Reconstructing and Modelling the Last Glacial Maximum:
Beyond CLIMAP
K. Herterich, S. Determann, B. Grieger*, I. Hansen, P. Helbig, S. Lorenz,
A. Manschke, M. Matthies, A. Paul, R. Schlotte and U. Wyputta
Universitat Bremen, Fachbereich Geowissenschaften, Postfach 33 0440,
D-28334 Bremen, Germany
*Corresponding author (e-mail):bgrieger@palmod.uni-bremen.de
Abstract: The update and extension of the CLIMAP data set -preliminarily called "CLIMAP 2000"is discussed. Although newer data exist, CLIMAP (1981) is still the most widely used source of
boundary conditions for modelling the last glacial maximum. Besides the new data, CLIMAP 2000
should also incorporate climate models to create global fields of sea surface temperatures (SSTs) and
other climate parameters. Atmospheric general circulation models can be used to check the consistency
of SSTs and sea ice margins with data on certain land conditions. In a similar way tracer concentrations
resulting from ocean models including biogeochemical processes can be compared with marine
proxy data. Coupled atmosphere-ocean models applicable to paleoclimate, which are still under
development, would yield complete SST fields. The reconstruction of ice-sheets and vegetation
zones can be improved by considering corresponding models. Inverse models can be used to extend
sparse data sets by integrating various types of data. From this review, a three-step concept for
CLIMAP 2000 is suggested and the key points of the new CLIMAP 2000 data base and maps are
listed.
Introduction
During the last two decades, the number of modellers interested in simulating the paleoclimate has
steadily increased. The basis for paleoclimate
modelling is a growing data set of climate parameters documenting climate change during Earth's
history. The motivation for modelling the
paleoclimate is manyfold.The increase of atmospheric greenhouse gases within the last decades
has encouraged the development of comprehensive
models for simulating climate variability and predicting climate change. The simulation of
paleoclimates presents the unique possibility to test
these models against proxy data. If they are successful in simulating a climatic state which strongly
deviates from the modern one we may have more
confidence in the model results concerning future
climate change. In addition, we can learn much
about climate dynamics on longer time scales beyond the recent period of direct measurements. The
knowledge on paleoclimatic change stems from indirect climatic observations, mainly from the geological record, which has conserved certain parameters related to the climatic conditions during and
after sedimentation. With these parameters as input a model can generate a variety of further climate variables which were not documented in the
paleoclimatic record. In this way the paleoclimate
can be reconstructed in more detail.
The lack of paleodata to retrieve the boundary
conditions for atmospheric models was one major
reason for the formation of the CLIMAP
(Climate:Long-Range Investigation Mapping and
Prediction) project. In 1976, the CLIMAP project
members were a consortium of 36 scientists from
19 different institutions (13 US and 6 European).
The main goals were to reconstruct the Earth's
From FISCHER G, WEFER G (eds), 1999, Use of Proxies in Paleoceanography: Examples from the South Atlantic.Springer·Verlag
Berlin Heidelberg, pp 687-714
Beyond CLIMAP
K. Herterich, S. Determann, B. Grieger*, I. Hansen, P. Helbig, S. Lorenz,
A. Manschke, M. Matthies, A. Paul, R. Schlotte and U. Wyputta
Universitat Bremen, Fachbereich Geowissenschaften, Postfach 33 0440,
D-28334 Bremen, Germany
*Corresponding author (e-mail):bgrieger@palmod.uni-bremen.de
Abstract: The update and extension of the CLIMAP data set -preliminarily called "CLIMAP 2000"is discussed. Although newer data exist, CLIMAP (1981) is still the most widely used source of
boundary conditions for modelling the last glacial maximum. Besides the new data, CLIMAP 2000
should also incorporate climate models to create global fields of sea surface temperatures (SSTs) and
other climate parameters. Atmospheric general circulation models can be used to check the consistency
of SSTs and sea ice margins with data on certain land conditions. In a similar way tracer concentrations
resulting from ocean models including biogeochemical processes can be compared with marine
proxy data. Coupled atmosphere-ocean models applicable to paleoclimate, which are still under
development, would yield complete SST fields. The reconstruction of ice-sheets and vegetation
zones can be improved by considering corresponding models. Inverse models can be used to extend
sparse data sets by integrating various types of data. From this review, a three-step concept for
CLIMAP 2000 is suggested and the key points of the new CLIMAP 2000 data base and maps are
listed.
Introduction
During the last two decades, the number of modellers interested in simulating the paleoclimate has
steadily increased. The basis for paleoclimate
modelling is a growing data set of climate parameters documenting climate change during Earth's
history. The motivation for modelling the
paleoclimate is manyfold.The increase of atmospheric greenhouse gases within the last decades
has encouraged the development of comprehensive
models for simulating climate variability and predicting climate change. The simulation of
paleoclimates presents the unique possibility to test
these models against proxy data. If they are successful in simulating a climatic state which strongly
deviates from the modern one we may have more
confidence in the model results concerning future
climate change. In addition, we can learn much
about climate dynamics on longer time scales beyond the recent period of direct measurements. The
knowledge on paleoclimatic change stems from indirect climatic observations, mainly from the geological record, which has conserved certain parameters related to the climatic conditions during and
after sedimentation. With these parameters as input a model can generate a variety of further climate variables which were not documented in the
paleoclimatic record. In this way the paleoclimate
can be reconstructed in more detail.
The lack of paleodata to retrieve the boundary
conditions for atmospheric models was one major
reason for the formation of the CLIMAP
(Climate:Long-Range Investigation Mapping and
Prediction) project. In 1976, the CLIMAP project
members were a consortium of 36 scientists from
19 different institutions (13 US and 6 European).
The main goals were to reconstruct the Earth's
From FISCHER G, WEFER G (eds), 1999, Use of Proxies in Paleoceanography: Examples from the South Atlantic.Springer·Verlag
Berlin Heidelberg, pp 687-714