Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 4.524 IF 4.524
  • IF 5-year value: 5.558 IF 5-year
    5.558
  • CiteScore value: 4.84 CiteScore
    4.84
  • SNIP value: 1.425 SNIP 1.425
  • IPP value: 4.65 IPP 4.65
  • SJR value: 3.034 SJR 3.034
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 55 Scimago H
    index 55
  • h5-index value: 52 h5-index 52
Volume 3, issue 1
The Cryosphere, 3, 21-30, 2009
https://doi.org/10.5194/tc-3-21-2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.
The Cryosphere, 3, 21-30, 2009
https://doi.org/10.5194/tc-3-21-2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.

  09 Feb 2009

09 Feb 2009

Measured and modelled sublimation on the tropical Glaciar Artesonraju, Perú

M. Winkler1, I. Juen1, T. Mölg1, P. Wagnon2, J. Gómez3, and G. Kaser1 M. Winkler et al.
  • 1Tropical Glaciology Group, Faculty of Geo- and Atmospheric Sciences, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria
  • 2IRD Great Ice, Laboratoire de Glaciologie et Geóphysique de l'Environnement, Saint Martin d'Hères, France
  • 3Unidad de Glaciología y Recursos Hídricos, Huaráz, Perú

Abstract. Sublimation plays a decisive role in the surface energy and mass balance of tropical glaciers. During the dry season (May–September) low specific humidity and high surface roughness favour the direct transition from ice to vapour and drastically reduce the energy available for melting. However, field measurements are scarce and little is known about the performance of sublimation parameterisations in glacier mass balance and runoff models.

During 15 days in August 2005 sublimation was measured on the tongue of Glaciar Artesonraju (8°58' S, 77°38' W) in the Cordillera Blanca, Perú, using simple lysimeters. Indicating a strong dependence on surface roughness, daily totals of sublimation range from 1–3 kg m−2 for smooth to 2–5 kg m−2 for rough conditions. (The 15-day means at that time of wind speed and specific humidity were 4.3 m s−1 and 3.8 g kg−1, respectively.)

Measured sublimation was related to characteristic surface roughness lengths for momentum (zm) and for the scalar quantities of temperature and water vapour (zs), using a process-based mass balance model. Input data were provided by automatic weather stations, situated on the glacier tongue at 4750 m a.s.l. and 4810 m a.s.l., respectively. Under smooth conditions the combination zm=2.0 mm and zs=1.0 mm appeared to be most appropriate, for rough conditions zm=20.0 mm and zs=10.0 mm fitted best.

Extending the sublimation record from April 2004 to December 2005 with the process-based model confirms, that sublimation shows a clear seasonality. 60–90% of the energy available for ablation is consumed by sublimation in the dry season, but only 10–15% in the wet season (October–April). The findings are finally used to evaluate the parameterisation of sublimation in the lower-complexity mass balance model ITGG, which has the advantage of requiring precipitation and air temperature as only input data. It turns out that the implementation of mean wind speed is a possible improvement for the representation of sublimation in the ITGG model.

Publications Copernicus
Download
Citation
Share