基于Sentinel-5P的粤港澳大湾区NO2污染物时空变化分析

Analysis of temporal and spatial variation characteristics of NO2 pollutants in Guangdong-Hong Kong-Macao Greater Bay Area based on Sentinel-5P satellite data

基于最新的TROPOMI反演的对流层NO2垂直柱浓度数据,利用Google Earth Engine平台分析了粤港澳大湾区近2a对流层NO2垂直柱浓度的分布及变化特征.结果表明,TROPOMI传感器反演的对流层NO2垂直柱浓度与地表NO2浓度监测值具有较好的相关性,反演产品能够反映地面真实的NO2污染状况;粤港澳大湾区NO2柱浓度分布呈现出较为显著的圈层结构,高NO2柱浓度区域面积约为4468km^2,占大湾区总面积的8%,低NO2柱浓度地区的面积约为25331km^2,占比超过了45%;大湾区上空的对流层NO2垂直柱浓度存在明显的“冬高夏低,春秋过度”的季节性差异和周期性波动特征;影响因子回归模型结果表明人类活动强度(DNB,夜间灯光)、植被状况(NDVI,植被指数)和地形因子(DEM,数字高程)与地区对流层NO2垂直柱浓度的分布有明显的相关性.本研究成果可为政府和决策者制定相关政策和措施提供借鉴.

The TROPOMI(TROPOspheric Monitoring Instrument)on the Sentinel-5Precursor(also known as sentinel-5p)had emerged as base data for spatial analysis of regional NO2 pollution due to its excellent temporal and spatial resolution.Considering the lack of application analysis based on Sentinel-5P NO2 concentration products in Guangdong,Hong Kong and Macao Bay Area(GBA)at present,based on the latest tropospheric NO2 vertical column concentration(troNO2)data produced by TROPOMI,this paper analyzed the distribution and change characteristics of atmospheric NO2 pollutants in recent 2years through Google Earth Engine platform.The results showed that:1)the troNO2 retrieved by TROPOMI had a high correlation with the monitoring value of surface NO2 concentration,and the inversion product can reflect the real NO2 pollution on the ground;2)the concentration distribution of troNO2 in GBA showed a significant circle structure:the area of high NO2 density was about 4468km^2,accounting for 8% of the total area of GBA,and the area of low NO2 density was about 25331km^2,accounting for more than 45%;3)the troNO2 over GBA was characterized by"high in winter and low in summer,and excessive in spring and Autumn";4)the impact factor analysis showed that the human activities intensity(DNB,nighttime light),vegetation status(NDVI,vegetation index)and terrain factor(DEM,elevation)had strong correlation with the troNO2.The results of this study can assist the government and policymakers to make more targeted policies to implement NO2 emission reduction and improve air quality.