• Bracegirdle, T. J., , and G. J. Marshall, 2012: The reliability of Antarctic tropospheric pressure and temperature in the latest global reanalyses. J. Climate, 25, 71387146, doi:10.1175/JCLI-D-11-00685.1.

    • Search Google Scholar
    • Export Citation
  • Bromwich, D. H., , J. P. Nicolas, , and A. J. Monaghan, 2011: An assessment of precipitation changes over Antarctica and the Southern Ocean since 1989 in contemporary global reanalyses. J. Climate, 24, 41894209, doi:10.1175/2011JCLI4074.1.

    • Search Google Scholar
    • Export Citation
  • Bromwich, D. H., , J. P. Nicolas, , A. J. Monaghan, , M. A. Lazzara, , L. M. Keller, , G. A. Weidner, , and A. B. Wilson, 2013: Central West Antarctica among the most rapidly warming regions on Earth. Nat. Geosci., 6, 139145, doi:10.1038/ngeo1671; Corrigendum, 7, 76, doi:10.1038/ngeo2016.

    • Search Google Scholar
    • Export Citation
  • Chapman, W. L., , and J. E. Walsh, 2007: A synthesis of Antarctic temperatures. J. Climate, 20, 40964117, doi:10.1175/JCLI4236.1.

  • Clem, K. R., , and R. L. Fogt, 2013: Varying roles of ENSO and SAM on the Antarctic Peninsula climate in austral spring. J. Geophys. Res. Atmos., 118, 11 48111 492, doi:10.1002/jgrd.50860.

    • Search Google Scholar
    • Export Citation
  • Clem, K. R., , and R. L. Fogt, 2015: South Pacific circulation changes and their connection to the tropics and regional Antarctic warming in austral spring, 1979–2012. J. Geophys. Res. Atmos., 120, 27732792, doi:10.1002/2014JD022940.

    • Search Google Scholar
    • Export Citation
  • Dee, D. P., and et al. , 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quart. J. Roy. Meteor. Soc., 137, 553597, doi:10.1002/qj.828.

    • Search Google Scholar
    • Export Citation
  • Ding, Q., , and E. J. Steig, 2013: Temperature change on the Antarctic Peninsula linked to the tropical Pacific. J. Climate, 26, 75707585, doi:10.1175/JCLI-D-12-00729.1.

    • Search Google Scholar
    • Export Citation
  • Fogt, R. L., , A. J. Wovrosh, , R. A. Langen, , and I. Simmonds, 2012: The characteristic variability and connection to the underlying synoptic activity of the Amundsen-Bellingshausen Seas low. J. Geophys. Res., 117, D07111, doi:10.1029/2011JD017337.

    • Search Google Scholar
    • Export Citation
  • Folland, C. K., , J. A. Renwick, , M. J. Salinger, , and A. B. Mullan, 2002: Relative influences of the interdecadal Pacific oscillation and ENSO on the South Pacific convergence zone. Geophys. Res. Lett., 29, doi:10.1029/2001GL014201.

    • Search Google Scholar
    • Export Citation
  • Garreaud, R., , and D. S. Battisti, 1999: Interannual (ENSO) and interdecadal (ENSO-like) variability in the Southern Hemisphere tropospheric circulation. J. Climate, 12, 21132123, doi:10.1175/1520-0442(1999)012<2113:IEAIEL>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Holland, P. R., 2014: The seasonality of Antarctic sea ice trends. Geophys. Res. Lett., 41, 42304237, doi:10.1002/2014GL060172.

  • Holland, P. R., , and R. Kwok, 2012: Wind-driven trends in Antarctic sea-ice drift. Nat. Geosci., 5, 872875, doi:10.1038/ngeo1627.

  • Hosking, J. S., , A. Orr, , G. J. Marshall, , J. Turner, , and T. Phillips, 2013: The influence of the Amundsen–Bellingshausen Seas low on the climate of West Antarctica and its representation in coupled climate model simulations. J. Climate, 26, 66336648, doi:10.1175/JCLI-D-12-00813.1.

