Ice flux evolution in fast flowing areas of the Greenland ice sheet over the 20th and 21st centuries

Peano, Daniele; Colleoni, Florence; Quiquet, Aurélien; Masina, Simona

doi:10.1017/jog.2017.12

Cited by 21 publications

(22 citation statements)

References 95 publications

(207 reference statements)

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“…5G-H). This increase-decrease ice velocity pattern has been also reported by Peano et al (2017), using GRISLI forced by CMIP5 models under the RCP8.5 scenario.…”

Section: Grislisupporting

confidence: 83%

Assessment of the Greenland ice sheet – atmosphere feedbacks for the next century with a regional atmospheric model fully coupled to an ice sheet model

clec’h¹,

Fettweis²,

Quiquet³

et al. 2017

Preprint

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Abstract. In the context of global warming, the projected Greenland sea level rise contribution is mainly controlled by the interactions between the Greenland ice sheet (GrIS) and the atmosphere, in particular through the temperature and surface mass balance -elevation feedback. In order to evaluate the importance of these feedbacks, we used three methods to represent the interactions between the GrIS model GRISLI and the polar regional atmosphere model MAR, under the RCP 8.5 scenario from 2020 to 2150. In the simplest method, there is no coupling, MAR computes varying atmospheric conditions using a constant 5 GrIS geometry (topography and extent) set to observations and GRISLI is forced by these results. The second is a one-way coupling method which represents the interactions by correcting offline the MAR outputs to account for topography changes computed by GRISLI. The third method is a full two-way coupling in which the ice sheet topography and extent seen by the atmospheric model evolve after each ice sheet model time step. Due to the ice sheet elevation feedback, the two-way coupling method amplifies the projected decrease in surface mass balance, the increase in surface temperature and the GrIS surface 10 thinning for the coastal regions, compared to the no coupling method. Compared to both the one-way and the no coupling methods, the two-way coupling allows the changes of fine scale processes to be represented, such as the increase in katabatic winds over the coast. As a consequence, in 2150, the two-way coupling method computes a GrIS melting contribution to sea level rise 9.3 % larger than the no coupling method, and 2.5 % larger than the one-way coupling methods. After 150 years, the GrIS extent seen by MAR in the two-way method is 52 400 km 2 lower than with the no coupling method. Furthermore, 15 in 2150, using a fix ice sheet mask, as in the no coupling method, overestimates by 24 % the SLR contribution from SMB compared to the use of the ice sheet mask as simulated in the two-way method. Beyond the century time-scale, a two-way method becomes necessary in order to avoid an underestimation of the projected ice sheet volume, topography and ice extent reduction. The one-way coupling method however seems to be sufficient to represent the interactions for projections until the end of the 21 st century. The no coupling method always underestimates the projected ice sheet volume loss significantly due 20 to the lack of feedback between the GrIS and the atmosphere. 1The Cryosphere Discuss., https://doi

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“…5G-H). This increase-decrease ice velocity pattern has been also reported by Peano et al (2017), using GRISLI forced by CMIP5 models under the RCP8.5 scenario.…”

Section: Grislisupporting

confidence: 83%

Assessment of the Greenland ice sheet – atmosphere feedbacks for the next century with a regional atmospheric model fully coupled to an ice sheet model

clec’h¹,

Fettweis²,

Quiquet³

et al. 2017

Preprint

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“…the extension of the geographical domain and the duration of the simulated period. For century scale applications, the resolution varies 15 from 5 km for Greenland to 15 km for Antarctica (Peano et al, 2017;Ritz et al, 2015). For multi-millenial applications the resolution increases to 15 km for Greenland and 40 km for the whole Northern Hemisphere and Antarctica.…”

Section: Numerical Featuresmentioning

confidence: 99%

The GRISLI ice sheet model (version 2.0): calibration and validation for multi-millennial changes of the Antarctic ice sheet

Quiquet¹,

Dumas²,

Ritz³

et al. 2018

Preprint

Self Cite

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Abstract.In this paper we present the GRISLI (Grenoble Ice Sheet and Land Ice) model in its newest revision (version 2.0). Whilst GRISLI is applicable to any given geometry, we focus here on the Antarctic ice sheet because it highlights the importance of grounding line dynamics. Important improvements have been implemented since its original version (Ritz et al., 2001) including notably an explicit flux computation at the grounding line based on the analytical formulations of Schoof (2007) 5 and Tsai et al. (2015) and a basal hydrology model. A calibration of the mechanical parameters of the model based on an ensemble of 150 members sampled with a Latin Hypercube method is used. The ensemble members performance is assessed relative to the deviation from present-day observed Antarctic ice thickness. The model being designed for multi-millenial longterm integrations, we also present glacial-interglacial ice sheet changes throughout the last 400 kyr using the best ensemble members. To achieve this goal, we construct a simple climatic perturbation of present-day climate forcing fields based on 10 two climate proxies, both atmospheric and oceanic. The model is able to reproduce expected grounding line advances during glacials and subsequent retreats during terminations with reasonable glacial-interglacial ice volume changes.

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“…Greve and Otsu (2007) succeed in reproducing a correct magnitude of its speed by increasing the basal sliding under the NEGIS by 3 orders of magnitude relative to the rest of the ice sheet, but they fail in reproducing its geometry. A good agreement between model and data is found in Price et al (2011) and Peano et al (2017), who use a spatially variable basal friction coefficient derived from an iterative inverse method to match the observed velocities. Our imperfect reproduction of the NEGIS is probably related to a combination of low spatial resolution (10 km) and problems in capturing the dynamics at the base of the ice sheet.…”

Section: Model Performance On the Whole Grismentioning

confidence: 71%

Submarine melt as a potential trigger of the North East Greenland Ice Stream margin retreat during Marine Isotope Stage 3

et al. 2019

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The Northeast Greenland Ice Stream (NEGIS) has been suffering a significant ice mass loss during the last decades. This is partly due to increasing oceanic temperatures in the subpolar North Atlantic, which enhance submarine basal melting and mass discharge. This demonstrates the high sensitivity of this region to oceanic changes. In addition, a recent study suggested that the NEGIS grounding line was 20-40 km behind its present-day location for 15 ka during Marine Isotope Stage (MIS) 3. This is in contrast with Greenland temperature records indicating cold atmospheric conditions at that time, expected to favour ice-sheet expansion. To explain this anomalous retreat a combination of atmospheric and external forcings has been invoked. Yet, as the ocean is found to be a primary driver of the ongoing retreat of the NEGIS glaciers, the effect of past oceanic changes in their paleo evolution cannot be ruled out and should be explored in detail. Here we investigate the sensitivity of the NEGIS to the oceanic forcing during the last glacial period using a three-dimensional hybrid ice-sheet-shelf model. We find that a sufficiently high oceanic forcing could account for a NEGIS ice-margin retreat of several tens of kilometres, potentially explaining the recently proposed NEGIS groundingline retreat during Marine Isotope Stage 3.

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Ice flux evolution in fast flowing areas of the Greenland ice sheet over the 20th and 21st centuries

Cited by 21 publications

References 95 publications

Assessment of the Greenland ice sheet – atmosphere feedbacks for the next century with a regional atmospheric model fully coupled to an ice sheet model

Assessment of the Greenland ice sheet – atmosphere feedbacks for the next century with a regional atmospheric model fully coupled to an ice sheet model

The GRISLI ice sheet model (version 2.0): calibration and validation for multi-millennial changes of the Antarctic ice sheet

Submarine melt as a potential trigger of the North East Greenland Ice Stream margin retreat during Marine Isotope Stage 3

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