Why do we care about Antarctic climate?

Dr Andrew RussellBrunel University

andrew.russell@brunel.ac.uk@dr_andy_russell@Antarctic_news

Antarctic talk• Background (map, trivia, history)• The Antarctic ozone “hole”• Antarctic temperature and sea ice trends• Ice cores• Why I care about Antarctic climate i.e. my

own research• Why you should care about Antarctic

climate i.e. ice sheets and sea level rise

Image: BAS

Antarctic trivia• Coldest continent – lowest recorded

temperature is -89°C• Driest – strictly a desert (South Pole

receives <10 cm per year, on average)• Windiest – the katabatic wind• Highest – ice up to 5km thick, average

1.6km across continent• Home to 90% of world’s ice• Population: 1000-5000

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses

Wikipedia – image of 17th Century Chinese map

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition

Wikipedia

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded1957-1958: International Geophysical Year (IGY), suggested by leading scientists

(including S. Fred Singer) in 1950, gave rise to year of Antarctic science

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded1957-1958: International Geophysical Year (IGY), suggested by leading scientists

(including S. Fred Singer) in 1950, gave rise to year of Antarctic science1959: Signing of the Antarctic Treaty (e.g. Article 1 – The area to be used for peaceful

purposes only; military activity, such as weapons testing, is prohibited but military personnel and equipment may be used for scientific research or any other peaceful purpose)

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von

Bellingshausen and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded1957-1958: International Geophysical Year (IGY), suggested by leading scientists

(including S. Fred Singer) in 1950, gave rise to year of Antarctic science1959: Signing of the Antarctic Treaty (e.g. Article 1 – The area to be used for peaceful

purposes only; military activity, such as weapons testing, is prohibited but military personnel and equipment may be used for scientific research or any other peaceful purpose)

1985: Discovery of the Antarctic "ozone hole" by BAS

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von Bellingshausen

and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded1957-1958: International Geophysical Year (IGY), suggested by leading scientists

(including S. Fred Singer) in 1950, gave rise to year of Antarctic science1959: Signing of the Antarctic Treaty (e.g. Article 1 – The area to be used for peaceful

purposes only; military activity, such as weapons testing, is prohibited but military personnel and equipment may be used for scientific research or any other peaceful purpose)

1985: Discovery of the Antarctic "ozone hole" by BAS2002: Larsen B ice shelf collapses

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known

landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von Bellingshausen

and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition)

claimed to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded1957-1958: International Geophysical Year (IGY), suggested by leading scientists

(including S. Fred Singer) in 1950, gave rise to year of Antarctic science1959: Signing of the Antarctic Treaty (e.g. Article 1 – The area to be used for peaceful

purposes only; military activity, such as weapons testing, is prohibited but military personnel and equipment may be used for scientific research or any other peaceful purpose)

1985: Discovery of the Antarctic "ozone hole" by BAS2002: Larsen B ice shelf collapses

Antarctic history25 million years ago: Antarctica formed from the gradual break up of Gondwana1st Century AD: Ptolemy suggested the idea to preserve the symmetry of known landmasses1773: Cook came within 75 miles of Antarctica but retreated in the face of ice1820: 1st confirmed sighting of Antarctica by the Russian expedition of von Bellingshausen

and Lazarev (sighted twice more in 1820 by Bransfield and Palmer)1839: US expedition from Australia discovers Wilkes Land1841: James Clark Ross passed through the Ross Sea and discovered Ross Island1909: Mawson, David and Mackay (from Sir Ernest Shackleton's Nimrod Expedition) claimed

to have found the South Magnetic Pole (72°S 155°E at that time)1911: Roald Amundsen became the first to reach the geographic South Pole (14 Dec)1912: Scott reaches the pole1914: Shackleton's Endurance expedition1956: Halley Research Station and Amundsen-Scott South Pole Station founded1957-1958: International Geophysical Year (IGY), suggested by leading scientists (including

S. Fred Singer) in 1950, gave rise to year of Antarctic science1959: Signing of the Antarctic Treaty (e.g. Article 1 – The area to be used for peaceful

purposes only; military activity, such as weapons testing, is prohibited but military personnel and equipment may be used for scientific research or any other peaceful purpose)

1985: Discovery of the Antarctic "ozone hole" by BAS2002: Larsen B ice shelf collapses2004: Dome C ice core data (~800,000 years) published

What’s black and white and red all

over?

