Scientists deploy a CTD and water sampler over the side.
A CTD is an electronic
instrument package that accurately reports conductivity, temperature
and depth and transmits data up the conducting wire to a computer on board.
the computer calculates salinity from conductivity and temperature. Together,
salinity and temperature determine the density of seawater, which in turn affects its
movements; and temperature affects biological rates and behavior. The gray cylinders
around the top are Niskin bottles which are closed at depths where scientists want to
obtain water samples. The closure is controlled electronically from the ship's lab.
The hose which you see coming off the unit is attached to a pump on deck so that the
scientists can get continuous and large volumes of water from various depths.
"Paying out hose for the pumping
system." Here the pumping system is overboard, and people on deck are
paying out 80 meters of
hose which has to be lowered behind the CTD.
Pumping system hose between deployments of the CTD.
