For the second year in a row, June saw widespread fires flaring up across the far northeast of Siberia and in the Arctic Circle. The Copernicus Atmosphere Monitoring Service (CAMS), implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) is monitoring the fire activity and the resulting pollution to assess its impact on the atmosphere.
The fires have been particularly intense in Russia’s Sakha Republic and Chukotka Autonomous Okrug in the far northeast of Siberia, both of which have been experiencing much warmer-than-usual conditions over the past months. Alaska and parts of northwest Canada have also experienced wildfires, but on a much smaller scale.
Those who followed 2019’s Arctic fire season might feel a sense of déjà vu.
“The evolution in fire activity in the Arctic this summer has so far been very similar to what we saw in 2019, with both years exhibiting extraordinarily intense wildfires compared to other years since 2003 that we have data for,” explains CAMS Senior Scientist Mark Parrington. “Whilst both years have been very unusual, this year we have been seeing some more fire activity further east in Siberia.”
CAMS incorporates observations of wildfires from the MODIS instruments on NASA’s Terra and Aqua satellites into its Global Fire Assimilation System (GFAS) to monitor fires and estimate the pollution that they emit. The emissions estimates are then combined with ECMWF’s weather forecast system to predict how the pollution will move around the world and impact global atmospheric composition.
Wildfire smoke consists of a wide range of pollutants including carbon monoxide, nitrogen oxides, volatile organic compounds, and solid aerosol particles. Arctic wildfires emitted the equivalent of 56 megatonnes of carbon dioxide in June compared to 53 megatonnes in June 2019, as well as significant amounts of carbon monoxide and particulate matter.
CAMS compared the total column of carbon monoxide in the atmosphere for June 2020 with the 2003–2019 June average, and found that, although carbon monoxide levels over most of the northern hemisphere were generally lower than normal last month, levels over the northeast of Siberia were anomalously high over the region of the fires.
CAMS also keeps an eye on the aerosol particles emitted by fires by monitoring Aerosol Optical Depth (AOD) – a measure of how much sunlight is blocked by aerosols in the atmosphere. Last month, there were a lot of aerosols in the air over northeast Siberia compared to the average since 2003.
Although smoke can travel between continents, CAMS aerosol and carbon monoxide forecasts did not see smoke travelling very far in June. However, a plume of smoke travelled high up into the Arctic in early July. This is a concern if the plume is close to the surface as when dark aerosol particles settle on the ice, they can cause the ice to absorb more heat, which exacerbates global warming. Aside from the Siberian fires, an intense fire in Quebec in mid-June also released a lot of aerosol particles that were clearly visible in the CAMS AOD forecasts.
CAMS smoke forecasts for the next five days indicate that the fires in Siberia will continue to produce a lot of smoke.
“The entirety of summer 2019 was unusual in terms of fire activity at high northern latitudes and 2020 so far seems to be evolving in a similar manner,” concludes Mark. “This suggests that we could be seeing intense fire activity continue in the Arctic in the weeks ahead, especially as Boreal wildfire season typically peaks in July and August.”
CAMS global operational biomass burning aerosol optical depth forecast valid for 6–11 July, initialised on 6 July 2020.