沧州市大气自净能力特征分析

The Characteristic Analysis of Amospheric Self-purification Capability in Cangzhou

利用沧州1975—2018年逐日地面气象观测资料和2013—2018年环境监测资料,采用国标法计算并分析了沧州地区大气自净能力的时空变化特征,探讨了气象要素、污染物指数与大气自净能力之间的关系。结果表明:沧州大气自净能力年变化呈显著减小趋势,气候倾向率为1.05×10^4km^2·a^-1·(10a)^-1,春季3—5月大气自净能力较强,8月、11月、12月和1月较弱;风速、小风频率年变化与大气自净能力的相关性显著,相关系数分别为0.910、-0.807,风向出现频率与大气自净能力的相关性较差,降水日平均大气自净能力小于非降水日;O3、CO和SO2分指数与大气自净能力相关性较好,大气自净能力对区域空气质量变化具有指示意义。

The daily surface meteorological observation data in Cangzhou from 1975 to 2018 and the environmental monitoring data from 2013 to 2018 were applied.The spatial and temporal variation characteristics of atmospheric self-purification ability in Cangzhou area were calculated and analyzed using national standard method,and the relationship between meteorological elements,pollutant index and atmospheric self-purification ability was discussed.The results showed that the annual change of atmospheric self-purification capability in Cangzhou showed a significant decrease trend,and the climate trend rate was 1.05×10^4km^2·a^-1·(10a)^-1.The atmospheric self-purification capability was relatively strong from March to May,and was relatively weak in August,November,December and January.The annual variations of wind speed and small wind frequency had a significant correlation with atmospheric self-purification ability.The correlation coefficients were 0.910 and -0.807,respectively.The correlation between the occurrence frequency of wind direction and atmospheric self-purification ability was poor.The average atmospheric self-purification capability on precipitation days was smaller than that on non-precipitation days.The correlation between O3,CO and SO2 sub-indexes and atmospheric self-purification ability was good,and atmospheric self-purification ability was indicative of regional air quality change.