We arrived at our first data collection point today - known as a station. For those of you following my journey on the Garmin website, I dropped a pin on the location and labeled it Station 1. The boat is able to stay relatively still in the water (other than the seemingly never-ending rocking) by using its thrusters. The Marine Techs (or MTs) got right to work lowering the CTD array into the water. Because the water is still pretty rough, no one other than the MTs were allowed to get near to the CTD as it dropped off the starboard side. Fortunately, we will be deploying a lot of CTDs on this trip, so while I am using someone else's photo today, I'll have more chances to get up-close images on another, calmer day.
Marine techs aboard the Nathaniel B. Palmer near the Drake Passage in the South Atlantic Ocean lower the CTD array into the water. Photo by Katie Pena (PolarTREC 2008).
CTD stands for Conductivity (which is a measure of salinity) and Temperature with Depth. Here is some math for you to try out - we were in about 2000 meters of water, and the CTD had to go all they way to the bottom to collect a sample. If the winch was letting out line at a rate of one meter per second, how long did it take in minutes for the CTD to reach the seafloor? It was then raised back up at about the same rate, this time collecting 24 water samples along the way. During its journey down and back, the CTD sent real-time data about the salinity and temperature of the water it was moving through. Further analysis of water samples can provide additional information about where the water is coming from and what it is carrying, including the amount of chlorophyll present.
Dr. Isa Rosso checks the water samples from the 24 bottles on the CTD array after it traveled more than 2000 meters to the sea floor to collect data on salinity and temperature.
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