Search Results
1. Introduction Understanding the salt balance in estuaries is an important process to examine how the salinity structure responds to river, wind, and tidal forcing on subtidal time scales. This dynamic relationship among salinity structure, forcing conditions, and feedbacks can be broken into river forcing, baroclinic exchange, and mixing components. From this simple balance, researchers have been able to describe the salt storage of a system and how the salinity structure and estuary length
1. Introduction Understanding the salt balance in estuaries is an important process to examine how the salinity structure responds to river, wind, and tidal forcing on subtidal time scales. This dynamic relationship among salinity structure, forcing conditions, and feedbacks can be broken into river forcing, baroclinic exchange, and mixing components. From this simple balance, researchers have been able to describe the salt storage of a system and how the salinity structure and estuary length
cooling, uniform in the down-channel direction, produced an evolution of the current in that direction such that an along-channel pressure gradient in geostrophic balance drove fluid to the right-hand boundary of the channel where it underwent strong sinking. In contrast to earlier work, the model develops a mixed layer of very weak but nonzero vertical stratification in which the sinking occurs but the lateral temperature gradients in the layer drive a geostrophic flow forcing the downwelling. This
cooling, uniform in the down-channel direction, produced an evolution of the current in that direction such that an along-channel pressure gradient in geostrophic balance drove fluid to the right-hand boundary of the channel where it underwent strong sinking. In contrast to earlier work, the model develops a mixed layer of very weak but nonzero vertical stratification in which the sinking occurs but the lateral temperature gradients in the layer drive a geostrophic flow forcing the downwelling. This
quantify the sea ice response to changes in atmospheric and oceanic forcing on interannual and decadal time scales. We have developed a coupled ice–ocean model, which we refer to as the Bering Ecosystem Study Ice–Ocean Modeling and Assimilation System (BESTMAS). In this paper, we use this model to quantify the interannual and decadal variability of the Bering Sea ice cover over the period 1970–2008. Specifically, we seek to quantify the following: 1) the mechanisms controlling the observed variability
quantify the sea ice response to changes in atmospheric and oceanic forcing on interannual and decadal time scales. We have developed a coupled ice–ocean model, which we refer to as the Bering Ecosystem Study Ice–Ocean Modeling and Assimilation System (BESTMAS). In this paper, we use this model to quantify the interannual and decadal variability of the Bering Sea ice cover over the period 1970–2008. Specifically, we seek to quantify the following: 1) the mechanisms controlling the observed variability
that stable antisymmetric inertial subgyres appeared for some wind stress strengths and can be explained by an analytical modon solution. Thus far, most studies of double gyres using middle-range complexity have been conducted under constant (time independent) wind forcing. In the real atmosphere and oceans, seasonal wind forcing with westerly and trade winds generates subtropical and subpolar gyres arising from western boundary currents and internal currents. Recently, Sakamoto (2006) showed
that stable antisymmetric inertial subgyres appeared for some wind stress strengths and can be explained by an analytical modon solution. Thus far, most studies of double gyres using middle-range complexity have been conducted under constant (time independent) wind forcing. In the real atmosphere and oceans, seasonal wind forcing with westerly and trade winds generates subtropical and subpolar gyres arising from western boundary currents and internal currents. Recently, Sakamoto (2006) showed
between these seasonal changes and variations in wind forcing over the North Atlantic has been extensively studied ( Schott and Zantopp 1985 ; Lee et al. 1985 ; Lee and Williams 1988 ). Most observational studies agree with the model results of Anderson and Corry (1985a , b) , Fanning et al. (1994) , and Greatbatch et al. (1995) , identifying local and remote along-isobath wind stress forcing as a driving mechanism for annual and higher-frequency variability, while modeling studies by Böning et
between these seasonal changes and variations in wind forcing over the North Atlantic has been extensively studied ( Schott and Zantopp 1985 ; Lee et al. 1985 ; Lee and Williams 1988 ). Most observational studies agree with the model results of Anderson and Corry (1985a , b) , Fanning et al. (1994) , and Greatbatch et al. (1995) , identifying local and remote along-isobath wind stress forcing as a driving mechanism for annual and higher-frequency variability, while modeling studies by Böning et
