14 June 2004

Joined: 23 Mar 2004 Posts: 87

June 14, 2004
Monday 4:00 PM Alaska time

The eight-person service team provides reference water-quality data for all SBI scientists to use. Six of the scientists are from the University of California, San Diego Scripps Institution of Oceanography's Shipboard Technical Support Oceanographic Data Facility (ODF) and Shipboard Electronics Group (SEG), one scientist is from University of Delaware and another scientist is from University of Alaska, Fairbanks.

Throughout my journals I have often mention the CTD in conjunction with collecting water samples. It is much more than a water sampler. It is a SeaBird CTD hydrographic package owned by the Coast Guard. It contains a rosette of twelve 30-liter Niskin water collection bottles, temperature probes, Photosynthetically Active Radiance (PAR) and conductivity sensors, a transmissometer for measuring particles in the water and a fluorometer that also measures particles, but with a different light source than the transmissometer. During the SBI cruises, the Service Team runs and maintains the CTD package.

Doug Masten

Dan Schuller

The two chemical technicians from ODF, Doug Masten and Dan Schuller, are responsible for the nutrient profiling. Samples are taken from every CTD cast for every collected depth and indexed by station, cast and bottle number. They measure six nutrients: nitrate, nitrite, phosphate, silicate, ammonium and urea using an auto analyzer. Doug works from 11:30 AM to 11:30 PM and Dan works from 11:30 PM to 11:30 AM so one or the other is always on duty. This is important because the samples must be processed without delay.

When the service team needed another chemical technician for this cruise, they asked Jennifer Sheldon from the CALCOFI division of Scripps to join them. She collects water for dissolved oxygen (DO) levels. The DO procedure Jennifer uses requires her to immediately fix the sample. This also allows her some flexibility in her sample processing so she is able to work from 11:30 AM to 11:30 PM. If a CTD cast is made when Jennifer is off-shift, Dan collects and fixes the DO samples.

Rob Palomares is a senior electronics technician from SEG. On the Healy, he keeps the CTD package running. Whenever a bottle leaks or does not trigger properly, Rob troubleshoots the issue, discovers the problem and fixes it. He also does the CTD data acquisition, tripping bottles to take water samples at prescribed depths. This also entrails giving instructions to the winch operator on how far to take the CDT to the ocean bottom depths without "crashing" the CTD package on the seafloor.

Kristin Sanborn is in charge of the CTD casts from midnight until noon. She also supervises the technicians. When a CTD is not being sampled, Kristin is in the future lab processing data. She ensures that usable data is available to the scientists the next day and the final data are ready before the end of the cruise. She also has been cross-training Jennifer to do data processing during this cruise. Furthermore, Kristin makes plots available to the scientists by providing them to the JOSS website. She and Jennifer put together all the service team data for salinity, oxygen and nutrients with the CTD data that allows the science party to see how their data fits into the grand scheme. Kristin also acts as "water cop." In this capacity, she insures that the bottles on the rosette are quickly emptied using pre-defined, sampling-order protocol.

Jim Swift is the scientific advisor of ODF. He is in charge of the CTD casts from noon to midnight. Jim interprets data through a graphical package called Java Ocean Atlas (JOA) and writes reports for the service team. His reports are made available to the scientists via an onboard, intranet system. Jim also performs the CTD acquisition just as Rob does.

Dave Huntley, from University of Delaware, oversees the Acoustic Doppler Current Profiler (ADCP). The ADCP vertically profiles and records the velocity and direction of the currents underneath the Healy. Dave must adjust the readings when we are turning or backing and ramming the ice, which we have done frequently on this cruise. He also sends daily reports to his home office. Some of the plots that Dave produces are of the ocean with the arrows showing the current movement. Sometimes the arrows look like they are all going in different directions.

Dean Stockwell, from the University of Alaska, runs the chlorophyll analysis for the service team. Chlorophyll is found in the primary producers so it can be used to get an idea where the biomass distribution is in the water column. Typically, high biomass will be found where light levels are low and nutrients levels are high. The CTD operates 24 hours a day, and Dean is the only person in the Service Group who can do chlorophyll. He is what is called a "floater," meaning that whenever a CTD cast is made Dean must be there to sample regardless how many hours he has worked or how little sleep he has had.

To see photographs taken by Steve Roberts of UCAR/JOSS, click here.