By Peter Weiss
Besides using up energy to move sand dunes, create waves, and otherwise rearrange the scenery, winds exhaust their force on inner processes, too. Collisions between gas molecules, for instance, convert kinetic energy to heat in so-called viscous processes.
Using a soap film that mimics the atmosphere of Earth or other planets (SN: 8/22/98, p.118), physicists now have measured how much energy a thin sheet of turbulent fluid gives up to those types of losses. The scientists say they can use flat fluid systems to model large-scale motions in atmospheres because, compared with the diameter of a planet, an atmosphere is hardly more than a vaporous, two-dimensional skin.