The Role of Antarctica in Understanding the Earth’s Atmosphere and Climate

Richard Brandt

University of Washington

and

Paul Smith’s College

Institut Polaire Français National Science Foundation

Office of Polar ProgramsItalian National Research

Program in Antarctica

James ElkensNOAA-CMDL2001

http://books.nap.edu/catalog/10139.html

What are the atmospheric gasses that cause the greenhouse effect? 

Not the major gasses:N2 78%

O2 21%

Ar 1% 

On earth (unlike venus and mars) it is the minor gasses that are responsible for the greenhouse:

H2O

CO2

O3

CH4

N2O

Determining Earth’s past climate 1. Human record (only~2000 years)

2. Ice cores in Antarctica and Greenland. (up to 475,000 years ago)

3. Tree ring analysis, extent of pollen deposition(up to millions of years)

4. Ocean sediments and geochemistry(over a half billion years)

The Dome C δD record resembles Vostok and Dome F records over their common parts

EPICA Community paper, Nature, 2004

Jones, P.D. and Moberg, A., 2003: Hemispheric and large-scale surface air temperature variations: An extensive revision and an update to 2001. Journal of Climate, 16, 206-223.

T.P. Barnett, D.W. Pierce, R. Schnur, Science 292, 270 (2001)

 1. Feedbacks: two positive examples CO2 insulation SST evaporation H2O

insulation SST

CO2 insulation SST sea ice extent

albedo absorbed sunlight SST

Why is predicting our future climate so difficult?

2. Feedbacks: two negative examples CO2 insulation SST evaporation H2O

clouds SST

CO2 insulation SST phytoplankton DMS

Cloud condensation nucleii clouds SST

Why is predicting our future climate so difficult?

1. Detailing climate feedbacks properly to get the correct climate amplification (example is ice-albedo feedback)

2. Improving our understanding of albedo, temperature, water vapor, cloud cover, atmospheric dynamics of the less populated parts of earth, especially the polar regions. (Few or no weather and climate records) 3. Climate models are computationally intensive and there are complexities due to such a highly nonlinear system (for example atmospheric turbulence which is chaotic). We are limited by our computing power for regional scale modeling.

Why is predicting our future climate so difficult?