Characterization of particulate matter and its extinction ability during different seasons and weather conditions in Sinkiang, China: two case studies

Abstract

Aerosol optical properties and its extinction ability at Shihezi and Urumqi in Sinkiang were investigated based on a year observation, conducted in the 2015-2016. In Shihezi, PM2.5 was lower than 100μg/m 3 for all seasons, especially in summer, stable at about 10μg/m 3 . PM2.5 in winter was up to 261.26μg/m 3 , and PM10 was even close to 500μg/m 3 in polluted days in Shihezi, the highest loading of PM10 was close to 1600μg/m 3 in Urumqi. And the average concentration of PM2.5 in winter was above 200μg/m 3 , with serious pollution in Urumqi, where the concentrations of PM0.5 and PM1 in winter were about 50μg/m 3 and 100-200μg/m 3 , respectively. The seasonal variation of PM2.5/PM10 in Urumqi and Shihezi is as follows: winter> autumn> spring>summer. Under dust storm, haze and fine days, PM0.5 <PM0.5-1 <PM1-2.5 <PM2.5-5 <PM5-10. For all seasons, Shihezi and Urumqi are the largest proportion of PM5-10, with the highest in summer, 35.70-47.98% and 41.72-58.51%, respectively. The range of organic carbon/element carbon (OC/EC) was 2.02-13.44 μg/m 3 in Shihezi, and 2.40-17.65 μg/m 3 in Urumqi. Visibility fluctuated between 0.58-16.20km in Shihezi, and 0.7-20km in Urumqi. The Extinction coefficient of for above six sizes (0.5, 1, 2.5, 5, 10, 100μm) particles, respectively, and obtain the corresponding values is 2.62, 2.61, 2.34, 2.21, 2.13, and 2.03 during the observation period. It is concluded that the diameter is a more important factor for particle extinction than what？. This is the first study in Shihezi and Urumqi, Sinkiang assessing the characterization of particle matter and its extinction ability.