Publication:
Influence of Antarctic oscillation on intraseasonal variability of large-scale circulations over the Western North Pacific

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Authors
Burton, Kenneth R., Jr.
Subjects
Antarctic oscillation
Rossby wave dispersion
Large scale tropical circulations
Intraseasonal variability
Advisors
Harr, Patrick A.
Date of Issue
2005-03
Date
March 2005
Publisher
Monterey California. Naval Postgraduate School
Language
Abstract
This study examines Southern Hemisphere mid-latitude wave variations connected to the Antarctic Oscillation (AAO) to establish connections with the 15- to 25-day wave activity in the western North Pacific monsoon trough region. The AAO index defined from the leading empirical orthogonal functions of 700 hPa height anomalies led to seven distinct circulation patterns that vary in conjunction with the 15- to 25-day monsoon trough mode. For nearly one half of the significant events the onset of 15- to 25-day monsoon trough convective activity coincided with a peak negative AAO index and the peak in monsoon trough convection coincided with a peak positive index. The remaining events either occur when the AAO is not significantly varying or when the AAO-related Southern Hemisphere mid-latitude circulations do not match 15- to 25-day transitions. When a significant connection occurs between the Southern Hemisphere mid-latitude circulations related to the AAO and the 15- to 25-day wave activity in the western North Pacific monsoon trough, the mechanism is via equatorward Rossby-wave dispersion. When wave energy flux in the Southern Hemisphere is directed zonally, no connection is established between the AAO and the alternating periods of enhanced and reduced convection in the western North Pacific monsoon trough.
Type
Thesis
Description
Series/Report No
Department
Department of Meteorology
Other Units
Naval Postgraduate School (U.S.).
Identifiers
NPS Report Number
Sponsors
Funder
Format
xviii, 93 p. : ill. (some col.)
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.
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