USCGC Healy Cruise HLY-1502

US Arctic Geotraces

Weekly CTD/Hydrographic Team Report 06

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

Sunday, 20 September 2015, 1:30 pm, local date and time (2115 20 September UTC)

82°23’N, 149°33’W (over the northern Canada Basin)

air -4.3 degC / 24 degF

water -1.5 degC / 29 degF

wind 7 knots from W

en route to station 045 (a repeat hydrography station)

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 have completed our crossing of waters above the Alpha Ridge and early tomorrow will be engaged on a station which begins a long track south toward Alaska across the Canada Basin of the Arctic Ocean, one of the more nearly isolated areas of the World Ocean. The crossing of the Alpha Ridge - the bathymetric boundary between the northern Makarov Basin and the northern Canada Basin - came out nicely in the CTD/hydrographic data. Even in that far north reach of the Makarov Basin its ties to the Atlantic-dominated Eurasian sector were clear, contrasting with a greater degree of isolation from that influence on the south side of the ridge.

On my longer research cruises, there has been a point well into the cruise where problems of various sorts pop up. We seem be dealing with a touch of that: the wear and tear of weeks of work in the Arctic is evident in equipment quirks (and failures) and a few data issues which defy untangling. One also sees on some faces traces of dealing with the sameness and oddities of shipboard life and being away. But everyone adapts to this twilight zone and pushes through together to the finale.

Speaking of twilight, during the past week the sun began going below the horizon every evening. In the wee hours the dim, flat natural light makes it more difficult to navigate the ship through heavy ice fields. The transition from 24-hour light to day-and-night comes very quickly if one is heading south from the Pole near the equinox, as we are doing. Will we first run out of heavy ice cover or will we run out of sufficient light to drive through heavy ice at night? Considering that the autumnal equinox is almost upon us with its 12 daily hours of sun below the horizon, I’m guessing that darkness will hold up our progress some, though we plan to do station work when the ship must stop during darkness. (The navigators in the aloft conning station must be able to see pressure ridges sufficiently well in advance to avoid them. The ship has searchlights, but I’m told their reach is often not quite far enough.)

The ship’s two evaporators supply the large quantities of fresh water required for the 145 persons on board, including for the galley, showers, laundry, and labs. One of them went out of service last week, and so we are now on the same water restrictions we abide by on long ‘super stations’ - very short showers, paper plates & plastic tableware, and no laundry. My guess is that the situation is sustainable in that the laundry was opened for 24 hours today.

We have had snowy weather. The deck crew shovels and salts the decks, but some areas of the decks are icy. We certainly feel as though winter is chasing us south. We also experienced a week of cold (around -12°C/10°F), and that took its toll on science operations. For example, the CTD/hydro program’s rosette water sampler, loaded with electronics, is stored between casts in a two-deck- high space called the starboard staging bay, which has a tall roll-up ‘garage door’. The motor mechanism which raises and lowers that door stopped working last week. There is a hand crank mechanism to very slowly raise the door above the height of the rosette, requiring at least 15 minutes of hard labor - the deck crew takes turns. Meanwhile this exposed the rosette’s electronics to the cold air for longer than desirable. We compensated by blowing warm air (from a large ducted heater-fan) onto the electronics right up until launch over the side, but this does not always work well enough. The dissolved oxygen sensor in particular is freeze-sensitive and we are slowly going through our inventory of spares to replace cold-damaged units. On last night’s cast, however, the door motor worked! The Geotraces trace metal clean rosette is stored outdoors (partly to keep it clear of contaminants), and even though it is covered and has heaters in critical places, it has suffered more from the cold, and yesterday the CTD on that rosette failed. A spare unit has been installed and measurements will go on.

Over the Alpha Ridge we traversed what is likely the heaviest ice overall we will encounter this cruise. But the navigators in the aloft control station were always able to spot a feasible route, avoiding heavy, impassible pressure ridges. Sometimes it took some back-and-ram operations to get through a thicker, older ice floe, but, still, progress was remarkable for a single icebreaker in this domain. For example, Healy made it solo through some areas last week that were too tough for Healy and Oden together in 2005; hence Healy may be the first surface ship to gather scientific data from some of these areas. Once we were over the south portion of the ridge, there were many- miles-long, wide leads that Healy followed. Watching from the bridge, it was almost like navigating a river with ‘shores’ of ice on either side - a remarkable experience.

As we were plowing through the ice the other day, we came across a polar bear

  • appeared to be a relatively young one - who first moved away but then came right up to the ship as we motored by. (I’ll attach a couple of photos.) Then something spooked the bear, who took off at a speed that impressed and alarmed those who work on the ice - that bear could really move!

The galley keeps the food coming - lots of baked goods including bakery quality pastries, good soups, and some nice salads such as cous-cous with vegetables, and one made from asparagus, blue cheese, and croutons. Some items are in short supply but most of these are of the type to be expected on a long voyage.

This week my closing line is, “All is well, but we hope the second evaporator is back in operation soon.”

Jim Swift

Research Oceanographer

UCSD Scripps Institution of Oceanography

We are still restricted to 100k total message size in and out. I’ve squeezed in two photos of that inquisitive young bear. The close up was taken by Cory Mendenhall, US Coast Guard, and the photo of people photographing the bear was taken by Croy Carlin, OSU.