Greenland Ice Sheet surface melt amplified by snowline migration and bare ice exposure

J. C. Ryan; L. C. Smith; D. van As; S. W. Cooley; M. Cooper; L. H. Pitcher; Alun Hubbard

doi:10.1126/sciadv.aav3738

Greenland Ice Sheet surface melt amplified by snowline migration and bare ice exposure

J. C. Ryan
, L. C. Smith
, D. van As
, S. W. Cooley
, M. Cooper
, L. H. Pitcher
, Alun Hubbard

Adran Daearyddiaeth a Gwyddorau Daear

Brown University
University of California, Los Angeles
Geological Survey of Denmark and Greenland

Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

134 Dyfyniadau (Scopus)

190 Wedi eu Llwytho i Lawr (Pure)

Crynodeb

Greenland Ice Sheet mass loss has recently increased because of enhanced surface melt and runoff. Since melt is critically modulated by surface albedo, understanding the processes and feedbacks that alter albedo is a prerequisite for accurately forecasting mass loss. Using satellite imagery, we demonstrate the importance of Greenland’s seasonally fluctuating snowline, which reduces ice sheet albedo and enhances melt by exposing dark bare ice. From 2001 to 2017, this process drove 53% of net shortwave radiation variability in the ablation zone and amplified ice sheet melt five times more than hydrological and biological processes that darken bare ice itself. In a warmer climate, snowline fluctuations will exert an even greater control on melt due to flatter ice sheet topography at higher elevations. Current climate models, however, inaccurately predict snowline elevations during high melt years, portending an unforeseen uncertainty in forecasts of Greenland’s runoff contribution to global sea level rise

Iaith wreiddiol	Saesneg
Rhif yr erthygl	eaav3738
Nifer y tudalennau	10
Cyfnodolyn	Science advances
Cyfrol	5
Rhif cyhoeddi	3
Dynodwyr Gwrthrych Digidol (DOIs)	https://doi.org/10.1126/sciadv.aav3738
Statws	Cyhoeddwyd - 06 Maw 2019

NDC y CU

Mae’r allbwn hwn yn cyfrannu at y Nod(au) Datblygu Cynaliadwy canlynol

NDC 13 Gweithredu ar y Newid yn yr Hinsawdd

Mynediad at Ddogfen

10.1126/sciadv.aav3738Trwydded: CC BY-NC

Greenland Ice Sheet surface melt amplified by snowline migration and bare ice exposureFersiwn derfynol wedi’i chyhoeddi, 1.02 MBTrwydded: CC BY-NC

Cysylltiad parhaol

Dolen barhaus

Ffeiliau eraill a chysylltiadau

Dolen i’r cyhoeddiad yn Scopus

Investigating Meltwater Flow Beneath the Greenland Ice Sheet using a Multi-tracer Approach
Hubbard, A. (Arweinydd y Prosiect)
Natural Environment Research Council
01 Mai 2011 → 30 Ebr 2015
Prosiect: Ymchwil a ariannwyd yn allanol
A Holistic Model of Outlet Calving, Dynamic Acceloration and Drawdown for the Greenland Ice Sheet
Hubbard, A. (Arweinydd y Prosiect), King, M. (Cyd‑arweinydd Ymchwil) & Vieli, A. (Cyd‑arweinydd Ymchwil)
Natural Environment Research Council
01 Meh 2009 → 31 Mai 2011
Prosiect: Ymchwil a ariannwyd yn allanol
Dynamic Response of the Greenland Ice Sheet to Climate Forcing using a geophysical, Remote sensing and Numerical Modelling Framework
Hubbard, A. (Arweinydd y Prosiect) & Quincey, D. J. (Cyd‑arweinydd Ymchwil)
Natural Environment Research Council
01 Maw 2009 → 31 Ion 2013
Prosiect: Ymchwil a ariannwyd yn allanol

Dyfynnu hyn

@article{f4767a93f40f42be849e59001943ec6b,

title = "Greenland Ice Sheet surface melt amplified by snowline migration and bare ice exposure",

abstract = "Greenland Ice Sheet mass loss has recently increased because of enhanced surface melt and runoff. Since melt is critically modulated by surface albedo, understanding the processes and feedbacks that alter albedo is a prerequisite for accurately forecasting mass loss. Using satellite imagery, we demonstrate the importance of Greenland{\textquoteright}s seasonally fluctuating snowline, which reduces ice sheet albedo and enhances melt by exposing dark bare ice. From 2001 to 2017, this process drove 53\% of net shortwave radiation variability in the ablation zone and amplified ice sheet melt five times more than hydrological and biological processes that darken bare ice itself. In a warmer climate, snowline fluctuations will exert an even greater control on melt due to flatter ice sheet topography at higher elevations. Current climate models, however, inaccurately predict snowline elevations during high melt years, portending an unforeseen uncertainty in forecasts of Greenland{\textquoteright}s runoff contribution to global sea level rise",

