Thawing permafrost and carbon-rich runoff from Canada’s Mackenzie River are releasing more carbon dioxide (CO2) than it absorbs in parts of the Arctic Ocean. NASA research I found it.
The findings point to a threat to the oceans, where the planet’s vital carbon sinks and is thought to absorb as much as 180 million tons of carbon per year, more than three times the amount that New York City emits annually. be.
For decades, scientists have studied how carbon cycles between the open ocean and the atmosphere, a process called atmosphere-sea carbon dioxide flux. However, observation records are sparse along the Arctic coastline, where topography, sea ice, and the long polar night can make long-term monitoring and experiments difficult.
“With our model, we are trying to explore the real contribution of coastal margins and rivers to the Arctic carbon cycle,” said lead author Clément Bertin, a scientist at the French Society of Coastal Environment and Sociology. .
Approximately half of the Arctic Ocean’s area is made up of coastal waters, and these insights are critical because of the complex intertwining of land and sea. And while this study focuses on one corner of the Arctic Ocean, it could help tell the larger story of environmental changes occurring in the region.
The study was conducted using state-of-the-art computer modeling to study rivers such as the Mackenzie River, which flow into a region of the Arctic Ocean called the Beaufort Sea. The model assimilates nearly all available ocean observations collected over 20 years by ocean- and satellite-based instruments (e.g., sea surface observations from the Jason series altimeters and ocean floor pressure from the GRACE and GRACE follow-on missions). ). ).
Scientists used the model to simulate the emissions of freshwater and the elements and compounds it contains, such as carbon, nitrogen and silica, over a period of about 20 years (from 2000 to 2019).
Like much of the Arctic, the Mackenzie River and its delta have faced significant increases in seasonal temperatures in recent years, leading to increased melting and thawing of waterways and landforms.
Researchers from France, the United States and Canada have found that river discharges are causing extremely intense gas emissions in the southeastern Beaufort Sea, upsetting the carbon balance and leading to a net release of 130,000 tonnes of CO2 per year. . This is approximately the same amount. That’s the equivalent of the annual emissions from 28,000 gasoline-powered cars. The release of CO2 into the atmosphere varied by season, and was more pronounced during warmer months when river flows were higher and there was less sea ice to cover and trap the gas.
Since the 1970s, the Arctic has warmed at least three times faster than anywhere else on Earth, changing its waters and ecosystems, scientists said. Some of these changes will promote an increase in her CO2 emissions in this region, while others will lead to an increase in CO2 uptake.
Seawater remains an important buffer against climate change, sequestering as much as 48% of the carbon produced by burning fossil fuels, so scientists are tracking changes in the Arctic and surrounding regions .
© IE Online Media Services Pvt Ltd
Date first published: Dec 23, 2023 21:44 IST
