A Webb Slocum glider named Rusalka is an autonomous underwater vehicle aka a robot that is joining the cruise research efforts. Rusalka was deployed on Sunday afternoon and will be gliding through the water in the research area until Wednesday afternoon. It was an exciting deployment day, because the first attempted was unsuccessful as Rusalka detected a leak during her first dive at a depth of 65 meters. After detecting the leak Rusalka returned to the surface and sent us a message telling us to come for her. In a small boat launched from the R/V Thompson we had a smooth recovery of Rusalka in some rather large swell (10 feet). After opening the glider, cleaning up the drips and troubleshooting back in the lab Rusalka was successfully deployed and swam off to begin her sampling. The glider will be checking in with the ship about every four hours to update us on her progress. The glider dives to a depth of 100m and then return to the surface in a seesaw pattern moving about 1 km/hr (about .6 miles/hour).
Gliders are neat research robots because they move independent of the ship and are one approach to study complex subsurface ocean dynamics. Gliders can estimate phytoplankton population and can observe physical subsurface features including fronts, eddies, internal waves, and integrated subsurface current velocities and direction. Rusalka on this cruise will be running a 14 km transect over a seamount. It is theorized that the seamount might be having on influence on regional ocean physics, chemistry, and biology and Rusalka will be helping gather data to test the theory.
The glider was equipped with variety of sensors including a Sea-Bird conductivity-temperature-depth sensor, a GPS, Iridium communications enabling daily data transmission, and WET labs ECO pucks optical instruments. The optical sensors included three fluorometers with excitation/emission channels that measured chlorophyll a, colored dissolved organic matter (CDOM) and phycoerythrin/ rhodamine (540nm/570nm), and an optical backscatter sensor at 3 wavelengths.
Posted by Bridget