Submesoscale potential vorticity

Abstract. Application of the Brown-Samelson theorem, which shows that particle motion is integrable in a class of vorticity-conserving, two-dimensional incompressible flows, is extended here to a class of explicit time dependent dynamically balanced flows in multilayered systems. Particle motion for nonsteady two-dimensional flows with discontinuities in the vorticity or potential vorticity fields (modon solutions) is shown to be integrable. An example of a two-layer modon solution constrained by observations of a Gulf Stream ring system is discussed.

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Potential vorticity transport in weakly and strongly magnetized plasmas

Physics of Plasmas ◽

10.1063/5.0041072 ◽

2021 ◽

Vol 28 (4) ◽

pp. 042301

Author(s):

Chang-Chun Chen ◽

Patrick H. Diamond ◽

Rameswar Singh ◽

Steven M. Tobias

Keyword(s):

Potential Vorticity ◽

Magnetized Plasmas ◽

Vorticity Transport

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Changes in U.S. East Coast Cyclone Dynamics with Climate Change

Journal of Climate ◽

10.1175/jcli-d-14-00418.1 ◽

2015 ◽

Vol 28 (2) ◽

pp. 468-484 ◽

Cited By ~ 29

Author(s):

Christopher G. Marciano ◽

Gary M. Lackmann ◽

Walter A. Robinson

Keyword(s):

Climate Change ◽

Boundary Conditions ◽

Potential Vorticity ◽

East Coast ◽

The United States ◽

Sea Level Pressure ◽

Cyclone Intensity ◽

Field Amplification ◽

Lateral Boundary Conditions ◽

Relative Potential

Abstract Previous studies investigating the impacts of climate change on extratropical cyclones have primarily focused on changes in the frequency, intensity, and distribution of these events. Fewer studies have directly investigated changes in the storm-scale dynamics of individual cyclones. Precipitation associated with these events is projected to increase with warming owing to increased atmospheric water vapor content. This presents the potential for enhancement of cyclone intensity through increased lower-tropospheric diabatic potential vorticity generation. This hypothesis is tested using the Weather Research and Forecasting Model to simulate individual wintertime extratropical cyclone events along the United States East Coast in present-day and future thermodynamic environments. Thermodynamic changes derived from an ensemble of GCMs for the IPCC Fourth Assessment Report (AR4) A2 emissions scenario are applied to analyzed initial and lateral boundary conditions of observed strongly developing cyclone events, holding relative humidity constant. The perturbed boundary conditions are then used to drive future simulations of these strongly developing events. Present-to-future changes in the storm-scale dynamics are assessed using Earth-relative and storm-relative compositing. Precipitation increases at a rate slightly less than that dictated by the Clausius–Clapeyron relation with warming. Increases in cyclone intensity are seen in the form of minimum sea level pressure decreases and a strengthened 10-m wind field. Amplification of the low-level jet occurs because of the enhancement of latent heating. Storm-relative potential vorticity diagnostics indicate a strengthening of diabatic potential vorticity near the cyclone center, thus supporting the hypothesis that enhanced latent heat release is responsible for this regional increase in future cyclone intensity.

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Correlation between Buoyancy Flux, Dissipation and Potential Vorticity in Rotating Stratified Turbulence

Atmosphere ◽

10.3390/atmos12020157 ◽

2021 ◽

Vol 12 (2) ◽

pp. 157

Author(s):

Duane Rosenberg ◽

Annick Pouquet ◽

Raffaele Marino

Keyword(s):

Energy Dissipation ◽

Kinetic Energy ◽

Potential Vorticity ◽

Isotropic Turbulence ◽

Joint Probability ◽

Buoyancy Flux ◽

Turbulent Regime ◽

Stratified Turbulence ◽

Low Dissipation ◽

Linear And Nonlinear

We study in this paper the correlation between the buoyancy flux, the efficiency of energy dissipation and the linear and nonlinear components of potential vorticity, PV, a point-wise invariant of the Boussinesq equations, contrasting the three identified regimes of rotating stratified turbulence, namely wave-dominated, wave–eddy interactions and eddy-dominated. After recalling some of the main novel features of these flows compared to homogeneous isotropic turbulence, we specifically analyze three direct numerical simulations in the absence of forcing and performed on grids of 10243 points, one in each of these physical regimes. We focus in particular on the link between the point-wise buoyancy flux and the amount of kinetic energy dissipation and of linear and nonlinear PV. For flows dominated by waves, we find that the highest joint probability is for minimal kinetic energy dissipation (compared to the buoyancy flux), low dissipation efficiency and low nonlinear PV, whereas for flows dominated by nonlinear eddies, the highest correlation between dissipation and buoyancy flux occurs for weak flux and high localized nonlinear PV. We also show that the nonlinear potential vorticity is strongly correlated with high dissipation efficiency in the turbulent regime, corresponding to intermittent events, as observed in the atmosphere and oceans.

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