Turbulent Rain Clouds: Sudden Downpours Demystified?
Friday, 25 January 2008, 15:15
Lecture room F
We study the dynamics of small particles suspended in a turbulent flow
(e.g. sand grains in an accretion disk around a growing star, water
droplets in clouds).We describe how the particles cluster together and
collide. The aim is to understand the time it takes to rain from a
vigorously turbulent rain cloud.
Downpours Demystified?, Science Now:
As anyone who's been caught without an umbrella knows, even a fluffy,
innocuous-looking cloud can unleash a sudden torrent of rain. A new theory
may explain why.
Caustic Purge, Nature Physics:
A summer afternoon: the air is hot, and a flock of cumulus clouds hover in
the blue sky. Suddenly it pours down. Such an abrupt onset of rainfall
from these clouds might be due to the formation of so-called caustics in
the velocity field of the raindrops.