基于卫星观测的青海高原对流层臭氧时空分布特征研究

Temporal and spatial distribution characteristics of tropospheric ozone in Qinghai Plateau based on satellite observations

基于OMI-MLS对流层臭氧总量数据集对2005—2019年青海高原对流层大气臭氧总量进行提取分析,探讨其时空分布格局及气象因子的影响.结果表明:(1)OMI-MLS对流层臭氧总量数据在青海高原的适用性良好.(2)青海高原的多年平均对流层臭氧总量分布整体呈东北高西南低的态势,受地形和大气环流形势影响较大.海东市的对流层臭氧总量最高,其次是西宁市、格尔木市、德令哈市,玉树市的对流层臭氧总量最低.对流层臭氧总量月变化在一定程度上表现为"倒V"型特点:峰值位于6—7月,谷值位于1月,与气温变化密切相关.对流层臭氧总量季节变化明显,空间异质性强,夏季最高,春季、秋季次之,冬季最低.(3)近15年青海高原对流层臭氧总量呈显著增加趋势,年平均增加速率为0.22 DU,4个季节的对流层臭氧总量均呈波动上升趋势,冬季的对流层臭氧总量增加速率最快,其次是春季、夏季,秋季增加速率较慢.(4)影响青海高原对流层大气臭氧总量的主要气象因子是气温和降水,而次要因子表现略有不同.

Based on the total tropospheric ozone data set retrieved from OMI-MLS, the spatiotemporal distributions of total amount of atmospheric ozone in the Qinghai Plateau from 2005 to 2019 were analyzed, and the effect of meteorological factors on it were also discussed. The results derived from the paper are as follows:(1)The total tropospheric ozone data obtained from OMI-MLS presents a good applicability over the Qinghai Plateau.(2)Over all, The distribution of the multi-year average total tropospheric ozone in the study area is higher in the northeast than southwest, which is greatly affected by the terrain and atmospheric circulation. Further, Haidong has the highest value, followed by Xining, Golmud, Delingha, and Yushu has the lowest value. The monthly changes show an "inverted V" shape to some extent: the peak value occurs from June to July, and the lowest is in January, which is closely related to temperature changes. Meanwhile, obvious seasonal changes appear strong spatial heterogeneity, with the highest value in summer, followed by spring and autumn, and the lowest in winter.(3)In the past 15 years, the total tropospheric ozone in the Qinghai Plateau has shown a significant increasing trend, with an average annual increase rate of 0.22 DU, and with a fluctuating upward trend in the four seasons. That is, the increase rate is fastest in winter, followed by spring and summer, and the slower rate in autumn.(4)The main meteorological factors affecting the total ozone in the troposphere in the Qinghai Plateau are temperature and precipitation, while the secondary factors is slightly different.