An Analysis of Near-Surface Winds, Air Temperature, and Cyclone Activity in Terra Nova Bay, Antarctica, from 1993 to 2009

Shelley L. Knuth Cooperative Institute for Research in Environmental Studies and Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado

Search for other papers by Shelley L. Knuth in
Current site
Google Scholar
PubMed
Close
and
John J. Cassano Cooperative Institute for Research in Environmental Studies and Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado

Search for other papers by John J. Cassano in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

In September 2009, the first unmanned aerial vehicles were flown over Terra Nova Bay, Antarctica, to collect information regarding air–sea interactions. Prior to the field season, wind and temperature data from a local automatic weather station (AWS) were collected from 1993 to 2007 and compared with an August–October 2006–08 satellite cyclone analysis to place the September 2009 observations into a broader context. AWS wind data revealed a strong tendency toward downslope flow in the region regardless of season, as the majority (55%) of winds were from the west to northwesterly directions. Most winds observed at the site were less than 20 m s−1, but 83% of the stronger winds were associated with downslope flow. Of 15 strong wind events (greater than 20 m s−1 for more than 10 h) evaluated during the cyclone analysis period, 100% occurred in the presence of a cyclone in the adjacent Ross Sea. Winter experienced the greatest number of strong wind events (68%), and summer had the least (4%). Most temperatures were between −15° and −25°C, with temperatures influenced by wind fluctuations. The cyclone analysis revealed that 64% of systems were comma shaped, and most cyclones (84%) within the Ross Sea were mesocyclones. A comparison of AWS data for Septembers 1993–2007 and September 2009 showed more strong wind events during 2009, while the cyclone analysis revealed a shift in cyclonic activity eastward. Reanalysis data comparing September 1993–2007 and September 2009 show an eastward shift in a deeper upper-level trough, indicating that September 2009 was an anomalous year.

Corresponding author address: Shelley L. Knuth, Cooperative Institute for Research in Environmental Studies and Department of Atmospheric and Oceanic Sciences, University of Colorado, 216 UCB, Boulder, CO 80309. Email: shelley.knuth@colorado.edu

Abstract

In September 2009, the first unmanned aerial vehicles were flown over Terra Nova Bay, Antarctica, to collect information regarding air–sea interactions. Prior to the field season, wind and temperature data from a local automatic weather station (AWS) were collected from 1993 to 2007 and compared with an August–October 2006–08 satellite cyclone analysis to place the September 2009 observations into a broader context. AWS wind data revealed a strong tendency toward downslope flow in the region regardless of season, as the majority (55%) of winds were from the west to northwesterly directions. Most winds observed at the site were less than 20 m s−1, but 83% of the stronger winds were associated with downslope flow. Of 15 strong wind events (greater than 20 m s−1 for more than 10 h) evaluated during the cyclone analysis period, 100% occurred in the presence of a cyclone in the adjacent Ross Sea. Winter experienced the greatest number of strong wind events (68%), and summer had the least (4%). Most temperatures were between −15° and −25°C, with temperatures influenced by wind fluctuations. The cyclone analysis revealed that 64% of systems were comma shaped, and most cyclones (84%) within the Ross Sea were mesocyclones. A comparison of AWS data for Septembers 1993–2007 and September 2009 showed more strong wind events during 2009, while the cyclone analysis revealed a shift in cyclonic activity eastward. Reanalysis data comparing September 1993–2007 and September 2009 show an eastward shift in a deeper upper-level trough, indicating that September 2009 was an anomalous year.

Corresponding author address: Shelley L. Knuth, Cooperative Institute for Research in Environmental Studies and Department of Atmospheric and Oceanic Sciences, University of Colorado, 216 UCB, Boulder, CO 80309. Email: shelley.knuth@colorado.edu

Save
  • Arndt, D. S., M. O. Baringer, and M. R. Johnson, Eds. 2010: State of the Climate in 2009. Bull. Amer. Meteor. Soc., 91 , S1S224.

  • Arrigo, K. R., and G. L. van Dijken, 2003: Phytoplankton dynamics within 37 Antarctic coastal polynya systems. J. Geophys. Res., 108 , 3271. doi:10.1029/2002JC001739.

    • Search Google Scholar
    • Export Citation
  • Arrigo, K. R., and G. L. van Dijken, 2004: Annual changes in sea-ice, chlorophyll a, and primary production in the Ross Sea, Antarctica. Deep-Sea Res. II, 51 , 117138.

