By Eric Lindstrom
If you all are waiting to see some action at sea, I am sorry it is taking a bit to unfold. It takes about a week from Woods Hole to reach our study site at 25N, 38W. It’s good for us to have the time to check and re-check the instruments, get people trained in various procedures and ready to stand watch for 24/7 operations, and get to know our work mates. However, everyone that has prepared for more than a year for the expedition finds this week a long one. We want to be getting gear in the water and a flood of data passing through our computers. We want to be up all night, busy with deployments, water sampling, and scientific analysis. Everyday on the research site will be brimming with new data and constant planning for the next event.
All eyes in CTD operations.
The chief scientist has his hands full keeping the entire show operating smoothly. We have mooring, Argo float, and drifter deployments, glider operation, underway profiling, station profiling, autonomous profilers, and more meteorological sensors than can be easily counted. Everything needs to be working, providing good data, calibrated, checked and re-checked, and while many things can happen simultaneously, nothing should interfere with anything else.
Meteorological tower on the bow of the R/V Knorr.
Preparing a slocum glider.
The order of business is, very roughly, to get the sensors we want in the water (to supplement what the research vessel can do), off the ship and doing their job. The moorings and Argo floats take a lot of space and only serve us when deployed, so we will spend much of the first days on site getting these in the water. While we move from one site to another deploying equipment, we will also be mapping the ocean with instruments we lower from the ship on station or tow behind the boat while underway. During just about every moment, we try to gather data from the upper 1300 feet (400 meters), to characterize the salinity field and ocean circulation.
Once we have all our assets in the water, we can focus on using them in conjunction with the ship to characterize the ocean environment on time scales from minutes to weeks and from inches to a hundred miles. Over about three weeks we will do our best to map and understand how salinity varies at this spot in the ocean and why it does what it does. When the ship leaves, we leave many of these instruments in the water, to continue our work for the next 12 months. Expeditions in six months and 12 months from now will maintain and eventually recover many of the instruments we deploy in the coming week. We think of it as deploying a sensor web in the ocean.
This kind of intense study is the basic work that helps us understand and interpret the weekly global maps of salinity we get from Aquarius. There are more esoteric and nerdy scientific questions that get answered along the way (making it very satisfying to all the scientists involved), but everyone is highly motivated by the opportunity Aquarius offers to study the global salinity field. SPURS is realizing that opportunity.