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An assessment of multiple westward propagating signals in sea level anomalies
Citation
Maharaj, AM and Holbrook, NJ and Cipollini, P, An assessment of multiple westward propagating signals in sea level anomalies, Journal of Geophysical Research - Oceans, 114, (C12016) pp. 1-14. ISSN 0148-0227 (2009) [Refereed Article]
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Copyright Statement
Copyright 2009 by the American Geophysical Union.
Official URL: http://www.agu.org/journals/jc/
Abstract
The characteristics of multiple westward propagating signals in the satellite observed
South Pacific sea level anomalies (SLA) between 10S and 50S are analyzed using the
two-dimensional Radon transform (2D-RT). We test the hypothesis that these signals are
most likely to be the signature of the first few baroclinic Rossby wave modes. This
involves a comparison of the estimated phase speeds of the 2D-RT peaks against the first
four baroclinic mode Rossby wave speeds predicted from the extended theory. The 2D-RT
analysis typically identified up to three propagating signals in the SLA and very
occasionally, a fourth. The first Radon transform (RT) peak phase speeds corresponded
very well with first baroclinic mode Rossby wave phase speed estimates from linear
theory between 15S and 25S and the extended theory phase speed estimates poleward of
25S. RT peak 2 speeds were less coherent but fell within the range of extended theory
estimates of the first four baroclinic Rossby wave modes, consistent with large-scale
Rossby wave dynamics. The relationship between peaks 3 and 4 and the extended theory
higher-order baroclinic mode speed estimates varied markedly across the basin. Regional
variability in the spectral characteristics of the peaks suggests that different dynamical
regimes dominate north and south of 30S in the South Pacific basin. The presence of
secondary peaks in the middle to high latitudes suggests that higher-order modes may play
a role in these regions.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | Rossby waves, sea level anomalies, radon transform |
| Research Division: | Earth Sciences |
| Research Group: | Oceanography |
| Research Field: | Physical oceanography |
| Objective Division: | Environmental Management |
| Objective Group: | Marine systems and management |
| Objective Field: | Oceanic processes (excl. in the Antarctic and Southern Ocean) |
| UTAS Author: | Holbrook, NJ (Professor Neil Holbrook) |
| ID Code: | 57371 |
| Year Published: | 2009 |
| Web of Science® Times Cited: | 19 |
| Deposited By: | Geography and Environmental Studies |
| Deposited On: | 2009-07-12 |
| Last Modified: | 2010-04-14 |
| Downloads: | 1 View Download Statistics |
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