The application of a distributed energy balance model over nine years at an hourly time step to a 20 × 20 m grid cell over Glacier Zongo (Bolivia, 16°S) enabled assessment of the climate factors that control the interseasonal and interannual variability of its surface mass balance. The model was validated by comparing the measured and simulated discharge at the outlet, albedo at the Automatic Weather Station, surface state and annual mass balance both glacier-wide and as a function of altitude. Analysis of the mean monthly energy fluxes highlighted the importance of the meteorological conditions over October and November on the variability of the annual surface mass balance. Two sensitivity analyses are presented, one of the distribution of precipitation over time which maintains a physical coherence between the different meteorological variables and one of the impact of prolonged periods of intense cloud radiative forcing on the surface mass balance. The distribution of precipitation events over time and their associated amounts are the main drivers of the interannual variability of the surface mass balance via an albedo feedback effect. Additionally, prolonged periods of negative cloud radiative forcing, specifically over the month of November, notably reduce the melt rate.
Bibliographical noteFunding Information:
This study has been realized within the framework of the Andean part of the French Service National d’Observation GLACIOCLIM (www.glacioclim.osug.fr, UGA-OSUG, CNRS-INSU, IRD, IPEV, INRAE), and the International Joint Laboratory LMI GREAT-ICE (IRD, EPN-Quito). The glaciological program is coordinated in La Paz by Dr. Soruco (IGEMA-UMSA) who organizes, in particular, the follow-up of the glaciological measurements in Bolivia. The authors are grateful to everyone that has been involved in the long-term in situ monitoring program on Zongo Glacier. All authors acknowledge the support of LabEx OSUG@2020 (Investissements d’Avenir—ANR10_LABX56).
This study has been realized within the framework of the Andean part of the French GLACIOCLIM ( www.glacioclim.osug.fr , UGA‐OSUG, CNRS‐INSU, IRD, IPEV, INRAE), and the International Joint Laboratory LMI GREAT‐ICE (IRD, EPN‐Quito). The glaciological program is coordinated in La Paz by Dr. Soruco (IGEMA‐UMSA) who organizes, in particular, the follow‐up of the glaciological measurements in Bolivia. The authors are grateful to everyone that has been involved in the long‐term in situ monitoring program on Zongo Glacier. All authors acknowledge the support of LabEx OSUG@2020 (—ANR10_LABX56). Service National d’Observation Investissements d’Avenir
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- climate sensitivity
- glacier surface energy balance
- glaciological modeling
- tropical Andes of Bolivia
- Zongo Glacier