摘要
为研究城市PM_(10)对大气辐射环境的影响,利用2013年6月1日—2014年5月31日成都市ρ(PM_(10))和空气吸收剂量率的逐日监测数据,采用DCCA(去趋势互相关分析)法对二者的相关性进行分析.结果表明:在1 a的时间尺度上,成都市ρ(PM_(10))与空气吸收剂量率之间存在显著的正相关性(标度指数为0.928),并且这种正相关性具有长期、持续的特征,但相关性的强度却随时间以幂函数形式缓慢衰减.冬夏两季ρ(PM_(10))与空气吸收剂量率的相关性存在显著差异.在冬季重度灰霾期间,二者DCCA标度指数为0.968,说明高ρ(PM_(10))已对城市大气辐射环境产生了影响;而夏季二者的DCCA曲线分为两段,标度指数分别为0.579、1.519,折点位置对应的特征时间尺度约为2个月,推测这与当地夏季降雨的时间分布模式有关.研究表明,在当前灰霾日益频发的背景下,需要重视城市重度灰霾对城市大气辐射环境造成的影响.
This paper aims to study the cross-correlation between PM10 concentrations and air absorbed dose rate in Chengdu City. Daily monitoring data of PM10 concentrations and air absorbed dose rate in Chengdu City from June 2013 to May 2014 were analyzed using detrended cross-correlation analysis（ DCCA）. The results indicated that a notable positive correlation existed between PM10 concentrations and air absorbed dose rate in Chengdu City in a time scale,with a cross-correlation exponent of 0. 928. The long-term cross-correlation relationship suggested that the cross-correlation between PM10 concentrations and air absorbed dose rate was displayed as slowly decaying in the form of power-law with time. Furthermore,cross correlation between PM10 concentrations and air absorbed dose rate were analyzed by using DCCA in the winter and summer. The results showed that the cross-correlation relationships between PM10 concentrations and air absorbed dose rate had significant differences in winter and summer. PM10 concentrations and temporal distribution characteristics of rainfall were the main factors responsible for the differences. Meanwhile,the cross-correlation exponent between PM10 concentrations and air absorbed dose rate was 0. 968 in the winter. This shows that high PM10 concentrations have a certain impact on the radiation environments of the atmosphere during severe haze. However,in summer,the DCCA curve of the two is divided into two segments with respective scaling index being 0. 579,1. 519. The corresponding feature time scale of breakpoint position is about two months,which is speculated to be associated with the time distribution mode of rainfall in summer. New insights into the relationship between PM10 concentration and air absorbed dose rate maybe contribute to new policies for atmospheric environmental management.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2016年第7期972-977,共6页
Research of Environmental Sciences
基金
国家自然科学基金地区科学基金项目(41465010)
湖南省教育厅科学研究一般项目(15C1117)
湖南省研究生培养创新基地开放项目(JDST201506)
关键词
PM10
空气吸收剂量率
去趋势互相关分析法
相关性
成都市
PM10
air absorbed dose rate
detrended cross-correlation analysis
cross-correlation
Chengdu City
