Quantification of subsurface heat storage in the GCM ECHO-g: Effects of shallow bottom boundary placement
Recent studies indicate that shallow bottom boundary conditions (BBCs) used in state-of-the-art GCMs impose an artificial limit to the amount of heat that can be absorbed by the subsurface. Since this is an important issue for determining the energy partitioning among climate model subsystems. To better quantify this effect, the energy accumulation from the ECHO-g soil model is compared to the energy accumulation in a finite difference land- surface model (FDLSM) driven by the ECHO-g based IPCC A2 and B2 future climate simulation. The FDLSM is run with a BBC at the same depth as the ECHO-g soil model (10m) to verify that the soil models are thermodynamically equivalent. A run with a deep, causally detached BBC is also carried out. Results show that the deep FDLSM run captures several times more energy than the ECHO-g soil model for the time period 1991- 2100 CE. The spatial distribution of the FDLSM enhanced heat storage is described. These results suggest that shallow BBCs in GCMs prevent large amounts of heat from being stored in the subsurface and that this effect could be relevant in simulations of future climate change.
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- 1600 GLOBAL CHANGE;
- 1622 Earth system modeling (1225);
- 1631 Land/atmosphere interactions (1218;