Reconstructing geographical boundary conditions for palaeoclimate modelling during the Cenozoic
Studies on the palaeoclimate and palaeoceanography using numerical model simulations may be considerably dependent on the implemented geographical reconstruction. Because building the palaeogeographic datasets for these models is often a time-consuming and elaborate exercise, palaeoclimate models fr...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-08-01
|
| Series: | Climate of the Past |
| Online Access: | http://www.clim-past.net/12/1635/2016/cp-12-1635-2016.pdf |
| Summary: | Studies on the palaeoclimate and palaeoceanography using numerical model
simulations may be considerably dependent on the implemented geographical
reconstruction. Because building the palaeogeographic datasets for these
models is often a time-consuming and elaborate exercise, palaeoclimate models
frequently use reconstructions in which the latest state-of-the-art plate
tectonic reconstructions, palaeotopography and -bathymetry, or vegetation
have not yet been incorporated. In this paper, we therefore provide a new
method to efficiently generate a global geographical reconstruction for the
middle-late Eocene. The generalised procedure is also reusable to create
reconstructions for other time slices within the Cenozoic, suitable for
palaeoclimate modelling. We use a plate-tectonic model to make global masks
containing the distribution of land, continental shelves, shallow basins and
deep ocean. The use of depth-age relationships for oceanic crust together
with adjusted present-day topography gives a first estimate of the global
geography at a chosen time frame. This estimate subsequently needs manual
editing of areas where existing geological data indicate that the altimetry
has changed significantly over time. Certain generic changes (e.g. lowering
mountain ranges) can be made relatively easily by defining a set of masks
while other features may require a more specific treatment. Since the
discussion regarding many of these regions is still ongoing, it is crucial to
make it easy for changes to be incorporated without having to redo the entire
procedure. In this manner, a complete reconstruction can be made that
suffices as a boundary condition for numerical models with a limited effort.
This facilitates the interaction between experts in geology and palaeoclimate
modelling, keeping reconstructions up to date and improving the consistency
between different studies. Moreover, it facilitates model inter-comparison
studies and sensitivity tests regarding certain geographical features as
newly generated boundary conditions can more easily be incorporated in
different model simulations. The workflow is presented covering a middle-late
Eocene reconstruction (38 Ma), using a MatLab script and a complete
set of source files that are provided in the supplementary material. |
|---|---|
| ISSN: | 1814-9324 1814-9332 |