Summertime wildfire activity is increasing in boreal forest and tundra ecosystems in the

Northern Hemisphere. However, the impact of long range transport and deposition of wildfire

aerosols on biogeochemical cycles in the Arctic Ocean is unknown. Here, we use satellite-based

ocean color data, atmospheric modeling and back trajectory analysis to investigate the trans-

port and fate of aerosols emitted from Siberian wildfires in summer 2014 and their potential

impact on phytoplankton dynamics in the Arctic Ocean. We detect large phytoplankton blooms

near the North Pole (up to 82°N in the eastern Eurasian Basin). Our analysis indicates that these

blooms were induced by the northward plume transport and deposition of nutrient-bearing

wildfire aerosols. We estimate that these highly stratified surface waters received large

amounts of wildfire-derived nitrogen, which alleviated nutrient stress in the phytoplankton

community and triggered an unusually large bloom event. Our findings suggest that changes in

wildfire activity may strongly influence summertime productivity in the Arctic Ocean.