Intense winter surface melt on an Antarctic ice shelf

P. Kuipers Munneke, A. J. Luckman, S. L. Bevan, C. J. P. P. Smeets, E. Gilbert, M. R. Van Den Broeke, W. Wang, C. Zender, B. Hubbard, D. Ashmore, A. Orr, J. C. King, B. Kulessa

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

66 Dyfyniadau (Scopus)
190 Wedi eu Llwytho i Lawr (Pure)

Crynodeb

The occurrence of surface melt in Antarctica has hitherto been associated with the austral summer season, when the dominant source of melt energy is provided by solar radiation. We use in‐situ and satellite observations from a previously unsurveyed region to show that events of intense surface melt on Larsen C Ice Shelf occur frequently throughout the dark Antarctic winter, with peak intensities sometimes exceeding summertime values. A regional atmospheric model confirms that, in the absence of solar radiation, these multi‐day melt events are driven by outbreaks of warm and dry föhn wind descending down the lee side of the Antarctic Peninsula mountain range, resulting in downward turbulent fluxes of sensible heat that drive sustained surface melt fluxes in excess of 200 W m−2. From 2015 to 2017 (including the extreme melt winter of 2016), ∼23% of the annual melt flux was produced in winter, and spaceborne observations of surface melt since 2000 show that wintertime melt is widespread in some years. Winter melt heats the firn layer to the melting point up to a depth of ∼3 m, thereby facilitating the formation of impenetrable ice layers, and retarding or reversing autumn and winter cooling of the firn. While the absence of a trend in winter melt is consistent with insignificant changes in the observed southern hemisphere atmospheric circulation during winter, we anticipate an increase in winter melt as a response to increasing greenhouse gas concentration.
Iaith wreiddiolSaesneg
Tudalennau (o-i)7615-7623
Nifer y tudalennau9
CyfnodolynGeophysical Research Letters
Cyfrol45
Rhif cyhoeddi15
Dyddiad ar-lein cynnar15 Mai 2018
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 16 Awst 2018

Ôl bys

Gweld gwybodaeth am bynciau ymchwil 'Intense winter surface melt on an Antarctic ice shelf'. Gyda’i gilydd, maen nhw’n ffurfio ôl bys unigryw.

Dyfynnu hyn