One-year measurements of surface heat budget on the ablation zone of Antizana Glacier 15, Ecuadorian Andes

tropical Andes of Ecuador (inner tropics). These variables were used to compute the annual cycle of the local surface energy balance (SEB). The four radiative fluxes were directly measured, and the turbulent fluxes were calculated using the bulk aerodynamic approach, calibrating the roughness length by direct sublimation measurements. The meteorological conditions are relatively homogeneous throughout the year (air temperature and air humidity). There is a slight seasonality in precipitation with a more humid period between February and June. During June-September, wind velocity shows high values and is responsible for intense turbulent fluxes that cause reduction of melting. Considering the SEB over the whole year, it is dominated by net radiation, and albedo variations govern melting. During the period under consideration the net short-wave

[1]  S. Hastenrath.  The glaciation of the Ecuadorian Andes , 1981 .

[2]  Wouter H. Knap,et al.  The annual cycle of the surface energy balance , 1997 .

[3]  W. Ambach.  Nomographs for the determination of meltwater from snow- and ice surfaces , 1986 .

[4]  Georg Kaser,et al.  Glacier-climate interaction at low latitudes , 2001, Journal of Glaciology.

[5]  M. Vuille,et al.  New evidence for an ENSO impact on low-latitude glaciers: Antizana 15, Andes of Ecuador, 0°28'S , 2004 .

[6]  Johannes Oerlemans,et al.  Model study of the spatial distribution of the energy and mass balance of Morteratschgletscher, Switzerland , 2002, Journal of Glaciology.

[7]  N. Graham,et al.  Recent changes in tropical freezing heights and the role of sea surface temperature , 1996, Nature.

[8]  E. Brun,et al.  A numerical model to simulate snow-cover stratigraphy for operational avalanche forecasting , 1992, Journal of Glaciology.

[9]  P. Wagnon,et al.  Clear-sky albedo measurements on a sloping glacier surface: A case study in the Bolivian Andes , 2001 .

[10]  A. Meesters,et al.  Turbulence Observations Above a Smooth Melting Surface on the Greenland Ice Sheet , 1997 .

[11]  S. Hastenrath,et al.  The dramatic retreat of Mount Kenya's glaciers between 1963 and 1987: greenhouse forcing , 1992 .

[12]  Bernard Francou,et al.  Tropical climate change recorded by a glacier in the central Andes during the last decades of the twentieth century: Chacaltaya, Bolivia, 16°S , 2003 .

[13]  F. Obleitner,et al.  On Intercomparison Of Instruments Used Within The Vatnajökull Glacio-Meteorological Experiment , 1999 .

[14]  Glacier fluctuations and climate in the Cordillera Blanca, Peru , 1990 .

[15]  D. S. Munro,et al.  Surface Roughness and Bulk Heat Transfer on a Glacier: Comparison with Eddy Correlation , 1989, Journal of Glaciology.

[16]  R. Hock,et al.  Some aspects of energy balance and ablation of Storglaciaren, northern Sweden , 1996 .

[17]  J. Schieldge,et al.  Anomalous behavior of the atmospheric surface layer over a melting snowpack , 1981 .

[18]  J. Monteith,et al.  Boundary Layer Climates. , 1979 .

[19]  F. K. Hare,et al.  World Survey of Climatology , 1975 .

[20]  P. Wagnon,et al.  Anomalous heat and mass budget of Glaciar Zongo, Bolivia, during the 1997/98 El Niño year , 2001, Journal of Glaciology.

[21]  W. Schwerdtfeger.  Climates of Central and South America , 1976 .

[22]  Edgar L. Andreas,et al.  A theory for the scalar roughness and the scalar transfer coefficients over snow and sea ice , 1987 .

[23]  A. Casinière.  Heat exchange over a melting snow surface , 1974 .

[24]  J. Oerlemans.  The atmospheric boundary layer over melting glaciers , 1998 .

[25]  J.,et al.  A 1 year record of global radiation and albedo in the ablation zone of Morteratschgletscher, Switzerland , 1998, Journal of Glaciology.

[26]  Johannes Oerlemans,et al.  Energy Balance of a Glacier Surface: Analysis of Automatic Weather Station Data from the Morteratschgletscher, Switzerland , 2002 .

[27]  B. Denby,et al.  The use of bulk and profile methods for determining surface heat fluxes in the presence of glacier winds , 2000, Journal of Glaciology.

[28]  D. Scherer,et al.  Problems in the determination of sensible heat flux over snow , 2002 .

[29]  Melvin J. Dubnick.  Army Corps of Engineers , 1998 .

[30]  B. Grisogono,et al.  Glacier winds and parameterisation of the related surface heat fluxes , 2002 .

[31]  J. King,et al.  Heat and water vapour fluxes and scalar roughness lengths over an Antarctic ice shelf , 1994 .

[32]  Roger G. Barry,et al.  Mountain weather and climate , 1982 .

[33]  E. Martin,et al.  An Energy and Mass Model of Snow Cover Suitable for Operational Avalanche Forecasting , 1989, Journal of Glaciology.

[34]  Raymond S. Bradley,et al.  Mean annual temperature trends and their vertical structure in the tropical Andes , 2000 .

[35]  R. Hock.  Modelling of glacier melt and discharge , 1998 .

[36]  D. R. Hardy,et al.  Solar‐radiation‐maintained glacier recession on Kilimanjaro drawn from combined ice‐radiation geometry modeling , 2003 .

[37]  S. Hastenrath.  Climate dynamics of the tropics , 1985 .

[38]  B. Santer,et al.  Multidecadal changes in the vertical temperature structure of the tropical troposphere , 2000, Science.

[39]  The Influence of Cloudiness on The Net Radiation Balance of A Snow Surface with High Albedo , 1974 .

[40]  M. Broeke.  Momentum, Heat, and Moisture Budgets of the Katabatic Wind Layer over a Midlatitude Glacier in Summer , 1997 .

[41]  Stephen G. Warren,et al.  Optical Properties of Snow , 1982 .

[42]  E. Morris.  Turbulent transfer over snow and ice , 1989 .

[43]  S. Martín.  Wind Regimes And Heat Exchange On Glacier De Saint-Sorlin , 1975, Journal of Glaciology.

[44]  R. D. Moore.  On the Use of Bulk Aerodynamic Formulae Over Melting Snow , 1983 .

[45]  B. Francou,et al.  Glacier Evolution in the Tropical Andes during the Last Decades of the 20th Century: Chacaltaya, Bolivia, and Antizana, Ecuador , 2000 .

[46]  Bernard Bourges,et al.  Improvement in solar declination computation , 1985 .

[47]  R. Bradley,et al.  Climate Variability in the Andes of Ecuador and Its Relation to Tropical Pacific and Atlantic Sea Surface Temperature Anomalies , 2000 .

[48]  P. Wagnon,et al.  Annual cycle of energy balance of Zongo Glacier, Cordillera Real, Bolivia , 1999 .

[49]  D. H. Male,et al.  Snow surface energy exchange , 1981 .

[50]  A 1 year record of global radiation and albedo in the ablation zone of Morteratschgletscher, Switzerland , 1998 .

[51]  Jeff Dozier,et al.  Climate and energy exchange at the snow surface in the Alpine Region of the Sierra Nevada: 2. Snow cover energy balance , 1992 .