Some mathematical remarks concerning the localisation of planetary waves in a stochastic background flow

2001 ◽  
pp. 345-368 ◽  
Author(s):  
Peter Imkeller ◽  
Adam Hugh Monahan ◽  
Lionel Pandolfo
Keyword(s):  
Planetary Waves ◽  
Background Flow ◽  
Stochastic Background

Initially Forced Long Planetary Waves in the Presence of Nonzonal Mean Flow

2006 ◽  
Vol 36 (3) ◽  
pp. 507-525 ◽  
Author(s):  
Ivana Cerovečki ◽  
Roland A. de Szoeke
Keyword(s):  
Steady Flow ◽  
Forced Response ◽  
Planetary Waves ◽  
Subtropical Gyre ◽  
Ekman Pumping ◽  
Mean Flow ◽  
Background Flow ◽  
Uppermost Layer ◽  
Lateral Extent ◽  
Long Wave Approximation

Abstract The purpose of this paper is to understand how long planetary waves evolve when propagating in a subtropical gyre. The steady flow of a wind-driven vertically sheared model subtropical gyre is perturbed by Ekman pumping that is localized within a region of finite lateral extent and oscillates periodically at about the annual frequency after sudden initiation. Both the background flow and the infinitesimal perturbations are solutions of a 2½-layer model. The region of forcing is located in the eastern part of the gyre where the steady flow is confined to the uppermost layer (shadow zone). The lateral scales of the forcing and of the response are supposed to be small enough with respect to the overall gyre scale that the background flow may be idealized as horizontally uniform, yet large enough (greater than the baroclinic Rossby radii) that the long-wave approximation may be made. The latter approximation limits the length of time over which the solutions remain valid. The solutions consist of (i) a forced response oscillating at the forcing frequency in which both stable (real) and zonally growing (complex) meridional wavenumbers are excited plus (ii) a localized transient structure that grows as it propagates away from the region of forcing. Application of the method of stationary phase provides analytical solutions that permit clear separation of the directly forced part of the solution and the transient as well as estimation of the temporal growth rate of the transient, which proves to be convectively unstable. The solutions presented here are relevant to understanding the instability of periodic (including annual period) perturbations of oceanic subtropical gyres on scales larger than the baroclinic Rossby radii of deformation.

A note on geostrophic scale analysis of planetary waves

Tellus ◽  
1968 ◽  
Vol 20 (3) ◽  
pp. 548-550 ◽  
Author(s):  
Robert E. Dickinson
Keyword(s):  
Planetary Waves ◽  
Scale Analysis

scholarly journals Jet propulsion of a squid-inspired swimmer in the presence of background flow

2021 ◽  
Vol 33 (3) ◽  
pp. 031909
Author(s):  
Yang Luo ◽  
Qing Xiao ◽  
Qiang Zhu ◽  
Guang Pan
Keyword(s):  
Background Flow ◽  
Jet Propulsion

scholarly journals Gravitational wave signals of dark matter freeze-out

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Danny Marfatia ◽  
Po-Yan Tseng
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Gravitational Waves ◽  
Order Phase Transition ◽  
First Order ◽  
Stochastic Background ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
First Order Phase ◽  
Freeze Out

Abstract We study the stochastic background of gravitational waves which accompany the sudden freeze-out of dark matter triggered by a cosmological first order phase transition that endows dark matter with mass. We consider models that produce the measured dark matter relic abundance via (1) bubble filtering, and (2) inflation and reheating, and show that gravitational waves from these mechanisms are detectable at future interferometers.

scholarly journals Seasonality and Dynamics of Atmospheric Teleconnection from the Tropical Indian Ocean and the Western Pacific to West Antarctica

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 849
Author(s):  
Hyun-Ju Lee ◽  
Emilia-Kyung Jin
Keyword(s):  
Indian Ocean ◽  
Rossby Wave ◽  
Tropical Indian Ocean ◽  
Western Pacific ◽  
Tropical Region ◽  
Formation Mechanisms ◽  
West Antarctica ◽  
Background Flow ◽  
The Impact ◽  
The Western Pacific

The global impact of the tropical Indian Ocean and the Western Pacific (IOWP) is expected to increase in the future because this area has been continuously warming due to global warming; however, the impact of the IOWP forcing on West Antarctica has not been clearly revealed. Recently, ice loss in West Antarctica has been accelerated due to the basal melting of ice shelves. This study examines the characteristics and formation mechanisms of the teleconnection between the IOWP and West Antarctica for each season using the Rossby wave theory. To explicitly understand the role of the background flow in the teleconnection process, we conduct linear baroclinic model (LBM) simulations in which the background flow is initialized differently depending on the season. During JJA/SON, the barotropic Rossby wave generated by the IOWP forcing propagates into the Southern Hemisphere through the climatological northerly wind and arrives in West Antarctica; meanwhile, during DJF/MAM, the wave can hardly penetrate the tropical region. This indicates that during the Austral winter and spring, the IOWP forcing and IOWP-region variabilities such as the Indian Ocean Dipole (IOD) and Indian Ocean Basin (IOB) modes should paid more attention to in order to investigate the ice change in West Antarctica.

Planetary waves in polar basins: Some exact solutions

2021 ◽  
Vol 117 ◽  
pp. 107121 ◽  
Author(s):  
Madeleine Cockerill ◽  
Andrew P. Bassom ◽  
Lawrence K. Forbes
Keyword(s):  
Exact Solutions ◽  
Planetary Waves
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