abstract:

Based on the observed hourly meterological data, atmospheric composition data, and the Micro-Pulse Lidar (MPL) detecting data over Suzhou during 2010 to 2014, this study concentrates on revealing the characteristics of haze weather and the atmospheric boundary layer height during the periods with different category of haze over Suzhou. The main results are shown as follows: The haze frequency over Suzhou is 30.9% with the frequency of 18% for the slight haze, 7.8% for the light haze, 3.1% for the moderate haze and 2.0% for the heavy haze. The haze frequency shows an obvious diurnal variation with a peak (valley) value at the local solar time around 08:00~09:00 am (14:00~16:00pm).The haze happens much more frequent in nighttime than in daytime. The atmospheric boundary layer height (ABLH) associated with haze also shows a clear diurnal variation. The mean ABLH over Suzhou during the period of haze is more (less) than 1000m (500m) in daytime (nighttime). Meanwhile, the ABLH during the period of haze is higher in summer than in winter. In addition, the mean ABLH during the period without (with) haze is around 700m (500m) in winter. The diurnal variation of the ABLH during the period of moderate to heavy haze in winter ranges from 350m to 500m, which is less than the winter mean ABLH by 50~150m.

KEY WORDS: Micro-Pulse Lidar; haze frequency; moderate and heavy haze；atmospheric boundary layer height