[1] Eddy diffusivities in the Labrador Sea (LS) are estimated from deep eddy resolving float trajectories, moored current meter records, and satellite altimetry. A mean residence time of 248 days in the central LS is observed with several floats staying for more than 2 years. By applying a simple random walk diffusion model, the observed distribution of float residence times in the central LS c...

The ion–aerosol balance equations are solved to get the profiles of atmospheric electric parameters over the ground surface in an aerosol-rich environment under the conditions of surface radioactivity. Combining the earlier results for low aerosol concentrations and the present results for high aerosol concentrations, a relation is obtained between the average value of atmospheric electric spac...

Observations suggest that the timeand zonal-mean state of the extratropical atmosphere adjusts itself such that the so-called ‘‘criticality parameter’’ (which relates the vertical stratification to the horizontal temperature gradient) is close to one. T. Schneider has argued that the criticality parameter is kept near one by a constraint on the zonal momentum budget in primitive equations. The ...

The evolution and structure of the steady state of an idealized nocturnal drainage flow over a large uniformly-sloping surface are studied using a nonstationary model with a height-dependent eddy diffusivity profile and a specified surface cooling rate. The predicted mean velocity and temperature profiles are compared with Prandtl’s stationary analytical solutions based on the assumption of a c...

The diffusive effect on barotropic models of mesoscale eddies is addressed, using the Melnikov method from dynamical systems. Simple geometric criteria are obtained, which identify whether a given eddy grows or drains out, under a diffusive (and forcing) perturbation on a potential vorticity conserving flow. Qualitatively, the following are shown to be features conducive to eddy growth (and, th...

4 Observations suggest that the timeand zonal-mean state of the extra-tropical atmosphere 5 adjusts itself such that the so-called “criticality parameter” (which relates the vertical strat6 ification to the horizontal temperature gradient) is close to one. Schneider has argued that 7 the criticality parameter is kept near one by a constraint on the zonal momentum budget in 8 primitive equations...

We study generation of magnetic fields involving large spatial scales by time-and space-periodic small-scale parity-invariant flows. The anisotropic magnetic eddy diffusivity tensor is calculated by the standard procedure involving expansion of magnetic modes and their growth rates in power series in the scale ratio. Our simulations, conducted for flows with random harmonic composition and expo...

An exact solution to the barotropic potential vorticity equation is used to examine the properties of barotropic vortices under arbitrary nth-order hyper-diffusivity. Analytical expressions are derived for an eddy’s lifetime, meridional drift, decay in size, and energy, as functions of the Coriolis parameter, order and magnitude of diffusivity, and the eddy’s size, shape and strength. These exp...

Abstract Diffusive theories for the meridional atmospheric energy transport can summarize our understanding of this central aspect general circulation. They also be utilized in simple models Earth’s balance to help interpret response system perturbations. A theory diffusivity eddy heat is described based on Rhines scaling and global entropy budget, each which provides a constraint between kinet...