Robert

McC

abe

The Antarctic “ozone hole”

Ozone depletion and “hole”

CFCl3 + hν → CFCl2 + Cl

Cl + O3 → ClO + O2

ClO + O3 → Cl + 2 O2

+

chemical reactions on polar stratospheric clouds in the cold Antarctic stratosphere

=

Antarctic temperature trends

Is Antarctica warming, cooling or do we not really know?

Is Antarctica warming, cooling or do we not really know?

Yes

Turner et al. (2005) “Antarctic climate change during the last 50 years” International Journal of Climatology 25, 279-294.

Image: United States Historical Climatology Network

USA: 1000 observing stations, some go back to late 1800s

Antarctica: 55 stations, very few go back to before 1957

Image: NASA

Can we be clever?

Steig et al. (2009) “Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year” Nature 457, 459-462.

O’Donnell et al. (2011). Improved methods for PCA-based reconstructions: case study using the Steig et al. (2009) Antarctic temperature reconstruction Journal of Climate, in press

Antarctic sea ice

NSIDCZhang (2004)

1. Surface temperature increases2. Upper ocean warms3. Ice growth decreases4. Decrease in salt rejection from new ice5. Salinity of the upper ocean falls6. Lower salinity and warmer water7. Lower water density in the upper ocean8. Fresher, less dense upper water9. Increased stratification of ocean layers10. Weaker convective overturning11. Less ocean heat is transported upwards12. Decrease in ice melting from ocean heat13. Increase in net ice production14. Sea ice increases

Antarctic sea ice

skepticalscience.com

Antarctic ice cores

Bubbles and gases

*V

BAS

Wha

t per

iod

do ic

e co

res

cove

r?

Petit et al. (1999)

Tilt

Eccentricity

Precession

WikipediaIPCC

EPICA (2004) Nature

Phew

!

Wikipedia

But CO2 lags

temperature in these

records so how does this

explain the warming?

Idea “borrowed” from Richard Alley.

An analogy..

Initial credit card debt of £1000

Pay off £5 per month

20% APR interest

Can an initial forcing be amplified by some other mechanism?

Credit card analogy

0

1000

2000

3000

4000

5000

6000

0 20 40 60 80 100 120

Months

Va

lue

(£

)

Debt

Payments

Interest (20%)

Idea “borrowed” from Richard Alley.

Not well understood but most likely some interplay of ocean processes like:

• ocean circulation• ocean temperature/salinity• marine biological activity• ocean-sediment interactions• seawater carbonate chemistry• air-sea exchange

My work on Antarctic weather and climate

Changes in the Southern Annular Mode

IPCC (2007)

IPCC (2007)

The Southern Annular Mode

http

://ww

w.n

iwa.co

.nz

NIWA

The Southern Annular Mode

http

://ww

w.n

iwa.co

.nz

Negative SAM index

Positive SAM index

Changes in the Southern Annular Mode

Gillett and Thompson (2003) ScienceThompson and Solomon (2002) Science

IPCC (2007)Marshall (2003)

Russell et al. (2008) ASL

Russell & McGregor (2010) Climatic ChangeRussell et al. (2004) Tellus A

Russell et al. (2006) GRL

http://nsidc.org/iceshelves/larsenb2002/animation.html

Southern Annular Mode

BAS

Why you should be a bit concerned about

Antarctic climate

IPCC (2007) Bindschadler et al. (1998) EoS

“Ice sheet models indicate that this would be offset by tens of percent by increased ice discharge, but still give a negative contribution to sea level, of –0.8 m by 3000 in one simulation with Antarctic warming of about 4.5°C”

Antarctic ice sheet

Rignot and Thomas (2002)

Peter Boyer

Under the Antarctic ice sheet

Oppenheimer (1998) Nature

Under the Antarctic ice sheet

Shepherd et al. (2001) ScienceVaughan et al. (2006) GRL

Pine Island Glacier

"Parts of the Antarctic ice sheet that rest on bedrock below sea level have begun to discharge ice fast enough to make a significant contribution to sea level rise. Understanding the reason for this change is urgent in order to be able to predict how much ice may ultimately be discharged and over what timescale. Current computer models do not include the effect of liquid water on ice sheet sliding and flow, and so provide only conservative estimates of future behaviour."

Chris Rapley, former director of BAS

84m sea level rise!

Benfield Hazard Research Centre.

This plot is silly.

Worse case scenario - complete WAIS collapse - would result in 4-6m of sea level rise.

Why you should be very interested in Antarctic climate

Ted Scambos

Manchester Science Festival

22-30 October 2011