Time Continuous Climate Models for the Cretaceous
Abstract
Conventional paleoclimate studies use a "timeslice" approach in which climate simulations are run for a particular time interval (e.g. K/T, 66 Ma). This standard approach, however, has limited applicability for understanding the climatic transitions that take place between time intervals and the long-term pattern of climatic change. We present a new approach called "Time Continuous" Climate Modeling (TCCM), which is designed to evaluate global and regional climatic changes as continents slowly move, mountains ranges are built and eroded, and mid-ocean ridges and subduction zones evolve. To evaluate the impacts of these slow paleogeographic changes, simulations are run over closely spaced time intervals (1-5 million years). At such high-resolution time steps, we will be able to detect climatic tipping points, the importance of subtle changes in geography, the changes in global climatic as continents move across the globe, and the pattern of climate change that takes place over tens of millions of years. The TCCM approach is made possible by the use of: 1) high-performance Linux clusters 2) more efficient climates models (i.e., FOAM) and, 3) the availability of paleogeographic and paleobathymetric maps at one million year intervals (PALEOMAP Project). The initial simulation, in this case for the Late Cretaceous (66 Ma), is a standard 100-year coupled run. Each subsequent simulation, however, substitutes a new paleogeography (68 Ma), and uses the previous climatic end-results as the initial conditions for the subsequent simulation. Since the paleogeography only changes slightly between runs, the new simulation quickly stabilizes (~10 model years). Should instabilities develop, a full simulation, or ocean-only simulations can be run to resolve the problems. TCCM provides a new look at climatic evolution over longer time scales while minimizing the cost in terms of computing time and expense.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFMPP23B1343G
- Keywords:
-
- 0473 Paleoclimatology and paleoceanography (3344;
- 4900);
- 1620 Climate dynamics (0429;
- 3309);
- 3040 Plate tectonics (8150;
- 8155;
- 8157;
- 8158);
- 3337 Global climate models (1626;
- 4928);
- 9610 Cretaceous