Comments: Plumes from this infamous volcano have been generally difficult to observe since the advent of the satellite, except on occasion with high resolution geo-mapping satellites. The structure of this plume is interesting, suggesting either regular explosions at Anak Krakatau, or (more likely), a lee wave set up by the southeasterly wind flowing over Krakatau. In areas of ascending air the plume shows strongly as the volcanic water vapour condenses; in descending air some cloud evaporates and the plume is harder to see.