    • Search Google Scholar
    • Export Citation
  • Kidson, J. W., 1999: Principal modes of Southern Hemisphere low-frequency variability obtained from NCEP–NCAR reanalyses. J. Climate, 12, 28082830, doi:10.1175/1520-0442(1999)012<2808:PMOSHL>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Kiladis, G. N., , H. von Storch, , and H. van Loon, 1989: Origin of the South Pacific convergence zone. J. Climate, 2, 11851195, doi:10.1175/1520-0442(1989)002<1185:OOTSPC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • L’Heureux, M. L., , and D. W. J. Thompson, 2006: Observed relationships between the El Niño–Southern Oscillation and the extratropical zonal-mean circulation. J. Climate, 19, 276287, doi:10.1175/JCLI3617.1.

    • Search Google Scholar
    • Export Citation
  • Liebmann, B., , and C. A. Smith, 1996: Description of a complete (interpolated) outgoing longwave radiation dataset. Bull. Amer. Meteor. Soc., 77, 12751277.

    • Search Google Scholar
    • Export Citation
  • Mantua, N. J., , S. R. Hare, , Y. Zhang, , J. M. Wallace, , and R. C. Francis, 1997: A Pacific interdecadal climate oscillation with impacts on salmon production. Bull. Amer. Meteor. Soc., 78, 10691079, doi:10.1175/1520-0477(1997)078<1069:APICOW>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Mo, K. C., , and R. W. Higgins, 1998: The Pacific–South American modes and tropical convection during the Southern Hemisphere winter. Mon. Wea. Rev., 126, 15811596, doi:10.1175/1520-0493(1998)126<1581:TPSAMA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Mo, K. C., , and J. N. Paegle, 2001: The Pacific–South American modes and their downstream effects. Int. J. Climatol., 21, 12111229, doi:10.1002/joc.685.

    • Search Google Scholar
    • Export Citation
  • Nicolas, J. P., , and D. H. Bromwich, 2011: Climate of West Antarctica and influence of marine air intrusions. J. Climate, 24, 4967, doi:10.1175/2010JCLI3522.1.

    • Search Google Scholar
    • Export Citation
  • Nicolas, J. P., , and D. H. Bromwich, 2014: New reconstruction of Antarctic near-surface temperatures: Multidecadal trends and reliability of global reanalyses. J. Climate, 27, 80708093, doi:10.1175/JCLI-D-13-00733.1.

    • Search Google Scholar
    • Export Citation
  • O’Donnell, R., , N. Lewis, , S. McIntyre, , and J. Condon, 2011: Improved methods for PCA-based reconstructions: Case study using the Steig et al. (2009) Antarctic temperature reconstruction. J. Climate, 24, 20992115, doi:10.1175/2010JCLI3656.1.

    • Search Google Scholar
    • Export Citation
  • Rayner, N. A., , D. E. Parker, , E. B. Horton, , C. K. Folland, , L. V. Alexander, , D. P. Rowell, , E. C. Kent, , and A. Kaplan, 2003: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res., 108, 4407, doi:10.1029/2002JD002670.

    • Search Google Scholar
    • Export Citation
  • Schneider, D. P., , C. Deser, , and Y. Okumura, 2012: An assessment and interpretation of the observed warming of West Antarctica in the austral spring. Climate Dyn., 38, 323347, doi:10.1007/s00382-010-0985-x.

    • Search Google Scholar
    • Export Citation
  • Seager, R., , N. Harnik, , Y. Kushnir, , W. Robinson, , and J. Miller, 2003: Mechanisms of hemispherically symmetric climate variability. J. Climate, 16, 29602978, doi:10.1175/1520-0442(2003)016<2960:MOHSCV>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Steig, E. J., , D. P. Schneider, , S. D. Rutherford, , M. E. Mann, , J. C. Comiso, , and D. T. Shindell, 2009: Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year. Nature, 457, 459462, doi:10.1038/nature07669.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., 1991: General characteristics of El Niño–Southern Oscillation. Teleconnections Linking Worldwide Climate Anomalies, M. Glantz, R. W. Katz, and N. Nicholls, Eds., Cambridge University Press, 13–41.

