Search Results
.g., Vallis et al. 2004 ; Ring and Plumb 2007 ; Barnes et al. 2010 ; Ronalds et al. 2018 ). This is especially useful when studying Rossby wave dynamics, which can be well represented in a simple barotropic model setup, as demonstrated by Vallis et al. (2004) . It is well appreciated that Rossby wave dynamics and their resulting feedbacks with the mean flow are foundational to large-scale dynamics and will be at play in the fully coupled climate system (e.g., Strong and Magnusdottir 2010 ; Vallis
.g., Vallis et al. 2004 ; Ring and Plumb 2007 ; Barnes et al. 2010 ; Ronalds et al. 2018 ). This is especially useful when studying Rossby wave dynamics, which can be well represented in a simple barotropic model setup, as demonstrated by Vallis et al. (2004) . It is well appreciated that Rossby wave dynamics and their resulting feedbacks with the mean flow are foundational to large-scale dynamics and will be at play in the fully coupled climate system (e.g., Strong and Magnusdottir 2010 ; Vallis
captured correctly for accurate numerical weather prediction and climate modeling. The results obtained in this paper show that applying an explicit filter in addition to an implicit filter in LES of a turbulent barotropic flow in spectral space can improve the results and accurately predict the behavior of the coherent structures in the flow. REFERENCES Bardina , J. , J. H. Ferziger , and W. C. Reynolds , 1983 : Improved turbulence models based on large eddy simulation of homogeneous
captured correctly for accurate numerical weather prediction and climate modeling. The results obtained in this paper show that applying an explicit filter in addition to an implicit filter in LES of a turbulent barotropic flow in spectral space can improve the results and accurately predict the behavior of the coherent structures in the flow. REFERENCES Bardina , J. , J. H. Ferziger , and W. C. Reynolds , 1983 : Improved turbulence models based on large eddy simulation of homogeneous
Dengg et al. 1996 ). In this paper we will analyze the steady barotropic flow in basins with steep sloping boundaries. Our analysis assumes an f plane. This can be done without a loss of generality because the results also apply to cases with a varying Coriolis parameter, f , by considering f / H instead of the topography, H , when f is varying. We demonstrate that as long as the Rossby number is larger than the Ekman number, steady anticyclonic flow in a basin will be characterized by
Dengg et al. 1996 ). In this paper we will analyze the steady barotropic flow in basins with steep sloping boundaries. Our analysis assumes an f plane. This can be done without a loss of generality because the results also apply to cases with a varying Coriolis parameter, f , by considering f / H instead of the topography, H , when f is varying. We demonstrate that as long as the Rossby number is larger than the Ekman number, steady anticyclonic flow in a basin will be characterized by
the consequences of eddies in the ocean and their impact on the climate system. The focus of this study is to assess the contribution of striations to eddy energy budgets and mixing in a barotropic quasigeostrophic (QG) ocean model on a β plane with a background mean flow imposed. Use of the barotropic QG model, which is one of the simplest systems that produces banded structures, allows us to focus on both the elementary dynamics and consequences of striations. In this model, Rhines jets can
the consequences of eddies in the ocean and their impact on the climate system. The focus of this study is to assess the contribution of striations to eddy energy budgets and mixing in a barotropic quasigeostrophic (QG) ocean model on a β plane with a background mean flow imposed. Use of the barotropic QG model, which is one of the simplest systems that produces banded structures, allows us to focus on both the elementary dynamics and consequences of striations. In this model, Rhines jets can
; Majda and Wang 2006 ), generally cannot be used in developing statistical closures for such flows. In this paper, we investigate the inhomogeneous statistics of what may be the simplest flow subject to rotation, large-scale forcing, and dissipation that exhibits mixing and no-mixing regions in statistically steady states: barotropic flow on a rotating sphere driven by linear relaxation toward an unstable zonal jet. Depending on a single control parameter, namely the relaxation time, this prototype
; Majda and Wang 2006 ), generally cannot be used in developing statistical closures for such flows. In this paper, we investigate the inhomogeneous statistics of what may be the simplest flow subject to rotation, large-scale forcing, and dissipation that exhibits mixing and no-mixing regions in statistically steady states: barotropic flow on a rotating sphere driven by linear relaxation toward an unstable zonal jet. Depending on a single control parameter, namely the relaxation time, this prototype
