厦门市PM_(2.5)与分布特征及能见度关系的研究

Research on Distribution Characteristics of PM_(2.5) and its Relationship with Visibility in Xiamen City

利用2011-2012年厦门市PM2.5监测资料和气象要素资料,分析PM2.5分布规律,及与海陆风、低能见度天气的关系;尝试分不同季节,在不同主导气象要素场背景下,建立PM2.5与能见度的关系式,试图用能见度推算PM2.5浓度,探索AQI预报中PM2.5浓度预报的技术方法。结果表明:厦门市低能见度天气与PM2.5浓度关系密切,通过相对湿度、降水概率、风向风速以及对应典型的天气形势等差异可清晰表现出来;区分季节性气象要素,计算PM2.5浓度与能见度的相关系数,并建立7个关系式,发现夏季PM2.5浓度与能见度显著负相关,夏季是用能见度推算PM2.5浓度相对最容易、最准确的季节;秋冬春三季PM2.5与能见度关系分别可建立两种关系式,主要为负相关关系,且春季预报PM2.5的难度最大。

Based on the monitoring data of PM2.5and meteorological elements data from 2011 to 2012 in Xiamen City, the variation of PM2.5, main impact factors such as land-sea breeze, and relationship between PM2.5and low visibility weather were analyzed. Under the context of different seasons and dominant meteorological element fields, the formulas between PM2.5and visibility were developed by using the method of calculating concentration of PM2.5by visibility, in order to find out the technological method of forecasting the concentration of PM2.5in AQI prediction,. The results showed that, the low visibility weather and the concentration of PM2.5in Xiamen City were closely related, which was clearly manifested by the differences between relative humidity, precipitation probability, precipitation, wind direction, wind speed, and corresponding typical weather situation. The correlation coefficient between the concentration of PM2.5and visibility was calculated and then seven formulas were established by distinguishing seasonal meteorological elements. The correlation between the concentration of PM2.5and visibility in summer was significant negative. Thus summer was the easiest and most accurate season of calculating concentration of PM2.5by visibility. In addition, it could be established two kinds of formulas between the concentration of PM2.5and visibility each in spring, autumn and winter, with the key positive correlation and secondary negative correlation.And it was most difficult to forecast PM2.5in spring, due to the various meteorological elements considered and irregular trend.