ZHANG Qianqian, 2024. Temporal Variability of Tropospheric NO2 over Cities in the United States, Western Europe and China from 2005 to 2022. Chinese Geographical Science, 34(6): 983−992. DOI: 10.1007/s11769-024-1454-5
Citation: ZHANG Qianqian, 2024. Temporal Variability of Tropospheric NO2 over Cities in the United States, Western Europe and China from 2005 to 2022. Chinese Geographical Science, 34(6): 983−992. DOI: 10.1007/s11769-024-1454-5

Temporal Variability of Tropospheric NO2 over Cities in the United States, Western Europe and China from 2005 to 2022

  • Anthropogenic Nitrogen oxides (NOx = NO2 + NO) emissions are highly concentrated in urban area, and the weekly cycles, seasonal patterns and long-term trends of tropospheric NO2 columns over cities differ from region to region due to different emission sectoral compositions and human activities. In this study, we used satellite observed tropospheric NO2 column data to compare the long- and short-term NO2 column density time series over cities in the United Sates (the U.S.), western Europe and China. The results showed that in all the targeted cities, the outbreak of the Corona Virus Disease in 2019 (COVID-19) moved the December peak of the city-level NO2 columns forward to November and October or even earlier in 2020 and 2021. On weekly level, cities in the U.S. show the lowest NO2 columns ratio on weekend/work day, then come the western European cities, and a weak weekly pattern is seen in Chinese cities. For all the cites, we find a higher weekend/work day NO2 ratio in cold seasons than in warm seasons, indicating a higher contribution from NOx emission sectors of residential, industry and power plants in the warm seasons. In the long-term, NO2 columns over the U.S. and western European cities declined by a fraction twice that of the regional mean level from 2004 to 2021. In China, NO2 columns started to decrease since 2012, at a similar rate between the city and regional level. This work confirms the importance to quantify and control NOx emissions from cities.
  • loading

Catalog

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return