the climate system from a polar perspective

The climate system from a polar perspective

Peter LemkeAlfred Wegener Institute

for Polar and Marine ResearchBremerhaven

Institute for Environmental Physics

University of Bremen

The complex climate system

32

1

4 65

1.Stochastic climate models

2.Oceanic surface layer

3.Sea ice/ocean interaction

4.Sea ice dynamics

5.Sea ice ecosystem

6.Cryosphere (IPCC)

1 The climate system: Basic characteristics

Rapid atmosphere: DaysSluggish ocean: Months-500 yearsIce sheets: Millennia

Hasselmann, 1976

Energy balanceclimate model(Lemke, 1977)

1 Variance in the antarctic sea ice boundary

FrequencyPeriod

Vari

an

ce in

sea ice b

ou

nd

ary

Variations in sea ice can also be described with a sea ice model, i.e. through the Brownian motion approach. 1980

The complex climate system

2

1.Stochastic climate models

2.Oceanic surface layer

3.Sea ice/ocean interaction

4.Sea ice dynamics

5.Sea ice ecosystem

6.Cryosphere (IPCC)

2 Oceanic surface layer under the sea ice

The seasons in the Arctic Ocean

Salt content ofthe surface layer

Depth of the surface layer

Summer Winter

Summer

Winter

1984

20m

50m

The complex climate system

3

1.Stochastic climate models

2.Oceanic surface layer

3.Sea ice/ocean interaction

4.Sea ice dynamics

5.Sea ice ecosystem

6.Cryosphere (IPCC)

3 Sea ice/ocean interaction

Polynya experiment

Thickness of the sea ice

Salt content of the surface layer

Temperature of the surface layer

Depth of the surface layer

1987

The complex climate system

4

1.Stochastic climate models

2.Oceanic surface layer

3.Sea ice/ocean interaction

4.Sea ice dynamics

5.Sea ice ecosystem

6.Cryosphere (IPCC)

4 Sea ice drift and deformation from SAR images

RADARSAT Geophysical Processor System.

Due to a large swath width (~400 km) in ScanSAR mode, an image is obtained at least every 7th day

(by courtesy of Ron Kwok).

4 SIMIP sea ice model optimization

1997

The complex climate system

5

1.Stochastic climate models

2.Oceanic surface layer

3.Sea ice/ocean interaction

4.Sea ice dynamics

5.Sea ice ecosystem

6.Cryosphere (IPCC)

5 The sea ice ecosystem

5 Working on sea ice

5 Sampling

5 The sea ice ecosystem

Brine channelsin the sea ice

© J. Weissenberger © R. Kiko

© M. Kramer

© R. Kiko

The complex climate system

1.Stochastic climate models

2.Oceanic surface layer

3.Sea ice/ocean interaction

4.Sea ice dynamics

5.Sea ice ecosystem

6.Cryosphere (IPCC)

6

6 Climate report (IPCC) - Chpt. 4

2007

Frequently Asked Question 4.1:

Is the Amount of Snow and Ice on the Earth Decreasing?

Yes.

Snowfields in the northern hemisphere shrinking Glacial retreat worldwide Greenland and Antarctic ice sheets shrinking Permafrost thawing in many areas Significant reduction in Arctic sea ice

Aktualisiert von IPCC AR4 (2007)

Sept. 2007

Decline in summer minimum(-8 % per decade)

6 Arctic sea ice - extent in summer

2070Arctic ice-free in summer

Measuring sea ice thickness

EM bird

Rabenstein, Hendricks,Leinweber, 2007

AWI sea ice group

6 km

Significant rise in average global temperatures

GISS Data

2009

2008

1990 1995 2000 2005 2010 2015

Fo

ssil

Fu

el E

mis

sio

n (G

tC y

-1)

5

6

7

8

9

10

A1B

A1FI

A1T

A2

B1

B2

Carbon Dioxide Information Analysis Center

International Energy Agency

CO2 emissions (billion metric tons carbon dioxide/year)

Raupach et al. 2007, PNAS, updated; Le Quéré et al. 2009, Nature-geoscience; International Monetary Fund 2009

... are far higher than the IPCC's worst-case scenarios

2100:ΔT ~ 4°C

Thank you!Bayer AG

Klaus Hasselmann

Our colleagues at

MPI for Meteorology, Hamburg

Princeton University

Institute of Marine Sciences, Kiel

Alfred Wegener Institute, Bremerhaven

IUP, University of Bremen

Hildegard, Saskia, Mark, Stefan

Nature's sculptures

Our challenge:

To make sustainable use of a constantly changing planet

Thank you for your attention.