2015—2018年海南省城市臭氧时空分布特征

Spatiotemporal distribution of ozone in cities of Hainan from 2015 to 2018

基于2015—2018年海南省18个市县O3浓度监测数据和气象观测资料,结合Cressman客观插值方法对城市O3浓度时空分布特征进行深入分析.结果表明,海南省O3最大8小时平均值(O3-8 h)浓度空间分布呈西部、北部和东部沿海高,中部山区和南部沿海低的分布特征.四季O3-8 h浓度的空间分布与年平均基本一致,但是季节变化特征明显.O3-8 h浓度受气象因子影响显著,其中与年平均气温、年日照时数和平均风速呈正相关关系,与年降水量、年降水日数和相对湿度呈反相关关系.O3浓度日变化呈现单峰型变化特征,高值主要出现在15:00—18:00之间,其中夏季峰值出现最早,冬季最晚,春季和秋季介于两者之间.O3-8 h浓度逐月变化表现为单峰单谷型,7月最低,10月最高.区域性O3污染(O3-8 h浓度超标市县≥3个)特征分析表明,近4年海南省共有40 d发生了区域性O3污染,发生概率为2.73%,其中2017年的区域性O3污染强度最强,年平均的O3-8 h浓度超标市县数达到7.38个,超标率为41%.

Based on the O3 concentrations monitored data and meteorological data from 18 cities and counties in Hainan Province from 2015 to 2018,combined with the Cressman interpolated method,the temporal and spatial distribution characteristics of O3 concentration in Hainan were analyzed.The results showed that O3-8 h(defined as maximum result of 8 hour average)was lower in the central mountainous and southern coast than that in the western coast,northern coast and eastern coast.Additional,the spatial distribution of O3-8 h in four seasons was similar with the annual average with obvious seasonal variation.O3-8 h in Hainan Province was affected by meteorological factors significantly,which showed that there was a positive correlation between O3-8 h and annual average temperature,annual sunshine hours and average wind speed,and a negative correlation with annual precipitation,annual rainy days and relative humidity.The diurnal variation of O3 showed a single peak distribution,high values mainly occurring between 15:00 and 18:00,and the peak appearing earliest in summer,spring and autumn followed,winter was the latest.Otherwise,Monthly variation of O3-8 h showed a single peak and single valley type,the lowest value occurred in July,and the highest value occurred in October.Characteristic analysis of regional O3 pollution(defined as≥3 cities and counties with O3-8 h concentration exceeding the standard)indicated that there had 40 d of regional O3 pollution in the pasted 4 years over Hainan Province,with an occurrence probability of 2.73%.Among them,the intensity of regional O3 pollution in 2017 was strongest,the number of polluted cities and counties reached 7.38,and with 41%polluted rate.