    • Search Google Scholar
    • Export Citation
  • Bove, R., and G. Paolo, 2009: Convective snowfalls linked to the interaction of a boundary-layer front with a mesoscale cyclone near Terra Nova Bay, Antarctica. Bound.-Layer Meteor., 131 , 465478.

    • Search Google Scholar
    • Export Citation
  • Bromwich, D. H., 1989: An extraordinary katabatic wind regime at Terra Nova Bay, Antarctica. Mon. Wea. Rev., 117 , 688695.

  • Bromwich, D. H., 1991: Mesoscale cyclogenesis over the southwestern Ross Sea linked to strong katabatic winds. Mon. Wea. Rev., 119 , 17361753.

    • Search Google Scholar
    • Export Citation
  • Bromwich, D. H., and D. D. Kurtz, 1984: Katabatic wind forcing of the Terra Nova Bay polynya. J. Geophys. Res., 89 , (C3). 35613572.

  • Bromwich, D. H., J. F. Carrasco, Z. Liu, and R. Y. Tzeng, 1993: Hemispheric atmospheric variations and oceanographic impacts associated with katabatic surges across the Ross Ice Shelf, Antarctica. J. Geophys. Res., 98 , 1304513062.

    • Search Google Scholar
    • Export Citation
  • Buffoni, G., A. Cappelletti, and P. Picco, 2002: An investigation of thermohaline circulation in Terra Nova Bay polynya. Antarct. Sci., 14 , 8392.

    • Search Google Scholar
    • Export Citation
  • Carleton, A. M., and M. Fitch, 1993: Synoptic aspects of Antarctic mesocyclones. J. Geophys. Res., 98 , 1299713018.

  • Carrasco, J. F., and D. H. Bromwich, 1994: Climatological aspects of mesoscale cyclogenesis over the Ross Sea and Ross Ice Shelf regions of Antarctica. Mon. Wea. Rev., 122 , 24052425.

    • Search Google Scholar
    • Export Citation
  • Carrasco, J. F., D. H. Bromwich, and A. J. Monaghan, 2003: Distribution and characteristics of mesoscale cyclones in the Antarctic: Ross Sea eastward to the Weddell Sea. Mon. Wea. Rev., 131 , 289301.

    • Search Google Scholar
    • Export Citation
  • Cassano, J. J., J. A. Maslanik, C. J. Zappa, A. L. Gordon, R. I. Cullather, and S. L. Knuth, 2010: Wintertime observations of an Antarctic polynya with unmanned aircraft systems. Eos, Trans. Amer. Geophys. Union, 91 .doi:10.1029/2010EO280001.

    • Search Google Scholar
    • Export Citation
  • Davis, D. D., and Coauthors, 2008: A reassessment of Antarctic plateau reactive nitrogen based on ANTCI 2003 airborne and ground based measurements. Atmos. Environ., 42 , 28312848.

    • Search Google Scholar
    • Export Citation
  • Fogt, R. L., and D. H. Bromwich, 2006: Decadal variability of the ENSO teleconnection to the high-latitude South Pacific governed by coupling with the southern annular mode. J. Climate, 19 , 979997.

    • Search Google Scholar
    • Export Citation
  • Fogt, R. L., and S. Barreira, 2010: Atmospheric circulation. Bull. Amer. Meteor. Soc., 91 , S127S128.

  • Gallée, H., 1996: Mesoscale atmospheric circulations over the Southwestern Ross Sea sector, Antarctica. J. Appl. Meteor., 35 , 11291141.

    • Search Google Scholar
    • Export Citation
  • Hauser, A., M. Lythe, and G. Wendler, 2002: Sea-ice conditions in the Ross Sea during spring 1996 as observed on SAR and AVHRR imagery. Atmos.–Ocean, 40 , 281292.

    • Search Google Scholar
    • Export Citation
  • Heinemann, G., 1990: Mesoscale vortices in the Weddell Sea region (Antarctica). Mon. Wea. Rev., 118 , 779793.

  • Kern, S., 2009: Wintertime Antarctic coastal polynya area: 1992–2008. Geophys. Res. Lett., 36 , L14501. doi:10.1029/2009GL038062.

  • Kidson, J. W., 1999: Principal modes of Southern Hemisphere low-frequency variability obtained from NCEP–NCAR reanalyses. J. Climate, 12 , 28082830.

