Abstract:
Three ice mass-balance buoys (IMBs) were deployed on 2, 4 and 12 October 2007 at sites Brussels and Liège at locations close to the clean sampling sites during a 27 day occupation of an ice station floe (Ice Station Belgica(ISB)) in the Bellingshausen Sea. IMBs were designed and constructed by the Cold Regions Research and Engineering Laboratory and equipped with data acquisition systems mounted
... on steel framed tables anchored to the sea ice. Instrumentation on each buoy consisted of a common suite of sensors including thermistors in the upper ocean, sea ice, snow and air at 0.05 or 0.10 m interval; acoustic range-finder sounders to record the ice bottom and snow surface elevation. Additional sensors included an underwater radiometer (1 buoy) and Seabird conductivity–temperature–depth (CTD) sensors (2 buoys). The buoys were equipped with global positioning system (GPS) receivers and communications equipment that utilized System ARGOS satellite uplink to transmit data. The Seabird 1 buoy installed at Liège was recovered prior to departure from ISB due to problems with its CTD sensor, while the other two IMBs operated for 55 and 73 days. During ISB the IMBs drifted eastward with the floe, changing directions midway to a westward track. After departing ISB, the surviving IMBs (radiometer and Seabird 2) drifted primarily in a northeast direction, extending northward beyond Peter I Island until 23 November, at which time, the GPS position records diverged and the IMB trajectories separated near 69.001°S, 91.453°W. The buoy sensors provided two-hourly data for the duration of the drift. However, premature loss of thermistors, snow pinger and air temperature sensors occurred on the radiometer buoy on 1 November and the radiometer stopped operating around 26 November. The Seabird 2 IMB maintained thermistor data transmissions until 6 December, at which time the buoy ceased to operate at approximately 67.717°S, 89.244°W. On 14 December (67.295°S, 85.665°W), the radiometer buoy ceased transmission of barometric pressure and GPS location. 
