A Scale‐Dependent Analysis of the Barotropic Vorticity Budget in a Global Ocean Simulation
[1];
[2];
[3];
[4];
[5];
[2];
- Department of Earth, Ocean and Ecological Sciences University of Liverpool Liverpool UK, Atmospheric and Oceanic Sciences Program Princeton University Princeton NJ USA
- Atmospheric and Oceanic Sciences Program Princeton University Princeton NJ USA, NOAA Geophysical Fluid Dynamics Laboratory Princeton NJ USA
- Department of Mechanical Engineering University of Rochester Rochester NY USA
- Department of Physics and INFN University of Rome Tor Vergata Roma Italy
- Department of Mechanical Engineering University of Rochester Rochester NY USA, Laboratory for Laser Energetics University of Rochester Rochester NY USA
- NOAA Geophysical Fluid Dynamics Laboratory Princeton NJ USA
- Canadian Centre for Climate Modelling and Analysis Victoria BC Canada
Abstract The climatological mean barotropic vorticity budget is analyzed to investigate the relative importance of surface wind stress, topography, planetary vorticity advection, and nonlinear advection in dynamical balances in a global ocean simulation. In addition to a pronounced regional variability in vorticity balances, the relative magnitudes of vorticity budget terms strongly depend on the length‐scale of interest. To carry out a length‐scale dependent vorticity analysis in different ocean basins, vorticity budget terms are spatially coarse‐grained. At length‐scales greater than 1,000 km, the dynamics closely follow the Topographic‐Sverdrup balance in which bottom pressure torque, surface wind stress curl and planetary vorticity advection terms are in balance. In contrast, when including all length‐scales resolved by the model, bottom pressure torque and nonlinear advection terms dominate the vorticity budget (Topographic‐Nonlinear balance), which suggests a prominent role of oceanic eddies, which are of km in size, and the associated bottom pressure anomalies in local vorticity balances at length‐scales smaller than 1,000 km. Overall, there is a transition from the Topographic‐Nonlinear regime at scales smaller than 1,000 km to the Topographic‐Sverdrup regime at length‐scales greater than 1,000 km. These dynamical balances hold across all ocean basins; however, interpretations of the dominant vorticity balances depend on the level of spatial filtering or the effective model resolution. On the other hand, the contribution of bottom and lateral friction terms in the barotropic vorticity budget remains small and is significant only near sea‐land boundaries, where bottom stress and horizontal viscous friction generally peak.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 2369749
- Alternate ID(s):
- OSTI ID: 2369751
- Journal Information:
- Journal of Advances in Modeling Earth Systems, Journal Name: Journal of Advances in Modeling Earth Systems Journal Issue: 6 Vol. 16; ISSN 1942-2466
- Publisher:
- American Geophysical Union (AGU)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Barotropic motions and the exchange of angular momentum between the oceans and solid Earth
Numerical model of the wind-driven transient motion in Bass Strait