Astronomer Snaevarr Gudmundsson took this photo along with hundreds of others as the eruption was occuring.
He shared his incredible experience with Universe Today:
“I stayed near the volcano from about 16:00 hours to 22:00 hours on Saturday and watched its impressive eruption,” Gudmundsson said in an email to me. “Amazing event, awesome explosions of 1200 C hot magma reaching ice and water. I shot more than 550 images during these hours of continuous enjoyment. Sounds ridiculous but its ever changing appearance was never boring.”
Yet another fantastic lightning image within the ash plume.
This image is from a ground-based LIDAR (Light detection and ranging) using a 532 nanometer cross polarization NFOV (Narrow field of view) telescope. The ash cloud is the brighter pocket of red and dark orange which sinks over time.
According to the SIRTA website out of France (research site for atmospheric detection--loose translation), the instrument is "capable of retrieving the optical and microphysical caracteristics of clouds and aerosols particles in the boudary layer and the troposphere (between 0.1 km and 15 km). Two wavelengths are emitted by the laser: 532 nm and 1.064 µm ; the detection system is capable of measuring the signal at 532 nm with the same polarization than the emitted beam." In other words, instead of using conventional radar, which sends a microwave signal, this uses a laser.
A great simulation from the Rhenish Institute for Environmental Research at the University of Cologne showing the ash plume descending over Europe since last Wednesday.