Transcript (APEX) What do we mean by EXtremes?

Arctic Palaeoclimate and its EXtremes
(APEX)
What do we mean by EXtremes?
• Conditions that represent the end points of
magnitude / frequency behaviour (e.g. maximum
ice sheet extent, very fast ice flow, maximum air
temperatures, rapid changes in
palaeoceanography)
• Their definitions are spatially and temporally
specific (e.g. Eurasian ice sheet versus an
individual ice stream, or ice extent during the Last
Glacial Maximum versus the Little Ice Age)
• They may be defined by dimensions or with
respect to process
• Their definition requires understanding of the
background, or “steady state” of a particular
system
Why do EXtremes matter?
• They establish boundary conditions that constrain
our understanding of the Arctic and the role of the
Arctic in global climate change
• They are relevant to predictions of future climate
change
• They provide excellent modelling targets
APEX themes
Cold Extremes: Arctic marine and terrestrial glacial maxima,
sea level minima and maxima, Arctic Ocean palaeoceanography,
ice shelf extent, palaeoatmospheric circulation
Warm Extremes: interglacial environments, sea level
maximum, sea-ice minimum, Arctic Ocean palaeoceanography, ice
shelf extent
Hydrological extremes: Fluvial-marine interaction,
freshwater budget and ice-dammed lakes
Permafrost extremes: Maximum and minimum extent,
rates of change, response to climate change
Glacio-dynamical extremes: Ice sheet instability,
palaeo-ice stream dynamics and feedback mechanisms
Some APEX scientific challenges
What were the dimensions, age and palaeoglaciology of the Arctic ice sheets during
glacial maxima?
Was there a large Arctic Ocean ice-shelf during glacial maxima, and how did coastal ice
shelves respond to Holocene climate change?
How large were the MIS 6 ice sheets and what were its climate impacts?
How large was the Greenland ice sheet during interglacials?
How fast can an ice sheet develop?
How does the Eemian compare to the Holocene in the Arctic?
How warm can Arctic interglacials be?
How did palaeo-ice streams operate within the Eurasian, Iceland and Greenland ice
sheets and effect their stability?
Can we develop a chronology for the Eemian?
Was there influx of Atlantic Water into the central Arctic Ocean during glacial maxima?
What caused the development of extreme cold and dry climatic conditions in eastern
Siberia?
APEX Methodology
• Builds on PONAM and QUEEN legacy
• Strong integration between land and ocean
investigations
• Strong integration between modeling and field data
• Emphasis on both patterns and processes
How are we going to promote this?
• The role of the Arctic in the global climate system
• Emphasis on the extremes
• Analogues for future climate change, e.g. Greenland
Ice Sheet mass balance and sea ice thickness and
extent
• Multi- and interdisciplinary
• Proven track record from PONAM and QUEEN
• Embrace new EU member states into APEX
APEX and the International Polar Year 2007 – 2008
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Status: to determine the present environmental status of the
polar regions
Change: to quantify, and understand, past and present
natural environmental and social change in the polar regions;
and to improve projections of future change
Global Linkages: to advance understanding on all scales of
the links and interactions between polar regions and the rest
of the globe, and of the processes controlling these
New Frontiers: to investigate the frontiers of science in the
polar regions
Vantage Point: to use the unique vantage point of the
polar regions to develop and enhance observatories from the
interior of the Earth to the Sun and the cosmos beyond
Human Dimension: to investigate the cultural, historical, and
social processes that shape the sustainability of circumpolar
human societies, and to identify their unique contributions to
global cultural diversity and citizenship
Concept of IPY as defined in “A framework for the International Polar Year”, www,ipy.org
APEX planned field activities
2005:
05-1. Beringia 2005, Icebreaker Oden/ USCGC Healy
“A pan-Arctic transect for linking Eurasian and
Amerasian records to constrain the
paleoenvironmental evolution of the Arctic
Ocean”
05-1
07/08-1
IPY 2007-08:
07/08-1. Lomonosov/Greenland, Icebreaker Oden
“Geological coring and geophysical seafloor
mapping using an Autonomous Underwater
Vehicle (AUV) under the pack ice to study the
glacial history of the Arctic Ocean”
Scott Polar
Research Institute
Southampton
Oceanography Centre
Polarstern 2005-06
1. Polarstern
“Variability of water mass exchange during
interglacials in the Arctic”
2. Polarstern
“High-resolution marine records of Late
Quaternary Eurasian ice sheets”
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IFM-GEOMAR
1. Field campaign
North and NE Greenland ice sheet / ocean
interactions
2: Field campaign
West Greenland LGM and Holocene ice sheet
and palaeoceanography
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3: Field campaign
Iceland ice sheet dimensions and
palaeoglaciology
Integration between modeling and field data
GCM
Ice Sheet
Ocenography
Bristol Glaciology Centre
University of Bristol