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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
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
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
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
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
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
sector and Atlantic sector, called the Antarctic dipole (ADP; Yuan and Martinson 2001 ). Previous studies have linked the ADP with individual modes of large-scale climate variability like the Southern Annular Mode (SAM), El Niño–Southern Oscillation (ENSO), wavenumber-3 pattern, and semiannual oscillation, among which SAM and ENSO are the primary drivers ( Liu et al. 2004 ; Simpkins et al. 2012 ; Maksym 2019 ). The positive phase of the SAM is characterized by an “annular” structure with a deep
sector and Atlantic sector, called the Antarctic dipole (ADP; Yuan and Martinson 2001 ). Previous studies have linked the ADP with individual modes of large-scale climate variability like the Southern Annular Mode (SAM), El Niño–Southern Oscillation (ENSO), wavenumber-3 pattern, and semiannual oscillation, among which SAM and ENSO are the primary drivers ( Liu et al. 2004 ; Simpkins et al. 2012 ; Maksym 2019 ). The positive phase of the SAM is characterized by an “annular” structure with a deep
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
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
) 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
) 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
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
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
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
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
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
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
variability, including sea level, and its barotropic response is a dominant feature south of 50°S over a broad range of periods from a few days to one year ( Vivier et al. 2005 ). In the Southern Ocean, the variation of wind stress affects sea level over a broad range of periods, from a few days to century time scales. The dominant atmospheric mode in the Southern Hemisphere is the Antarctic Oscillation [AAO; also known as the southern annular mode (SAM)] ( Thompson and Wallace 2000 ), which is
variability, including sea level, and its barotropic response is a dominant feature south of 50°S over a broad range of periods from a few days to one year ( Vivier et al. 2005 ). In the Southern Ocean, the variation of wind stress affects sea level over a broad range of periods, from a few days to century time scales. The dominant atmospheric mode in the Southern Hemisphere is the Antarctic Oscillation [AAO; also known as the southern annular mode (SAM)] ( Thompson and Wallace 2000 ), which is
