TROPOMI enables high resolution SO flux observations from Mt. Etna, Italy, and beyond.

The newly launched imaging spectrometer TROPOMI onboard the Sentinel-5 Precursor satellite provides atmospheric column measurements of sulfur dioxide (SO) and other gases with a pixel resolution of 3.5 × 7 km. This permits mapping emission plumes from a vast number of natural and anthropogenic emitters with unprecedented sensitivity, revealing sources which were previously undetectable from space.

Quantification of ash sedimentation dynamics through depolarisation imaging with AshCam.

Even modest ash-rich volcanic eruptions can severely impact a range of human activities, especially air travel. The dispersal of ash in these eruptions depends critically on aggregation and sedimentation processes - however these are difficult to quantify in volcanic plumes. Here, we image ash dynamics from mild explosive activity at Santiaguito Volcano, Guatemala, by measuring the depolarisation of scattered sunlight by non-spherical ash particles, allowing the dynamics of diffuse ash plumes to be investigated with high temporal resolution (>1 Hz).