Canadian GEOTRACES Arctic Expedition 2015

By Jay T. Cullen

The science enabled icebreaker CCGS Amundsen being loaded for its annual Arctic expedition at the Coast Guard Base in Quebec City. The ship leaves Quebec in July and returns again in October at the end of Arctic operations. Photo by Tereza Jarníková

From July 10 to August 20 I will be aboard the CCGS Amundsen working with a group of scientists to better understand how climate change in the Arctic is affecting important physical, biological and chemical processes and conditions in the marine environment.

The main scientific objectives of this program are as follows:

  1. develop novel water & circulation tracers to monitor future circulation changes in the Canadian Arctic Archipelago (CAA), an important flow path where the Pacific, Arctic and Atlantic Ocean waters are connected
  2. assess the effect of ocean acidification on metal speciation, bioavailability and toxicity to marine organisms
  3. document the effect of trace chemical elements on plant and animal growth & greenhouse gas emissions
  4. develop better models to predict changes in ocean circulation & productivity in the CAA, their consequences in the N. Atlantic, and globally

The Arctic Ocean is experiencing rapid change as a result of climate-driven alterations in sea ice cover and surface ocean circulation, which are expected to strongly impact biological productivity, air-sea exchange of greenhouse gases (e.g. CO2 and CH4) and the distribution of contaminants (e.g. mercury, lead). In addition to climate change, other human pressures like commercial fishing, shipping and exploitation of fossil fuel and mineral resources, particularly in the Canadian Arctic Archipelago (CAA) are increasing. The scientific community is limited in its ability to project what changes and impacts are likely by a relatively poor understanding of the interacting chemical, physical and biological processes which shape the functional characteristics and resiliency of Arctic waters. To bridge this critical knowledge gap, we will participate in an international, pan-Arctic field study (Arctic-GEOTRACES) measuring a suite of chemical tracers that provide information on key biological, physical and chemical processes in the Arctic Ocean and CAA. The group will map the distribution of these tracers across the Arctic, following main flow paths of Pacific waters through the CAA to study the biological, physical and chemical transformations which occur as waters move towards the Atlantic Ocean. We will couple our chemical measurements with detailed surveys of water mass structure and circulation, and the results will be incorporated into computer models predicting Arctic Ocean responses to climate change and other human-related disturbances. We will also conduct ship-board manipulation experiments to directly assess the potential influence of ocean acidification (caused by increasing surface ocean CO2 levels) and changes in trace metal concentrations on productivity and species abundances at the base of the Arctic marine food web. Some of the work will focus on measuring artificial radionuclides from atomic weapons testing, nuclear accidents (e.g. Fukushima and Chernobyl) and fuel reprocessing that provide insight into ocean mixing and circulation.

On July 10 we left port in Quebec bound for the Labrador Sea, Baffin Bay and transit through the CAA toward the Beaufort Sea. The first leg of the expedition lasts until Aug. 20 when most of the scientific crew will depart at Kugluktuk (Coppermine) in the western CAA. Our cruise track is shown below.

Planned expedition track of the icebreaker CCGS Amundsen in the North Atlantic and Canadian Arctic Ocean for the GEOTRACES program 2015

ICYI (in case you’re interested) From time to time I will update on our progress and share a little about life and work on a science icebreaker. My colleagues at the University of British Columbia are maintaining a blog about the expedition here.

Some photos from mobilization of the ship and our clean chemistry operations are shown below.

How do you work under metal clean conditions on an iron ship? Build a plastic bubble that is continually filled with filtered air. PhD student Dave Janssen shown helping the crew frame in our lab and hang the plastic sheeting.

UBC student Manuel Colombo and I in our clean sampling container. A 10ft shipping container modified for trace metal clean work. Note the HEPA filtration units on the ceiling to make the air particle and metal free.

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2 Responses to Canadian GEOTRACES Arctic Expedition 2015

  1. Darren Begley says:

    Hi Jay – What kind of control samples do you take/measure to see what background levels you get of various metals from the ship/yourselves/etc?

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    • Hi Darren – This is perhaps the least satisfying part of working at sea. A true process blank would have us return a bottle full of high purity water in the sampling rosette to the deck and check the resulting levels as we filter, acidify and analyze the sample. We do process blanks in the lab of course but at sea we rely on making onboard analyses of contamination prone elements like Zn and Fe. PhD Dave Janssen is using a fluorometric method to measure dissolved Zn on the ship. When resulting depth profiles deviate from correlated, non-contamination prone properties we expect contamination. Suspect samples can be flagged and analyzed for other properties and excluded from interpretation later on. It is challenging working on the ship to be sure.

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