Satellite UV-Vis spectroscopy: implications for air quality trends and their driving forces in China during 2005-2017

• 来源期刊: 光：科学与应用（英文版）
• 年，卷（期）: 2019,（6）
• 页码范围: 998-1009
• 页数: 12页
• 语种: 英文

摘要

Abundances of a range of air pollutants can be inferred from satellite UV-Vis spectroscopy measurements by using the unique absorption signatures of gas species.Here,we implemented several spectral fitting methods to retrieve tropospheric NO2,SO2,and HCHO from the ozone monitoring instrument (OMI),with radiative simulations providing necessary information on the interactions of scattered solar light within the atmosphere.We analyzed the spatialdistribution and temporal trends of satellite-observed air pollutants over eastern China during 2005-2017,especially inheavily polluted regions.We found significant decreasing trends in NO2 and SO2 since 2011 over most regions,despitevarying temporal features and turning points.In contrast,an overall increasing trend was identified for troposphericHCHO over these regions in recent years.Furthermore,generalized additive models were implemented to understandthe driving forces of air quality trends in China and assess the effectiveness of emission controls.Our results indicatedthat although meteorological parameters,such as wind,water vapor,solar radiation and temperature,mainlydominated the day-to-day and seasonal fluctuations in air pollutants,anthropogenic emissions played a unique role inthe long-term variation in the ambient concentrations of NO2,SO2,and HCHO in the past 13 years.Generally,recentdeclines in NO2 and SO2 could be attributed to emission reductions due to effective air quality policies,and theopposite trends in HCHO may urge the need to control anthropocgenic volatile organic compound (VOC) emissions.