Convection in a Nearly Isothermal Atmosphere.

The onset of thermal convection is studied in a fluid layer having a basic density stratification that decreases almost exponentially with height. The coefficients of viscosity and thermal conductivity are assumed to be constant and a stratification parameter which measures the ratio of the depth of the fluid layer to the scale height is introduced. Critical Rayleigh numbers and wave-lengths are computed for various values of the stratification parameter. Finally, the problems associated with convection in a rapidly rotating centrifuge with its walls differentially heated are discussed. Author