ITP 107 Deployment
ITP 107 was the first ITP deployed during the 2018 JOIS cruise on the CCGS Louis S. St. Laurent and was paired with a S-IMB to constitute an Ice-Based Observatory. The weather was excellent – clear skies, low wind speeds, and air temperature around -9 deg °C. The ice wasn’t particularly thick, but it appeared that there could be some floes approached 1 m thick. An ice survey is performed on a large diameter floe that is absent of the somewhat darker melt ponds that were typical in the vicinity. Concerned that the ice could be too thin for landing the helicopter, the man basket is used from the forward starboard crane to lower personnel to the ice to drill 2 sites which turn out to be 70 and 84 cm thick – hence thick enough for the deployments. Within the next hour, the gangplank is lowered, the ITP and SIMB buoys are lowered onto the ice and 2 wire baskets with the rest of the deployment gear. By 10:46 local time, the 10” holes are augured for the buoys and ice thickness at the ITP and SIMB site are 78 and 72 cm. There are about 2-4 inches of snow on the ice surface. The ITP anchor is deployed at 11:22, profiler installed and IM circuit tested successfully at 11:43, SAMI attached to the wire at 12:51, and buoy in place at 13:00, with the final IM test completed by 13:10. Meanwhile the SIMB is plugged in at 11:18, but the blue light does not go out in 10 minutes, so the unit is repowered and the blue does go out this time, and the unit is lowered into the hole shortly thereafter. Distance of SIMB sounder to ice/snow surface is 45.25 cm, and the distance from the top of the ice thermistor chain to the ice/snow surface is 40.0 cm.
Ice analyses were also performed by others in the science party while the IBO deployment operations took place.
More information and photos on the deployment operations are also available at: https://archives.whoi.edu/beaufortgyre/www.whoi.edu/page.do@pid=163016.html
