2021—2022年辽宁省降水pH值变化特征分析  

Characteristics of pH value of precipitation in Liaoning province from 2021 to 2022

作　　者：代家庚 赵胡笳[1] 徐嘉 王扬锋[1] 王鹏 马文博 苏晓蕾 徐蕾 DAI Jiageng;ZHAO Hujia;XU Jia;WANG Yangfeng;WANG Peng;MA Wenbo;SU Xiaolei;XU Lei(Institute of Atmospheric Environment,China Meteorological Administration,Shenyang 110166,China;Longfengshan Regional Atmospheric Background Station,Harbin 150200,China;Ecological Meteorology Center in Heilongjiang,Harbin 150030,China;Yanji Meteorological Service,Yanji 133001,China)

机构地区：[1]中国气象局沈阳大气环境研究所,辽宁沈阳110166 [2]龙凤山区域大气本底站,黑龙江哈尔滨150200 [3]黑龙江省生态气象中心,黑龙江哈尔滨150030 [4]延吉市气象局,吉林延吉133001

出　　处：《气象与环境学报》2024年第5期50-56,共7页Journal of Meteorology and Environment

基　　金：龙凤山科技野外试验平台开放项目(LFS202107);国家自然科学基金面上项目(42175185)共同资助。

摘　　要：利用2021—2022年辽宁省14个地市酸性降水观测资料结果,指出了辽宁省降水pH值的空间分布以及月、季变化特征,初步对辽宁省不同地市酸性降水发生频率及其与酸性气态污染物相关性进行了分析。结果表明:辽宁省沿海地区降水pH值较小,大连年均降水pH值最小为5.77,锦州年均降水pH值最大为6.74。辽宁省年均降水pH值在12月最小为5.72、酸性降水发生频率最高为7.94%,降水pH值在4月最大为6.25,酸性降水发生频率为1.72%。14个地市中鞍山酸性降水发生频率最小为0.24%,葫芦岛酸性降水发生频率最大为11.79%。由于碱性气溶胶粒子的冲刷和降水的湿清除作用,辽宁省降水pH值在春季较高,夏季和秋季减小,冬季最低。本溪、丹东、大连和葫芦岛地区SO2和NO2浓度月变化呈夏季低、冬季高的变化趋势,局地排放源在冬季对酸性降水具有一定的影响作用,而夏季酸性降水受到湿清除的作用较大。降水量在50 mm以内,降水pH值减小、酸性降水增多;当降水量大于100 mm时,降水pH值升高,集中分布在6~7。风向对影响降水pH值的主要大气污染物的源汇具有重要影响,春季主导风向引发的沙尘天气导致大气中碱性气溶胶增加,有利于降水pH值升高,夏季南向气流带来充足水汽,酸性降水形成事件增多。This study analyzes the acid rain observation data from 14 cities in Liaoning province from 2021 to 2022,mapping the spatial distribution as well as the monthly and seasonal variations of precipitation pH values.It assesses that the frequency of acid precipitation and its correlation with acidic gaseous pollutants in different cities of Liaoning province.The results show that the average annual precipitation pH value across coastal areas is low.Dalian has the lowest average annual precipitation pH at 5.77,while Jinzhou has the highest at 6.74.The minimum annual pH value of 5.72 is recorded in December,the highest frequency of acid precipitation is 7.94%;while,the highest annual pH value is 6.25 in April,and the frequency of acid precipitation is 1.72%.Among the 14 cities,Anshan records the lowest occurrence of acid rain at 0.24%,while Huludao exhibits the highest frequency at 11.79%.Due to the washout effect of alkaline aerosol particles and the wet removal process during precipitation,the pH values in Liaoning province are higher in spring,decrease during summer and autumn,and reach their lowest in winter.Monthly variations of SO 2 and NO 2 concentrations in Benxi,Dandong,Dalian,and Huludao show lower levels in summer and higher levels in winter,which indicating a local emissions influence on acid precipitation in winter,while summer acid precipitation is significantly impacted by wet removal processes.Furthermore,the pH value decreases and the frequency of acid precipitation increase when precipitation is less than 50 mm.Conversely,the pH value rises and concentrates between 6 and 7 when precipitation exceeds 100 mm.Wind directions influence significantly the source and sink dynamics of key atmospheric pollutants affecting the pH value of precipitation.Dust storms driven by prevailing spring winds contribute to an increase in atmospheric alkaline aerosols,which in turn elevate precipitation pH levels.In summer,southward airflow brings in substantial moisture,leading to a rise in acid precipitation events.

关 键 词：降水PH值 酸性降水频率 气态污染物 

分 类 号：X513[环境科学与工程—环境工程]