  • Turner, J., and et al. , 2004: The SCAR READER Project: Toward a high-quality database of mean Antarctic meteorological observations. J. Climate, 17, 28902898, doi:10.1175/1520-0442(2004)017<2890:TSRPTA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Turner, J., and et al. , 2005: Antarctic climate change during the last 50 years. Int. J. Climatol., 25, 279294, doi:10.1002/joc.1130.

    • Search Google Scholar
    • Export Citation
  • Turner, J., , T. Phillips, , J. S. Hosking, , G. J. Marshall, , and A. Orr, 2013: The Amundsen Sea low. Int. J. Climatol., 33, 18181829, doi:10.1002/joc.3558.

    • Search Google Scholar
    • Export Citation
  • Vincent, D. G., 1994: The South Pacific convergence zone (SPCZ): A review. Mon. Wea. Rev., 122, 19491970, doi:10.1175/1520-0493(1994)122<1949:TSPCZA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Widlansky, M., , P. Webster, , and C. Hoyos, 2011: On the location and orientation of the South Pacific convergence zone. Climate Dyn., 36, 561578, doi:10.1007/s00382-010-0871-6.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 162 162 20
PDF Downloads 98 98 10

Austral Spring Southern Hemisphere Circulation and Temperature Changes and Links to the SPCZ

View More View Less
  • 1 School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
© Get Permissions
Restricted access

Abstract

Significant austral spring trends have previously been observed in West Antarctica and Antarctic Peninsula temperatures and in atmospheric circulation across the southern Pacific and Atlantic. Here, physical mechanisms for the observed trends are investigated through analysis of monthly circulation and temperatures from the ERA-Interim dataset and outgoing longwave radiation (OLR) data. The negative pressure trend over the South Pacific during spring is strongest in September, while the positive pressure trend over the South Atlantic is strongest in October. Pressure trends in November are generally nonsignificant. The authors demonstrate that a significant September trend toward increased convection (reduced OLR) in the poleward portion of the South Pacific convergence zone (SPCZ) is statistically related to Rossby wave–like circulation changes across the southern oceans. The wave response is strongest over the South Pacific in September and propagates eastward to the South Atlantic in October. OLR-related changes are linearly congruent with around half of the observed total changes in circulation during September and October and are consistent with observed trends in South Pacific sea ice concentration and surface temperature over western West Antarctica and the western Antarctic Peninsula. These results suggest SPCZ variability in early spring, especially on the poleward side of the SPCZ, is an important contributor to circulation and surface temperature trends across the South Pacific/Atlantic and West Antarctica.

Corresponding author address: Kyle R. Clem, School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Cotton Building, Room 311, Wellington 6140, New Zealand. E-mail: kyle.clem@vuw.ac.nz

This article is included in the Connecting the Tropics to the Polar Regions Special Collection.

Abstract

Significant austral spring trends have previously been observed in West Antarctica and Antarctic Peninsula temperatures and in atmospheric circulation across the southern Pacific and Atlantic. Here, physical mechanisms for the observed trends are investigated through analysis of monthly circulation and temperatures from the ERA-Interim dataset and outgoing longwave radiation (OLR) data. The negative pressure trend over the South Pacific during spring is strongest in September, while the positive pressure trend over the South Atlantic is strongest in October. Pressure trends in November are generally nonsignificant. The authors demonstrate that a significant September trend toward increased convection (reduced OLR) in the poleward portion of the South Pacific convergence zone (SPCZ) is statistically related to Rossby wave–like circulation changes across the southern oceans. The wave response is strongest over the South Pacific in September and propagates eastward to the South Atlantic in October. OLR-related changes are linearly congruent with around half of the observed total changes in circulation during September and October and are consistent with observed trends in South Pacific sea ice concentration and surface temperature over western West Antarctica and the western Antarctic Peninsula. These results suggest SPCZ variability in early spring, especially on the poleward side of the SPCZ, is an important contributor to circulation and surface temperature trends across the South Pacific/Atlantic and West Antarctica.

Corresponding author address: Kyle R. Clem, School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Cotton Building, Room 311, Wellington 6140, New Zealand. E-mail: kyle.clem@vuw.ac.nz

This article is included in the Connecting the Tropics to the Polar Regions Special Collection.

Save