[A-CG35] Global Carbon Cycle Observation and Analysis

[ACG35-09] Estimation of NO_x/CO₂ emissions based on space-based NO₂ and CO₂ observations over India using regional model WRF-GHG/Chem

*Jagat Bisht¹, Prabir Patra¹, Masayuki Takigawa¹, Masahiro Yamaguchi², Yugo Kanaya¹, Takashi Sekiya¹, Hiroshi Tanimoto² (1.Japan Agency for Marine-Earth Science and Technology , 2.National Institute for Environmental Studies)

Carbon dioxide (CO₂) is a major greenhouse gas (GHG) in the Earth’s atmosphere which continues increasing mainly due to fossil fuel combustion. Since fossil fuel combustion at high temperatures produces nitrogen monoxide (NO) as a byproduct, which rapidly reacts with Ozone (O₃) to form Nitrogen dioxide (NO₂), the presence of NO₂ near emission sources serves as a suitable tracer for freshly emitted CO₂. In this study, we seek to use the available observation of CO₂and NO₂ to estimate CO₂ emissions. This study performed a coupled modeling with WRF full chemistry (WRF-Chem) and GHG together (hereafter referred as WRF-Chem/GHG) over India during January 2022 to simulate both CO₂ and NO₂ concentrations. Simulations are performed in two-way nested setting (27 km and 9 km) with EDGAR (v6.1 for air pollutants and v7 for GHG) anthropogenic emission inventories. We evaluated the model performances with TROPOMI (TROPOspheric Monitoring Instrument) tropospheric NO₂ column amount and estimate NO_x fluxes inside the 9 km domain. The top-down NOx emission estimate suggests that EDGAR anthropogenic emission inventory overestimated the NO_x emissions by 22% over Indo-Gangetic plane. Our aim is to estimate the CO₂ emission by using CO₂ concentration observations from the satellites such as, GOSAT and OCO-2, and in-situ observations and utilize NO₂ emission information corresponding to co-located emission sources from the facilities such as power plant, automobile traffic, residential facility, etc. This study anticipates the observation datasets from future satellites, such as GOSAT-GW, for simultaneous NO₂/CO₂ observations.