基于甘肃省卫星遥感的对流层NO2时空变化

基于OMI卫星遥感反演的NO₂柱浓度数据，分析了近11a甘肃省对流层NO₂柱浓度的时空变化及相关影响因素，同时利用HYSPLIT模型探究了大气污染物的来源.结果表明：从空间上，NO₂柱浓度呈现出由甘肃东北区向西南区递减趋势，最高值主要分布于庆阳市全境和平凉市少部分地区.从2008~2014年NO₂柱浓度值不断增长至最高值，高值区逐步扩大；2015~2018年NO₂柱浓度值波动变化，呈现出向周围区域递减的趋势，高值区范围缩小；从时间上，2008~2018年对流层NO₂柱浓度整体呈上升趋势，对流层NO₂柱浓度四季均值分布为：夏季>春季>秋季>冬季；NO₂柱浓度每年在6~8月达峰值，9月后开始下降，年内谷值出现在12月份~次年2月份；对研究区NO₂柱浓度的贡献最大的是自然要素.高温、降水有利于土壤排放NO₂，植被覆盖率对NO₂起到一定的消减作用.利用HYSPLIT得出2009~2018年每年7月庆阳市NO₂的外部输送路径，其中主要路径以陕西地区为主.

Temporal and spatial variation of tropospheric NO2 based on satellite remote sensing in Gansu Province

Based on the NO₂ column concentration data retrieved from OMI satellite remote sensing, the temporal and spatial changes of tropospheric NO₂ column concentration and related influencing factors in Gansu Province in the past 11 years were analyzed. And the HYSPLIT model was used to explore the source of atmospheric pollutants. In terms of spatial distribution, the NO₂ column concentration showed a decreasing trend from the northeast to the southwest in Gansu, and the highest values were mainly distributed in the entire of Qingyang City and a small part of Pingliang City. The NO₂ column concentration value had continuously increased to the highest from 2008 to 2014, and the high value area had gradually expanded; The concentration of NO₂ column fluctuated from 2015 to 2018, and it showed a decreasing trend toward the surrounding area, however, the range of the high value area narrowed in the same term. In terms of temporal distribution, the NO₂ column concentration in tropospheric showed an upward trend from 2008 to 2018. The seasonal mean distribution were:summer > spring > autumn > winter; the NO₂ column concentration peaked from June to August every year, and it started to decline after September, and the lowest point appeared during the year from December to February of the following year. Natural factors contributed the most to the NO₂ column concentration in the study area. High temperature and precipitation were conducive to NO₂ emissions from the soil. However, vegetation coverage had a certain effect on reducing NO₂ concentration.Using the HYSPLIT model, it can be concluded that in July of each year from 2009 to 2018, the external transport route of NO₂ in Qingyang was mainly towards Shanxi.