广州市近地面臭氧时空变化及其与气象因子的关系

利用2012年1月至2016年2月广州市环境空气自动监测数据和气象观测数据,对广州市近地面臭氧的时空分布特征及其与气象因子的关系进行分析。结果表明:2012—2015年广州市臭氧日最大8 h滑动平均值的第90百分位数波动变化,年变化率依次为-14.3%、5.8%、-12.1%;广州市臭氧浓度呈现夏、秋季高,春、冬季低的显著季节变化特征;臭氧日最大8 h平均值的月均值和第90百分位数最高的月份一般分别出现在10月和7—8月;臭氧浓度的日变化曲线为单峰型,最大值一般出现在14:00或15:00;臭氧浓度随垂直高度的升高而增大,从低层(6 m点位或地面站)到中层(118 m和168 m点位)、中层到高层(488 m点位)臭氧日最大8 h滑动平均值的增长率分别为18.3%和39.1%;广州市中心城区臭氧浓度低于南北部城郊,夏、秋季高值区与夏、秋季主导风向相对应;臭氧浓度受降水、气温、相对湿度和风速等气象因子影响,臭氧浓度的超标是多种因素综合作用的结果。

Spatial-temporal Variation of Surface Ozone in Guangzhou and Its Relations with Meteorological Factors

The temporal and spatial distribution of surface ozone in Guangzhou and its relations with meteorological factors were analyzed by using the data of ambient airquality monitoring stations and meteorological observation data from January 2012 to February 2016.The results indicated that:90th percentile concentrations of daily maximum of 8-h ozone moving averages fluctuated during the years of 2012-2015, and the annual rates of change were -14.3%, 5.8% and -12.1% successively; ozone concentration in Guangzhou showed significant seasonal variation characteristic with high concentration in summer and autumn and low in spring and winter; the highest values for monthly means of daily maximum of 8 h ozone moving averages and 90^th percentile were generally seen in October and July-August respectively;diurnal variations of ozone concentrationsexhibitedthe characteristic of single peak, andshowed the peakat around 14:00 or 15:00;ozone concentration increased with increasing vertical height, with increasing rates of 18.3% from the bottom layer (6 m siteor ground site) to the middle layer (118 m and 168 m site), and 39.1% from middle layer to the top layer (488 m site);the concentration of ozone in the central urban area of Guangzhou was lower than that in the north-south suburbs, and the high-value area in summer and autumn correspond to the dominant wind direction in both seasons;ozone concentration was affected by meteorological factors such as precipitation, temperature, relative humidity, and wind speed, and the excessive concentration of ozone was the result of the combination of various factors.