Volcanic Twilights ex Africa

The Northern Hemisphere is once again experiencing colourful sunsets and twilights.

Rafael Schmall caught these unusual sunsets and twilight rays on 17th and 18th August '11 at Somogy, Kaposfő, Hungary.

The intense yellow orange twilight arch and diffuse pink crepuscular rays are characteristic of sunlight scattering by aerosol and dust in the lower stratosphere.

The culprit is likely the eruption of the long dormant African Nabro Volcano on the Eritrean and Ethiopean border. Ash, steam and copious sulfur dioxide were ejected on June 15th to form a long plume reaching 15 km high. The sufate aerosol is probably now dispersed around the Northern Hemisphere stratosphere to form these sunsets.

The two lowest images are NASA photographs of the early plume and a pre-eruption view of the caldera.

Images ©Rafael Schmall, shown with permission.