Tag: SPURS

by Eric Lindstrom / Eastern Tropical Pacific Ocean /

Eric Lindstrom is Physical Oceanography Program Scientist at NASA Headquarters. For the last 20 years, his primary job has been supporting NASA satellite missions related to measuring physical characteristics of the ocean (principally, temperature, salinity, sea level, and winds) and supporting the oceanographers that generate knowledge from such data. He was recently aboard the Research Vessel (R/V) Roger Revelle in the Pacific Ocean as part of the Salinity Processes in the Upper Ocean Regional Study-2 (SPURS-2) field campaign. SPURS is undertaking oceanographic field experiments to further understand the essential role of the ocean in the global water cycle using a plethora of oceanographic equipment and technology, including salinity-sensing satellites, research cruises, floats, drifters, autonomous gliders and moorings.

What lives below us?  This is a question that mariners have wondered for ages.  We no longer think of the darker answers to this question—the sea monsters, the Kraken, the great whales.  For most aboard, the thinking is akin to a fisherman’s—tuna, mahimahi, sharks.  But for SPURS-2, Sophie Clayton is answering this question in terms of microscopic life, namely diverse phytoplankton (plant life) and zooplankton (animal life).

Sophie is an oceanographer interested in understanding how ocean currents at all scales shape the distribution and biodiversity of phytoplankton. She uses a combination of numerical models, large-scale data analysis, and targeted observations made at sea. Her Ph.D. in Physical Oceanography from the Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program. Now she is a postdoctoral fellow at the University of Washington, working extensively with observations of phytoplankton distributions made using an Imaging FlowCytobot (IFCB) that analyzes discrete samples with video and a hyperspectral optical sensor for recording the continuous optical properties of the water.

An IFCB is an instrument that is used primarily to count cells, but it also can detect and record information on different properties of the cells that it counts. A water sample is channeled into a thin stream that is passed in front of a laser, and the scatter and fluorescence from each cell that passes along the stream is detected and recorded. In the IFCB, the camera is triggered to take a picture only when fluorescence over a threshold value is detected. This means that the instrument only takes pictures of cells that contain chlorophyll. The images are then stored for analysis back on shore. In addition to the images that are collected, we use the optical properties of the cells (fluorescence and scatter) in the analysis.

Sophie’s work is enabled by surface water collected from the salinity snake while we are underway or from bottle samples taken during Conductivity- Temperature-Depth (CTD) casts. Similar mosaics are made from surface water every 20 minutes. Overall, there will be close to 2,000 mosaics of cellular life to examine.  Samples are also held for later DNA analysis.

Out here, for the most part, the plankton are actually most abundant below the surface at 40-70 meters depth. Deeper down, below the surface layer mixed by the wind, life has better access to the chemical nutrients of the deep sea while still having enough light for photosynthesis.  Plant life thrives in a layer that best balances the light and nutrient requirements.   Of course, the grazing microscopic animals follow this layer closely.  So Sophie is keen to collect water from this layer during our CTD casts.  She can tell where to sample by optical properties also measured on CTD casts.

Understanding plankton abundance and diversity is a core requirement for ocean climate science.  Phytoplankton are responsible for about half of all photosynthetic production on the planet. (Land plants are also responsible for about half.) It makes them a key part of the carbon cycle on the planet.  Over long periods, phytoplankton can remove carbon from the upper ocean and return it to sediment for long-term sequestration.  Over hundreds of thousands of years, phytoplankton act to reverse the greenhouse effect caused by pulses of carbon dioxide injected into the atmosphere by volcanoes or humans.

In a prior blog,  I wondered about the fate of life in the sea. What would become of that abundant life with the continued impacts of ocean acidification, industrial fishing, and plastics pollution?  Science struggles to make any predictions.  Oceanographers particularly, because of our close affinity and observation of the sea, hope that the assaults of society on the sea do not damage its inherent ability to stabilize and heal the rapid changes overtaking the planet.  Our baseline understanding of the complex marine ecosystem is still quite primitive.  The kind of “survey” work that Sophie is undertaking is absolutely necessary to further our understanding of the biogeography of the ocean and how it is changing.  Let’s hope she has a successful career!

Eric Lindstrom is Physical Oceanography Program Scientist at NASA Headquarters. For the last 20 years, his primary job has been supporting NASA satellite missions related to measuring physical characteristics of the ocean (principally, temperature, salinity, sea level, and winds) and supporting the oceanographers that generate knowledge from such data. He is currently aboard the Research Vessel (R/V) Roger Revelle in the Pacific Ocean as part of the Salinity Processes in the Upper Ocean Regional Study-2 (SPURS-2) field campaign. SPURS is undertaking oceanographic field experiments to further understand the essential role of the ocean in the global water cycle using a plethora of oceanographic equipment and technology, including salinity-sensing satellites, research cruises, floats, drifters, autonomous gliders and moorings.

You can read more about SPURS field campaign through Eric’s Notes from the Field blogs.

