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Qigang Wu and Xiangdong Zhang

sea surface temperature (SST) in the extratropics have a profound effect on the southern annular mode [SAM, also called Antarctic Oscillation (AAO); Thompson and Wallace 1998 ] ( Watterson 2001 ; Marshall and Connolley 2006 ; Sen Gupta and England 2007 ). Sea ice is also an active component in the climate system. Not only is it sensitive to dynamic and thermodynamic forcings from overlying atmosphere and underlying ocean, it also modulates atmospheric and oceanic circulations through altered

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B. Pohl, N. Fauchereau, C. J. C. Reason, and M. Rouault

1. Introduction The Antarctic Oscillation (AAO) ( Rogers and van Loon 1982 ; Thompson and Wallace 2000 ), also called the southern annular mode (SAM), is the leading mode of atmospheric low-frequency variability south of 20°S. It basically consists of a seesaw in atmospheric pressure between the Antarctic region and the southern midlatitudes. In the positive phase of the AAO, anomalous low (high) pressure occurs over Antarctica (the midlatitudes of the Southern Hemisphere). The midlatitude

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Chundi Hu, Qigang Wu, Song Yang, Yonghong Yao, Duo Chan, Zhenning Li, and Kaiqiang Deng

1. Introduction There is a growing effort to predict the atmospheric circulation on seasonal-to-interannual time scales related to extratropical ocean–atmosphere interaction [see review by Kushnir et al. (2002) ]. In the Southern Hemisphere (SH), the Antarctic Oscillation (AAO, also called the southern annular mode; Gong and Wang 1999 ) is the leading mode of the empirical orthogonal function (EOF) analysis based on the month-to-month sea level pressure (SLP) or geopotential height south of

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D. Cerrone, G. Fusco, I. Simmonds, G. Aulicino, and G. Budillon

resulting in thinner sea ice near the coast and thicker ice near the edge, and vice versa in negative phases of the SAM. Lefebvre et al. (2004) argued that the sea ice responds to SAM oscillations as of out-of-phase concentrations in the Ross and Weddell Seas, rather than a zonally symmetric response. Liu et al. (2004) pointed out that the observed SAM index trend could not explain the total trend in Antarctic sea ice of the Amundsen–Bellingshausen and Weddell Seas, and Yuan and Li (2008) remarked

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Maria Flatau and Young-Joon Kim

) was noted by Miller et al. (2003) , who found that positive AO months were associated with the MJO convection concentrated in the Indian Ocean. The opposite was true for the negative AO. In the Southern Hemisphere (SH), the influence of Antarctic Oscillation (AAO) was limited to the polar regions. Zhou and Miller (2005) showed that the MJO influences the AO through the Rossby wave dispersion in the Pacific. L’Heureux and Higgins (2008) related the eastward progression of the MJO to the

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Kyle R. Clem, James A. Renwick, and James McGregor

the two leading modes of Southern Hemisphere atmospheric circulation: the southern annular mode (SAM) and El Niño–Southern Oscillation (ENSO). Our approach builds on previous work and aims to place recent Antarctic SAT change in a longer and seasonal context. Another goal of this study, which has not been previously explored, is to examine the influence of sea ice concentration anomalies and their connection to the ASL and the seasonal SAT patterns. Previous studies have linked patterns of

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Julie M. Jones and Martin Widmann

Hemisphere extratropical circulation, the Antarctic Oscillation (AAO). The AAO, which has also been termed the “Southern Annular Mode” ( Thompson and Wallace 2000 ), is a zonally symmetric mode representing exchange of mass between the midlatitudes near 45°S and high latitudes poleward of 60°S, and characterizes fluctuations in the strength of the circumpolar vortex. This mode has been found to be present at various atmospheric levels ( von Storch 1999 ), for example, SLP ( Gong and Wang 1999 ; Rogers

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Kwesi A. Quagraine, Bruce Hewitson, Christopher Jack, Izidine Pinto, and Christopher Lennard

phenomenon is in the El Niño (La Niña) phase; however, the regional response to ENSO is varied both spatially, and under different ENSO events. There have been a number of notable exceptions where strong El Niño has occurred with little or no regional rainfall response (see Lyon and Mason 2007 ). Another teleconnective feature is the Antarctic Oscillation (AAO), which is known to affect variability in midlatitude circulations that have direct influence on precipitation and temperature over the region

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Lana Cohen, Sam Dean, and James Renwick

grounding-line retreat of the West Antarctic Ice Sheet . Science , 286 , 280 – 283 . Cullather , R. I. , D. H. Bromwich , and M. L. Van Woert , 1996 : Interannual variations in Antarctic precipitation related to El Niño-Southern Oscillation . J. Geophys. Res. , 101 , 19 109 – 19 118 . Cullather , R. I. , D. H. Bromwich , and M. L. Van Woert , 1998 : Spatial and temporal variability of Antarctic precipitation from atmospheric methods . J. Climate , 11 , 334 – 367 . Fogt , R. L

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Jin-Song von Storch

1. Introduction Thompson and Wallace (1998 , 2000) found that the primary modes of the geopotential height field in each hemisphere are remarkably similar. Both modes, referred to as the Antarctic and the Arctic Oscillations (AAO and AO), are related to meridional dipoles in zonal-mean zonal wind field and to seesaws in atmospheric mass in the polar regions and the low-latitude zonal rings. While the similarity between the primary modes in the two hemispheres became more apparent in the

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