    • Search Google Scholar
    • Export Citation
  • McMahon, C., M. Hindell, T. Dorr, and R. A. Massom, 2002: Winter distribution and abundance of crabeater seals off George V Land, East Antarctica. Antarct. Sci., 14 , 128133.

    • Search Google Scholar
    • Export Citation
  • Monaghan, A. J., D. H. Bromwich, J. G. Powers, and K. W. Manning, 2005: The climate of the McMurdo, Antarctica region as represented by one year of forecasts from the Antarctic Mesoscale Prediction System. J. Climate, 18 , 11741189.

    • Search Google Scholar
    • Export Citation
  • Morales Maqueda, M. A., A. J. Willmott, and N. R. T. Biggs, 2004: Polynya dynamics: A review of observations and modeling. Rev. Geophys., 42 , RG1004. doi:10.1029/2002RG000116.

    • Search Google Scholar
    • Export Citation
  • Parish, T. R., and D. H. Bromwich, 1989: Instrumented aircraft observations of the katabatic wind regime near Terra Nova Bay. Mon. Wea. Rev., 117 , 15701585.

    • Search Google Scholar
    • Export Citation
  • Parish, T. R., and J. J. Cassano, 2001: Forcing of the wintertime Antarctic boundary layer winds from the NCEP–NCAR global reanalysis. J. Appl. Meteor., 40 , 810821.

    • Search Google Scholar
    • Export Citation
  • Parish, T. R., and J. J. Cassano, 2003: The role of katabatic winds on the Antarctic surface wind regime. Mon. Wea. Rev., 131 , 317333.

    • Search Google Scholar
    • Export Citation
  • Petrelli, P., N. L. Bindoff, and A. Bergamasco, 2008: The sea ice dynamics of Terra Nova Bay and Ross Ice Shelf polynyas during a spring and winter simulation. J. Geophys. Res., 113 , C09003. doi:10.1029/2006JC004048.

    • Search Google Scholar
    • Export Citation
  • Seefeldt, M. W., and J. J. Cassano, 2008: An analysis of low-level jets in the greater Ross Ice Shelf region based on numerical simulations. Mon. Wea. Rev., 136 , 41884205.

    • Search Google Scholar
    • Export Citation
  • Seefeldt, M. W., G. J. Tripoli, and C. R. Stearns, 2003: A high-resolution numerical simulation of the wind flow in the Ross Island region, Antarctica. Mon. Wea. Rev., 131 , 435458.

    • Search Google Scholar
    • Export Citation
  • Seefeldt, M. W., J. J. Cassano, and T. R. Parish, 2007: Dominant regimes of the Ross Ice Shelf surface wind field during austral autumn 2005. J. Appl. Meteor. Climatol., 46 , 19331955.

    • Search Google Scholar
    • Export Citation
  • Stearns, C. R., L. M. Keller, G. A. Weidner, and M. Sievers, 1993: Monthly mean climatic data for Antarctic automatic weather stations. Antarctic Meteorology and Climatology: Studies Based on Automatic Weather Stations, D. H. Bromwich and C. R. Stearns, Eds., Antarctic Research Series, Vol. 61, Amer. Geophys. Union, 1–21.

    • Search Google Scholar
    • Export Citation
  • Turner, J. T., 2004: The El Niño–Southern Oscillation and Antarctica. Int. J. Climatol., 24 , 131.

  • Turner, J. T., and S. Pendlebury, Eds. 2000: The International Antarctic Weather Forecasting Handbook,. British Antarctic Survey, 700 pp.

    • Search Google Scholar
    • Export Citation
  • Turner, J. T., G. J. Marshall, and T. A. Lachlan-Cope, 1998: Analysis of synoptic-scale low pressure systems within the Antarctic Peninsula sector of the circumpolar trough. Int. J. Climatol., 18 , 253280.

    • Search Google Scholar
    • Export Citation
  • Turner, J. T., S. N. Chenoli, A. abu Samah, G. Marshall, T. Phillips, and A. Orr, 2009: Strong wind events in the Antarctic. J. Geophys. Res., 114 , D18103. doi:10.1029/2008JD011642.

    • Search Google Scholar
    • Export Citation
  • van Woert, M. L., 1999: Wintertime dynamics of the Terra Nova Bay polynya. J. Geophys. Res., 104 , 77537769.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 388 217 73
PDF Downloads 251 90 3