Abstract:

Based on the meteorological and pollutant concentration data at the Heishantou station which is located in the northern part of the Urumqi city from April 2013 to March 2015, variation characteristics of atmospheric visibility and the related meteorological elements and pollutant factors were investigated in this study. The results are as follows: (1) The diurnal, monthly and seasonal variation characteristics of visibility were obvious. The diurnal variation was similar to each other in spring, summer and autumn, but it was quite different in winter. Maximum visibility appeared in summer, while the minimum appeared in winter. The visibility had little change in spring, summer and autumn of 2013 and 2014, however, the visibility in winter was distinctly better in 2014 than that in 2013.(2) The visibility was positively related to temperature and wind speed, but negatively related to relative humidity and air pressure, and temperature had a most significant relativity. Furthermore, visibility was negatively related to PM10, PM2.5 and PM1.0 concentration, and PM2.5 affected it most remarkably,  the influence of PM1.0 was least. (3) The relation between visibility and relative humidity (temperature) presented an exponential function, while the relation between it and concentration of PM10, PM2.5 and PM1.0 followed a power function. Moreover, a multiple nonlinear fitting model was established based on visibility and meteorological elements and pollutant factors, and through inspection, it could forecast variation of visibility well.

Key words: northern part of Urumqi, visibility, characteristics, influence factors

摘要：

基于2013年4月—2015年3月乌鲁木齐北部城区黑山头气象自动站资料和大气成分站资料，对大气能见度和气象、污染要素进行相关性和回归分析，以探究乌鲁木齐北部城区大气能见度的变化规律，进而揭示气象和污染要素对大气能见度的影响。结果表明：（1）乌鲁木齐北部城区大气能见度日、月及季节变化特征明显。春、夏、秋季的大气能见度日变化规律类似，冬季则差异较大。夏季能见度最高，冬季最低。2014年与2013年相比，春、夏、秋季的大气能见度均值变化不大，但2014年冬季大气能见度明显优于2013年；（2）大气能见度与相对湿度、气压呈负相关，与温度、风速呈正相关，其中温度影响最显著。大气能见度与PM10、PM2.5和PM1.0呈负相关，其中PM2.5影响最显著，PM10影响最小；（3）大气能见度与相对湿度和温度呈显著的指数函数关系，与PM10、PM2.5和PM1.0呈显著的幂函数关系，通过回归分析拟合建立的大气能见度与相对湿度、温度、PM2.5和PM1.0的多元非线性模型，经验证该模型能很好地反映大气能见度的变化规律。

关键词: 乌鲁木齐北部城区, 能见度, 特征, 影响因素