HLY1502 letter 10 from Jim Swift
final letter from sea
Sunday, 11 October 2015, 3:00 pm, local date and time (2300 11 October UTC)
54.3°N, 166.4°W (about 26 miles north of Dutch Harbor in the Aleutian Islands)
air 6 degC / 43 degF
water 9 degC / 48 degF
wind 26 knots from W
on final approach to Dutch Harbor, Alaska
Dear Family, Friends, and Colleagues,
Our final days of oceanographic work on HLY-1502 continued the wait-for-a-weather-window theme of the previous week, although science operations transpired without incident during the times we were able to work. Working over the stern – required at Geotraces station locations – was restricted to wind and sea conditions unlikely to result in problems with the oceanographic cables, and with fall storms in the area those times were fewer than hoped. But Geotraces did manage a sequence of three continental slope stations (at 3465, 1000, and 85 meters water depth) and a 35 meter deep continental shelf station. The CTD/rosette casts my team carries out use the starboard A-frame. From there we can work in a somewhat broader weather window and so we were able to add casts at 2600, 1600, 500, 300, 160, and 68 meters deep. Overall these sum to a fine cross-section of measurements over the abrupt Canada Basin – continental slope – Beaufort shelf transitions.
The ODF CTD/rosette program (my program) went well right to the end. Over the course of a 64-day expedition there were very few rosette problems, the analysts maintained outstanding data quality (there were only a few nutrients or oxygen values coded ‘bad’ out of thousands the entire cruise), and there was excellent attention to data processing. The CTD/hydrographic data the science teams will carry home is ready for initial research use, with little change expected from the few final data processing steps remaining ashore.
Following completion of the oceanographic work, after waiting a bit for acceptable flying weather, two officials from the Department of Homeland Security (which includes the Coast Guard) were brought out by helicopter from Barrow to ride the ship to Dutch Harbor. The next day a crew member was flown ashore for medical attention, and then the Healy began a fast transit south. (See photo of helicopter operations.) Winds have often been above 20 knots, and there was a stretch where sustained winds of about 40 knots were recorded, but fortune has smiled upon us: the winds have been behind us, giving us a fast and relatively comfortable “downhill” ride almost all the way.
In the early parts of the past week, there were partly clear nights several times, with active auroras. Even the somewhat rarer pinkish aurora was seen (see attached photo).
Last night the science team cooked dinner. The Healy has an excellent galley staff, but we held our own with a meal of coq au vin (for which we used the last of the ship’s onions and carrots), rice, grilled corn, macaroni and cheese, dinner rolls (which I helped make), and ice cream cookie sandwiches. It was a fun time for the science team and all hands seemed to enjoy the dinner. [If you are wondering about the “coq au vin” on a “dry” ship, note that the Healy’s cooking wine is a salt-added commercial product made for these situations. I joked that the cooking wine was only a little less salty (15 on the salinity scale) than some of the surface waters we ran into (just over 20 on the same scale).]
We should arrive in port early this evening, a half day ahead of schedule (thanks to those tail winds). The Dutch Harbor port period will be very busy for most on the science team, who are leaving the ship. Nearly all unloading will take place when the ship returns to Seattle in November, but all labs must be stripped, packed, and cleaned, and every item left on board must be securely tied down for the Healy’s possibly rough transit across the Gulf of Alaska after it leaves Dutch Harbor.
I have never seen one of the TV fishing shows that features Dutch Harbor so I did not realize until we were told today that we will see a very much busier Dutch Harbor than we left two months ago. That was the slow time – who knew? The crab fishing season starts mid-week and we were told the town is teeming, the bars are full (including with some looking for a fight), and that we should take special care. We had all been looking forward to socializing – well, we are not looking for trouble so maybe it won’t find us.
A wide range of scientific inquiry will be made possible by the new repeat hydrography data. Because this is intended for a general audience I will say simply that my program’s results bear strongly on aspects of the ocean such as ocean warming, ocean acidification, increased stratification of the oceans, and large scale shifts of the distribution of waters away from their source regions.
All of this would not have been possible without the enthusiastic and capable support provided by Captain Hamilton, the officers & crew of USCGC Healy, and the science teams. I owe them and the US Coast Guard and National Science Foundation my heartfelt thanks for making these outstanding sections across the Makarov and Canada basins possible.
A few reflections in closing…
I have long been interested in the polar regions, and I am also drawn to hydrography, a word oceanographers use to encompass both the measurement of temperature, salinity, and other properties of seawater and also the interpretation of those data to describe aspects of the nature and circulation of ocean waters. A stroke of great good fortune brought me to Knut Aagaard, my graduate advisor at the University of Washington, who remains my oceanographic mentor and stout friend. And Joe Reid generously guided and supported me at the Scripps Institution of Oceanography, providing me not only the opportunity to work with him and his group, but also to study the World Ocean itself. I have since enjoyed an exciting career working with visionary scientists and supportive ship operators, and been honored to participate on great voyages with wonderfully talented technical teams, thinking especially of the SIO Oceanographic Data Facility measurement specialists to whom I owe so much.
The plans for USCGC Healy Cruise 1502 represented a once in a lifetime opportunity to measure and interpret change in some of the world’s waters I love best. To have now sailed the oceanographically-rich track on which we engaged has been a dream come true, and, seeing this is intended to be my final oceanographic cruise, a fitting finale to the seagoing aspect of my career.
That the National Science Foundation and other Federal agencies which support science at sea, the Scripps Institution of Oceanography, and my family have so wholeheartedly supported me on these endeavors for so many years is a great privilege for which I will always be indebted. I enjoy an abiding satisfaction that comes from doing something worthwhile, and doing it well.
UCSD Scripps Institution of Oceanography