The deck of the SARMIENTO seems empty compared to other cruises, where usually anchors, sensors and other bulky equipment is piled up.
On the deck there are only two instruments strapped to the wooden floor. They look like well-fed yellow fish with a propeller at their tail.
These two instruments are called a SeaSoar and they are a key component to the survey we started 3 days ago. Once lowered into the water the instrument will be towed behind the ship at around 8 knots while it uses its wings to undulate between the surface and up to 400m taking continuous measurements of the water characteristics on its way.
These measurements include salinity, temperature, pressure, oxygen and fluorescence. The towed instrument provides much more profiles then a regular CTD sensor could achieve in the same time, since the traditional measurements require the ship to stop in order to lower the sensor.
Combining these measurements with the ships underway system, which collects temperature, salinity and fluorescence at the sea surface and maps ocean currents up to a depth of 600 meters, we collect a highly resolved data set of the upper water column.
The detailed pictures that we got after only a few days are truly fascinating. There is a sharply separated fresh feature in the upper 100 meters in the South and little pockets of subsurface salinity maxima detectable(see picture to the right).
|Salinity from SeaSoar and Underway systems|
|Watching the sunset. while the SeaSoar is at work|