新疆库尔勒市近地面臭氧变化特征及其影响因素

Variation of Surface Ozone Concentration and Its Affecting Factors in Korla City,Xinjiang

高浓度臭氧对人体健康造成伤害,还会影响植物生长;臭氧也是一种重要的温室气体,影响全球气候变化。利用库尔勒市2010年7月1日至2012年6月30日连续自动地表臭氧浓度观测数据,结合相应气象要素资料,对地表臭氧质量浓度的日、周、月、季节与不同天气条件下日变化特征进行了分析,探讨影响臭氧变化的主要因素。结果表明:①臭氧浓度日变化具有明显的单峰型日变化规律,夜间变化平缓,白天变化剧烈。②臭氧浓度变化具有周末效应。最高值出现在星期日,最低值出现在星期三。③最高月平均浓度为82.1μg·m-3,最低月平均浓度为19.2μg·m-3,2011年1—12月变化规律明显,以6月为中心分布非常对称,两边逐渐降低。④春、夏季臭氧质量浓度较高,秋季和冬季明显低于春季和夏季,与沿海内地大中型城市变化特征基本一致。⑤4个季节中臭氧浓度日变化剧烈的是夏季和春季,秋季其次,变化最小的是冬季。不同天气情况下,日变化最剧烈的是晴天,其次为沙尘天气,阴天和雨天日变化平缓。⑥臭氧浓度日变化与PM10质量浓度日变化具有明显的相反变化趋势,但在时间变化上有一定的滞后性,臭氧浓度变化明显早于PM10的变化。⑦晴天少云的天气情况下臭氧浓度明显要高于阴雨(雪)天,相对湿度、风速、风向、日照时数同时影响近地面臭氧浓度的变化,臭氧污染的发生是多种因素共同作用的结果。

High surface ozone concentration causes harm to human health and also affects plant growth. Ozone is a kind of important greenhouse gas and affects global climate change. In this paper,the daily,weekly,monthly and seasonal variations of surface ozone concentration under different weather conditions were analyzed based on the observation data of surface ozone concentration in Korla City,the largest city in south Xinjiang during the period from July 1,2010 to June 30,2012 and also the corresponding meteorological data. Moreover,the main factors affecting the variation of ozone concentration were discussed. The results were as follows： ① The daily variation curve of ozone concentration was unimodal,and the nocturnal variation was gentle but the diurnal one was significant; ② The highest value of ozone concentration occurred on Sunday and the lowest one on Wednesday; ③ The highest average monthly concentration was 82. 1 μg ·m^- 3and occurred in June 2011,and the lowest one was19. 2 μg·m^- 3; ④ Ozone concentration in spring and summer was higher than that in autumn and winter,and the variation trend was similar to that in other coastal and mainland large-and medium-sized cities; ⑤ Seasonally,the daily ozone concentration varied the most significantly in summer and spring,then in autumn,and the slightest in winter. Under different weather conditions,the daily ozone concentration varied the most significantly on sunny day,then on dust weather day,and gently on rainy and cloudy days; ⑥ The daily variation of PM10concentration was contrary to that of ozone concentration,and the latter was significantly earlier than the former; ⑦ The variation of near surface ozone concentration could be affected by some meteorological factors,such as the relative humidity,wind speed,wind direction and sunshine duration,so ozone pollution was jointly affected by many factors.