Four Moorings Redeployed, and O Canada!
The moorings are essentially a series of instruments attached to kevlar line and some small lengths of steel chain (typically painted to avoid corrosion). This is a small frame with an ADCP for measuring current speed and direction at a variety of distances, an external battery and logger, and an SBE37 microcat for measuring temperature and salinity.
Another instrument commonly deployed on these moorings are Aanderaa RCM-8s, current meters made back in the '80s. Nowhere near as high-tech as the ADCPs, they measure velocity and direction of horizontal currents at one depth -- simple and sturdy still goes a long way in observational oceanography.
So why are we deploying these things? There are two interesting currents here at the base of Davis Strait -- warm, salty Atlantic water flows northward along the western coast of Greenland, and cold, fresher Arctic water flows southward the eastern coast of northern Canada. There's some recirculation that happens to differing amounts during the year and it would be good to know what affects the strength of that recirculation; there's the question of whether there are any trends in the overall net southward flow -- is it warming? is there more or less ice or ice melt coming through? Combined with the analyses that will be done on the water samples taken during all those CTD casts, there should be a pretty good story about the water masses that flow through Davis Strait, a/k/a the Arctic Gateway to the Atlantic.
PS: The grad student working on the physical oceanography side of this is B. Curry, not me. I just got lucky this year with timing and got to be the one on the cruise.
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