Priority Research Topics in Antarctic Climate
and Environmental Variability
ITASE research will enable a greater understanding of Southern Hemisphere climate and ocean teleconnections, particularly associated with the ENSO phenomena, in the Pacific Ocean and the Southern Ocean region through the collaboration of ice core scientists with paleoclimatologists specialising in, for example, tree ring and coral climate records, and the PAGES Annual Records of Tropical Systems (ARTS) programme.
A number of key research topics related to Southern Hemisphere atmospheric and oceanic circulation, are potential foci for ITASE collaborative research. ITASE research will enable regional comparisons of interannual variability in circum-polar trough sea-level pressure, sea surface temperature, meridional wind stress and meridional sea ice extent associated with the Antarctic Circumpolar Wave (ACW) (White and Peterson, 1996), and their relationship to interannual variability in precipitation and hence surface mass balance across Antarctica (Cullather et al., 1996). Such regional comparisons can be extended from the last two decades of satellite and field observations to the last 200 years through the interpretation of the ice core derived climate and environmental proxies.
The 200 year proxy climate histories for Antarctica will also enable the determination of the effects of pre and post anthropogenic influence on air temperature, atmospheric circulation and atmospheric chemistry. Discovery of the ozone hole provided a wake-up call to the international scientific community by demonstrating that even the remotest regions of earth can be affected by human activity. Observed modern changes in mass balance and sea ice extent may reflect not only responses to natural climate variability but also the effects of changes in CO2 and ozone produced by humans.
More specific regional research topics are outlined below.
Austral Southern Ocean and South Pacific Ocean Sector
- The relationship between Antarctic precipitation variability with ENSO associated climate, particularly, precipitation variability in Southern Australia (Allan and Haylock, 1993), and perhaps South America.
- Variations in cyclogenesis, storm tracks, moisture flux and the strength of the low pressure cells in and off the Wilkes Land coast at E 110-120deg., and in the Amundsen Sea at W 110-130deg. (Figure 3).
- Interannual and decadal variability in sea ice extent and concentration, persistence and maintenance of coastal `latent heat' polynyas in the Ross Sea and off Terre AdÈlie.
Figure 3 - Typical annual pressure patterns for (a) normal (1980) and (b) reduced (1982) West Antarctic precipitation events. Vectors represent vertically integrated moisture flux (maximum is 200 kg/m/s). Mean sea level pressure field contoured every 2 hPa. From Cullather et al. (1996).
Atlantic Ocean Sector
- Variations in cyclogenesis, storm tracks, moisture flux and the strength of the low pressure cell in the Haakon VII Sea (E 10-20deg.), off the Dronning Maud Land coast (Figure 3).
- Correlation with North Atlantic climate history.
- Weddell Sea `sensible heat' polynya behaviour, bottom water production and biogenic productivity.
Indian Ocean Sector
- Variations in cyclogenesis, storm tracks, moisture flux and the strength of the low pressure cells off the Dronning Maud Land coast (E 10 -20deg.), and the Wilkes Land coast at (E 110-120deg.) (Figure 3).
- Southern Indian Ocean and atmospheric circulation modes (notably ENSO and Indian monsoon).
- Volcanic events and temperature.
- Interannual and decadal variability in sea ice extent and concentration, persistence and maintenance of coastal `latent heat' polynya, known as the Cosmonaut Polynya, off Enderby Land.