Doppler weather radar observations of the 2009 eruption of Redoubt Volcano, Alaska

► We report on the first use of an innovative volcano monitoring radar system. ► Rapid cloud rise and stratospheric cloud heights were documented. ► Observation of rapid formation of tephra-ice aggregates ► Radar-derived eruption durations not well correlated with other estimates ► Accelerated removal of fine-grained ash may be typical process at Redoubt.