eprintid: 1433948
rev_number: 29
eprint_status: archive
userid: 608
dir: disk0/01/43/39/48
datestamp: 2014-07-04 20:08:14
lastmod: 2021-09-19 22:25:55
status_changed: 2016-01-28 14:17:52
type: article
metadata_visibility: show
item_issues_count: 0
creators_name: Whitfield, AJ
creators_name: Johnson, ER
title: Rotation-induced nonlinear wavepackets in internal waves
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F59
note: © 2014 AIP Publishing LLC
abstract: The long time effect of weak rotation on an internal solitary wave is the decay into inertia-gravity waves and the eventual formation of a localised wavepacket. Here this initial value problem is considered within the context of the Ostrovsky, or the rotation-modified Korteweg-de Vries (KdV), equation and a numerical method for obtaining accurate wavepacket solutions is presented. The flow evolutions are described in the regimes of relatively-strong and relatively-weak rotational effects. When rotational effects are relatively strong a second-order soliton solution of the nonlinear Schrödinger equation accurately predicts the shape, and phase and group velocities of the numerically determined wavepackets. It is suggested that these solitons may form from a local Benjamin-Feir instability in the inertia-gravity wave-train radiated when a KdV solitary wave rapidly adjusts to the presence of strong rotation. When rotational effects are relatively weak the initial KdV solitary wave remains coherent longer, decaying only slowly due to weak radiation and modulational instability is no longer relevant. Wavepacket solutions in this regime appear to consist of a modulated KdV soliton wavetrain propagating on a slowly varying background of finite extent.
date: 2014-05
official_url: http://dx.doi.org/10.1063/1.4879075
vfaculties: VMPS
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_source: WoS-Lite
elements_id: 960262
doi: 10.1063/1.4879075
lyricists_name: Johnson, Edward
lyricists_id: ERJOH80
full_text_status: public
publication: Physics of Fluids
volume: 26
number: 5
article_number: 056606
issn: 1070-6631
citation:        Whitfield, AJ;    Johnson, ER;      (2014)    Rotation-induced nonlinear wavepackets in internal waves.                   Physics of Fluids , 26  (5)    , Article 056606.  10.1063/1.4879075 <https://doi.org/10.1063/1.4879075>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1433948/1/WhitfieldJ14.pdf