forcing terms for the EDJs via the nonlinear interaction of intraseasonal Yanai waves ( Ascani et al. 2015 ), which are independent of the EDJs. It follows that the nonlinear terms in the zonal momentum budget can be parameterized as a dissipation and forcing in a linear model of the EDJs. Regardless of the actual driving mechanism, the EDJs must be maintained over a considerable depth range while they propagate vertically. This becomes apparent from an estimate of the effective lateral diffusivity
forcing terms for the EDJs via the nonlinear interaction of intraseasonal Yanai waves ( Ascani et al. 2015 ), which are independent of the EDJs. It follows that the nonlinear terms in the zonal momentum budget can be parameterized as a dissipation and forcing in a linear model of the EDJs. Regardless of the actual driving mechanism, the EDJs must be maintained over a considerable depth range while they propagate vertically. This becomes apparent from an estimate of the effective lateral diffusivity
1. Introduction At middle and high latitudes, the stochastic component of wind forcing associated with atmospheric “weather” on synoptic time scales is comparable in magnitude to the wind forcing associated with the seasonal cycle ( Willebrand 1978 ; Chave et al. 1991 ; Samelson and Shrayer 1991 ), and observations reveal that the stochastic component exerts considerable influence on the ocean circulation (e.g., DeRycke and Rao 1973 ; Niiler and Koblinsky 1989 ; Brink 1989 ; Koblinsky et
1. Introduction At middle and high latitudes, the stochastic component of wind forcing associated with atmospheric “weather” on synoptic time scales is comparable in magnitude to the wind forcing associated with the seasonal cycle ( Willebrand 1978 ; Chave et al. 1991 ; Samelson and Shrayer 1991 ), and observations reveal that the stochastic component exerts considerable influence on the ocean circulation (e.g., DeRycke and Rao 1973 ; Niiler and Koblinsky 1989 ; Brink 1989 ; Koblinsky et
of the North Atlantic circulation, the model includes idealizations, which are intended to make calculations possible and to simplify the analysis. The task of identifying the role of eddies in the near-equilibrium state has to rely on the analysis of the eddy flux convergences. These convergences can be tentatively interpreted as internally generated eddy forcing that maintains or resists the jetlike anomalies in, for example, the vorticity and buoyancy equations. The action of the eddy
of the North Atlantic circulation, the model includes idealizations, which are intended to make calculations possible and to simplify the analysis. The task of identifying the role of eddies in the near-equilibrium state has to rely on the analysis of the eddy flux convergences. These convergences can be tentatively interpreted as internally generated eddy forcing that maintains or resists the jetlike anomalies in, for example, the vorticity and buoyancy equations. The action of the eddy
1. Introduction Weakly damped systems have the potential to become resonant when the forcing is closely tuned to the preferential or natural frequency response of the system. In the case of the ocean mixed layer, which has a dominant response to wind stress in the form of inertial motions with frequencies near the local Coriolis frequency f , resonance is likely to occur when the wind stress vector ( τ ) either rotates in phase with the mixed layer inertial motions or forces the mixed layer in
1. Introduction Weakly damped systems have the potential to become resonant when the forcing is closely tuned to the preferential or natural frequency response of the system. In the case of the ocean mixed layer, which has a dominant response to wind stress in the form of inertial motions with frequencies near the local Coriolis frequency f , resonance is likely to occur when the wind stress vector ( τ ) either rotates in phase with the mixed layer inertial motions or forces the mixed layer in
1. Introduction There is increasing evidence that the decadal variability of the midlatitude ocean (e.g., Kushnir 1994 ; Deser et al. 1999 ) primarily reflects the variability of the atmosphere via stochastic wind stress forcing. Considering a stratified model with an open western boundary, Frankignoul et al. (1997) found that the oceanic response was largest at decadal frequency, but no spectral peak appeared (see also Sirven et al. 2002 ). LaCasce (2000) and Cessi and Louazel (2001
1. Introduction There is increasing evidence that the decadal variability of the midlatitude ocean (e.g., Kushnir 1994 ; Deser et al. 1999 ) primarily reflects the variability of the atmosphere via stochastic wind stress forcing. Considering a stratified model with an open western boundary, Frankignoul et al. (1997) found that the oceanic response was largest at decadal frequency, but no spectral peak appeared (see also Sirven et al. 2002 ). LaCasce (2000) and Cessi and Louazel (2001
