中山市2000~2014年霾天气特征及气象影响因子

利用中山市2000~2014年气象资料及2013~2014年环境监测站资料,分析中山市霾特征及气象影响因子,结果表明,中山市霾日数年际变化明显,最少为11d,出现在2005年;最多为134d,出现在2008年.霾天气主要发生在秋冬季节,霾日数最多的月份是1月,平均为10.5d.霾日PM_2.5的平均浓度是非霾日的2.26倍,PM_2.5是霾天气的重要污染物.中山市霾日典型天气形势有7种:大陆高压型、海上高压型、均压场型、冷锋前部型、台风外围下沉气流型、槽前脊后型、低压槽型.其中以大陆高压型占比例最高,为52.03%,冷锋前部型造成的能见度最低.气流轨迹聚类分析表明,影响中山的气流轨迹有7类,主要来源于东北方向的大陆和偏东方向的沿海;在东北方向气流轨迹影响下,污染物浓度较高;在东部沿海的气流轨迹下,能见度较低,表明中山市的霾天气受区域传输影响显著.

Haze characteristics associated with meteorological factors in Zhongshan during 2000~2014

Based on meteorological data from 2000 to 2014 and environmental monitoring data from 2013 to 2014 in Zhongshan, the haze characteristics and meteorological factors were analyzed. The result showed that haze days had obvious annual variability, there were 11 haze days in 2005 and 134 days in 2008. Haze in Zhongshan mainly occurred in autumn and winter. From 2000 to 2014, the average of haze days was 10.5 days in January, which was the most frequent month of haze pollution. PM_2.5 was one of the most important pollutants causing haze. When haze occurred, the average concentration of PM_2.5 was 2.26 times higher than non-haze days. The typical synoptic patterns associated with haze over South China could be summarized into 7major categories: mainland high pressure, ridge on South China Sea, equalizing pressure, foreside of cold front, downward flow of typhoon periphery, foreside of trough or backside of ridge, and trough over South China. The type of mainland high pressure caused the most haze days, taking up by 52.03%, while the type of foreside of cold front caused the lowest visibility. By using cluster analysis, the results revealed that airflow transport channels near the ground in Zhongshan could be divided into 7types. The mainly transport channels were from the northeast China and coastal areas in the East. The northeast channels could cause high pollutant concentration, and the east channels could cause low visibility. The result demonstrated that haze in Zhongshan was noticeably affected by regional airflow transport.