东北地区近50年来霾天气气候特征

利用东北地区194个地面气象观测站的1961~2013年观测资料,对东北地区霾日及不同等级霾日的空间分布特征和时间演变规律进行分析.结果表明:东北地区霾日空间分布差异显著,辽宁中部和黑龙江中北部霾日相对较多,年平均霾日超过50d,吉林西部地区霾日最少,年平均霾日不超过2d,不同等级的霾日日数空间分布与总霾日日数基本一致;东北地区霾日主要集中在冬季,占全年霾日57.9%,秋季次之,春季最少;1961~2103年东北地区平均霾日呈显著增加趋势(2.9d/10a),其中1981~2000年时段增加最为显著,轻微霾日、轻度霾日、中度霾日和重度霾日均呈增加趋势,但轻度霾日、中度霾日和重度霾日21世纪以来较80年代略有减少.

Climatic characteristics of haze days in Northeast of China over the past 50 years.

Based on the surface meteorological data from 194 weather stations located in the Northeast of China during 1961~2013, temporal and spatial characteristics of haze days and haze with varied intensity have been analyzed. In terms of spatial distribution, there are two high-value centers located in the central Liaoning Province and north central Heilongjiang Province respectively, where annual total haze events generally exceed 50days. The least haze events occur in the west of Jilin Province with less than 2days per year.Furthermore, the spatial distribution of varied intensity (slight, mild, moderate and severe) haze days is approximately consistent with that of the total haze days.Haze events are more frequently observed in winter (57.9%), followed by autumn and they are least frequently in springs. Average number of annual haze days in study area has a significant increasing trend of 2.9d/decade during 1961~2013 with greatest increase occurring during 1980~2000. Days with slight ,mild, moderate and severe haze have also increased, but mild, moderate and severe haze days reduced slightly in the 21st century compared with the 1980s.