Dynamics of a dense gravity current flowing over a corrugation


Ilicak M. , LEGG S., ADCROFT A., HALLBERG R.

OCEAN MODELLING, cilt.38, ss.71-84, 2011 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

In this study, we investigate the dynamics of a dense gravity currents over different sizes of ridges and canyons. We employ a high resolution idealized isopycnal model and perform a large number of experiments changing the aspect ratio of a ridge/canyon, the Coriolis parameter, the reduced gravity, the background slope and initial overflow thickness. The control run (smooth topography) is in an eddy-regime and the frequencies of the eddies coincide with those of the Filchner overflow (Darelius et al., 2009). Our idealized corrugation experiments show that corrugations steer the plume downslope, and that ridges are more effective than canyons in transporting the overflow to the deep ocean. We find that a corrugation Burger number (Bu-c) can be used as a parameter to describe the flow over topography. Bu-c is a combination of a Froude number and the aspect ratio. The maximum downslope transport of a corrugation can be increased when the height of the corrugation increases (Bu-c increases) or when the width of the corrugation decreases (Bu-c increases).