基于卫星观测的南京臭氧时空分布及变化特征

Ozone Spatial-temporal Distribution and Trend over Nanjing: Insight from Satellite

随着城市化及工业化进程的加快,南京市的臭氧污染问题也愈发突出。利用OMI(ozone monitoring instrument)的卫星观测数据与Ziemke数据集对南京市2008-2017年臭氧时空分布特征进行遥感反演和统计分析,为制定南京臭氧控制策略提供科学依据及参考。结果如下,10年间南京上空臭氧总量总体缓慢上升,最低值出现在2008年(284.46 DU);最高值在2010年(297.27 DU)。春季臭氧总量最高,秋季最低。10年间,冬、春季臭氧总量波动上升,而夏、秋季则相反。臭氧总量的月变化呈周期性分布,4月和10月分别为峰值和谷值。臭氧总量的空间分布呈现明显的北高南低的纬度分布特征。而对流层臭氧柱浓度在2008-2017年波动上升,季节均值最大值出现在夏季(48.8 DU),冬季最小(34.1 DU)。10年间,春季对流层柱臭氧浓度呈下降趋势,其他季节均与之相反。对流层臭氧柱浓度的月变化呈现单峰分布,6月的对流层臭氧柱浓度最高(54.9 DU),最低值出现在1月,较臭氧总量的月变化推迟2-3个月。研究表明,南京上空的臭氧时空变化特征明显,为大气环流、气候变化及人类活动等多方面因素共同影响的结果。

With the acceleration of urbanization and industrialization, the problem of ozone pollution in Nanjing has aroused wide concern. This study conducted an in-depth research on the characteristics of spatial and temporal evolution of ozone pollution by analyzing the observation data of the Ozone Monitoring Instrument(OMI) data and Ziemke datasets in Nanjing from 2008 to 2017. This paper aims to provide scientific basis and reference for ozone control strategies. The results indicated that total ozone of Nanjing had risen slowly in recent 10 years. For the time distribution, the minimum value of total ozone was 284.46 DU, appeared in 2008 and the highest value was 297.27 DU, appeared in 2010. In terms of seasonal changes, total ozone levels presented the highest value in spring and the lowest value in autumn. During past 10 years, the total ozone in spring and winter rised, while decreased in summer and autumn. The monthly variation of the total ozone in China exhibited marked periodic variations and the maximum and the minimum values appear in April and October respectively. The spatial distribution of total ozone showed obvious latitude distribution characteristics, and value of total ozone in northern area was larger than that in southern area. The tropospheric ozone concentration exhibited an overall upward trend from 2008 to 2017. The maximum seasonal mean of tropospheric ozone concentration(48.8 DU) occurred in summer, at 48.8 DU while a minimum of 34.1 DU in winter. In past 10 years, tropospheric ozone in Nanjing showed a downward trend in spring, while other seasons showed an upward trend. The average monthly change of tropospheric ozone concentrations showed a single peak distribution, with the tropospheric ozone concentration appeared highest value(54.9 DU) in June(54.9 DU) and the lowest value in January. Compared to the total ozone, it delayed by 2 to 3 months. This studies has shown that the temporal and spatial variation of ozone over Nanjing is obvious, and it is the result of various factors such as atmospheric circulation, climate change and human activities.