Detecting Cyclogenesis in East Antarctica with MODIS

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Detecting Cyclogenesis in East Antarctica with
MODIS
Kelly Amundsen Ohio State University Byrd Polar
Research Center
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East Antarctica?
PM
WeddellSea
Bellingshausen Sea
Ross Sea
ID
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Motivation

• Cyclogenesis in Antarctica is a relatively new
  discovery
• East Antarctica has received less attention than
  the western portions of the continent
• Past studies indicate East Antarctica may be
  baroclinic/cyclogenetic
• The topography, upper-level patterns, and
  interaction with mid-latitude systems in East
  Antarctica may be leading to cyclogenesis
• The debate

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The Debate

• Cyclone Tracking
• Sinclair et al.
• ECMWF Analyses
• Geostrophic Vorticity at 1000 hPa
• Systems must move at least 1200 km when within
  500 km of coast
• Finds little cyclogenesis at high latitudes
• Simmonds et al.
• NCEP-NCAR reanalysis
• Local pressure minima
• Finds moderate cyclogenesis at high latitudes
• Walsh et al.
• Plot data on sigma levels
• Finds moderate cyclogenesis at high latitudes

• Satellite Studies
• Carrasco et al., Bromwich
• Frequent cyclogenesis occurs along coasts of West
  Antarctica
• Due to katabatic winds, upper-level forcing,
  land-sea temperature contrast
• Turner et al.
• Cyclogenesis is frequent near Peninsula

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Why use MODIS?
Year-round manned stations
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230 km
Jan. 1, 2004 1300 Z
Jan. 2, 2004 0745 Z
Jan. 3, 2004 0650 Z
Jan. 4, 2004 0735 Z
Jan. 4, 2004 2000 Z
Jan. 5, 2004 0640 Z
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Conclusions

• East Antarctica is most likely cyclogenetic
• The current literature disagrees widely on this
  issue
• Global analyses, reanalyses, and cyclone tracking
  schemes cannot resolve mesoscale cyclones along
  coastal Antarctica
• MODIS, GPS RO, and other remote sensors may
  likely resolve these issues

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