講演情報
[AAS08-P21]Model analysis of long-range transport of black carbon from India to the Arctic
*池田 恒平1、鄧 彦閣1、谷本 浩志1 (1.国立環境研究所)
キーワード：
ブラックカーボン、インド、北極、化学輸送モデル、エアロゾル、南アジア
Black carbon (BC) aerosol has a positive radiative forcing by absorbing solar radiation in the atmosphere and reducing surface albedo of snow and ice after deposition. India is one of the largest source regions of anthropogenic BC, accounting for 20 % of global emissions in 2023. BC emitted from India can influence the climate over remote regions such as the Arctic. However, its impacts on the Arctic climate and environment remain insufficiently understood. In this study, we investigated the long-range transport of BC from India to the Arctic and quantified its contributions using tagged BC simulations with a chemical transport model GEOS-Chem.
We simulated BC aerosols using the GEOS-Chem model version 13.1.2 with a horizontal resolution of 2° × 2.5°. Tagged tracer simulations were employed to attribute BC concentrations to specific source regions and source types (anthropogenic and biomass burnig). For anthropogenic sources, Asia was divided into five regions: India, Japan, the Korean Peninsula, North China, and South China. Anthropogenic emissions were obtained from the CEDSv2025-04-18 inventory. The simulations were conducted for the period 2019-2023.
Our model showed that the contribution of BC emitted from India to the Arctic (66–90°N) peaked in January–April and decreased during summer. In terms of altitude, the contribution was largest in the upper troposphere around 300 hPa due to uplift during long-range transport. The relative contribution from India to the annual mean BC concentration at 300 hPa was estimated to be 20%. In contrast, BC emitted from China was transported mainly through the middle troposphere into the Arctic during winter and spring. The contribution from China to the Arctic had a maximum at about 500 hPa. These results indicate that the altitudes at which BC reaches the Arctic differ between South Asia and East Asia.
We simulated BC aerosols using the GEOS-Chem model version 13.1.2 with a horizontal resolution of 2° × 2.5°. Tagged tracer simulations were employed to attribute BC concentrations to specific source regions and source types (anthropogenic and biomass burnig). For anthropogenic sources, Asia was divided into five regions: India, Japan, the Korean Peninsula, North China, and South China. Anthropogenic emissions were obtained from the CEDSv2025-04-18 inventory. The simulations were conducted for the period 2019-2023.
Our model showed that the contribution of BC emitted from India to the Arctic (66–90°N) peaked in January–April and decreased during summer. In terms of altitude, the contribution was largest in the upper troposphere around 300 hPa due to uplift during long-range transport. The relative contribution from India to the annual mean BC concentration at 300 hPa was estimated to be 20%. In contrast, BC emitted from China was transported mainly through the middle troposphere into the Arctic during winter and spring. The contribution from China to the Arctic had a maximum at about 500 hPa. These results indicate that the altitudes at which BC reaches the Arctic differ between South Asia and East Asia.