Scripps Contributution to ICESCAPE

From June 23 to July 29, 2011, a group of Scripps scientists took part in ICESCAPE, a multi-year study of the effects of climate change on Arctic ecosystems. From aboard U.S. Coast Guard Cutter Healy, Jim Swift, a research oceanographer at Scripps Institution of Oceanography, UC San Diego, kept a log of the cruise.  

He joined the US Coast Guard research icebreaker Healy in Dutch Harbour, Alaska, on 26^th June 2011 for a near-repeat of last summer's NASA-sponsored "ICESCAPE" Chukchi Sea and Arctic Ocean cruise. Swift was on board in a support role: measuring seawater characteristics (temperature, salinity, oxygen, and nutrients) in the water column wherever the ICESCAPE team of biologists and seawater optics specialists ask, providing them large amounts of seawater from their designated levels, helping put their water sample data together, and I helping the science team with their interpretation of the data. It's a significant difference from the chief scientist role he had on a research cruise before.

 

Many of the science team returned to this edition of the ICESCAPE journey after last year, and this helped make loading and installing the science gear go more smoothly this time around. The first science station, near the mouth of the Yukon River.

 

Towards the end of the research cruise and collecting samples using a CTD/Rosette, Swift noticed that the upper layer of the ocean was in general less salty than observed on some past cruises to the area. This freshening phenomenon seems pervasive in high latitude regions, and if so can lead to increased stratification (increased density difference) relative to the waters underneath, which could reduce the downward reach of the effects of sea surface processes into the underlying ocean. If fresher water accumulates in the upper layer of the Arctic Ocean and later flushes out into the Atlantic Ocean via the Greenland-Spitsbergen Passage (called Fram Strait) and/or the Canadian Archipelago, it then has the potential to increase stratification in the North Atlantic Ocean, which may have some relationship to the effectiveness of the so-called "ocean conveyor belt" in maintaining exchange between the surface and deep ocean. But this cruise was not about that. The science teams seemed very happy with their samples and are working away to study the relationship between sea ice, upper ocean waters, solar radiation, biological productivity, and ecosystem assessment, meanwhile linking with satellite measurements. I would think that NASA, our sponsor, will be satisfied and proud.