Evolution of the Irminger Current anticyclones in the Labrador Sea from hydrographic data
Citable URI
https://hdl.handle.net/1912/1777Location
Labrador SeaDOI
10.1575/1912/1777Keyword
Eddies; HydrographyAbstract
The continuous supply of heat and fresh water from the boundaries to the interior
of the Labrador Sea plays an important role for the dynamics of the region and in
particular, for the Labrador Sea Water formation. Thus, it is necessary to understand
the factors governing the exchange of properties between the boundary and
interior. A significant fraction of heat and fresh water, needed to balance the annual
heat loss and to contribute to the seasonal freshening of the Labrador Sea, is thought
to be provided by coherent long-lived anticyclonic eddies shed by the Irminger Current.
The population, some properties, rates and direction of propagation of these
anomalies are known but the evolution and the mechanism of their decay are still far
from obvious. In this work I investigated their water mass properties and evolution
under the strong wintertime forcing using hydrographic data from 1990-2004 and a
1-dimensional mixed layer model. There were 50 eddies found in the hydrographic
data record, 48 of which were identified as anticyclones. Vertical structure of the eddies
was investigated, leading to the categorization of all the anticyclones into three
classes: 12 - with a fresh surface layer and no mixed layer, 18 - without a fresh layer
and at least one mixed layer, and 18 with ambiguous vertical structure. Four eddies
of the second group appeared to have cores extending to as deep as 1500 m vertically
and an isopycnal displacement of 400-600 m. A number of eddies without a fresh
water cap contained Labrador Sea Water from the previous year at mid-depths.
Description
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2006
Collections
Suggested Citation
Thesis: Rykova, Tatiana A., "Evolution of the Irminger Current anticyclones in the Labrador Sea from hydrographic data", 2006-06, DOI:10.1575/1912/1777, https://hdl.handle.net/1912/1777Related items
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