scholarly journals Current relaxation time scales in toroidal plasmas

1989 ◽  
Vol 1 (2) ◽  
pp. 333-339 ◽  
Author(s):  
D. R. Mikkelsen
2017 ◽  
Vol 74 (5) ◽  
pp. 1533-1547 ◽  
Author(s):  
William J. M. Seviour ◽  
Darryn W. Waugh ◽  
Richard K. Scott

Abstract The Martian polar atmosphere is known to have a persistent local minimum in potential vorticity (PV) near the winter pole, with a region of high PV encircling it. This finding is surprising, since an isolated band of PV is barotropically unstable, a result going back to Rayleigh. Here the stability of a Mars-like annular vortex is investigated using numerical integrations of the rotating shallow-water equations. The mode of instability and its growth rate is shown to depend upon the latitude and width of the annulus. By introducing thermal relaxation toward an annular equilibrium profile with a time scale similar to that of the instability, a persistent annular vortex with similar characteristics as that observed in the Martian atmosphere can be simulated. This time scale, typically 0.5–2 sols, is similar to radiative relaxation time scales for Mars’s polar atmosphere. The persistence of an annular vortex is also shown to be robust to topographic forcing, as long as it is below a certain amplitude. It is therefore proposed that the persistence of this barotropically unstable annular vortex is permitted owing to the combination of short radiative relaxation time scales and relatively weak topographic forcing in the Martian polar atmosphere.


2019 ◽  
Vol 99 (17) ◽  
Author(s):  
Mauro Schiulaz ◽  
E. Jonathan Torres-Herrera ◽  
Lea F. Santos

2004 ◽  
Vol 121 (15) ◽  
pp. 7341-7346 ◽  
Author(s):  
Anatolii V. Mokshin ◽  
Renat M. Yulmetyev ◽  
Peter Hänggi

Fractals ◽  
2013 ◽  
Vol 21 (03n04) ◽  
pp. 1350021 ◽  
Author(s):  
RAFFAELE PASTORE ◽  
MASSIMO PICA CIAMARRA ◽  
ANTONIO CONIGLIO

We investigate via Monte Carlo simulations the kinetically constrained Kob-Andersen lattice glass model showing that, contrary to current expectations, the relaxation process and the dynamical heterogeneities seems to be characterized by different time scales. Indeed, we found that the relaxation time is related to a reverse percolation transition, whereas the time of maximum heterogeneity is related to the spatial correlation between particles. This investigation leads to a geometrical interpretation of the relaxation processes and of the different observed time scales.


2005 ◽  
Vol 138 (3-4) ◽  
pp. 841-846
Author(s):  
R. Ragan ◽  
K. Grunwald ◽  
B. Batell

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