author = "Ryan, \{J. C.\} and Smith, \{L. C.\} and \{van As\}, D. and Cooley, \{S. W.\} and M. Cooper and Pitcher, \{L. H.\} and Alun Hubbard",

note = "Funding Information: We thank Polar Field Services Inc. and Kangerlussuaq International Science Support (KISS) for providing the logistical support that assisted the conceptualization of the manuscript, with assistance from K. Young, S. Zager, and K. Cosper. We also thank H. Johnson (Brown University) for computing support. RCM outputs from MAR3.9 were provided by X. Fettweis. RCM outputs from RACMO2.3p2 were provided by B. No{\"e}l and M. van den Broeke. This research was funded by a NASA Cryosphere Program grant managed by T. P. Wagner. Publisher Copyright: Copyright {\textcopyright} 2019 The Authors.",

year = "2019",

month = mar,

day = "6",

doi = "10.1126/sciadv.aav3738",

language = "English",

volume = "5",

journal = "Science advances",

issn = "2375-2548",

publisher = "American Association for the Advancement of Science",

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AU - Ryan, J. C.

AU - Smith, L. C.

AU - van As, D.

AU - Cooley, S. W.

AU - Cooper, M.

AU - Pitcher, L. H.

AU - Hubbard, Alun

N1 - Funding Information: We thank Polar Field Services Inc. and Kangerlussuaq International Science Support (KISS) for providing the logistical support that assisted the conceptualization of the manuscript, with assistance from K. Young, S. Zager, and K. Cosper. We also thank H. Johnson (Brown University) for computing support. RCM outputs from MAR3.9 were provided by X. Fettweis. RCM outputs from RACMO2.3p2 were provided by B. Noël and M. van den Broeke. This research was funded by a NASA Cryosphere Program grant managed by T. P. Wagner. Publisher Copyright: Copyright © 2019 The Authors.

PY - 2019/3/6

Y1 - 2019/3/6

N2 - Greenland Ice Sheet mass loss has recently increased because of enhanced surface melt and runoff. Since melt is critically modulated by surface albedo, understanding the processes and feedbacks that alter albedo is a prerequisite for accurately forecasting mass loss. Using satellite imagery, we demonstrate the importance of Greenland’s seasonally fluctuating snowline, which reduces ice sheet albedo and enhances melt by exposing dark bare ice. From 2001 to 2017, this process drove 53% of net shortwave radiation variability in the ablation zone and amplified ice sheet melt five times more than hydrological and biological processes that darken bare ice itself. In a warmer climate, snowline fluctuations will exert an even greater control on melt due to flatter ice sheet topography at higher elevations. Current climate models, however, inaccurately predict snowline elevations during high melt years, portending an unforeseen uncertainty in forecasts of Greenland’s runoff contribution to global sea level rise

AB - Greenland Ice Sheet mass loss has recently increased because of enhanced surface melt and runoff. Since melt is critically modulated by surface albedo, understanding the processes and feedbacks that alter albedo is a prerequisite for accurately forecasting mass loss. Using satellite imagery, we demonstrate the importance of Greenland’s seasonally fluctuating snowline, which reduces ice sheet albedo and enhances melt by exposing dark bare ice. From 2001 to 2017, this process drove 53% of net shortwave radiation variability in the ablation zone and amplified ice sheet melt five times more than hydrological and biological processes that darken bare ice itself. In a warmer climate, snowline fluctuations will exert an even greater control on melt due to flatter ice sheet topography at higher elevations. Current climate models, however, inaccurately predict snowline elevations during high melt years, portending an unforeseen uncertainty in forecasts of Greenland’s runoff contribution to global sea level rise

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DO - 10.1126/sciadv.aav3738

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SN - 2375-2548

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JO - Science advances

JF - Science advances

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ER -

Greenland Ice Sheet surface melt amplified by snowline migration and bare ice exposure

Crynodeb

NDC y CU

Mynediad at Ddogfen

Cysylltiad parhaol

Ffeiliau eraill a chysylltiadau

Ôl bys

Prosiectau

Investigating Meltwater Flow Beneath the Greenland Ice Sheet using a Multi-tracer Approach

A Holistic Model of Outlet Calving, Dynamic Acceloration and Drawdown for the Greenland Ice Sheet

Dynamic Response of the Greenland Ice Sheet to Climate Forcing using a geophysical, Remote sensing and Numerical Modelling Framework

Dyfynnu hyn