Long-range transport of CO and aerosols from Siberian biomass burning over northern Japan during 18–20 May 2016

• Published in: Environmental pollution (1987) 2023-04, Vol.322, p.121129, Article 121129
• Main Authors: Ngoc Trieu, Tran Thi, Morino, Isamu, Uchino, Osamu, Tsutsumi, Yukitomo, Izumi, Toshiharu, Sakai, Tetsu, Shibata, Takashi, Ohyama, Hirofumi, Nagahama, Tomoo
• Format: Article
• Language: English
• Subjects: Aerosol optical depth; Aerosols - analysis; Air Pollutants - analysis; Air Pollution - analysis; Backward trajectory; Biomass; Carbon monoxide; Environmental Monitoring - methods; Fires; Ground-based and satellite observations; Japan; Wildfire
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2023.121129

High CO concentration and dense aerosol layers at 1–6 km altitude in the free troposphere were observed over Rikubetsu, Japan, in ground-based Fourier transform spectrometer (FTS) and lidar measurements during 18–20 May 2016, days after intense wildfires east of Lake Baikal, Siberia. The column-averaged dry-air mole fraction of CO (XCO) was observed to be ∼150 ppb from 11:15 to 13:50 JST on 19 May, and peak aerosol optical depths (AODs) of 1.41 and 1.28 were observed at 15:40 JST 18 May and 11:20 JST 19 May, respectively. We used the HYSPLIT model to calculate five-day backward trajectories from Rikubetsu on May 18, 2016 at 2, 3 and 5 km altitude. The results show that the air parcels passed over the Siberian wildfires during 16–17 May. It was found that the high CO concentrations originated from forest fires were transported to the upper layers of Hokkaido. This will contribute to the understanding of the regional effects of air pollution in northern Japan due to air masses originating from forest fires. By combining these independent datasets such as AERONET aerosol optical thickness (AOT), MODIS fire data, and Infrared Atmospheric Sounding Interferometer (IASI) total CO columns, we confirmed that the lidar measurements of enhanced aerosol concentrations and FTS measurements of maximum XCO over Rikubetsu resulted from a persistent smoke plume transported from Siberian wildfires. Relatively large-scale forest fires have been frequently occurring in Siberia recently. However, the effects of CO and other gases released from them over northern Japan are not well known. We observed high concentrations of CO over the TCCON station in Rikubetsu, Japan, which we believe to be of forest fire origin. Therefore, we analyzed it as a case study to confirm its origin and impact on the upper atmosphere over northern Japan. [Display omitted] •Dense aerosol and trace gas enhancements in the atmosphere over Rikubetsu, Japan.•Use backward trajectories and atmospheric data analysis to uncover pollution origin.•A persistent smoke plume transported from Siberian wildfires over northern Japan.•Aerosol and CO joint detection by lidar and FTS measurements from biomass burning.