Brief communication: Potential of satellite optical imagery to monitor glacier surface flow velocity variability in the tropical Andes

Abstract. We present an analysis of glacier dynamics in mountain ranges of the tropical Andes of southern Peru and Bolivia using satellite data from 2013 to 2022. Despite the challenges posed by small glaciers (width<500 m), low velocities (<100myr-1), and high cloudiness during the monsoon, we map annually aggregated surface velocities and quantify the seasonal variability in the fastest parts of the glaciers. Limited trends are observed in the annual velocities over the last decade, but significant seasonal changes between the wet and dry seasons are found, likely controlled by the seasonality in meltwater production and the related changes in the hydrological conditions at the glacier–bedrock interface.