不同时间角度下的中国霾日数时空变化格局研究(1961年～2015年)

摘要

Frequent haze weather has become one of the focuses concerned by various circles of the society.In the present work,2474 station data.From the perspective of interannual,monthly and weekly changes,variation characteristics of haze days in China from 1961 to 2015 were calculated with a variety of methods such as linear trend and inverse distance weight interpolation.The results show that:on the inter-annual scale,average annual haze days present increasing trend with fluctuation,which exhibits three section changes in detail,including increase from 1961 to 1980,stable from 1981 to 2000 and rapid raise from 2001 to 2015.On the monthly scale,on one hand average annual haze days from January to December display a ‘U’ shaped distribution.On the other hand,average annual haze days in all month reveal a tendency of increase.On the weekly scale,average annual haze days in China from Monday to Sunday follow the decreaseincrease-decrease pattern,while change little.The average annual haze days from Monday to Sunday increased consistency from 1961 to 2015.In space distribution,average annual haze days tend to have the spatial pattern of "southeast increasing significantlynorthwest increasing not significantly".The decadal average annual haze days in Northern China,Central and East China and Southern China area gradually vary with time from the negative anomaly evolution to positive anomaly.Area with average annual haze days in January and December more than 2.7 d/a has a wide distribution,while that with the other months range is relatively small.Area with average annual haze days from Monday to Sunday more than 4.5 d/a are mainly distributed in the area of Beijing and Tianjin,the Yangtze River Delta,Pearl River Delta,Shanxi and Shaanxi area.By contrast it is found that in different weeks the average annual haze days in spatial distribution changes little.%采用2 474个站点数据,从年际、月际和周际变化角度,利用线性趋势和反距离权重插值等多种方法,计算了1961年～2015年中国霾日数时空变化特征.结果表明:在年际尺度上,1961年～2015年中国年均霾日数在波动中呈“先上升(1961年～1980年)-后平稳(1981年～2000年)-再迅速上升(2001年～2015)”的三段式变化特征.在月际尺度上,1～12月份的年均霾日数呈现出“U”型分布,且所有月份的平均霾日数均呈现增加趋势.在周际尺度上,中国年均霾日数从周一到周日呈现出先减少后增加再减少的特征,但变化幅度不大.1961年～2015年中国周一到周日的平均霾日数均呈一致性增加趋势.在空间分布上,1961年～2015年中国年均霾日数变化趋势呈“东南增加显著-西北增加不显著”的空间分异格局.中国华北、华中、华东和华南地区的年代际年均霾日数随年代推移逐渐从负距平演变为正距平.不同月份的年均霾日数呈现出“东南高-西北低”的空间格局.1月和12月份年均霾日数达到2.7 d/a以上的地区分布较广,其它月份分布范围则相对较小.1961年～2015年周一到周日的年均霾日数超过4.5 d/a的地区主要分布在京津冀、长三角、珠三角、山西和陕西地区.通过对比可以发现不同星期的年均霾日数在空间分布上变化不大.