EGU2020-18037, updated on 13 Jan 2021
https://doi.org/10.5194/egusphere-egu2020-18037
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Comparison of the surface mass and energy balance of CESM and MAR forced by CESM over Greenland: present and future

Charlotte Lang1, Charles Amory1, Alison Delhasse, Stefan Hofer2, Christoph Kittel1, Leo van Kampenhout3, William Lipscomb4, and Xavier Fettweis1
Charlotte Lang et al.
  • 1University of Liège, Liège, Belgium (charlotte.lang@uliege.be)
  • 2School of Geographical Sciences, University of Bristol, UK
  • 3Institute for Marine and Atmospheric research Utrecht, Utrecht University, the Netherlands
  • 4National Center for Atmospheric Research, Boulder, CO, USA

We have compared the surface mass (SMB) and energy balance of the Earth System model (ESM) CESM (Community Earth System Model) with those of the regional climate model (RCM) MAR (Modèle Atmosphérique Régional) forced by CESM over the present era (1981 — 2010) and the future (2011 — 2100 with SSP585 scenario).

Until now, global climate models (GCM) and ESMs forcing RCMs such as MAR didn’t include a module able to simulate snow and energy balance at the surface of a snow pack like the SISVAT module of MAR and were therefore not able to simulate the SMB of an ice sheet. Evaluating the added value of an RCM compared to a GCM could only be done by comparing atmospheric outputs (temperature, wind, precipitation …) in both models. CESM is the first ESM including a land model capable of simulating the surface of an ice sheet and thus to directly compare the SMB of an RCM and an ESM the first time.

Our results show that, if the SMB and is components are very similar in CESM and MAR over the present era, they quickly start to diverge in our future projection, the SMB of MAR decreasing more than that of CESM. This difference in SMB evolution is almost exclusively explained by a much larger increase of the melter runoff in MAR compared to CESM whereas the temporal evolution of snowfall, rainfall and sublimation is comparable in both runs.

How to cite: Lang, C., Amory, C., Delhasse, A., Hofer, S., Kittel, C., van Kampenhout, L., Lipscomb, W., and Fettweis, X.: Comparison of the surface mass and energy balance of CESM and MAR forced by CESM over Greenland: present and future, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18037, https://doi.org/10.5194/egusphere-egu2020-18037, 2020

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Display material version 1 – uploaded on 06 May 2020
  • CC1: Comment on EGU2020-18037, Robin Smith, 07 May 2020

    Thanks Charlotte, this is really interesting. I'm glad you've done this analysis - we see an extremely similar thing with the UKESM GrIS SMB (also from elevation tiles) compared with MAR forced at the boundaries by the UKESM climate, but we haven't had a chance to explore it as you have

    • AC1: Reply to CC1, Charlotte Lang, 08 May 2020

      Thanks for you comment Robin. Yes, I remember that when Xavier offered me to do the MAR-CESM comparison there was also a discussion about comparing MAR and UKESM as well. But the SMB was only available at elevation bands and we couldn't work with that if I'm not mistaken.