Impact of the melt-albedo feedback on the future evolution of the Greenland Ice Sheet with PISM-dEBM-simple
- Surface melting of the Greenland Ice Sheet contributes a large amount to current and future sea level rise. Increased surface melt may lower the reflectivity of the ice sheet surface and thereby increase melt rates: the so-called melt-albedo feedback describes this self-sustaining increase in surface melting. In order to test the effect of the melt-albedo feedback in a prognostic ice sheet model, we implement dEBM-simple, a simplified version of the diurnal Energy Balance Model dEBM, in the Parallel Ice Sheet Model (PISM). The implementation includes a simple representation of the melt-albedo feedback and can thereby replace the positive-degree-day melt scheme. Using PISM-dEBM-simple, we find that this feedback increases ice loss through surface warming by 60 % until 2300 for the high-emission scenario RCP8.5 when compared to a scenario in which the albedo remains constant at its present-day values. With an increase of 90 % compared to a fixed-albedo scenario, the effect is more pronounced for lower surface warming under RCP2.6.Surface melting of the Greenland Ice Sheet contributes a large amount to current and future sea level rise. Increased surface melt may lower the reflectivity of the ice sheet surface and thereby increase melt rates: the so-called melt-albedo feedback describes this self-sustaining increase in surface melting. In order to test the effect of the melt-albedo feedback in a prognostic ice sheet model, we implement dEBM-simple, a simplified version of the diurnal Energy Balance Model dEBM, in the Parallel Ice Sheet Model (PISM). The implementation includes a simple representation of the melt-albedo feedback and can thereby replace the positive-degree-day melt scheme. Using PISM-dEBM-simple, we find that this feedback increases ice loss through surface warming by 60 % until 2300 for the high-emission scenario RCP8.5 when compared to a scenario in which the albedo remains constant at its present-day values. With an increase of 90 % compared to a fixed-albedo scenario, the effect is more pronounced for lower surface warming under RCP2.6. Furthermore, assuming an immediate darkening of the ice surface over all summer months, we estimate an upper bound for this effect to be 70 % in the RCP8.5 scenario and a more than 4-fold increase under RCP2.6. With dEBM-simple implemented in PISM, we find that the melt-albedo feedback is an essential contributor to mass loss in dynamic simulations of the Greenland Ice Sheet under future warming.…
Author details: | Maria ZeitzORCiDGND, Ronja ReeseORCiDGND, Johanna BeckmannORCiDGND, Uta Krebs-KanzowORCiDGND, Ricarda WinkelmannORCiDGND |
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DOI: | https://doi.org/10.5194/tc-15-5739-2021 |
ISSN: | 1994-0416 |
ISSN: | 1994-0424 |
Title of parent work (English): | The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union |
Publisher: | Copernicus |
Place of publishing: | Katlenburg-Lindau |
Publication type: | Article |
Language: | English |
Date of first publication: | 2021/12/20 |
Publication year: | 2021 |
Release date: | 2024/04/23 |
Volume: | 15 |
Issue: | 12 |
Number of pages: | 26 |
First page: | 5739 |
Last Page: | 5764 |
Funding institution: | Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [401011539]; Leibniz-Gemeinschaft (DominoES grant) |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 9 Geschichte und Geografie / 91 Geografie, Reisen / 910 Geografie, Reisen |
Peer review: | Referiert |
Publishing method: | Open Access / Gold Open-Access |
DOAJ gelistet | |
License (German): | CC-BY - Namensnennung 4.0 International |