RESULT2023年6月号　Vol. 34 No. 3（通巻391号）

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

  • Tran Thi Ngoc Trieu
    Research Associate, Satellite Remote Sensing Section and Satellite Observation Center, Earth System Division (Present address: the National Institute of Information and Communications Technology)
  • Isamu Morino
    Head, Satellite Remote Sensing Section and Satellite Observation Center, Earth System Division
  • Osamu Uchino
    Visiting Researcher, Satellite Observation Center, Earth System Division
  • Yukitomo Tsutsumi
    Expert, Satellite Remote Sensing Section and Satellite Observation Center, Earth System Division
  • Hirofumi Ohyama
    Senior Researcher, Satellite Remote Sensing Section and Satellite Observation Center, Earth System Division

Relatively large-scale forest fires have been frequently occurring in Siberia recently. However, the effects of enhanced CO and other gases released from them over northern Japan are not well known.

We observed high CO concentration and dense aerosol layers at 1–6 km altitude in the free troposphere over Rikubetsu, Japan, in ground-based Fourier transform spectrometer (FTS) and lidar measurements during 18–20 May 2016, days after intense forest fires 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 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 18 May 2016 at 2, 3 and 5 km altitude. The results show that the air parcels passed over the Siberian forest fires during 16–17 May. By combining these independent datasets such as AERONET aerosol optical thickness at Sapporo, 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 forest fires.

The Impact of Siberian forest fires over northern Japan is dependent on the fire scale and frequency of their occurrence and existing meteorological conditions. In addition, anthropogenic CO on the continent may also affect. This research is a case study, so the comprehensive elucidation of their impacts is limited. Long-term monitoring of atmospheric components over Japan and continuous investigation of their origin are desirable.

Figure 1: NOAA ARL HYSPLIT five-day backward trajectories driven by NCEP/NCAR global reanalysis meteorological data, beginning at 07:00 UTC 18 May 2016. Air parcels were initiated at altitudes of 2 km (red), 3 km (blue), and 5 km (green) over Rikubetsu. Siberian forest fire hotspots (red stars) are shown for comparison.
Figure 1: NOAA ARL HYSPLIT five-day backward trajectories driven by NCEP/NCAR global reanalysis meteorological data, beginning at 07:00 UTC 18 May 2016. Air parcels were initiated at altitudes of 2 km (red), 3 km (blue), and 5 km (green) over Rikubetsu. Siberian forest fire hotspots (red stars) are shown for comparison.