New insights into the decadal variability in glacier volume of a tropical ice cap, Antisana (0°29′ S, 78°09′ W), explained by the morpho-topographic and climatic context

Abstract. We present a comprehensive study of the evolution glaciers on Antisana ice cap (tropical Andes) over period 1956–2016. Based geodetic observations aerial photographs and high-resolution satellite images, we explore effects morpho-topographic climate variables glacier volumes. Contrasting behaviour was observed whole period, with two periods strong mass loss, 1956–1964 (−0.72 m w.e. yr−1) 1979–1997 (−0.82 yr−1), slight 1965–1978 (0.10 1998–2016 (−0.26 yr−1). There 42 % reduction in total surface area cap. Individually, responses were modulated by (e.g. maximum median altitude area), particularly case small tongues located at low elevations (Glacier 1, 5 16) which have been undergoing accelerated disintegration since 1990s will likely disappear coming years. Moreover, thanks to availability data, surging event detected Glacier 8 (G8) 2009–2011 period; such an is extremely rare this region deserves dedicated study. Despite effect complex topography, reacted agreement changes forcing, stepwise transition towards warmer alternating wet–dry conditions mid-1970s. Long-term decadal variability consistent warm–cold Pacific Ocean represented Southern Oscillation index.