Deep Convection in the Ocean
Abstract
Our long-term objective is to understand how deep convection, induced by strong buoyancy forcing at the ocean surface, influences the ocean circulation through convective plumes and geostrophic eddies. Issues specific to oceanic deep convection are the relatively strong role of rotation, such that convective Rossby numbers appropriate to the vertical motions may fall below unity; the highly intermittent nature of the forcing, with the strong impulses coming during the passage of atmospheric weather systems; the possible highly localized occurrence of deep convection; and the subsequent spatial redistribution and mixing of convected water by geostrophic mesoscale dynamics, which arise in part from instability of the localized convection regions. Our particular research projects are computational investigations intended to (1) quantify the extent to which penetrative mixing occurs at the base of a rotating convective layer, sharpening the pycnocline and entraining denser fluid from below; (2) determine how space/time intermittency in either the surface buoyancy flux or the pre-existing ocean stratication and circulation relate to the degree of localization of deep convection; and (3) explore the circumstances under which localized convected regions are persistent after the buoyancy forcing abates or undergo erosion through subsequent horizontal mixing and restratication of the gyre interior.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1998
- Accession Number
- ADA542388
Entities
People
- James C. McWilliams
- Sonya A. Legg
Organizations
- University of California, Los Angeles