CALYPSO: The role of high Rossby number processes on vertical pathways
Abstract
A study of vertical pathways in the upper ocean at scales from O10 m - 1 km is proposed, where the high relative vorticities of sur"face flows lead to high Rossby numbers processes such as filaments and vortices. These processes are not quasigeostrophic and their vertical velocities cannot be determined using established quasigeostrophic methods (i.e. the omega-equation). They arise in the fo"rward cascade of energy from low Rossby number features, and vertical velocities associated with them are expected to have larger ma"gnitudes but shorter timescales than those governed by quasigeostrophic dynamics. This work will address outstanding questions relat"ing to the role of high Rossby number processes and their associated vertical velocities on advective pathways in the upper ocean, u"sing both observations and numerical models.The observational component of the proposed work will employ ship-based bow chain survey"s in the western Alboran Sea to make measurements of temperature, salinity, fluorescence and oxygen at extremely high horizontal res""olution (~ 1 m) in the upper ocean at relatively high ship speeds (10 kn), reducing issues of space-time alias that have challenged" prior studies using this technology. Concurrent work will examine high Rossby number processes in a series of nonhydrostatic ideali"zed numerical models of a baroclinically unstable front, with parameters close to those observed in the western Alboran Sea. The sim"ulations will both aid interpretation of the bow chain measurements and also quantify the influence of model resolution and nonhydro"static processes on vertical pathways in frontal regions. Through collaboration with other DRI members, particle trajectories, Lagra""ngian pathways and barriers, and particle clustering and dispersion will be assessed in these simulations. The comparison of Lagrang""ian metrics at di~erent resolution will enable an assessment of the accuracy of vertical pathways determined in lower resolution, re"gional numerical models.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 26, 2018
- Source ID
- N000141812165
Entities
People
- John Toole
Organizations
- Office of Naval Research
- United States Navy
- Woods Hole Oceanographic Institution