Mass balance and area changes of glaciers in the Cordillera Real and Tres Cruces, Bolivia, between 2000 and 2016

Climate change has led to a significant shrinkage of glaciers in the Tropical Andes during the last decades. Recent multi-temporal quantifications of ice mass loss at mountain range to regional scale are missing. However, this is fundamental information for future water resource planning and glacier change projections. In this study, we measure temporally consistent glacier area changes and geodetic mass balances throughout the Bolivian Cordillera Real and Tres Cruces based on multi-sensor remote-sensing data. By analyzing multi-spectral satellite images and interferometric SAR data, a glacier recession of 81 ± 18 km2 (29%; 5.1 ± 1.1 km2 a−1), a geodetic mass balance of −403 ± 78 kg m−2 a−1 and a total ice mass loss of 1.8 ± 0.5 Gt is derived for 2000–2016. In the period 2013–2016, ice mass loss was 21% above the average rate. A retreat rate of 15 ± 5 km2 a−1 and a mass budget of −487 ± 349 kg m−2 a−1 are found in this more recent period. These higher change rates can be attributed to the strong El Niño event in 2015/16. The analyses of individual glacier changes and topographic variables confirmed the dependency of the mass budget and glacier recession on glacier aspect and median elevation.