Coastal Mixing and Optics
| Coastal Mixing and Optics was a project done in conjunction with Woods Hole Oceanographic Institute on the coastal shelf south of Martha's Vineyard, MA. Several long cruises took place in which a large patch of dye was deployed into the water and mapped using optical techniques (these cruises took place during the summers of 1996 and 1997). An ADCP was also used to look at the velocity field, together providing a coherent picture of where the water was moving. The cruise that took place during the summer of 1996 followed closely after the departure a hurricaine (Eduard). Resulting from the hurricaine was a large jet of cold water that meandered along the shelf (though roughly following the local isobaths). Below, can be seen the path of the ship following the dye patch, and the velocity profiles that were observed. |
The cruise, lasting from September 5 to 16, 1996 is most easily understood by breaking it up into smaller chunks (temporally-- and effectively spatially as well). The colored dots come from bottom depth measurements taken from the ADCP, and they are plotted over the bathymetry lines (those which fall within the range of 60-80 m). We will continue by breaking the data up further.
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To track the movement of the jet feature, observe the overall speed during each of four lattitude runs (where there is little change in longitude). Notice the peak in the speed and how it moves with the passage of time. During most of the cruise, it is hovering around 40.4 to 40.6 N, then it starts to drift some (though the drift may be due in part to the significant range in bathymetry at a given latitude).
Harvey Seim <harvey_seim@unc.edu>