四川盆地冬季霾日数的分布特征及其与气象条件和海温关系

利用四川盆地气象站点资料和NCEP/NCAR再分析资料,结合四川盆地冬季霾日数的时空变化特征,分析了影响盆地冬季霾日数的气象条件,探讨了海温异常对冬季霾日数的可能影响,基于海温关键区建立冬季霾日数预测模型,并检验了模型的预测能力。研究表明,四川盆地冬季霾日数呈弱增加趋势;四川盆地三大城市群为冬季霾多发区;四川盆地冬季霾日数与相对湿度、气温、降水日数关系显著。四川盆地冬季霾日数偏多(少)年,大气环流异常呈西伯利亚高压偏弱(强)、欧亚中高纬呈北低(高)南高(低)、东亚冬季风偏弱(强)、副热带西风急流偏弱(强)。秋季东北太平洋、热带太平洋以及北大西洋海温关键区暖海温(冷)发展,有利于盆地盆地冬季霾日数偏多(少)。前期秋季东北太平洋、热带太平洋、北大西洋海温异常是影响四川盆地冬季霾日数的年际预报信号,对四川盆地冬季霾日数的多寡具有较好的预测能力。

Distribution Characteristics of Winter Haze Days in Sichuan Basin And Their Relationships With Meteorological Conditions and SST

Based on the data of meteorological stations and NCEP/NCAR reanalysis and the spatial and temporal variations of haze days in winter in Sichuan Basin,the characteristics of the meteorological conditions and the SST anomaly were analyzed,which influenced haze days in winter in Sichuan Baisn. Based on the SST critical areas,a prediction model of winter haze days was established and validated. The results showed that the number of winter haze days increased weakly,three urban agglomeration were haze-prone areas,the relationship between the number of haze days in winter and relative humidity,temperature and precipitation days in Sichuan Basin was significant. The more(less)winter haze days in Sichuan Basin corresponded to the circulation characteristics of weaker(stronger)Siberian high,lower(higher)in the North and higher(lower)in the South of the Eurasian mid-high latitude,weaker(stronger)East Asian winter monsoon,weaker(stronger)East Asian subtropical jet. More(less)winter haze days were associated with warming(cooling)SST development in the key areas of Northeast Pacific,Tropical Pacific and North Atlantic. The previous autumn SST anomaly in the key areas of Northeast Pacific,Tropical Pacific and North Atlantic was interannual prediction signal,which significantly influenced winter haze days in Sichuan Basin.