Effects of hydrostatic approximation and resolution on the simulation of convective adjustment

A two-dimensional non-hydrostatic ocean model and a hydrostatic version of the same modelare used to simulate convective adjustment, without the use of an instantaneous adjustmentparameterization. The model geometry is a domain on the vertical plane of width 40 km anddepth 500 m. Model results for four cases are examined: hydrostatic and non-hydrostatic, at0.1 and 1 km spatial resolution. The convectively adjusted stable state obtained in all four casesare qualitatively similar; thus the hydrostatic approximation does not eliminate convectiveadjustment. The details of the simulated convective plumes depend on resolution and whetherthe hydrostatic approximation is made. The adjusted state has significant stratification whichcannot be captured by the conventional instantaneous adjustment or diffusion-based parameterizations.We also compare the results to the case when an instantaneous adjustmentparameterization is used. DOI: 10.1034/j.1600-0870.2002.00162.x