The findings were startling: the Mackenzie River's discharge led to such intense CO2 outgassing that it shifted the balance, causing a net release of 0.13 million metric tons of CO2 per year.
Lack of comprehensive data from this remote area left scientists uncertain about its true role in the carbon cycle. (Photo: Nasa)
New Delhi,UPDATED: Dec 22, 2023 13:26 IST
The Arctic Ocean, a vital carbon sink absorbing an estimated 180 million metric tons of carbon annually, is now facing a new challenge.
Recent scientific research has revealed that the Mackenzie River, one of North America's largest rivers, is contributing to a significant release of carbon dioxide (CO2) into the atmosphere from the Arctic Ocean, particularly in the Beaufort Sea region.
A study conducted earlier this year utilised advanced computer modeling to analyse the impact of the Mackenzie River on the Arctic Ocean's carbon cycle. The river, which originates near Alberta and traverses through Canada's Northwest Territories, carries a mix of mineral nutrients and organic matter to its delta. This influx of carbon-rich materials into the Beaufort Sea leads to a process known as outgassing, where CO2 is released into the atmosphere.
Historically, the southeastern Beaufort Sea was considered a moderate CO2 sink, but the lack of comprehensive data from this remote area left scientists uncertain about its true role in the carbon cycle.
To address this gap, researchers from France, the United States, and Canada employed the ECCO-Darwin model, developed by Nasa’s Jet Propulsion Laboratory and the Massachusetts Institute of Technology.
This model assimilates ocean observations collected over two decades, providing a detailed simulation of the river's discharge and its effects from 2000 to 2019.
The findings were startling: the Mackenzie River's discharge led to such intense CO2 outgassing that it shifted the balance, causing a net release of 0.13 million metric tons of CO2 per year. This amount is comparable to the annual emissions from approximately 28,000 gasoline-powered vehicles. The release was more pronounced during warmer months when river discharge peaked and sea ice was less prevalent to contain the gas.
The Arctic, warming at least three times faster than the rest of the planet since the 1970s, is undergoing profound transformations. Thawing permafrost and melting snow and ice are increasing river flows, flushing more organic matter into the ocean.
Concurrently, diminishing sea ice is allowing phytoplankton to bloom, capturing atmospheric CO2 through photosynthesis. These conflicting processes highlight the complex dynamics at play in the Arctic's response to climate change.
The ECCO-Darwin model is not only shedding light on the Beaufort Sea but also enhancing our understanding of broader environmental shifts in the Arctic. As the region continues to warm, monitoring these changes is crucial, given the ocean's role as a critical buffer against climate change, sequestering nearly half of the carbon produced by fossil fuel combustion.
Published By:
Sibu Kumar Tripathi
Published On:
Dec 22, 2023
English (US) ·