摘要
根据1992—2012年的酸雨观测记录,对天津市近20年的酸雨变化特征及长期趋势进行了统计分析。结果显示:天津市的降水pH值范围变化较大,1992 2012年的降水pH值在3.30 ～8.80变化,pH值低于5.6的酸性降水出现182次,出现频率21.2%。近20年来天津市降水pH值变化分两个阶段,1992-2002年降水pH年均值呈缓慢升高的趋势,pH值平均年增长率约为0.13 a ～(-1);2003—2012年为降水pH值波动阶段,增长趋势放缓,pH值平均年增长率约为0.11 a ～(-1)。近20年春季降水pH值变化趋势不明显,夏、秋两季降水pH值呈明显增加趋势,夏、秋季是主要影响天津的降水pH值长期变化趋势的季节。大气中SO_2和NO_2的浓度与降水pH值呈负相关,本地源和周边源都对天津市的降水酸度有影响。
Based on the acid rain records over 20 years in Tianjin,characteristics and long-term trend of acid rain were analyzed.The results show that the precipitation pH varies in the range of 3.30 — 8.80,with a large averaged seasonal variation from 1992 to 2012.Totally,there are 182 acid rain events（pH below 5.6）,and the frequency is 21.2%.The annual mean precipitation pH shows different variation patterns in the periods of 1992 — 2002 and 2003 — 2012.In the former period,it is a steady slow increasing trend and the averaged annual rate of precipitation pH is 0.13 a ^-1,in the later period,the increasing trend slows down and the averaged annual rate of precipitation pH is 0.11 a^-1.The seasonal variations of the pH values are different in recent 20 years.There is no obvious changes in spring,but significant increasing trend in summer and autumn.Precipitation pH value in summer and autumn is the most important factor that affects the pH values of long-term trend in Tianjin.The analysis of correlation indicates that the precipitation pH value is negatively correlated with concentrations of SO2 and NO2.Rainfall is acidic due to the influence of local air pollution in addition to the influence of the pollution source around Tianjin.
出处
《气象》
CSCD
北大核心
2016年第4期436-442,共7页
Meteorological Monthly
基金
国家自然科学基金项目(411075004)资助
