Check out this great news segment by Florida International University highlighting our 2015 Arctic GEOTRACES expedition!
On Sunday October 11 the USCGC Healy arrived in Dutch Harbor, Alaska successfully completing the U.S. GEOTRACES Arctic expedition. As we approached Dutch Harbor Captain Jason Hamilton gathered the science party and crew together for final remarks. He thanked everyone onboard for a successful mission, congratulated us for being part of the United States’ first solo mission to the North Pole on a surface vessel, and for working together through 64 days at sea.
Scientifically we accomplished ambitious goals to create one of the most unique chemical datasets of the Arctic Ocean. We were able to capture multiple points in the annual cycle of Arctic ice from late summer thawing, to thick multi-year ice at the North Pole, and early fall re-freezing. This data is vital to our understanding of how decreasing ice cover and thickness in the Arctic Ocean will change the chemistry and ecosystem dynamics of the basin in the near future.
Part of our cruise transect repeated hydrography stations that were occupied by previous missions in 1994, and 2005. Preliminary results show what we expected – the mixed layer at these locations is warmer and less saline due to melting ice over the past 20 years. NASA has used satellites to monitor sea ice change since 1978 and now oceanographers are accumulating enough data to piece together how these changes are affecting the Arctic Ocean. For many of the elements measured by the U.S. GEOTRACES program (i.e. mercury), there is no historical data for comparison; this is time zero for ocean chemistry in the Arctic and it could not have come at a more pivotal time. Temperatures in the Arctic are rising faster than anywhere else on the planet. The paramount of stepping off the ship at the North Pole this September was not that we were part of a small group of people to reach the top of the world, but that within our lifetime future explorers could be sailing through open water with no summer ice to walk on.
Two months is a long time to be at sea but we were rewarded on this trip with many once in a lifetime experiences (polar bears, northern lights, pictures with Santa at the North Pole to name a few!). I feel very lucky to have stumbled onto this career path and each adventure motivates me to work harder to keep moving forward with my work.
What’s next: After a few days relaxing in Dutch Harbor (and mingling with the Discovery Channel’s Deadliest Catch crew – it’s crabbing season!) the science party made their way home and the Coast Guard began their transit back to the Healy’s base port in Seattle, WA. The Healy will stop in Nome, Alaska to pick up family members who will sail the last few days of the transit and catch up with their loved ones. In November scientists will travel to Seattle to collect gear and samples, and then the work continues! It will take 2-3 years to analyze all of the samples that were collected on board, to interpret our results, and write manuscripts.
I would like to thank you for reading my blog this summer and taking an interest in the Arctic Ocean. A special thanks to Abigail Doyle who managed my postings above 75 N when I was without internet. I will continue to post sporadically between expeditions, please click the “follow” link if you would like to receive email updates. Stay curious!
“A mind that is stretched by a new experience can never go back to its old dimensions.” -Oliver Wendell Holmes, Jr.
As an update to my previous post, I am happy to report that the helicopter that delivered two government officials to the Healy this week also came with a bag of fruit. There was not enough fruit to feed over 100 people so ten lucky souls were chosen at random and gifted a piece of real, live, fresh fruit (may I remind you we have not had fresh fruit or vegetables for over one month). The fruit lottery was a big deal, names were read over the loud speaker after dinner with only a five minute window to claim your prize. I was not lucky enough to be chosen for the lottery, but lucky enough to be sitting next to Phoebe Lam who shared her orange with the whole table :)
Moments ago we crossed latitudinal line 66 °N officially exiting the Arctic. We intended to sample two more stations in the Bering Strait but all further science operations have been canceled due to rough seas. We will reach the Diomede Islands sometime this afternoon and enter port in Dutch Harbor on the morning of October 12. For now we are packing up labs, organizing samples, and enjoying our last few days at sea.
Earlier this week, two government officials arrived via helicopter from Barrow, Alaska to observe the Healy’s underway operations through to Dutch Harbor. Wearing flight helmets with ear and eye protection we were able to stand on deck to watch the craft land and practice lowering a man basket before returning to land. The following morning the helicopter was back for a medevac flight, transporting an ill crew member back to land for emergency medical attention. Medical emergencies on a ship can be dangerous, there are two medical officers on board the Healy but their resources are limited at-sea. The Polarstern (German GEOTRACES) also experienced a medical emergency in the Arctic forcing the ship to change course and head for land, both patients we have heard, are doing well.
At night the skies have been alive with dancing green light and shooting stars. The Aurora Borealis occurs when electrically charged particles from the sun (solar wind) interact with gases in Earth’s atmosphere. Solar wind is deflected by Earth’s magnetic field over most of the planet, but the magnetic field is weaker at the north and south poles allowing some particles to enter the atmosphere. We have seen mostly green auroras that are created when solar wind interacts with oxygen within 60 miles of Earth’s surface, there have also been some hints of red light from the interaction with oxygen at higher altitudes. Blue and purple colors can occur when solar wind interacts with nitrogen. All night you will find people on various decks of the ship with their heads up to the sky or faces pressed against the glass windows of the bridge which is kept dark to navigate at night. The U.S. National Oceanic and Atmospheric Administration uses satellite data and computer models to predict the location and visibility of the aurora everyday, we have been seeing a 4 out of 10 on the visibility scale and even that is spectacular.
The most abundant elements in seawater are salt ions (sodium, chloride, sulfate, magnesium, calcium, etc.), and on average one liter of seawater contains 35 grams of dissolved salt (one liter of seawater weighs roughly 1000 grams so salinity is measured as parts per thousand). The GEOTRACES program specializes in measuring the least abundant elements in the ocean, referred to as “trace-elements.” Concentrations of the trace-element mercury, for example, are often less than 0.000 000 000 200 grams dissolved in one liter of seawater (parts per trillion). From this perspective, finding a needle in a haystack sounds easier than searching for mercury in the ocean.
Because these elements are found at such low concentrations, even a small amount of contamination can significantly alter a sample. Collecting contamination-free samples is a delicate process – imagine the challenges that arise when looking for trace amounts of iron in seawater collected from a giant rusty ship! The GEOTRACES program has developed specific sampling protocols that include a number of inventive solutions such as plastic shower caps, Kevlar line, and hand carrying 4 ft long GoFlo bottles. The photos below outline the procedure for collecting contamination-free vertical profiles of seawater from the ocean surface to the ocean floor.