Seeding Clouds

In the remote South Atlantic, north of the Antarctic Circle, sit the volcanic Zavodovski and Visokoi islands. Though only roughly 500 and 1000 meters tall, respectively, each island disrupts the atmosphere nearby, often generating cloudy wakes. In today’s pair of images, the northerly Zavodovski has a particularly bright cloud wake, thanks to sulfate aerosols degassing from its volcano, Mount Curry. Though it’s hard to pick out the effect in the natural-color image above, the false-color version below shows the bright wake clearly. The filtering on this image turns snow and ice — like that on Visokoi’s peak — red and makes the water vapor of clouds white. The sulfates from Mount Curry act as nucleii for water droplets, forming many small, reflective drops that stand out against the rest of the sky. (Image credit: W. Liang; via NASA Earth Observatory)