Mesoscale forcing on ocean waves during Gulf Stream North Wall events

Approved for public release; distribution is unlimited === Under meteorological conditions associated with extreme cold air outbreaks (CAO) off the U.S. East Coast, large ocean waves sometimes develop along the North Wall of the Gulf Stream. These wave events produce wave heights above those expecte...

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Bibliographic Details
Main Author: Okon, John A.
Other Authors: Nuss, Wendell A.
Format: Others
Published: Monterey, California. Naval Postgraduate School 2012
Subjects:
Online Access:http://hdl.handle.net/10945/1077
Description
Summary:Approved for public release; distribution is unlimited === Under meteorological conditions associated with extreme cold air outbreaks (CAO) off the U.S. East Coast, large ocean waves sometimes develop along the North Wall of the Gulf Stream. These wave events produce wave heights above those expected given the short fetch and moderate winds. The highest waves are often very localized, which suggests localized forcing by the atmosphere. In this study, results from four cases are examined to characterize the role of high resolution, mesoscale wind forcing in generating localized regions of large ocean waves during events with large air-sea temperature differences. A known "true" atmosphere is simulated through the use of the Navy's Coupled Oceanographic and Atmospheric Mesoscale Prediction System (COAMPS). Model surface wind output from COAMPS is used to generate a wave field using Wavewatch Three (WW3), which is then compared to buoy observations and ship reports. Results of these cases show the mesoscale wind forcing of ocean waves during CAO and the importance of mesoscale atmospheric modeling in localized generation of ocean wind waves. Additionally, empirical wave forecast techniques are compared to WW3 model output for these cases to further reinforce the mesoscale atmospheric forcing during rapid growth of wind wave events in fetch limited environments. === Lieutenant Commander, United States Navy