The Unpredictable Nature of Internal Tides on Continental ShelvesSource: Journal of Physical Oceanography:;2012:;Volume( 042 ):;issue: 011::page 1981Author:Nash, Jonathan D.
,
Kelly, Samuel M.
,
Shroyer, Emily L.
,
Moum, James N.
,
Duda, Timothy F.
DOI: 10.1175/JPO-D-12-028.1Publisher: American Meteorological Society
Abstract: ackets of nonlinear internal waves (NLIWs) in a small area of the Mid-Atlantic Bight were 10 times more energetic during a local neap tide than during the preceding spring tide. This counterintuitive result cannot be explained if the waves are generated near the shelf break by the local barotropic tide since changes in shelfbreak stratification explain only a small fraction of the variability in barotropic to baroclinic conversion. Instead, this study suggests that the occurrence of strong NLIWs was caused by the shoaling of distantly generated internal tides with amplitudes that are uncorrelated with the local spring-neap cycle. An extensive set of moored observations show that NLIWs are correlated with the internal tide but uncorrelated with barotropic tide. Using harmonic analysis of a 40-day record, this study associates steady-phase motions at the shelf break with waves generated by the local barotropic tide and variable-phase motions with the shoaling of distantly generated internal tides. The dual sources of internal tide energy (local or remote) mean that shelf internal tides and NLIWs will be predictable with a local model only if the locally generated internal tides are significantly stronger than shoaling internal tides. Since the depth-integrated internal tide energy in the open ocean can greatly exceed that on the shelf, it is likely that shoaling internal tides control the energetics on shelves that are directly exposed to the open ocean.
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contributor author | Nash, Jonathan D. | |
contributor author | Kelly, Samuel M. | |
contributor author | Shroyer, Emily L. | |
contributor author | Moum, James N. | |
contributor author | Duda, Timothy F. | |
date accessioned | 2017-06-09T17:19:49Z | |
date available | 2017-06-09T17:19:49Z | |
date copyright | 2012/11/01 | |
date issued | 2012 | |
identifier issn | 0022-3670 | |
identifier other | ams-83294.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4226503 | |
description abstract | ackets of nonlinear internal waves (NLIWs) in a small area of the Mid-Atlantic Bight were 10 times more energetic during a local neap tide than during the preceding spring tide. This counterintuitive result cannot be explained if the waves are generated near the shelf break by the local barotropic tide since changes in shelfbreak stratification explain only a small fraction of the variability in barotropic to baroclinic conversion. Instead, this study suggests that the occurrence of strong NLIWs was caused by the shoaling of distantly generated internal tides with amplitudes that are uncorrelated with the local spring-neap cycle. An extensive set of moored observations show that NLIWs are correlated with the internal tide but uncorrelated with barotropic tide. Using harmonic analysis of a 40-day record, this study associates steady-phase motions at the shelf break with waves generated by the local barotropic tide and variable-phase motions with the shoaling of distantly generated internal tides. The dual sources of internal tide energy (local or remote) mean that shelf internal tides and NLIWs will be predictable with a local model only if the locally generated internal tides are significantly stronger than shoaling internal tides. Since the depth-integrated internal tide energy in the open ocean can greatly exceed that on the shelf, it is likely that shoaling internal tides control the energetics on shelves that are directly exposed to the open ocean. | |
publisher | American Meteorological Society | |
title | The Unpredictable Nature of Internal Tides on Continental Shelves | |
type | Journal Paper | |
journal volume | 42 | |
journal issue | 11 | |
journal title | Journal of Physical Oceanography | |
identifier doi | 10.1175/JPO-D-12-028.1 | |
journal fristpage | 1981 | |
journal lastpage | 2000 | |
tree | Journal of Physical Oceanography:;2012:;Volume( 042 ):;issue: 011 | |
contenttype | Fulltext |