Inside volcanic clouds: Remote sensing of ash plumes using microwave weather radars

Ash clouds due to volcanic eruptions can be detected in near real-time, quantitatively retrieved, and microphysically characterized by using ground-based microwave weather radars and their high-resolution spatial-temporal coverage. Remote sensing techniques represent a unique supporting tool to be exploited for this scope. They allow for observation of the evolution of some key parameters of volcanic eruptions without direct interaction between the measurement system and the target of the measure. Ground-based microwave scanning weather radars can gather three-dimensional information of ash cloud scattering volumes with ranges up to hundreds of kilometers in all weather conditions at a high spatial resolution and with a repetition cycle of several minutes. A quantitative estimate of ash category and concentration can be accomplished with a fairly good degree of confidence within the radar coverage area.