Sunday, June 1, 2014

UW joins the science party

After several strenuous days of sampling and working in the lab, we are now in the home stretch with quite a few sites of interest in our path. In coordination with NOAA-PMEL, Rachel Van Giessen represents the University of Washington on this cruise. Her team of three is playing an important role in both the grand design of our research onboard and the collaboration between NOAA and UW. They are analyzing both dissolved oxygen (DO) and collecting samples for the labs back at the university to analyze for dissolved inorganic carbon (DIC). Rachel's team has been supporting in every way on board by deploying the CTD with me each day and helping wherever is needed. Now that we are off the coast of Washington, there are specific sites that NOAA is particularly interested in that are now our target sites. These sites have been chosen because of their value for comparing data in the same location over time. We have monitored the water chemistry for many years from these exact spots and are able to see the changes, year to year. Entering the Strait of Juan De Fuca, we will be increasing our workload to collect data all along the way.
Their work:
Rachel Vander Giessen, UW, titrating to find DO in a sample
Hannah and Kit work together to collect the water sample
and poison the sample to stop the biological processes.
Titration mobile station.
Notice the cloudy precipitate in the glass vial.
Rachel, Hannah and Kit work together to carefully collect samples from various depths without any contamination. They are the first to sample from the CTD and make sure that no air in the Niskin enters their specialized glass containers. Contamination from the atmosphere is their number one concern  and the reason that they follow such tight protocols. As soon as the sample is taken without a single bubble, they poison the sample to stop any biological processes inside the bottle, freezing the chemistry of the water for analysis. Otherwise, the organisms within would continue using up the nutrients and change the oxygen and carbon dioxide content of the water. By adding 1 mL of manganese chloride and another milliliter of a combination of sodium hydroxide and nitrogen iodide, they create a precipitate, clear evidence of a chemical change. The solid (precipitate) that is formed is directly proportional to the DO (dissolved oxygen) that they ultimately want to calculate on board. Within a five day window, they add 1 mL of diluted sulfuric acid which frees the iodine and turns the basic solution to the acidic side of the pH scale (under 7). They then add a starch solution (think potato) to use as an indicator to determine when the solution becomes perfectly neutral. Using this method that has been used since the late 1800's (1888 to be exact), they titrate with a device that allows them to add one thousandth of a milliliter of sodium thiosulfate at a time, looking carefully for when the solution becomes completely clear. At this point, they record the amount of sodium thiosulfate that was needed and input this number into a formula to find the dissolved oxygen content, accurately and without contamination.

Rachel works on the deck with the chemicals used for DO calculations.
These calculations and those for the DIC (dissolved inorganic carbon) will be used in other formulas all over the vessel. It's a tight-knit family here with everyone collaborating, adding to the big picture one titration at a time.
Meet the team: 
Rachel Vander Giessen, 33, has had a passion for the ocean as long as she's lived in Seattle. All of her life. After graduating from high school, her passion propelled her to apply for the Maritime Marine Academy in Seattle, like so many of the full-time crew on board the Melville, but a subpar math score on the entrance exam kept her from pursuing this dream. Ironically, her degree now is in physics. "All it took was a good professor," she explained, to change her mind and turn her on to the mathematical world around us. After a few years of crewing private vessels through the inside passage to Alaska, she finished her degree and began volunteering at UW. It was on another research cruise as a volunteer with Jan Newton (UW) to repair the Cha Ba buoy (one of our sites of interest) that she was offered a permanent job with the university that has led to her work here with us.

Rachel holds the clipboard and lets each person know when
to start sampling. This helps avoid confusion and contamination.

Hannah Glover sampling for DO.
Hannah Glover, 23, moved from her lifelong northeastern home to Seattle after graduating from Bowdine College in Brunswick, Maine and working for a while with the Maine geological survey. Hannah is a natural at sea and loves the work and the outdoors. Her move to Seattle quickly turned into an internship at a land trust making maps before joining the UW applied physics lab as a volunteer. With UW and Rachel, she helped deploy ORCA buoys; as with everything in science, ORCA is an acronym for oceanic remote chemical analyzer. When asked if she wanted to join this science excursion, Hannah did not hesitate to join.

"Kit" Kallista Angeloff
"Kit" Kallista Angeloff, 26, graduated from Rhode Island School of Design (RISD) which led to work as an illustrator for a science team. She created technical drawings for archaeological finds. It was in this field, that she kindled a passion for science and realized that she had a desire to know more, especially in the area of chemistry, geochemistry, and marine chemistry. Kit moved to Seattle and started her Ph.D. at South Seattle Community College. But, determined to know more, she emailed and called all over UW's campus to find opportunities to learn first-hand. Her persistence led to her contact with Rachel, and here she is, working side-by-side with best oceanographers in the world.

Kit stops the biological processes,
preserving the chemistry of the sample.

The formula to calculate DO from
the Winkler Method.
Each volume is known;
they use these values in their calculations.
Each glass container has an exact
known volume to six places after the zero.
Adding the "poison"
Precipitate formed.

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