Earth System Modelling – Palaeoclimate and palaeoceanography through time

Getech’s Earth System Modelling work includes palaeoclimate, palaeoceanography, vegetation, tide and wave modelling results for every stratigraphic Stage from the beginning of the Jurassic to the Present Day.  This is the most comprehensive modelling project ever attempted in industry or academia. Two principal models are used: the HadCM3L coupled ocean-atmosphere general circulation model, which is run for us by Professor Paul Valdes, and Drs Dan Lunt and Claire Lopston at the University of Bristol; the ICOM (Imperial College Ocean Model), run on our behalf by Professor Peter Allison and his team at Imperial College, London.

Palaeoclimatology plays a major role in determining the style of deposition processes at different latitudes and has long been used in exploration (e.g. the prediction of coastal upwelling (Parrish et al., 1982)). At Getech we have a one of the most experienced teams outside of academia, with three professional, PhD-level palaeoclimatologists. We also have very close relationships with the academic groups with whom we work.

Schematic representation of the elements of the HadCM3L model

Schematic representation of the elements of the HadCM3L model

This expertise has been applied to generating the most extensive atlas of Earth System Model results currently available, with each of Getech’s Globe sea-level high stand palaeogeographic maps for each Stage used as boundary conditions for climate, ocean, vegetation and tide model runs.  These portfolios are now being extended with a systematic series of sensitivity experiments to test model-model differences, orbital variability (Milankovitch), boundary condition uncertainty and grid size effects. In all cases this provides cutting edge scientific insights that will help better constrain how and where the results of Earth System Modelling can be best applied in exploration.

Example of the output of the HadCM3L model showing the Berriasian Total Precipitation for the South Atlantic region. Note the band or aridity across central South America (including the Parana Basin) eastwards into Angola and northern Namibia.

Example of the output of the HadCM3L model showing the Berriasian Total Precipitation for the South Atlantic region. Note the band or aridity across central South America (including the Parana Basin) eastwards into Angola and northern Namibia.

HadCM3L – Atmosphere, Ocean and Vegetation

Within the HadCM3L atmospheric composition is set at a level appropriate for the timeslice being modelled, and solar constant is calculated for each stage using the formula of Gough (1981). The HadCM3L is also coupled to the Met Office Surface Exchange Scheme (MOSES 2) tiled land-surface model and the Top-down Representation of Interactive Foliage and Flora Including Dynamics model (TRIFFID).  The HadCM3L model uses a grid system with 19 levels going up into the atmosphere and 20 levels going down into the ocean at a resolution of 3.75 x 2.5 degrees. All results are reprocessed to a resolution of 0.5 degrees to be compatible with the original palaeogeographic maps.

Example of the mesh used in the Fluidity ICOM model (Berriasian)

Example of the mesh used in the Fluidity ICOM model (Berriasian)

ICOM – Tides and Waves

The ICOM (Imperial College Ocean Model) model is a 3D non-hydrostatic finite element model that uses a variable mesh, which changes resolution depending on the degree of detail required: a higher resolution mesh is used for areas of shallow water or complex bathymetry; whereas, a coarser  mesh is used for most of the deep ocean (>500 m). This is converted to a resolution of 0.1 degrees for the atlases we release.

Atlases of Earth System Modelling

Nine Atlases of Earth System Modelling have been produced to date; three Palaeotidal, three Palaeoclimate, and three Lithofacies Prediction Model results for the Cenozoic, Cretaceous and Jurassic.  Each of the Palaeoclimate and Palaeotidal Atlases includes a report, an mxd for each Stage and a geodatabase for each Stage. We also provide a folder of Layer Files for each Stage which allows the user to drag and drop the model layers into a separate mxd automatically formatted.  The Lithofacies Prediction Model Results include a report, a palaeolithofacies Atlas mxd and geodatabase for each Stage, and a palaeolithofacies toolbox mxd and geodatabase for each stage.

Example of the output of the HadCM3L model showing the Maastrichtian Mean Annual Surface Temperature in Orthographic view with the highstand line and hillshade included.

Example of the output of the HadCM3L model showing the Maastrichtian Mean Annual Surface Temperature in Orthographic view with the highstand line and hillshade included.

Palaeoclimatology and Exploration

Getech’s Earth System Modelling is a unique global palaeoclimate and palaeoceanography solution using state of the art modelling developed over many years, combined with continued research and development into the uses of the data produced in hydrocarbon play prediction.

The results produced by the models are being continuously validated against other models e.g. NCAR and palaeoclimate proxy data which is being collated within Getech’s Wells and Points database.

The results of the HadCM3L and ICOM model runs are then used within Getech’s Lithofacies Prediction Modelling project to evaluate global source rock potential. The results of the palaeoclimate and palaeoceanographic modelling are also used within Getech’s Commissions Group to assist in evaluating areas for hydrocarbon potential where little other data are available.

References Cited

Parrish, J.T. and R.B. Curtis (1982). “Atmospheric circulation, upwelling, and organic-rich rocks in the Mesozoic and Cenozoic eras” Palaeogeography, Palaeoclimatology, Palaeoecology, v.40 (1–3), p.31–66

To find out more about Getech’s Earth System Modelling please click to get in touch