Analysis of emission characteristics of urban areas in East Asia based on the relationship between NO2 and CO2 derived from satellite data

East Asia emits large amounts of greenhouse gases and air pollutants due to anthropogenic activities for socioeconomic development. The relationship between greenhouse gas and air pollutant concentration varies by region, depending on various factors, such as types of fuel and combustion and burning efficiency. This study investigated the relationship between Carbon dioxide (CO2) and Nitrogen dioxide (NO2) in several metropolitan cities in East Asia using measurements from the Geostationary Environment Monitoring Spectrometer (GEMS), Tropospheric Monitoring Instrument (TROPOMI), and Orbiting Carbon Observatory-3 (OCO-3). The regional differences in the NO2-CO2 relationship were discussed based on the regional anthropogenic activity pattern and various socioeconomic indicators. The NO2-CO2 relationship analysis can help understand the anthropogenic emission characteristics of each region. This study highlights the value of using recent satellite data in analyzing the relationship between air pollutants and greenhouse gases.