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Rossby waves mediate impacts of tropical oceans on west Antarctic atmospheric circulation in austral winter

Title
Rossby waves mediate impacts of tropical oceans on west Antarctic atmospheric circulation in austral winter
Authors
LiX.HollandD.M.GerberE.P.YooC.
Ewha Authors
유창현
SCOPUS Author ID
유창현scopus
Issue Date
2015
Journal Title
Journal of Climate
ISSN
0894-8755JCR Link
Citation
vol. 28, no. 20, pp. 8151 - 8164
Keywords
Atm/Ocean Structure/PhenomenaAtmosphere-ocean interactionAtmosphericCirculation/DynamicsDecadal variabilityPolar lowsRossby wavesTeleconnectionsVariabilityWaves
Publisher
American Meteorological Society
Indexed
SCI; SCIE; SCOPUS WOS scopus
Abstract
Recent studies link climate change around Antarctica to the sea surface temperature of tropical oceans, with teleconnections from the Pacific, Atlantic, and Indian Oceans making different contributions to Antarctic climate. In this study, the impacts of each ocean basin on the wintertime Southern Hemisphere circulation are identified by comparing simulation results using a comprehensive atmospheric model, an idealized dynamical core model, and a theoretical Rossby wave model. The results herein show that tropical Atlantic Ocean warming, Indian Ocean warming, and eastern Pacific cooling are all able to deepen the Amundsen Sea low located adjacent to West Antarctica, while western Pacific warming increases the pressure to the west of the international date line, encompassing the Ross Sea and regions south of the Tasman Sea. In austral winter, these tropical ocean basins work together linearly to modulate the atmospheric circulation around West Antarctica. Further analyses indicate that these teleconnections critically depend on stationary Rossby wave dynamics and are thus sensitive to the background flow, particularly the subtropical/midlatitude jet. Near these jets, wind shear is amplified, which strengthens the generation of Rossby waves. On the other hand, near the edges of the jets the meridional gradient of the absolute vorticity is also enhanced. As a consequence of the Rossby wave dispersion relationship, the jet edge may reflect stationary Rossby wave trains, serving as a waveguide. The simulation results not only identify the relative roles of each of the tropical ocean basins in the tropical-Antarctica teleconnection, but also suggest that a deeper understanding of teleconnections requires a better estimation of the atmospheric jet structures. © 2015 American Meteorological Society.
DOI
10.1175/JCLI-D-15-0113.1
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일반대학원 > 대기과학공학과 > Journal papers
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