In July 1969 I was watching Neil Armstrong take his first step on the moon at Tranquility Base, like everyone else with a TV at the time.  I was at USC Wrigley Marine Center on Catalina Island as a 13-year-old visiting my brother, who was spending the summer studying there.  If you had asked me then if I would wind up working for NASA, I would have said, “No, I’d rather pursue oceanography!”  Well, since 1997 I have been the Physical Oceanography Program Scientist at NASA Headquarters AND I am a dedicated sea-going oceanographer.  It stills feels kind of crazy what comes around in life.  I write my short career biography here for students who may consider working in oceanography or for NASA or both.

After graduating from Huntington Beach High School in California in 1973, I took the train across the country to begin my college career at the Massachusetts Institute of Technology.  After only one semester of MIT physics and mathematics problem sets, this boy gravitated to the Department of Earth and Planetary Sciences and asked them how I would train to be an oceanographer.  There were no undergraduate oceanography courses, so I was told to take physics and math (ouch!) and to get my degree in Earth Science I would have to take the required geology and geophysics courses, too.  I did all that, but rocks were not my first love.  Luckily, a Professor of Physical Oceanography at MIT, John Bennett, allowed me to work with him under MIT’s Undergraduate Research Opportunities Program (UROP) and sit in on his graduate level physical oceanography courses.  We worked together on an analysis of the coastal boundary layer in Lake Ontario, and I co-authored a paper with him that appeared in the Journal of Physical Oceanography in the summer of 1977.  UROP and that research paper were a big boost for my applications to graduate school.  I still donate money annually to MIT’s UROP to honor its impact.

For graduate school I sought out a diverse set of schools: UCSD Scripps Institution of Oceanography, University of Washington, Princeton, and University of Miami.  I was told that since I was at MIT, I should NOT apply to the MIT/Woods Hole Oceanographic Institution joint program (that was weird).  In the end I did have choices and settled at University of Washington working with Professor Bruce Taft.  It was the era of Apollo-Soyuz and USA-USSR cooperation in space and oceanography, so I embarked on studying eddies in the North Atlantic with a diverse set of US and USSR scientists.  The project was called POLYMODE.  It was a fun project with time at sea and lots of workshops and meetings, including a month in Moscow doing a data exchange.  The connection to the space program was remote and programmatic and I hardly noticed it at the time.  I received my PhD in September 1983, the day the Australian’s won the America’s Cup sailing race.  I celebrated, since I had signed up to move to Australia to do oceanography (and get married!) the very next month.

Australia was a hoot!  We moved to Hobart in Tasmania where the government was building a new marine science laboratory and eventually a new oceanographic research vessel as well.  It was  a growing field because 200-mile Exclusive Economic Zones had just been declared and Australia wanted to know all about the waters around the continent—good work for a newly minted oceanographer!  The team in Hobart had me focus on the western tropical zone, including the Coral Sea, Solomon Sea, Bismarck Sea, and the circulation around Australia’s neighbor Papua New Guinea.  Hardly anything was known so I worked with some of my buddies back in the USA on developing the Western Equatorial Pacific Ocean Circulation Study (WEPOCS).  It was a great success! We named some new ocean currents and replaced some old stale ideas with some fresh perspective on the role of the western tropical Pacific in climate.

While in Australia in the 1980s I also became involved in the planning of a huge international experiment – the World Ocean Circulation Experiment (WOCE).  My work on WOCE had the Australian government send me back to the USA to work at Texas A&M University, the U.S. WOCE Office.  That certainly began returning my roots to US soil.  After returning to Australia it was not long until headhunters from USA sought my return to work again in the USA at the project office in Boulder, Colorado, of the Coupled Ocean Atmosphere Response Experiment (COARE; an experiment just off the coast of Papua New Guinea).  The family decision was to make a return to the USA permanent.

Boulder only lasted about 18 months and then I returned to WOCE work as U.S. WOCE Program Scientist in Washington, D.C., in 1992 as an employee of Texan A&M University but under the direction of five federal agencies (each providing 20 percent of my support).  Gosh, the world is convoluted sometimes!  That, for me, began “interagency cooperation” in oceanography for which I am still deeply involved.  Broadly, the five agencies that fund global oceanography projects are the same now as they were then: NSF, NOAA, Navy, NASA, and Department of Energy.

Eventually, after five years working on WOCE and the new Global Ocean Observing System, I got a call from Bruce Douglas at NASA Headquarters.  He was serving a stint as Physical Oceanography Program Scientist and asked me to interview as his replacement.  NASA told me they were looking for someone who could integrate their oceanography (from space) into the federal family of oceanography agencies.   Certainly, I had experience for that.  However, I told them I had no particular experience with satellite oceanography.   Their idea, and response at the time, was that they had plenty of satellite oceanographers at NASA but that it might be good for their leader to be someone who had “touched seawater” and was open to learning about the new tools for satellite oceanography.  Wow, I said, you have found the right person!

So, here we are, after 20 years, I have learned my fair share of satellite oceanography and have thoroughly enjoyed NASA.  I have molded NASA Physical Oceanography into a community that fully supports its satellite missions with appropriate science at sea.  I hope I have helped to make satellites an everyday tool for oceanographers.  The positive feedback from the community has been most humbling.  I am very lucky indeed to have landed on my own Tranquility Base.