. Correspondingly, many text books present this model in some detail (e.g., Pedlosky 1987 ; Holton 1992 ; Etling 1996 ; Pichler 1997 ; Green 1999 ). Barotropic instability theory is concerned with wave growth in barotropic mean flows with meridional gradients of absolute vorticity, a problem of obvious interest to atmospheric dynamics. Kuo (1949) explored this problem and found that wave growth is possible (see also Kuo 1973 ). Given the relevance of this theory to the atmospheric circulation
. Correspondingly, many text books present this model in some detail (e.g., Pedlosky 1987 ; Holton 1992 ; Etling 1996 ; Pichler 1997 ; Green 1999 ). Barotropic instability theory is concerned with wave growth in barotropic mean flows with meridional gradients of absolute vorticity, a problem of obvious interest to atmospheric dynamics. Kuo (1949) explored this problem and found that wave growth is possible (see also Kuo 1973 ). Given the relevance of this theory to the atmospheric circulation
308 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLUM-38Barotropic Instability of Zonal Flows KA KIT TUNGMathematics Department, MIT, Cambridge, MA 02139(Manuscript received 28 April 1980, in final form 30 September 1980) ABSTRACT The problem of barotropic instability of zonal flows to infinitesimal normal-mode perturbations isconsidered. The zonal flow is assumed to be continuous, but
308 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLUM-38Barotropic Instability of Zonal Flows KA KIT TUNGMathematics Department, MIT, Cambridge, MA 02139(Manuscript received 28 April 1980, in final form 30 September 1980) ABSTRACT The problem of barotropic instability of zonal flows to infinitesimal normal-mode perturbations isconsidered. The zonal flow is assumed to be continuous, but
1. Introduction Internal tides in the ocean are forced by barotropic tidal flow over topography. The forcing can be prescribed either via the boundary conditions (e.g., Vlasenko et al. 2005 ) or via a buoyancy force, in the vertical momentum equation, arising from the vertical displacement of isopycnals by the barotropic flow (e.g., Baines 1982 ). Baines assumes the barotropic flow to be hydrostatic. This seems reasonable if the horizontal scale of the topography is large in comparison with
1. Introduction Internal tides in the ocean are forced by barotropic tidal flow over topography. The forcing can be prescribed either via the boundary conditions (e.g., Vlasenko et al. 2005 ) or via a buoyancy force, in the vertical momentum equation, arising from the vertical displacement of isopycnals by the barotropic flow (e.g., Baines 1982 ). Baines assumes the barotropic flow to be hydrostatic. This seems reasonable if the horizontal scale of the topography is large in comparison with
interactions during ENSO. In the equation for the barotropic component of the flow, the interactions with the baroclinic component are formally similar to the term traditionally described as a Rossby wave source, but their structure can be quantitatively and conceptually quite different than those based on upper-level divergent flow. For instance, if there is no vertical shear and no damping on the baroclinic mode associated with surface stress, then upper-level divergence in the baroclinic mode does not
interactions during ENSO. In the equation for the barotropic component of the flow, the interactions with the baroclinic component are formally similar to the term traditionally described as a Rossby wave source, but their structure can be quantitatively and conceptually quite different than those based on upper-level divergent flow. For instance, if there is no vertical shear and no damping on the baroclinic mode associated with surface stress, then upper-level divergence in the baroclinic mode does not
model of barotropic flow over topography. Two of these equilibria are stable, corresponding to zonal and blocked flow. However, in reality, the equilibria need to be unstable for regime transitions to occur. Indeed, in barotropic models with higher horizontal resolution, spherical geometry, and chaotic behavior, phase space regions with particularly high persistence and recurrence probability (i.e., regimes) were observed, and weakly unstablesteady solutions were found embedded within them ( Legras
model of barotropic flow over topography. Two of these equilibria are stable, corresponding to zonal and blocked flow. However, in reality, the equilibria need to be unstable for regime transitions to occur. Indeed, in barotropic models with higher horizontal resolution, spherical geometry, and chaotic behavior, phase space regions with particularly high persistence and recurrence probability (i.e., regimes) were observed, and weakly unstablesteady solutions were found embedded within them ( Legras
