Sarychev Peak volcano. Photo: NASA
I am fascinated by this photo taken by astronauts on the International Space Station on June 12. It shows the Sarychev Peak volcano, on Matua Island northeast of Japan, in the early stages of erupting. There are some parallels that can be made with a large convection column over a very active fire. The condensation near the top of the column would be called a pyrocumulus cloud if it were over a fire.
It is interesting that there appears to be a hole that was created in the cloud layer, through which the plume is penetrating. An article in LiveScience talks about a shock wave that was created in the atmosphere. Scientists have said that the surrounding atmosphere has been shoved up by the shock wave of the eruption.
I am no scientist, but it appears that the compression of the atmosphere caused by the introduction of a huge volume of rising gas increased the temperature of the air and lowered the relative humidity, causing the cloud to dissipate near the plume. And the radiant heat from the column probably contributed to the same effect.
Usually upper level winds will shear off a plume from a volcano, but that did not happen in this case.