Analysis of Fine Structure and Microstructure Data from Fieberling Guyot.

Abstract

Abstract : Collection, reduction, and analysis of ocean finestructure and microstructure profiles about Fieberling Guyot, a seamount in the northeast Pacific Ocean, formed the core of research. Our research focused on developing understanding of turbulent mixing associated with flow about major bathymetric features, and as such, contributed to the Topographic interactions Accelerated Research Initiative. The intensified mixing documented at Fieberling Guyot suggests that near rough bottom regions of the ocean are key to closing the cold to warm limb of the meridional overturning circulation. Above the seamount summit, intense mixing was found, associated with a tidally forced, diurnal period internal wave trapped to an anticyclonic vortex. Enhanced mixing was also observed above the rough flanks of the seamount: the product of instability within an internal wave field distorted by bottom reflection and/or bottom wave generation. In contrast, at distances more than 15 nmi from the seamount, the internal wave field was at climatological level and the turbulent mixing was weak at all depths sampled (to 3000 m). These results were synthesized by testing and extending models that relate the internal wave field to the turbulent dissipation.