TITLE:   Long-Term Ecological Research (Palmer LTER) on the Antarctic 
         Marine Ecosystem

AUTHOR:  Raymond C Smith

Institute of Computational Earth System Science (ICESS), University of
California Santa Barbara (UCSB), Santa Barbara, CA 93106 

Date:   APRIL 3-5, 2002
Place:  Hamilton College, New York
TITLE:  Antarctic Peninsula Climate Variability: A Historical and
        Paleoenvironmental Perspective (talk)
URL:    http://academics.hamilton.edu/workshops/antarctica/index.htm
URL (Abstract): 
      http://academics.hamilton.edu/workshops/antarctica/Abstracts/smith.html

AGU SPECIAL VOLUME ON ANTARCTIC PENiNSULA CLIMATE VARIABILITY
(AGU Research Series, in press) 

Abstract

The Antarctic Peninsula defines a strong climatic gradient between the cold dry
continental regime to its south and the warm moist maritime regime to its north.The potential for these contrasting climate regimes to shift in dominance from
season-to-season and year-to-year creates a highly variable environment that is
sensitive to climate perturbation.  Long-term studies in the western Antarctic
Peninsula (WAP) region show that the WAP is a premier example of a
climate-sensitive region experiencing major changes in species abundance and
composition due to changes in range and distribution.  This is a sea 
ice-dominated ecosystem where the annual advance and retreat of the sea ice
is a major physical determinant of spatial and temporal change in its structure
and function, from total annual primary production to the breeding success and
survival of seabirds.  The WAP region has experienced a statistically
significant warming trend during the past half century.  In addition, a
statistically significant anti-correlation between air temperatures and sea
ice extent has been observed for this region.  Consistent with this strong
coupling, sea ice extent in the WAP area has trended down during this period of
satellite observations and the sea ice season has become shorter.  Further,
both air temperature and sea ice have been shown to be significantly correlated
with the Southern Oscillation Index (SOI), which suggests possible linkages
between sea ice, cyclonic activity and global teleconnections.  Ecological
responses to this climate variability are evident at all trophic levels,
but are most clearly seen in a shift in the population size and distribution
of penguin species with different affinities to sea ice.