Français

Francisco J. Cuesta-Valero

Master's candidate at StFX

Supervisors: Dr. Hugo Beltrami & Dr. Laxmi Sushama
Enrolled in CREATE program in September 2014

Continental energy storage from CMIP5 simulations

Although the continental energy contribution to the Earth's energy budget is small in comparison with the ocean heat storage component, ascertaining the magnitude of the subsurface energy storage may be important for clarifying the long-term energy imbalance of the climate system, and it may help to understand energy dependent near-surface processes with potential climate feedback mechanisms such as permafrost degradation and soil carbon stability. Using data from the fifth phase of Coupled Model Intercomparison Project (CMIP5) simulations we examined the models' representation of subsurface heat storage from their land surface model soil components over the continents. Projected soil temperature anomalies with respect to a reference period between 1986 and 2005 show a warmer soil in the future, but with a wide range of variability. This range is approximately constant with the depth, but warmer scenarios have wider ranges of soil temperature variability particularly at high latitudes, where models show the largest discrepancy in their projections for the climate of the ground. Estimating the potential subsurface heat content using a conductive forward model driven by each models' simulated soil temperature anomalies to a depth of 500 m for the period 1950 to 2000, results yield a range of mean subsurface heat storage magnitudes ranging from 0.7×1021 to 10×1021 J for all continental areas between 60°N to 60°S. Estimates from borehole temperature data yield an estimate of about 8±1×1021 J during the second half of the 20th century. Preliminary analysis shows that a few of the simulations are able to account for the magnitude of the subsurface heat storage obtained from geothermal data, but we find no correlation between the soil model bottom boundaries and subsurface heat storage.