The ArcticMix mooring stands 3452 meters tall in the middle of the Beaufort Sea and when it was deployed early in September the scientists and crew of the R/V Sikuliaq literally watched as they let slip into the deep over half a million dollars worth of technology. And while there are plans and backup plans for how we will again find this undersea treasure, everyone aboard will sleep better when each meter of wire and scientific baubles are again tied to the deck. Still there is no better way to measure the ocean across its entire depth over a long period of time than employing ocean moorings. These hard-won scientific data from the real ocean are essential to formulating and tuning the global climate computer simulations that inform decision-makers and regularly make the headlines
The primary study zone for the ArcticMix voyage is right on top of what the National Snow and Ice Data Center (NSIDC) has called ‘a striking feature of the late 2015 melt season’, a period that has ended as the fourth lowest Arctic sea-ice minimum on record. Over 19 days, as the R/V Sikuliaq made additional ocean observations nearby, the ArticMix mooring stood steady listening and learning about its patch of the Beaufort Sea.
The Arctic is a strange place oceanographically, an up-side down version of the normal ocean in that the surface water is cold and fresh while lurking below is a reservoir of warmer, saltier water, heavier than the surface layer due to its high salt content. One hypothesis in a rapidly-changing Arctic is that increasing open water allows storms to mix this deeper ocean heat upward through the generation of undersea beams of energy called ‘internal waves’, in turn melting more ice. The peculiar nature of the Arctic is what makes a hypothesis of a positive climate change feedback based on vertical mixing possible.