Warming, Melting, Land Ice and the IPY

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Warming, Melting, Land Ice and the IPY

• Robert Bindschadler
• NASA
• Robert.A.Bindschadler_at_nasa.gov

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Me (Athabasca Glacier, 1970)
Hes a future glaciologist?
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Worldwide Glacier Retreat

• Glaciers in all regions are now retreating
• Retreat is accelerating

A bellwether of change, but
Source M. Dyurgerov
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Glaciers have limited global impact
East
West
2-6 of all water on Earth 70-80 of all fresh
water on Earth
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6 meter rise--Greenland Ice Sheet is equal to 6
meters
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Florida without Greenland ice sheet
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Global Warming is Real
Temperature Change (oC)
Source GISS
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Heating will be concentrated on land
Mean
Mean
Temperature Change (oC)IPCC AR4 scenario A2 mean
warming in 2090-99 vs.1980-99
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(us)
(our kids and grandkids)
Not only do almost all people experience
above-global-average warming, but the
uncertainties are skewed--things may be a little
better, or a good bit worse.
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Sea-Level History

• Less ice in warmer climates
• Ice sheets shrink faster than they grow
• Sea level change is not smooth

HIGH
SEA LEVEL
LOW
TEMPERATURE
WARM
COLD
THEN
NOW
Time
There will be less ice
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Sea level has gone up much faster

• Relatively steady over past 6000 yrs (2 mm/yr.)
• Periods of fast rise
• Up to 20 times present rate
• Cant be due to melting alone
• Ice flow dictates rapid sea level rise
• Accumulation variations average out on large scale

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maximum?
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Three Different Signatures Dramatic Land Ice
Chnages

• Outlet glaciers feeding ice shelves
• Summer acceleration
• Sustained acceleration of deep outlet glaciers

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1. Disintegrating Ice Shelves
Require gt10,000 years to form
2000 km2 of Larsen Ice Shelf disintegrated in 2
days.
Source T. Scambos
Disintegrate in weeks!
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Consequence of Ice Shelf Loss
up to 510 faster in 2 years
up to 400 faster in 2 years
(Scambos et al., 2004)
Formerly buttressed glaciers accelerate
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2. Summer Acceleration observed in Greenland
Surface meltwater can account for 10 increase in
annual speed
(from Zwally et al., 2002)
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Greenland Surface Water Flow
Process appears similar to mountain glaciers, but
there are some differences in timing
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Greenland melt extent is increasing
Observations show flow acceleration magnitude is
proportional to amount of melt
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3. Accelerating Outlet Glaciers
(Source I. Joughin)
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Rapid Retreat
Jacobshavns Isbrae
Kangerdlugssuaq Glacier
Jacobshavns Isbrae
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North and South
Source W. Krabill
The deepest outlet glaciers exiting into the
ocean are responding most. WHY?
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The most sophisticated ice-flow models cant
reproduce these behaviorsbut
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Tidewater glaciers are a good analogue to predict
ice sheet future
Muir Glacier, Alaska
1941
2004
Outlet glaciers are displaying classic drastic
retreat traits similar to Alaskan tidewater
glaciers
1971
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Drastic Retreat
Successive profiles of retreat
Retreat ? Deeper Water ? Increased Calving
Retreat continues until glacier bed rises above
sea level
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Columbia Glacier

• Last Alaskan tidewater glacier on extended
  moraine (in 1978)
• Retreat began in 1980
• 15 km retreat by 2000
• 40 km retreat expected

??
2000
1980
Source USGS
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Columbia Glacier, Alaska
Helheim Glacier, Greenland
1996 aerial photograph
2007 image (GoogleEarth)
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• Central region of Greenland is below sea level
• Jacobshavns Isbrae occupies subglacial channel
  connected to central depression

Russel Huff, Univ. of Colorado
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Antarctica
West Ant.
East Ant.
Nearly all of West Antarctica ice sheet and much
of East Antarctica ice sheet rests on bed below
sea level
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Links between Processes

• Acceleration causes drawdown upstream
• Drawdown accelerates surface melting processes
• Increased meltwater enhances acceleration

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The concept of IPY 2007-2008
An intensive burst of internationally
coordinated, interdisciplinary, scientific
research and observations focussed on the
Earths Polar regions. Time frame 1 March 2007
to 1 March 2009
Co-sponsored by ICSU and WMO
www.ipy.org
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Previous IPYs

• 1882-83 First International Polar Year.
  Organized by the International Meteorological
  Organization (later renamed WMO).
• 1932-33 Second International Polar Year (IMO/WMO)
• 1957-58 Third International Polar Year
• International Geophysical Year (ICSU and WMO)

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Outcomes of IGY (1957-58)

• Establishment of Arctic and Antarctic permanent
  bases and in-situ programmes
• Establishment of World Data Centres
• International Research Institutions (SCAR, SCOR,
  subsequently WCRP, etc)
• Antarctic Treaty System
• Major public impact
• A lasting legacy of data, network and motivation

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IPY 2007-2008Why now and what is different?

• IGY50 - but more importantly an opportunity for
  exciting, cutting-edge and relevant science.
• Involvement of key disciplines in all aspects of
  natural science and social science.
• Truly international involving more than
  traditional polar nations.
• Directions and objectives developed by the
  scientific community, but with full engagement of
  funding agencies in planning.

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IPY Planning Group (2003-2004)

• IPY Themes
• Current Status of Polar
• Regions
• Change in the Polar
• Regions
• Global Linkages
• New Frontiers
• Polar Regions as Vantage
• Points
• The Human Dimension

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Urgent, Significant
IPY PROJECT
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Urgent, Significant
International Partnerships
IPY PROJECT
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Urgent, Significant
International Partnerships
Builds Connections
IPY PROJECT
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Urgent, Significant
International Partnerships
Builds Connections
IPY PROJECT
Store, Share Data
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Urgent, Significant
International Partnerships
Builds Connections
IPY PROJECT
Store, Share Data
Education, Outreach
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Urgent, Significant
International Partnerships
Builds Connections
IPY PROJECT
Store, Share Data
Education, Outreach
Expand Polar Community
228 Projects 50,000 participants US 1.25
Billion
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31 nations have National Committees for IPY
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The IPY Legacy

• Scientific legacy observational systems and
  networks technologies baseline data sets
  understanding of the Earth System.
• Collaborative Legacy enhanced collaboration and
  joint funding information sharing.
• Human Legacy next generation of researchers and
  leaders involvement of Arctic residents public
  awareness and interest.

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Summary

• Land ice is going accelerating change
• Our future will contain less land ice and higher
  sea level
• Even the experts dont know how much or how fast,
  but were working hard to predict these
• IPY is a platform to communicate these changes to
  the public