Publication:
Using potential vorticity to characterize the forcing of a coastally trapped wind reversal along the California coast

Authors
Morris, Christopher M.
Subjects
coastally trapped wind reversal
potential vorticity
PV inversion
coastal meteorology
Advisors
Nuss, Wendell
Date of Issue
2015-03
Date
March 2015
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
Using the Climate Forecast System Reanalysis (CFSR) dataset, the synoptic environment of six historical coastally trapped wind reversals (CTWR) along the California coast is examined. Building on the Mass and Bond climatology of 1996, the study uses potential vorticity (PV) as a proxy for the coastal jet and seeks to characterize the forcing of the CTWRs by analyzing their 950-mb potential vorticity plumes. The study also pursues the ability to separate geostrophically-balanced wind reversals synonymous with synoptic systems from unbalanced wind reversals (CTWRs) by taking advantage of the invertibility of PV and using the inversion technique outlined in the August 1991 issue of Monthly Weather Review by Christopher Davis and Kerry Emanuel. The study then applied the methodology to data from July/August 2012/2013 in order to uncover possible CTWRs. The primary findings of this study are as follows: 1) the potential vorticity maximum generated through the offshore flow of the coastal jet is required to move off shore and establish an across-coast PV gradient in order for a CTWR to form/propagate northward of Point Conception and 2) the Davis Emanuel PV inversion technique yielded mixed results, heavily influenced by diurnal effects and subjected to instability due to topographical interactions.
Type
Thesis
Description
Series/Report No
Department
Meteorology
Meteorology
Other Units
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NPS Report Number
Sponsors
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Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.