USCGC Healy Cruise HLY-1502

US Arctic Geotraces

Weekly CTD/Hydrographic Team Report 05

from Jim Swift, UCSD/SIO, CTD/hydro team scientific leader at sea

Sunday, 13 September 2015, 7:00 pm, local date and time (0500 14 September UTC)

85°48’N, 150°34’W (on the northern flank of the Alpha Ridge)

air -13.4 degC / 8 degF

water -1.4 degC / 29 degF

wind 4 knots from NE

on an ice station following hydrographic station 041

Note: This is a hydrography-oriented report from Jim Swift, who is working with the SIO Oceanographic Data Facility (ODF) CTD/hydrographic team on the US Geotraces Arctic Ocean expedition led by Dr. David Kadko, FIU, chief scientist. This is not a report from Dr. Kadko or the other science teams.

Dear Colleagues,

We are now about 250 nautical miles south of the North Pole, following the planned track toward Alaska along 150°W longitude. Before heading back into the Makarov Basin we did a trio of stations over the Lomonosov Ridge to help define the waters there as compared to those over the Mendeleyev Ridge, which we crossed earlier during the cruise. Tomorrow we will leave the northeast reaches of the Makarov Basin and begin crossing over the very rarely visited Alpha Ridge, where a 55-hour Geotraces “superstation” is planned. Part of the area we traversed here from the Pole was not passable on my previous expeditions due to very heavy ice. The ice has changed over the past decade to the point where Healy has been able to work here solo. Still, the going has sometimes been tough, but we do keep on going. The Healy has plowed through long stretches of ice which appeared to be roughly two meters thick. There is quite a bit of snow on the ice, which impedes motion by increasing friction on the ship’s hull. The result has been some slow, long hauls between stations.

Our measurement work is a methodical process, following a planned and practiced suite of well-honed procedures. Sometimes the ice or the Arctic cold has its say. Today the skies cleared - the sun on the ice is beautiful - but meanwhile under those clear dry skies the air cooled quickly, temperature dropped to well below 10°F, and we needed to improvise a bit to keep sensors and samples from freezing. I confess that while we were later sampling water in the near-freezing rosette staging bay, I was thinking of the present heat wave back home - perhaps both we and those at home would have gladly switched places for at least a few minutes of relief.

Support from the ship continues to be excellent. We have enthusiastic, capable deck and MST crews that make rosette handling a nearly hands-off business for the SIO and STARC tech teams. Crew and science team alike are busy. The part of the program I oversee (the water column temperature, salinity, dissolved oxygen, and nutrient measurements) is going very well. This is a long cruise, but we have passed “hump day” - the halfway point. We press on with the CTD/hydro work, adapting it as needed to any adjustments made by the chief scientist and Geotraces leaders. For my part, I find the sameness of the work days helps the weeks go by, meanwhile feeling quite satisfied with our progress.

All is well.

Jim Swift

Research Oceanographer

UCSD Scripps Institution of Oceanography