Analysis of the melting from ice and snow in the tropical Andes using the energy balance approach : Glacier Antisana, Ecuador (0 ° 28'S).

• Main Author: Maisincho Guagrilla, Luis
• Other Authors: Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes, Escuela politécnica nacional (Quito), Bernard Francou
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2015
• Subjects: Glacier; Melt; Climat; Energy balance; Water resource; Fonte; Bilan d'énergie; Ressource en eau; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarc*; Antarctica
• Online Access: https://theses.hal.science/tel-01561610; https://theses.hal.science/tel-01561610/document; https://theses.hal.science/tel-01561610/file/MAISINCHO_2015_diffusion.pdf

Antisana Glacier 15 basin surface mass balance (SMB) (0.28 km2;0°28'S,78° 09'W, 5750 m), located in the tropical Andes of Ecuador, between 2000 and 2008 has been modeled using two models: an empirical positive degree-day (PDD) and other physical surface energy balance approach.As a first stage, melting was calculated using daily temperature and the cumulative precipitation while sublimation was computed as wind-speed function. The PDD was applied at daily-time step and calibrated at 4900 m a.s.l. The period time to calibrate was March 2002 - August 2003 and validated was January - November 2005. A significant link between melting rates and temperature was revealed when model discriminates snow and ice surface. This relationship is explained by the link between the short-wave radiation and air temperature. However, this relationship disappears under intense wind-speed events, however this events show low air temperature, therefore they are not affect the final results. The PDD model was applied for modeling SMB, ablation, snow-line position and equilibrium line altitude. The results show this model type fits to SMB measures over Antisana glacier. However, it should not apply to other tropical regions, particularly where there are high sublimation rates (pronounced dry seasons) or where glaciers are located under the isotherm 0 ° C.A second stage, a distributed surface energy balance (DBES) model over glacier 15a of the Antisana was applied to quantify ice and snow ablation. For this task was used a model adapted to tropical conditions from Adélie Land-Antarctica BES model. Initially, the model was applied at 4900 m.a.s.l. , with a slope of 28º and NW (45 °) azimuth. For computing DBES, the glacier was divided in 18 altitude strips ( 50m/level). The model generated slops and azimuths from a digital elevation model (DEM). The meteorological vertical gradients were measured in the study zone. This values was used into de model as constants during both periods calibration and validation. The DBES model reproduced the ...