One of the first tasks once we selected a starting point for our measurements was to deploy a drifting buoy. This buoy will produce surface measurements of wind, rain, and heat flux using the instruments mounted at the top of the platform as well as subsurface measurements of current, salinity, and temperature using a series of instruments suspended on chains below it. One of the benefits of this type of instrument is that it produces co-located atmospheric and oceanic measurements, which allows us to look at the conditions in both places simultaneously and see how the atmospheric conditions are forcing the ocean. Below the surface, this buoy has two upward-facing Acoustic Doppler Current Profilers (ADCP) and five Conductivity, Temperature, and Depth (CTD) instruments.
|Members of the Sikuliaq crew and science team stabilizing the buoy on deck (Photo credit: Rosalind Echols)|
|Eric Boget from the science team staging the bottom-most instrument, an ADCP, on deck (Photo credit: Rosalind Echols)|
|Preparing a CTD for deployment, with stabilizing tie-line at the ready (Photo credit: Rosalind Echols)|
This particular buoy is designed to drift along with subsurface currents, unlike the moored buoys that are used to gather long time series at a specific location. In order to accomplish this drifting, the buoy has a series of plastic vanes or “X-wings” suspended roughly 60 meters below it, that create substantial drag on the subsurface chain. (A longstanding engineering challenging in oceanography is achieving a design for drifters that will allow them to follow a parcel of water; this particular design seems to work pretty well). Right now, it has been drifting along following a group of floats we deployed at about the same time, which is the best situation we could hope for.
|X-wings hanging from the crane during deployment (Photo credit: Rosalind Echols)|
|Successfully deployed buoy drifting away! (Photo credit: Rosalind Echols)|