EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Assessing Arctic Ground Surface Temperatures from Borehole Temperatures and Paleoclimatic Model Simulations

Hugo Beltrami1, Fracisco José Cuesta-Valero1, Almudena García-García1,2, Stephan Gruber3, and Fernando Jaume-Santero4
Hugo Beltrami et al.
  • 1St. Francis Xavier University, Climate & Atmospheric Sciences Institute, Earth Sciences, Antigonish, Canada (
  • 2Department of Remote Sensing, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig, Germany
  • 3Department of Geography and Environmental Studies, Carleton University, Ottawa, ON, K1S 5B6, Canada
  • 4Universidad Complutense de Madrid, 28040 Madrid, Spain

The surface temperature response to changes in our planet’s external forcing is larger at higher latitudes, a phenomenon known as polar amplification. The Arctic amplification has been particularly intense during the last century, with arctic-wide paleoclimatic reconstructions and state-of-the-art model simulations revealing a twofold arctic warming in comparison with the average global temperature increase. As a consequence, Arctic ground temperatures respond with rapid warming, but this response varies with snow cover and permafrost processes. Thus, changes in arctic ground temperatures are difficult to reconstruct from data, and to simulate in climate models.

Here, we reconstruct the ground surface temperature histories of 120 borehole temperature profiles above 60ºN for the last 400 years. Past surface temperature evolution from each profile was estimated using a Perturbed Parameter Inversion approach based on a singular value decomposition method. Long-term surface temperature climatologies (circa 1300 and 1700 CE) and quasi-steady state heat flow are also estimated from linear regression through the depth range 200 to 300 m of each borehole temperature profile. The retrieved temperatures are assessed against simulated ground surface temperatures from five Past Millennium and five Historical experiments from the Paleoclimate Modelling Intercomparison Project Phase III (PMIP3), and the fifth phase of the Coupled Model Intercomparison Project (CMIP5) archives, respectively.

Preliminary results from borehole estimates and PMIP3/CMIP5 simulations reveal that changes in recent Arctic ground temperatures vary spatially and are related to each site’s earlier thermal state of the surface. The magnitudes of ground warming from data and simulations differ with large discrepancies among models. As a consequence, a better understanding of freezing processes at and below the air-ground interface is necessary to interpret subsurface temperature records and global climate model simulations in the Arctic.

How to cite: Beltrami, H., Cuesta-Valero, F. J., García-García, A., Gruber, S., and Jaume-Santero, F.: Assessing Arctic Ground Surface Temperatures from Borehole Temperatures and Paleoclimatic Model Simulations, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9222,, 2021.


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