Wildfire smoke may intensify phytoplankton blooms in the Arctic

New study from North Carolina State University and International Research Laboratory Takuvik (CNRS/Laval University) in Canada, suggest that smoke from wildfires in Siberia may have transported nitrogen to the Arctic Ocean and intensified the phytoplankton bloom.

Satellite image of a plume in the eastern Arctic Ocean, August 2014. Image Credit: North Carolina State University

The research highlights some of the potential environmental impacts of wildfires in the Northern Hemisphere, specifically when these fires become longer, larger and more powerful.

In the summer of 2014, satellite images found a larger-than-normal algal bloom in the Laptev Sea, located in the Arctic Ocean about 850 kilometers (528 miles) south of the North Pole.

For a boom of this magnitude to occur, the region would need a significant influx of new nitrogen supplies, as the Arctic Ocean is nitrogen-depleted.. So we needed to know the source of this nitrogen.

Douglas Hamilton, study co-author and Assistant Professor, Marine, Earth, and Atmospheric Sciences, North Carolina State University

Earlier, Hamilton was a research associate at Cornell University, where the study was conducted.

First, scientists considered “usual suspects” for nitrogen inputs, such as river drainage, melting sea ice, and fluctuations in ocean water, but they haven’t identified anything that justifies the amount of nitrogen needed to thrive.

However, at the same time, unusually large forest fires in Siberia, Russia, located directly upwind, have burned about 1.5 million hectares (or about 3.5 million acres) of land.

Scientists shifted their focus to the composition of the atmosphere. They used the Community Earth System Model (CESM), a computer model that can simulate what happens to emissions from human and natural sources as they arrive and leave the atmosphere.

Data on temperature, wind, and atmospheric composition—along with forest fire smoke composition—from the time scale were entered into the discussion in the model.

Simulations showed that during late July and August of 2014, during the Siberian boom and wildfires, nitrogen deposition from the atmosphere was almost double what it was in the previous and subsequent years.

The wildfires were in the rapidly warming northern regions, which had a lot of peat in thaw permafrost. Peat is very nitrogen-rich, and smoke from burning peat is assumed to be the most likely source of much of the additional nitrogen..

Douglas Hamilton, study co-author and Assistant Professor, Marine, Earth, and Atmospheric Sciences, North Carolina State University

Matteo Ardena, author and co-author of the study at the Taquique International Research Laboratory, said:We’ve known that fires can affect phytoplankton blooms, although nothing like this would be expected in the Arctic Ocean. Most likely, because fires are region specific and hard to predict, blooms like this won’t be the norm – but when these fires do occur, the nutrients they bring can lead to continuous or multiple blooms. ”

Next steps for the researchers could include studying the previous satellite record and then determining the chemical composition of the particles in the smoke to get a clearer perspective on how wildfires like these affect different ecosystems.

A one-off bloom like this won’t change the ecosystem’s structure, but both Siberia and Canada’s high Arctic are experiencing more wildfires. It may therefore be interesting to explore the potential end effects if fire activity and nutrient supply remain high

Douglas Hamilton, study co-author and Assistant Professor, Marine, Earth, and Atmospheric Sciences, North Carolina State University

The study was published in Earth and Environment Communications It was funded by the Department of Energy under grant number DE-SC0021302, the CNES Alg-O-Nord Research Project (National Center for Space Studies), the ArcticNet High Impact Publications Program, and the European Union’s Horizon 2020 Marie Sklodowska – Curie Grant (No. 746748).

magazine reference

ardena, m, and others. (2022) Aerosol deposition from wildfires likely amplifies Arctic phytoplankton blooms in summer. Earth and Environment Communications. doi.org/10.1038/s43247-022-00511-9.