Joey WenigOctober 7, 2014People had just had their plates filled and seated themselves for a meal of chicken wings and pasta in the mess last night when, at long last, the announcement we’d all been hoping to hear finally came over the intercom: “A polar bear has been spotted from the bridge”. Chairs were thrown back like caution to the wind and it’s a miracle no one was trampled in the stampede to retrieve cameras and make it onto the foredeck to catch a glimpse of the beast before it melted back into the frozen wasteland. We needn’t have rushed, however. The bear was off the starboard bow, running in the same direction we were traveling. We trailed it for a while as it zigzagged back and forth over ridges and across shallow ponds in the ice, alternating between ambling, trotting, galloping, and pausing briefly to stare back at us. It’s hard to believe this environment can support an animal of that size because apart from a few birds in the distance, I haven’t seen any sign of other life on the cruise. Polar bears can swim up to 300 km in a single go (following such a journey, they will apparently sleep for several days), but even so, it’s still incredible to see one this far from land (we’re about 380 nautical miles from Prince Patrick Island in the Canadian Archipelago, and over 400 from Barrow, AK). I can’t help but wonder if the bear was a panserbjorn out of The Golden Compass, but I can confirm that it wasn’t wearing any armor. The bear was still in sight, meandering along beside us, as people slowly succumbed to the icy wind biting through insufficient layers and trickled back indoors to warmth and a waiting dinner. Moods were light as we ate—I think that seeing the first polar bear of the cruise has taken a lot of pressure off us so that now we can relax and focus on spotting several more (from a safe distance) over the remaining week. It was a day of unusual sights: earlier in the afternoon there was also a flyover by a NOAA P-3 aircraft out of Fairbanks, AK. Out on deck waiting for the plane to appear, I noticed strange black streaks running across the sky through the otherwise slate-grey ceiling of clouds hanging low above us. Mike Dempsey explained that the streaks, called ‘water sky’, were reflections of leads in the ice. Apparently in the days before satellite imagery, northern mariners and travelers crossing the ice on foot or dogsled used the dark bands to locate open water from afar. Returning to yesterday’s ice station: one of the buoys deployed as part of the Ice Based Observatory was the Ice Mass Balance Buoy (IMBB, this one belonging to Champika Gallage at Environment Canada in Ottawa). The IMBB has three stand-alone components: a surface unit that contains an Iridium satellite antenna, a GPS antenna, an air temperature sensor, and a barometer; a sonar mast that extends above and below the ice; and a 4.5 meter pole with 45 evenly spaced thermistors along its length. The height of the snow and thickness of the ice below the sonar mast are measured manually when the buoy is deployed. From that point on, the upwards- and downwards- looking sonar measures changes in those values to record fluctuations in ice mass. Having a simultaneous record of the temperature gradient in the ice (from the thermistors) means scientists can connect heat flux through the ice to changes in ice mass, as well as to ice-related processes in the upper ocean. | |||||||||||||||||
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