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International Polar Year 2007–2008 - WMO

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contributes significantly to the New Tectonic Map of<br />

Antarctica (Grikurov and Leitchenkov, in press) as part<br />

of the IPY PLATES & GATES project. The information<br />

on this map, the characterisation of the Antarctic<br />

continent-ocean transitions (e.g. Gohl, 2008) and<br />

recent regional stratigraphic grids will be compiled<br />

in two follow-up, post-IPY projects Circum-Antarctic<br />

Stratigraphy and Paleobathymetry (CASP) and<br />

Antarctic Paleotopographic Maps (ANTScape). The<br />

generation of higher-resolution palaeobathymetric<br />

and palaeotopographic grids is a key condition for<br />

realistic simulations of palaeo-ocean currents.<br />

Within the PLATES & GATES project, Cenozoic and<br />

Mesozoic climate reconstructions are performed<br />

using a variety of Earth system models designed to<br />

evaluate the effect of ocean gateways and basins on<br />

palaeo-circulation patterns, the global carbon cycle<br />

and nature of polar ice-sheet development. These<br />

experiments include sensitivity runs incorporating<br />

new palaeobathymetric reconstructions arising from<br />

the new data acquisition described above. The results<br />

from these experiments are compared with other<br />

model simulations, which include different forcing<br />

factors such as atmospheric greenhouse gases and<br />

mountain uplift to determine the relative importance<br />

of palaeogeography on the evolution of polar and<br />

global climates over long geological timescales.<br />

An international effort<br />

PLATES & GATES was set up as a closely knit network<br />

project, consisting of 33 individual projects with 46 expeditions,<br />

of which 26 expeditions were land-based,<br />

27 were ship-based and 7 were conducted as combined<br />

marine-land expeditions. The split between<br />

Arctic/sub-Arctic and Antarctic/Southern Ocean expeditions<br />

is almost even. The following 16 nations with a<br />

total of about 60 scientists, technicians and students<br />

were active in funded polar expeditions for this project:<br />

Argentina, Chile, Denmark, Germany, Finland,<br />

Italy, Japan, New Zealand, Norway, Poland, Russia,<br />

Spain, Sweden, U.K., Ukraine and U.S.A.. At least two<br />

expeditions were conducted by Chile, Germany, Italy,<br />

Norway, Poland, Russia, Spain, Sweden and U.S.A. A<br />

summary of all funded PLATES & GATES projects and<br />

expeditions can be accessed at www.internationalpolar-year.de/Plates-and-Gates.28.0.html.<br />

Although the tectonic evolution of the polar<br />

ocean basins and their continental margins has been<br />

investigated over the last 40 years in various individual<br />

projects, PLATES & GATES is the first coordinated effort<br />

to bring together the relevant geoscientific disciplines<br />

with the ultimate objective to understand the tectonic<br />

and sedimentary processes leading to ocean gateway<br />

developments. Also new is the approach to involve<br />

the numerical palaeoclimate modelling community,<br />

as they are the ones which translate the resulting basin<br />

and margin bathymetries and topographies into their<br />

dynamic model geometries. The challenge will be to<br />

compile this vast amount of data and results from the<br />

individual PLATES & GATES projects for more realistic<br />

dynamic palaeobathymetric and palaeotopographic<br />

grids of geological epochs which were relevant for<br />

major events in the Earth’s climate history.<br />

At this stage, most collected data and samples are still<br />

being analyzed, models are being built and first publications<br />

are being written. First initial results were presented<br />

at the IPY Open Science Conference 2010 in Oslo.<br />

With the abundance of the large variety of data and<br />

samples, it will take several years to unify models and<br />

describe the processes of polar gateway and basin formation<br />

and their effects on long-term climate change.<br />

<strong>Polar</strong> Earth Observing Networks in<br />

<strong>International</strong> <strong>Polar</strong> <strong>Year</strong><br />

A dearth of geophysical observations in the polar<br />

regions has long been recognized, particularly from<br />

sites remote from permanent research stations or<br />

inhabited sites. Given the intensive global attention<br />

and accelerating research efforts focused on<br />

understanding ice sheet behaviour in response to<br />

climate change, the establishment of geophysical<br />

observing networks during IPY was particularly timely.<br />

Fundamental objectives of many of the projects<br />

involved in the IPY <strong>Polar</strong> Earth Observing Network<br />

(POLENET) program are focused on measuring solidearth<br />

phenomena that provide information on ice<br />

mass change and on controls on ice sheet evolution<br />

and dynamics. Predictions of the response of the ice<br />

sheets to changing global climate, including how<br />

ice mass will change, their modes of collapse and<br />

the rapidity of resultant sea-level rise, are crucial<br />

to planning for our changing environment. Robust<br />

predictions require systems-scale observations over<br />

s C I e n C e P r o g r a m 279

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