|Taking water samples from the rosette CTD|
|SBE #19 -- the CTD used on the mini-bongo and|
sub-surface nueston nets
Those water samples taken by the rosette CTD are filtered using a vacuum pump onto filter pads. These pads are taken and used to measure the concentrations of various chlorophylls in the water column.
A third device we use on every net tow is a flowmeter. This piece of gear looks like a tiny rocket and hangs in the net frame. We record the numbers on the side at the start and the end of the tow and use these, along with the size of the frame, to calculate the amount of water moving through the net.
Last but not least -- drifters! We have a pile of these large floating balls that we deploy at areas we think have an interesting current pattern. They have a long "sail" that hangs down through the water column and is supposed to prevent movement due to wind and aid with movement due to currents. A transmitter inside the drifter connects to satellites which relay its position back to us. From this information we can track direction and speed of currents.
|K. Doering removing the filter|
pads off the vacuum pump
to save them for further
|Drifter. The ball floats on top of the water while the blue sail|
(stretched out to the left) hangs down below.