Exploration of parametric uncertainty in a surface mass balance model applied to the Greenland ice sheet

Fitzgerald, Peter; Bamber, Jonathan; Ridley, Jeff; Rougier, Jonathan

doi:10.1029/2011jf002067

Cited by 30 publications

(32 citation statements)

References 86 publications

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“…This link is tightly coupled, because an increase in either term causes a reduction in albedo and therefore leads to a increase in melt. As found by previous studies (e.g., Fitzgerald et al, 2012), the representation of albedo is a critical component of melt and surface mass balance modeling. Here we also find that it is necessary to incorporate at least a simple treatment of albedo in order to properly simulate the changes in the snowpack.…”

Section: Discussionmentioning

confidence: 53%

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The importance of insolation changes for paleo ice sheet modeling

Robinson

Goelzer

2014

The Cryosphere

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Abstract. The growth and retreat of continental ice sheets in the past has largely been a response to changing climatic forcing. Since ablation is the principal component of mass loss for land-based ice sheets, the calculation of surface melt is an important aspect of paleo ice sheet modeling. Changes in insolation are often not accounted for in calculations of surface melt, under the assumption that the near-surface temperature transmits the majority of the climatic forcing to the ice sheet. To assess how this could affect paleo simulations, here we investigate the importance of different orbital configurations for estimating melt on the Greenland ice sheet. We find that during peak Eemian conditions, increased insolation contributes 20-50 % to the surface melt anomaly. However, this percentage depends strongly on the temperature anomaly at the time. For higher temperature anomalies, the role of insolation changes is less important. This relationship is not homogenous over the ice sheet, since the contribution of insolation to melt is modulated by the local surface albedo. In coupled simulations, the additional insolation-induced melt translates into up to threefold more ice volume loss, compared to output using a model that does not account for insolation changes. We also introduce a simple correction factor that allows reduced-complexity melt models to account for changes in insolation.

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Section: Discussionmentioning

confidence: 53%

“…This model has been validated with simulations of the Eurasian ice sheet (van den Berg et al, 2008) and the Greenland ice sheet (Robinson et al, 2010Fitzgerald et al, 2012). The insolationtemperature melt (ITM) equation approximates the melt rate, M (m s −1 ), as…”

Section: Melt Equationsmentioning

confidence: 99%

The importance of insolation changes for paleo ice sheet modeling

Robinson

Goelzer

2014

The Cryosphere

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“…For example, the mass balance parameters we use in ANICE (see de Boer et al, 2013) can be tested within a certain range of a physical parameter space (e.g. Fitzgerald et al, 2012). Similarly, ice flow and basal sliding can be varied (e.g.…”

Section: Discussionmentioning

confidence: 99%

A fully coupled 3-D ice-sheet–sea-level model: algorithm and applications

2014

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Abstract.Relative sea-level variations during the late Pleistocene can only be reconstructed with the knowledge of icesheet history. On the other hand, the knowledge of regional and global relative sea-level variations is necessary to learn about the changes in ice volume. Overcoming this problem of circularity demands a fully coupled system where ice sheets and sea level vary consistently in space and time and dynamically affect each other. Here we present results for the past 410 000 years (410 kyr) from the coupling of a set of 3-D ice-sheet-shelf models to a global sea-level model, which is based on the solution of the gravitationally selfconsistent sea-level equation. The sea-level model incorporates the glacial isostatic adjustment feedbacks for a Maxwell viscoelastic and rotating Earth model with coastal migration. Ice volume is computed with four 3-D ice-sheet-shelf models for North America, Eurasia, Greenland and Antarctica. Using an inverse approach, ice volume and temperature are derived from a benthic δ 18 O stacked record. The derived surface-air temperature anomaly is added to the present-day climatology to simulate glacial-interglacial changes in temperature and hence ice volume. The ice-sheet thickness variations are then forwarded to the sea-level model to compute the bedrock deformation, the change in sea-surface height and thus the relative sea-level change. The latter is then forwarded to the ice-sheet models. To quantify the impact of relative sea-level variations on ice-volume evolution, we have performed coupled and uncoupled simulations. The largest differences of ice-sheet thickness change occur at the edges of the ice sheets, where relative sea-level change significantly departs from the ocean-averaged sea-level variations.

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“…Since surface melt over the GrIS is mainly driven by the absorption of shortwave radiation , surface albedo is a primary factor governing ice sheet surface mass balance (SMB) (Bougamont et al, 2005;Tedesco et al, 2011;Fitzgerald et al, 2012) and surface energy balance (SEB) (Tedesco et al, 2008;. Ice albedo is mainly a function of impurity content, while snow albedo is sensitive to several snow physical properties, e.g., grain size, liquid water content, soot concentration and the presence of cryoconite.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the updated regional climate model RACMO2.3: summer snowfall impact on the Greenland Ice Sheet

et al. 2015

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Abstract. We discuss Greenland Ice Sheet (GrIS) surface mass balance (SMB) differences between the updated polar version of the RACMO climate model (RACMO2.3) and the previous version (RACMO2.1). Among other revisions, the updated model includes an adjusted rainfall-to-snowfall conversion that produces exclusively snowfall under freezing conditions; this especially favours snowfall in summer. Summer snowfall in the ablation zone of the GrIS has a pronounced effect on melt rates, affecting modelled GrIS SMB in two ways. By covering relatively dark ice with highly reflective fresh snow, these summer snowfalls have the potential to locally reduce melt rates in the ablation zone of the GrIS through the snow-albedo-melt feedback. At larger scales, SMB changes are driven by differences in orographic precipitation following a shift in large-scale circulation, in combination with enhanced moisture to precipitation conversion for warm to moderately cold conditions. A detailed comparison of model output with observations from automatic weather stations, ice cores and ablation stakes shows that the model update generally improves the simulated SMBelevation gradient as well as the representation of the surface energy balance, although significant biases remain.

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Exploration of parametric uncertainty in a surface mass balance model applied to the Greenland ice sheet

Cited by 30 publications

References 86 publications

The importance of insolation changes for paleo ice sheet modeling

The importance of insolation changes for paleo ice sheet modeling

A fully coupled 3-D ice-sheet–sea-level model: algorithm and applications

Evaluation of the updated regional climate model RACMO2.3: summer snowfall impact on the Greenland Ice Sheet

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