[H-CG26] 農業残渣焼却のもたらす大気汚染と健康影響および解決への道筋

[HCG26-08] Multiyear comparison of WRF-Chem simulated PM_2.5 with the widespread in-situ observation network during the autumn crop residue burning over North-west India

*Akash Biswal¹、Yutaka Matsumi³、Prabir Patra^1,2、Takigawa Masayuki²、Jagat Bisht²、Tomoki Nakayama⁴、Poonam Mangaraj¹、Sachiko Hayashida¹、Natsuko Yasutomi¹、Hikaru Araki¹、Mizuo Kajino⁵、Kazuyo Yamaji⁶ (1.Research Institute for Humanity and Nature、2.Japan Agency for Marine-Earth Science and Technology、3.Nagoya University、4.Nagasaki University、5.Meteorological Research Institute、6.Kobe University)

キーワード：Crop residue burning, PM2.5, Emission, Air quality

The "Aakash Project" at RIHN endeavors to mitigate the adverse effects of rice straw burning prevalent in northern India, striving for clean air, improved public health, and sustainable agricultural practices. This initiative seeks to comprehensively evaluate the repercussions of crop residue burning (CRB) on air quality, particularly in the vicinity of Delhi National Capital Territory (NCT), by employing quantitative assessments and establishing a robust scientific foundation to delineate the dispersion of air pollutants emanating from CRB activities across a wide geographical expanse. During the years 2022 and 2023, an intensive field campaign was undertaken, deploying a network of 30 compact sensors across urban and rural areas to monitor CRB-induced air pollution. Analysis indicates a decline in the prevalence of crop burning hotspots in 2023 compared to the preceding year, possibly attributed to climatic factors and the implementation of governmental policies aimed at curbing burning practices. To understand the spatial-temporal dynamics of PM_2.5 concentrations during crop burning episodes, a WRF-Chem modeling framework was developed, integrating FINN V1 NRT biomass fire emissions and EDGAR anthropogenic emissions datasets. The comparative assessment of simulated PM_2.5 concentrations against in-situ observations offers valuable insights for enhancing model accuracy. While the model adeptly captures diurnal PM_2.5 concentration patterns at most monitoring sites, discrepancies observed in certain areas, notably Delhi, suggest the presence of unaccounted emission sources within the city limits. Furthermore, the model demonstrates a favorable agreement with observed PM_2.5 levels in rural locations proximate to agricultural fields, underscoring its efficacy in capturing CRB-induced pollution dynamics. Notably, selected CRB emission events facilitate the transport of pollutant plumes to Delhi, exacerbating PM_2.5 concentrations, evident in both 2022 and 2023.

In conclusion, the multi-year comparison of WRF-Chem simulated PM_2.5 concentrations with widespread in-situ observations during autumn crop residue burning in northwest India, as part of the Aakash Project, underscores the project's significance in elucidating the complex interplay between agricultural practices, atmospheric dynamics, and air quality.