摘要
选用盆地1973-2013年12个气象站的资料,在定义一个适合四川盆地的霾天气识别标准的基础上,分析了四川盆地霾天气的变化特征。并对2013年2月的一次典型霾天气演变过程进行分析,探究霾天气的形成与其它气象因素的关系。结果表明,四川盆地近41 a总平均年霾日为97 d,没有明显的长期变化趋势,但是霾天气的变化可分为3个阶段,第一阶段为1973-1988年,盆地的平均年霾日为90 d,变化趋势为每10 a增加32 d。第2阶段为1989-1999年,平均年霾日可达112 d,没有明显变化趋势。第3阶段为2000-2013年,平均年霾日为95 d,变化趋势为每10 a减少12 d。四川盆地以30°N为界,南部为霾天气多发区域。在霾日的季节分布中,冬季最多,其次是春秋季,夏季最少,而且近40多a来夏季的霾日有增加的趋势。通过个例分析发现,霾天气的产生受低风速的影响最大,相反消散过程中近地面和对流层中层的风速都较高。霾天气发生时大气层结偏稳定,盆地冬天近地面普遍存在逆温现象现象,出现霾天气时逆温层强度明显较高。
This paper is to explore the variation characteristics and trends of haze weather in Sichuan Basin by using Basin data from 12 meteorological stations in 1973-2013 on the basis that a suitable haze weather identification standard is defined.In the meantime, a typical haze weather evolution process in February 2013 is discussed to investigate the relationship be-tween haze weather formation and other meteorological factors. The results show that, averagely annual haze days in Sichuan Basin in the past 41 years reach 97 d; no significant long-term trends are found, but the changes in haze weather can be di-vided into three stages: First stage(1973-1988) during which average annual haze days reach 90 d and increase 32 d every 10a; Second stage(1989-1999) during which average annual haze days reach 112 d and no significant trends are exhibited;Third stage(2000-2013) during which average annual haze days reach 95 d and decrease 12 d every 10 a. Bounded on 30 °N,southern part of Sichuan Basin is haze-prone region. In terms of seasonal distribution, haze days occur in winter most fre-quently, followed by autumn and spring. Summer witnesses the least haze days, but the number of haze days in summer in-creases year by year during the last 40 years. The case study of haze weather suggests that, the formation of haze weather is most severely affected by low wind speed, while in the dissipation process, near-ground and middle troposphere wind speeds are relatively high. As haze weather occurs, atmospheric stratification is relatively stable. In winter days, temperature inversion phenomenon can be found in near-ground area in Sichuan Basin, while in haze days, inversion intensity significantly increas-es.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2015年第S1期71-76,共6页
Environmental Science & Technology
关键词
四川盆地
霾天气
变化特征
气象因素
Sichuan Basin
haze
variation characteristics
meteorological factor
