To describe how the climatic system and, in particular, the
global ice sheets have responded to change in the insolation over
the last 250,000 years, with special emphasis on the glacial
inceptions, which started roughly 238,000 and 122,000 years ago.
Proxy records from ice cores will be used to obtain quantitative
information covering the last two climate cycles on atmospheric
CO2, methane, and aerosol concentration, air temperature and
elevation over Antarctica, Antarctic ice sheet accumulation rate,
and 18O of the air. In parallel, work will be performed
other research programmes to reconstruct environmental data from
land and oceanic cores. All this geological information will be
used to constrain the evolution of Northern Hemisphere ice sheets
through the two glacial cycles simulated by a hierarchy of
climate models, and the glaciological models will be used to
reconstruct isotopic storage.
Low order models (0 and 2-dimensional) including all components
of the climate system, three--dimensional ice-sheet models and
coupled ice-ocean-atmosphere climate models will indeed be used
to investigate these two well known climatic cycles, feedback
processes responsible for the amplification of the astronomical
forcing and resulting rapid growth of continental ice sheets, the
initiation of the ice sheets and the atmospheric and oceanic
circulation at different phases of their development, and the
role of the ice sheets in the CO2 and 18O cycles.
The lower-order models will be used to study the transient
behaviour of the climate system through the whole
glacial-interglacial cycles and as the main modelling tools for
the study of long-term climate dynamics, whereas 3-dimensional
climate models will simulate "snapshots" of the global climate at
selected climatic stages, in particular the glacial inceptions.
Funding SchemeCSC - Cost-sharing contracts
EH9 3JW Edinburgh
RG6 2AU Reading / Silchester