Today the sun did not rise. We have come so far north that we have reached a latitude where the sun did not come above the horizon on this winter day, where night lasted for 24 hours. We were treated instead to a few hours of incredible pink sky that turned the ice blue and rose. The colors are magical.
|Our not quite sunrise.|
We presently are working a grueling set of stations spaced 10 km (or about 5 nautical miles) apart. At each station we sample using the CTD (conductivity-temperature-depth) and associated sensors that are mounted on a rosette bearing 12 large Niskin bottles. With the sensors we measure temperature, salinity, dissolved oxygen, fluorescence (a measure of the plant pigment in the water), and light transmission (the amount of light that gets through the water indicates the amount of particles). With the Niskins, we collect seawater at selected depths to measure nutrient, oxygen, and chlorophyll concentration, organic carbon, and phytoplankton composition and abundance. We also sample at each station using a Video Plankton Recorder, which records images of the plankton and particles in the water column. At every other station we do tows with plankton nets to collect zooplankton. We also sort plankton collected from the nets to select copepods and krill for experiments such as determining grazing.
|Marine Science Technician (MST) Shannon Curtaz brings up the CTD as the sun tries to peek above the horizon.|
|Sam Laney peeks out between two Niskin bottles while sampling seawater (Photo by Krista Longnecker)|
The pace is pretty fast along the line. No sooner do we get the instruments back on board and the data backed up than it is almost time to do another station. We are transiting only at five knots, to buy time for the processing of data and samples. It is exhausting. After 12 hours of hurrying from lab to deck, of struggling into and then out of mustang suits (floatation suits that resemble a snow suit), pulling on heavy boots and socks, encasing hands in warm gloves, and fixing the hard hat on top of a face mask and warm hat, we can hardly wait to finish our watch and get some rest. Although it is exhausting, I wouldn’t be anywhere else!
|Ice and snow in the light of the near dawn.|