On the Nature of the Mesoscale Variability in Denmark StraitSource: Journal of Physical Oceanography:;2017:;Volume( 047 ):;issue: 003::page 567Author:Appen, Wilken-Jon von
,
Mastropole, Dana
,
Pickart, Robert S.
,
Valdimarsson, HéÐinn
,
Jónsson, Steingrímur
,
Girton, James B.
DOI: 10.1175/JPO-D-16-0127.1Publisher: American Meteorological Society
Abstract: ime series data from a mooring in the center of Denmark Strait and a collection of shipboard hydrographic sections occupied across the sill are used to elucidate the mesoscale variability of the dense overflow water in the strait. Two dominant, reoccurring features are identified that are referred to as a bolus and a pulse. A bolus is a large, weakly stratified lens of overflow water associated with cyclonic rotation and a modest increase in along-stream speed of 0.1 m s?1. When a bolus passes through the strait the interface height of the overflow layer increases by 60 m, and the bottom temperature decreases by 0.4°C. By contrast, a pulse is characterized by anticyclonic rotation, a strong increase in along-stream speed of >0.25 m s?1, a decrease in interface height of 90 m, and no significant bottom temperature signal. It is estimated that, on average, boluses (pulses) pass through the strait every 3.4 (5.4) days with no seasonal signal to their frequency. Both features have the strongest along-stream signal in the overflow layer, while the strongest cross-stream velocities occur above the Denmark Strait overflow water (DSOW). In this sense neither feature can be characterized as a simple propagating eddy. Their dynamics appear to be similar to that ascribed to the mesoscale variability observed downstream in the deep western boundary current. Strong correlation of bottom temperatures between the mooring in Denmark Strait and a downstream array, together with a match in the frequency of occurrence of features at both locations, suggests a causal relationship between the mesoscale variability at the sill and that farther downstream.
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contributor author | Appen, Wilken-Jon von | |
contributor author | Mastropole, Dana | |
contributor author | Pickart, Robert S. | |
contributor author | Valdimarsson, HéÐinn | |
contributor author | Jónsson, Steingrímur | |
contributor author | Girton, James B. | |
date accessioned | 2017-06-09T17:22:14Z | |
date available | 2017-06-09T17:22:14Z | |
date copyright | 2017/03/01 | |
date issued | 2017 | |
identifier issn | 0022-3670 | |
identifier other | ams-83960.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4227242 | |
description abstract | ime series data from a mooring in the center of Denmark Strait and a collection of shipboard hydrographic sections occupied across the sill are used to elucidate the mesoscale variability of the dense overflow water in the strait. Two dominant, reoccurring features are identified that are referred to as a bolus and a pulse. A bolus is a large, weakly stratified lens of overflow water associated with cyclonic rotation and a modest increase in along-stream speed of 0.1 m s?1. When a bolus passes through the strait the interface height of the overflow layer increases by 60 m, and the bottom temperature decreases by 0.4°C. By contrast, a pulse is characterized by anticyclonic rotation, a strong increase in along-stream speed of >0.25 m s?1, a decrease in interface height of 90 m, and no significant bottom temperature signal. It is estimated that, on average, boluses (pulses) pass through the strait every 3.4 (5.4) days with no seasonal signal to their frequency. Both features have the strongest along-stream signal in the overflow layer, while the strongest cross-stream velocities occur above the Denmark Strait overflow water (DSOW). In this sense neither feature can be characterized as a simple propagating eddy. Their dynamics appear to be similar to that ascribed to the mesoscale variability observed downstream in the deep western boundary current. Strong correlation of bottom temperatures between the mooring in Denmark Strait and a downstream array, together with a match in the frequency of occurrence of features at both locations, suggests a causal relationship between the mesoscale variability at the sill and that farther downstream. | |
publisher | American Meteorological Society | |
title | On the Nature of the Mesoscale Variability in Denmark Strait | |
type | Journal Paper | |
journal volume | 47 | |
journal issue | 3 | |
journal title | Journal of Physical Oceanography | |
identifier doi | 10.1175/JPO-D-16-0127.1 | |
journal fristpage | 567 | |
journal lastpage | 582 | |
tree | Journal of Physical Oceanography:;2017:;Volume( 047 ):;issue: 003 | |
contenttype | Fulltext |