Exploring atmospheric convection with physically sound nonlinear low-order models

Building physically sound low-order models of atmospheric dynamics is discussed. As an example, the issue of convective rolls vs cells in the atmospheric boundary layer resulting from the interplay of buoyancy and shear was explored using a nonlinear low-order model of 3D Rayleigh-Bénard convection with shear, with results comparable with observations. For moderate values of buoyancy, the shear alone proved capable of controlling the occurrence of rolls or cells, though the whole picture depended on both buoyancy and shear.