In the summer of 2003, investigators established an observational program to measure the freshwater content (in sea ice and in the ocean) of freshwater fluxes in the Beaufort Gyre using moorings and drifting buoys. They collected temperature time series, salinity, current, sea ice draft, and bottom pressure measurements. Investigators used conventional mooring systems containing a McLane Moored Profiler (MMP) to sample currents and hydrographic data from 50 m to 2050 m with 17-hour time intervals. They measured sea ice draft with an ASL Environmental Sciences 420 kHz upward-looking sonar (ULS). Using a high accuracy bottom pressure recorder (BPR), they measured sea level height variability and near-bottom seawater temperatures. Each mooring consisted of a surface floatation package at 50 m depth, which housed the ULS, a mooring cable containing the MMP, and dual acoustic releases and a BPR located immediately above the anchor. Investigators also deployed several ice-tethered beacons to provide concurrent temperature and salinity data at several discrete depths in the uppermost 40 m. The instruments suspended three SeaBird MicroCat C/T recorders and data were broadcast via the Argos data collection relay system, which also provided the drifter location.
