A δ-plane simulation of anticyclones perturbing circumpolar flows to form a transient north polar hexagon

Abstract

Saturn's North Polar Hexagon was discovered by Godfrey who pieced together map projections of images captured by the Voyager mission to unveil a hexagonal structure over the north pole of Saturn. This article attempts to answer whether or not a hexagonal structure can be formed through anticyclones impinging on the dominant eastward circumpolar flow and is in part based upon the proposed theory by Allison et al. that the Hexagon may be the result of at least one impinging anticyclone perturbing a circumpolar jet centrally located around the 76 • N latitude. A high-latitude δ-plane approximation is used to simulate the interaction between an initially circular circumpolar jet and at least one perturbing anticyclone. Our simulations with one perturbing anticyclone failed to form a hexagonal structure; yet by including an additional anticyclone it was found that depending on the strength, location and radius of the perturbing anticyclones a hexagonal feature could develop. However, the longevity and drift rate of the actual Hexagon must be attributed to other factors not considered in this paper.

Group theory analysis of early-time scale-dependent dynamics of the Rayleigh-Taylor instability with time varying acceleration

“…(1) leads to the Laplace equation h(l ) = 0 in the bulk(s) for θ > 0 (< 0) [7,8,31]. Here we consider a three-dimensional structure with space group p6mm [7,8,[31][32][33][34].…”