• Three-week cruise starts Feb. 25
• Follow along on the

With winter quarter in full swing and many students spending long hours in the library or the lab, a group of undergraduates will leave the coast of Japan for an unusually ambitious research and teaching expedition.

They leave Monday (Feb. 25) and will travel for about three weeks, flying back to Seattle in mid-March. It’s part of a senior-level course, , that will induct 11 seniors into the 91̽»¨tradition of ship-based undergraduate research.

“The students are going to find out exactly what oceanographers do, and they’re either going to like it or not,” said instructor , a 91̽»¨professor of oceanography. “For sure, it’s going to be something they’ll remember for the rest of their lives.”

Emerson and fellow instructor and oceanography professor are chief scientists on one of the UW’s most far-flung undergraduate cruises.

In previous years, students have gone on research cruises off the coast of Washington, Vancouver Island and between Seattle and Hawaii. Last year’s combined research and teaching cruise took place off the coast of Chile.

This year’s goal is to study the Pacific equivalent to the Gulf Stream, known as the Kuroshio Current, which flows northward along the coast of Japan. It’s known that the fast current absorbs unusually high quantities of carbon dioxide from the atmosphere, but the reason is a mystery.

91̽»¨faculty and graduate students hope to understand what role organisms play in absorbing carbon dioxide from the atmosphere, so they can improve computer models that try to predict how increased atmospheric carbon dioxide will affect the climate.

Four scientists and three graduate students will conduct their own research while assisting the undergraduates.

Students will carry out collecting data to study water movement, acidity, and the relationship between satellite imagery and abundance of marine plant and animal life. Their research will become senior-level theses, and in some cases could lead to scientific publications.

“It’s one thing to sit in class and learn the theory, or even help with someone else’s research,” said Mariela Tuquero, a 91̽»¨oceanography senior from Tacoma. “It’s another thing to have your own project that you care about, to be getting data that’s personal to you and interpreting the results.”

She said she’s excited, but also a little nervous – she has packed a box of Dramamine to help with seasickness.

Students begin in fall quarter learning about field research and designing their projects. In winter quarter they collect data and in the spring they will interpret that data, write a paper and present their findings.

During this year’s cruise 91̽»¨researchers will deploy 18 built in Riser’s lab, which will join more than 3,000 that already measure temperature and salinity in the top half mile of the world’s oceans. These new floats include sensors fine-tuned by 91̽»¨faculty and graduate students to precisely measure the amount of dissolved oxygen, which helps to detect the rate of photosynthesis.

Within a few hours of deployment, the new floats will begin to dive down, gradually rise to the surface, and beam data back to the UW. By this time next year the team will have a full year’s cycle of vertical profiles collected every 10 days. The floats will continue to collect data for about five years, until their batteries die and they sink to the ocean floor.

“Studying oxygen gives us some information about biological productivity,” Emerson said. “By March 2014 these floats will generate 18 annual cycles in different areas of the Kuroshio Current off of Japan.”

The cruise will take place on a Scripps Institution of Oceanography research vessel because the UW’s Thomas G. Thompson research vessel has been undergoing repairs. The research portion of the cruise is supported by the National Science Foundation. The student ship time is supported by the State of Washington, through an agreement that brought the Thompson to the 91̽»¨in 1991 in exchange for 40 days each summer of ship-based undergraduate research.

“I think it’s one of the greatest opportunities I’ve had at the university,” Tuquero said.

Oxygen in the upper waters of the North Pacific, an area that accounts for about 40 percent of the world’s oceans, decreased as much as 15 percent in a little under two decades between the early 1980s and late 1990s.

The change could be the result of climate shifts occurring at decade-long intervals — which should eventually shift back — or, it could be caused by global warming, says Steven Emerson, 91̽»¨ professor of oceanography. Emerson reported on the recently emerging findings this morning at the Ocean Sciences Meeting in Honolulu. The meeting, sponsored by the American Geophysical Union and American Society of Limnology and Oceanography, runs today through Friday.

It has been just in the last year that research teams — two from Japan and one led by Emerson, all working in different areas of the North Pacific — published three separate papers on findings of oxygen decreases of 10 percent to 15 percent from the top 100 to 600 meters (300 to 2,000 feet) of the ocean, referred to as the upper thermocline. The Emerson paper, the most recently published, is based on measurements made during expeditions funded by the National Science Foundation and the 91̽»¨in 1980 and 1981 compared to ones in 1991 and 1997.

Slower ocean circulation, an increased growth rate — or productivity — of plants in the surface waters or a combination of the two could result in less oxygen, Emerson says.

Emerson’s presentation comes just days after the publication of a paper in the Feb. 7 issue of Nature presenting evidence that circulation has slowed 25 percent since the mid-1970s in the equatorial and north Pacific Ocean, a significant change in the intensity, according to lead author Michael McPhaden, a scientist with the National Oceanic and Atmospheric Administration in Seattle and 91̽»¨affiliate faculty member.

With slowing circulation, water would linger longer in the thermocline. Plants and organic matter would have more time to decompose, Emerson says, a process that consumes oxygen when carbon released from decaying tissue is oxidized.

Some global-warming circulation models suggest that global warming would result in a decrease of oxygen in the upper thermocline, Emerson says.

Along with findings by scientists such as McPhaden that circulation is slowing, Emerson’s co-presenter at the Ocean Sciences Meeting used man-made chlorofluorocarbons, or CFCs, as tracers to consider the age of water in places where oxygen depletion was measured. Water was spending more time in the thermocline in the 1990s compared to the 1980s, according to Sabine Mecking, who earned her doctorate at the 91̽»¨and is now a post-doctoral fellow at Woods Hole Oceanographic Institution.

Emerson says other scientists, such as Dave Karl of the University of Hawaii, have evidence that productivity has increased. An increase in the rate or amount of plant growth nears the surface means increasing amounts of degradation in the thermocline, a process taking oxygen.

Documenting additional changes and finding ways of measuring changes in circulation and productivity will eventually help scientists improve models of how oceans react on a decadal scale.

“This work is going to get a lot of attention in the next 10 years,” Emerson says.
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— For more information: Emerson and Mecking will be in Honolulu Feb. 11 to 15; for help reaching them, call Sandra Hines, (206) 543-2580. When they return try: Emerson, (206) 543-0428, emerson@u.washington.edu, and Mecking, smecking@whoi.edu.

— McPhaden travels Feb. 7 through mid-February, use his e-mail mcphaden@pmel.noaa.gov.

— Emerson, Mecking and Jeffrey Abell, a 91̽»¨graduate student, are the co-authors of the most recently published paper on the declines in oxygen that appeared in the journal Global Biogeochemical Cycles last fall.

— Other lead authors publishing oxygen-depletion findings: Y.W. Watanabe and T. Ono in Geophysical Research Letters.