The circulation in Cape Cod Bay has been analyzed for late August/early September. We plan to complete the analysis up to date and send it on Friday.
Circulation features are more variable than in pre-existing literature and are controlled by a combination of buoyancy forcing and wind events. The most common buoyancy driven circulation flows in from Mass. Bay, around Cape Cod Bay usually as a rim current, and out at Race Point. It may or may not be associated with a closed cyclonic gyre. Wind events occurred and can be expected to occur with either a southerly (from the south) wind component or northerly wind component. The mixed layer at this time is generally less than 10m and there is a classic Ekman response, which yields upwelling from Scituate to Sandwich, in response to southerly winds, and, upwelling from Race Point to Dennis, in response to northerly winds.
After a wind event there is a period of 1 to 4 days during which the circulation can be quite variable as it is dominated both by buoyancy forces and wind responses. We have seen the following occurrences: an anti-cyclonic or unclosed cyclonic Cape Cod Bay gyre, the Mass Bay coastal current shifted off-shore, and a buoyancy surface current flowing to the NW or the SE in the center of Mass Bay (in or out of Cape Cod Bay).
In the buoyancy dominated regime, interesting AUV sub-mesoscale investigations are: inflow, rimflow and outflow to Cape Cod Bay. During wind event responses, the interesting regions are the upwelling regions on either side of Cape Cod Bay. For complex flows, regions need to be identified for specific cases.
In the vertical, the mixed layer is observed from 2 to 10m. The stratification extends typically to 20m. The chlorophyll maximum is located at the base of the mixed layer. There is often an associated zooplankton maximum. The nutricline is generally located below the chlorophyll maximum.
The proposed location of the mooring is: (70.40W, 41.93N), which is approximately on the 40m-isobath midway between Sandwich and Race Point.
There are two rendezvous points. For people coming on, it is as close as possible from Sandwich. For people coming off, it is at the mooring site [see (2) above].
The nominal meeting times are expected to be within:
On: 06:15 - 07:30 Off: 16:00 - 17:00