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A Rossby Wave Bridge from the Tropical Atlantic to West Antarctica

Title
A Rossby Wave Bridge from the Tropical Atlantic to West Antarctica
Authors
Li, XichenGerber, Edwin P.Holland, David M.Yoo, Changhyun
Ewha Authors
유창현
SCOPUS Author ID
유창현scopus
Issue Date
2015
Journal Title
JOURNAL OF CLIMATE
ISSN
0894-8755JCR Link

1520-0442JCR Link
Citation
JOURNAL OF CLIMATE vol. 28, no. 6, pp. 2256 - 2273
Publisher
AMER METEOROLOGICAL SOC
Indexed
SCIE; SCOPUS WOS
Document Type
Article
Abstract
Tropical Atlantic sea surface temperature changes have recently been linked to circulation anomalies around Antarctica during austral winter. Warming in the tropical Atlantic associated with the Atlantic multidecadal oscillation forces a positive response in the southern annular mode, strengthening the Amundsen-Bellingshausen Sea low in particular. In this study, observational and reanalysis datasets and a hierarchy of atmospheric models are used to assess the seasonality and dynamical mechanism of this teleconnection. Both the reanalyses and models reveal a robust link between tropical Atlantic SSTs and the Amundsen-Bellingshausen Sea low in all seasons except austral summer. A Rossby wave mechanism is then shown to both explain the teleconnection and its seasonality. The mechanism involves both changes in the excitation of Rossby wave activity with season and the formation of a Rossby wave guide across the Pacific, which depends critically on the strength and extension of the subtropical jet over the west Pacific. Strong anticyclonic curvature on the poleward flank of the jet creates a reflecting surface, channeling quasi-stationary Rossby waves from the subtropical Atlantic to the Amundsen-Bellingshausen Sea region. In summer, however, the jet is weaker than in other seasons and no longer able to keep Rossby wave activity trapped in the Southern Hemisphere. The mechanism is supported by integrations with a comprehensive atmospheric model, initial-value calculations with a primitive equation model on the sphere, and Rossby wave ray tracing analysis.
DOI
10.1175/JCLI-D-14-00450.1
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일반대학원 > 대기과학공학과 > Journal papers
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