Impact of physical processes on maritime frontogenesis

Abstract

A hydrostatic primitive equation model initialized in a highly baroclinically unsta- ble state was used to simulate maritime cydogeneais and &ontogenesis. In order to identify boundary layer physical procesaes important in maritime &ontogenesis, several dift'erent simulations were performed. An adiabatic and inviscid simulation provided the control for these experiments. The two dift'erent boundary layer pa- rameterizations used were a K-theory parameterization and a second-order closure scheme. Results indicated that strong warm and cold fronts formed in the adiabatic and inviscid case but that the near-surface wind speed and vertical motion fields were unrealistic. bi the K-theory simulation, the results were somewhat more realis- tic but convergence and vorticity were weaker. Results from the second-order closure simulation demonstrated that turbulent mixing of momentum was most important in producing the frontogenetic (and frontolytic) effects of the transverse secondary circulation.