Spatial Distribution Characteristics of Nitrogen Oxides in the Sichuan Basin from 2010 to 2021 

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  • 1. School of Atmospheric SciencesChengdu University of Information TechnologySichuan Province Field Scientific Observation and Research Station for Urban Meteorology and Environment in Chengdu PlainChengdu 610225SichuanChina
    2. Lanzhou UniversityLanzhou 730000GansuChina
    3. Chinese Academy of Meteorological SciencesInstitute of Atmospheric Composition and Environmental MeteorologyBeijing 100081China

Online published: 2025-06-26

Abstract

The level of nitrogen oxidesNOxemission is a key indicator for assessing anthropogenic atmospheric pollutant emissions. Understanding the long-term trends of NOx emissions and identifying emission hotspots are of significant importance for air pollution control. This study utilized OMI and TROPOMI data to analyze the long-term trends and spatial distribution characteristics of tropospheric NO2 column density across various regions of Sichuan and Chongqing from 2010 to 2021. Additionallyground-based NO2 concentration data from environmental monitoring stations and NOx emission data from the MEIC inventory were integrated to evaluate the long-term trends of NOx emissions observed by satellite. Ground-based NO2 concentration measurements and ME‐ IC NO x emission inventory data are incorporated to assess the accuracy of satellite observations. The results show that:(1The spatial distribution of NO2 column density in the Sichuan-Chongqing region reveals two hotspot areasincluding Chengdu and the central urban area of Chongqing. Compared to OMI satelliteTROPOMIwith its higher signal-to-noise ratio and resolutioncaptures more detailed spatial distribution features;(2tropo‐ spheric NO2 column density exhibits a declining trendwith rates of -0. 115×1015-0. 096×1015 and -0. 053×1015 molec·cm2·a-1 in the Chengdu PlainChongqingand the Sichuan-Chongqing regionrespectively;(3NO2 column density increased with rising NOx emissions from industrial and transportation sources during 2010 -2012. For the period of 2012 -2015NO2 column density decreased by 19. 91% across the SichuanChongqing regionwhich is mainly attributed to substantial emission reductions in power and industrial sectors. From 2015 to 2017NO2 concentrations increased by 10. 76%followed by a gradual decline;(4The trends in satellite-observed NO 2 column density closely align with ground-level ambient NO2 measurements;(5NO2 column density exhibits distinct seasonal variationsin the Sichuan Basinwinter NO2 concentrations are significantly higher than in other seasonsfollowed by spring and autumnwith summer concentrations being the low‐ est. In contrastin the western Sichuan PlateauNO2 concentrations are higher in summer than in winter due to natural sources.

Cite this article

HU Qin, YANG Xianyu, WANG Wenlei, LI Douwang, BEN Bingzheng, YANG Zhou, ZHANG Xiaoling . Spatial Distribution Characteristics of Nitrogen Oxides in the Sichuan Basin from 2010 to 2021 [J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2024.00107

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