Severe spatiotemporal heterogeneity of emissions sources and limited measurement networks have been hampering themonitoring and understanding of CO2 fluxes in large cities, a great concern in climate research as big cities are amongthe major sources o...
Severe spatiotemporal heterogeneity of emissions sources and limited measurement networks have been hampering themonitoring and understanding of CO2 fluxes in large cities, a great concern in climate research as big cities are amongthe major sources of anthropogenic CO2 in the climate system. To understand the CO2 fluxes in Seoul, Korea, CO2 fluxesat eight surface energy balance sites, six urban (vegetation-area fraction <15%) and two suburban (vegetation-area fraction>60%), for 2017–2018 are analyzed and attributed to the local land-use and business types. The analyses show thatthe CO2 flux variations at the suburban sites are mainly driven by vegetation and that the CO2 flux differences between theurban and suburban sites originate from the differences in the vegetation-area fraction and anthropogenic CO2 emissions.
For the CO2 fluxes at the urban sites; (1) vehicle traffic (traffic) and heating-fuel consumption (heating) contribute>80%to the total, (2) vegetation effects are minimal, (3) the seasonal cycle is driven mainly by heating, (4) the contribution ofheating is positively related to the building-area fraction, (5) the annual total is positively (negatively) correlated with thecommercial-area (residential-area) fraction, and (6) the traffic at the commercial sites depend further on the main businesstypes to induce distinct CO2 flux weekly cycles. This study shows that understanding and estimation of CO2 fluxes in largeurban areas require careful site selections and analyses based on detailed consideration of the land-use and business typesrefined beyond the single representative land-use type widely-used in contemporary studies.