[A-AS11] 大気化学

[AAS11-P28] Identification of Major Anthropogenic Emission Sources of CO₂ and CH₄ in Seoul, South Korea during the ASIA-AQ campaign

*hyeongseok Choi¹、Yongjoo Choi¹、Meehye Lee² (1.Department of Environmental Science, Hankuk University of Foreign Studies, Korea、2.Department of Earth and Environmental Science, Korea University, Korea)

キーワード：Carbon dioxide, Methane, Urban, STILT model

Estimating greenhouse gas (GHG) emissions from various urban sources is essential for implementing climate change mitigation policies and transitioning to a low-carbon society. Urban areas are significant contributors to global GHG emissions, primarily due to anthropogenic activities, including fossil fuel combustion, transportation, industrial activities, and residential heating. Considering their atmospheric lifetime, GHGs are influenced not only by local and regional emissions but also by transboundary transport, making it crucial to distinguish between domestic and external contributions to their observed concentrations. This study aims to characterize the behavior and emission sources of GHGs in Seoul Metropolitan Area. Measurements of CO2 and CH4 (GLA331-GGA, ABB-LGR Inc.) were conducted at Korea University (37.59 °N, 127.03 °E, 72 m a.s.l.) in Seoul from January to March 2024 including the Airborne and Satellite Investigation of Asian Air Quality (ASIA-AQ) campaign. Considering the characteristics of long-lived CO2 and CH4, background concentrations were calculated using the 14-day moving 5th percentile. To analyze the emission characteristics of Seoul, enhanced CO2 (ΔCO2) and enhanced CH4 (ΔCH4) were defined as the value obtained by subtracting the background concentration from the measured CO2 and CH4 concentration. Furthermore, to identify the major emission sources in Seoul, footprint analysis was conducted using the Stochastic Time-Inverted Lagrangian Transport (STILT) model, a widely used Lagrangian particle dispersion model. Then, the simulated foorprint was merged with CO2 and CH4 emissions data from the Emissions Database for Global Atmospheric Research (EDGAR_2024_GHG), allowing the determination of key emission sources impacting the measurement site. Based on a comparison of observation and back trajectory analysis, the diurnal variation of CO2 and CH4 was simulated throughout the study period indication that both gases peaked in the early morning and then decreased in the evening.