The effects of geothermal heating on the ocean overturning circulation
Date
2006
Authors
Mullarney, Julia C
Griffiths, Ross
Hughes, Graham
Journal Title
Journal ISSN
Volume Title
Publisher
American Geophysical Union
Abstract
We examine the response of an overturning circulation, driven by differential thermal forcing along the top horizontal boundary, to a small additional heat flux applied at the bottom horizontal boundary. The system forms a simple thermally-driven flow that provides insight into the ocean's meridional overturning circulation. We conclude that the additional destabilising (geothermal) heat flux tends to promote a more vigorous full-depth overturning having approximately 10% greater volume flux than with no bottom heating. No significant change is observed in the vertical density structure. In contrast, the addition of a stabilising heat flux at the base leads to a shallow, partial-depth circulation. The key diagnostic for the significance of the geothermal flux appears to be the ratio of the buoyancy flux supplied at the bottom to the residual buoyancy flux driving the downwelling plume through the base of the thermocline.
Description
Keywords
Keywords: Buoyancy; Geothermal heating; Heat flux; Temperature distribution; Thermal effects; Bottom heating; Buoyancy flux; Differential thermal forcing; Ocean overturning circulation; Oceanography; geothermal system; oceanic circulation; overturn
Citation
Collections
Source
Geophysical Research Letters
Type
Journal article
Book Title
Entity type
Access Statement
License Rights
Restricted until
2037-12-31
Downloads
File
Description