Applications of an Energy Balance Sensitivity Study to Paleo-glacier Modeling in Bolivia’s Cordillera Real

Location : University of Grenoble, LTHE, France.

Contacts :
Jean Emmanuel Sicart (LTHE), jean-emmanuel.sicart ird.fr
Antoine Rabatel, antoine.rabatel ujf-grenoble.fr
Thomas CONDOM, thomas.condom ird.fr

The Little Ice Age (LIA) stands out as the latest period of widespread glacial growth in the Holocene (Grove, 2013). Though the timing of the LIA varied, there is ample evidence for its occurrence in almost all currently glaciated regions (Grove, 2013). Understanding the climate of the LIA and factors that triggered subsequent glacial retreat frames our knowledge of the climatic trends contributing to the current accelerated deglaciation, which is unprecedented since the LIA (Rabatel et al., 2013).
Lichenometric dating has been performed on moraines of 15 glaciers in Bolivia’s Cordillera Real, placing the maximum extent in the late 17th century, with subsequent moraines formed by interruptions to long-term retreat (Rabatel et al., 2008). These glaciers include Zongo Glacier on the Huayna Potosí massif, the site of a two-decade-long mass balance and climate-monitoring program. In addition, energy balance models have been calibrated and run on Zongo Glacier (Sicart et al., 2011).
The proposed study will evaluate the potential of energy balance models to model the retreat of glaciers in the Cordillera Real since the LIA using a study of sensitivity to climatic variables. Zongo Glacier will serve as the test site, and the sensitivity of albedo feedback processes and subsequent ablation will be tested using an energy balance model. An approach to parameterize albedo optimized for tropical glaciers exists (Sicart et al., 2011), which will be utilized in the study. Inverse methods, such as Monte Carlo simulations, will be explored to generate climate scenarios. The study will precede and facilitate the use three-dimensional, distributed glacier energy balance modeling as tools to estimate paleoclimate.

References :

Grove, J.M. Little Ice Ages Vol1 Ed2. Routledge, 2013.

Rabatel, A., et al. "A chronology of the Little Ice Age in the tropical Andes of Bolivia (16 S) and its implications for climate reconstruction." Quaternary Research 70.2 (2008) : 198-212.

Rabatel, A., et al (2013). Current state of glaciers in the tropical Andes : a multi-century perspective on glacier evolution and climate change. The Cryosphere, 7(1), 81-102.

Sicart, J.E., et al. "Analysis of seasonal variations in mass balance and meltwater discharge of the tropical Zongo Glacier by application of a distributed energy balance model." Journal of Geophysical Research : Atmospheres (1984–2012) (2011).