ITP 122 Deployment
ITP 122 was the fourth ITP deployed as part of the third Ice-Based Observatory (IBO) during the JOIS 2021 cruise. On the morning of the deployment, the CCGS Louis S. St. Laurent tried to make it as far as possible to the northeast looking for what seemed to be immobile ice at the eastern edge of the gyre on the satellite imagery. Searching identified an arrowhead-shaped ice floe about 1.75nm at its widest and 1nm at its narrowest. The ice radar showed potential ridging or melt areas throughout the floe which cracked starboard aft of the ship upon entering and the first survey site just in front of those cracks and was deemed unsuitable, with ice thicknesses of 80cm and 55cm measured. Some scattered ridge rubble was visible off the starboard roughly parallel to the ship and there was an open rift in front of the vessel to starboard. The decision was to pull forward into the floe beyond the open rift turning to port away from it.
The second survey started portside, where there were fewer features in the ice. At this site, the sea ice thickness was 75cm, 80cm, 100cm, and 100cm at the TOP, SIMB, AOFB, and ITP sites respectively. The site was likely between four ridges, as seen on the ice radar, though no significant ridges were visible from the site. The TOP was deployed nearest to the ship, followed by the IMB, then the AOFB and finally the ITP. Snow cover was variable from one to five inches deep. Though the snow was generally firmer than at the previous station, there were numerous melt ponds hidden beneath the snow and almost everyone ended up with wet boots at one point or another. An ice survey was conducted forward of the IBO deployment.
More information and photos on the deployment operations are also available at: https://www2.whoi.edu/site/beaufortgyre/expeditions/2021-expedition/2021-dispatches/dispatch-14-the-final-ice-stations/
