Preprints
https://doi.org/10.5194/tc-2022-150
https://doi.org/10.5194/tc-2022-150
 
31 Aug 2022
31 Aug 2022
Status: this preprint is currently under review for the journal TC.

Representation of soil hydrology in permafrost regions may explain large part of inter-model spread in simulated Arctic and subarctic climate

Philipp de Vrese1, Goran Georgievski1, Jesus Fidel Gonzalez Rouco2, Dirk Notz1,3, Tobias Stacke1, Norman Julius Steinert4, Stiig Wilkenskjeld1, and Victor Brovkin1,5 Philipp de Vrese et al.
  • 1Max Planck Institute for Meteorology, The Ocean in the Earth System, Hamburg, 20146, Germany
  • 2University Complutense of Madrid, Department of Earth Physics and Astrophysics, Madrid, 28040, Spain
  • 3University of Hamburg, Faculty of Mathematics, Informatics and Natural Sciences, Hamburg, 20146, Germany
  • 4Norwegian Research Centre Climate and Environment, Bjerknes Centre for Climate Research, Bergen, 5007, Norway
  • 5University of Hamburg, Center for Earth System Research and Sustainability, Hamburg, 20146, Germany

Abstract. The current generation of Earth system models exhibits large inter-model differences in the simulated climate of the Arctic and subarctic zone, with differences in model structure and parametrizations being one of the main sources of uncertainty. One particularly challenging aspect in modelling is the representation of terrestrial processes in permafrost-affected regions, which are often governed by spatial heterogeneity far below the resolution of the models' land surface components. Here, we use the MPI Earth System model to investigate how different plausible assumptions for the representation of the permafrost hydrology modulate the land-atmosphere interactions and how the resulting feedbacks affect not only the regional and global climate, but also our ability to predict whether the high latitudes will become wetter or drier in a warmer future. Focusing on two idealized setups that induce comparatively "wet" or "dry" conditions in regions that are presently affected by permafrost, we find that the parameter settings determine the direction of the 21st-century trend in the simulated soil water content and result in substantial differences in the land-atmosphere exchange of energy and moisture. The latter leads to differences in the simulated cloud cover and thus in the planetary energy uptake. The respective effects are so pronounced that uncertainties in the representation of the Arctic hydrological cycle can help to explain a large fraction of the inter-model spread in regional surface temperatures and precipitation. Furthermore, they affect a range of components of the Earth system as far to the south as the tropics. With both setups being similarly plausible, our findings highlight the need for more observational constraints on the permafrost hydrology to reduce the inter-model spread in Arctic climate projections.

Philipp de Vrese et al.

Status: open (until 02 Nov 2022)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Philipp de Vrese et al.

Philipp de Vrese et al.

Viewed

Total article views: 218 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
143 71 4 218 24 2 2
  • HTML: 143
  • PDF: 71
  • XML: 4
  • Total: 218
  • Supplement: 24
  • BibTeX: 2
  • EndNote: 2
Views and downloads (calculated since 31 Aug 2022)
Cumulative views and downloads (calculated since 31 Aug 2022)

Viewed (geographical distribution)

Total article views: 202 (including HTML, PDF, and XML) Thereof 202 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 06 Oct 2022
Download
Short summary
The current generation of Earth system models exhibits large inter-model differences in the simulated climate of the Arctic and subarctic zone. We used an adapted version of the MPI Earth System model to show that differences in the representation of the soil hydrology in permafrost-affected regions could help explain a large part of the inter-model spread in the Arctic and subarctic climate and also have pronounced impacts on important whether systems as far to the south as the tropics.