Effects of climate change on carbon exchange dynamics in the Arctic

The absorption and release of carbon dioxide by the oceans is one of the primary factors controlling the concentration of CO2 in the atmosphere. CO2 is a major contributor to the planet’s greenhouse effect. In the ocean, the CO2 concentration is controlled by biological organisms, the circulation of the water, as well as basic water properties including temperature and salinity.

There exists a startling amount of variability in sea surface CO2 concentration, both from place to place, and with season at any one location. In general we expect regions of the Arctic Ocean, including its peripheral seas to actively take in atmospheric CO2.

High rates of CO2 uptake have been reported in northern seas and polynyas, hence it is important that we understand the extent to which CO2 is exchanged with the atmosphere in the Arctic, and why, to ensure that both our understanding of the marine carbon cycle, and our atmospheric CO2 budgets are accurate. The latter requires us to have accurate models of the carbon cycle for Arctic regions, and a means to observe sea surface CO2 on a regular basis, and over large areas. Satellite remote sensing is the best means to achieve the latter.

Measurements from the CGS Amundsen as part of its annual ArcticNet cruise are helping us understand something of the variation in surface seawater CO2 concentration across the Canadian coastal Arctic, including Hudson Bay, and we are learning how features like sea ice and river plumes affect seawater CO2 concentration, and the air-sea flux.

We measure not only CO2 in the air and sea water, but also important water properties (e.g., salinity, temperature, dissolved oxygen, biology), meteorological parameters and the flows of heat and radiation (e.g., sunlight) so that we can relate the CO2 concentration, and associated flux to the local environment. We are working towards bettering the way the CO2 concentration a flux is represented in ocean models.

We are also developing the means to monitor the air-sea flux using satellite remote sensing. Pronounced changes in the seawater’s CO2 concentration and air-sea flux will be indicative of fundamental changes to the region’s ecosystem and may come about with changing sea ice concentration and thickness, as well as through changing seawater circulation and properties, all of which are tied to climate change.

Study site locations

Monitoring systems have been in-stalled on the CGS Amundsen and we obtain a continuous stream of data while the ship is underway. Ice camp experiments have been conducted in Barrow Strait, near to Resolute, Nunavut.

Local collaborations

We collaborate extensively with virtually all ArcticNet ship-based teams given that the CO2 concentration in the sea water depends on the chemical, physical and biological makeup of the ocean and its surface (e.g., sea ice). In return, our team is able to supply others with valuable information on many of the ocean and atmosphere’s near-surface physical and biochemical properties.

Project contact information:

Tim Papakyriakou

Member of the Centre for Earth Observation Science
Associate professor in the Department of Environment and Geography at the University of Manitoba

papakyri@cc.umanitoba.ca 

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