Repository logo
 
Publication

Resonant gravity-wave drag enhancement in linear stratified flow over mountains

2005-07Journal article Open access
Simple item page
dc.contributor.authorTeixeira, M. A. C.
dc.contributor.authorMiranda, P. M. A.
dc.contributor.authorArgaín, José Luís Almaguer
dc.contributor.authorValente, M. A.
dc.date.accessioned2018-12-07T14:53:22Z
dc.date.available2018-12-07T14:53:22Z
dc.date.issued2005-07
dc.description.abstractHigh-drag states produced in stratified flow over a 2D ridge and an axisymmetric mountain are investigated using a linear, hydrostatic, analytical model. A wind profile is assumed where the background velocity is constant up to a height z(1) and then decreases linearly, and the internal gravity-wave solutions are calculated exactly. In flow over a 2D ridge, the normalized surface drag is given by a closed-form analytical expression, while in flow over an axisymmetric mountain it is given by an expression involving a simple 1D integral. The drag is found to depend on two dimensionless parameters: a dimensionless height formed with z(1), and the Richardson number, Ri, in the shear layer. The drag oscillates as z(1) increases, with a period of half the hydrostatic vertical wavelength of the gravity waves. The amplitude of this modulation increases as Ri decreases. This behaviour is due to wave reflection at z(1). Drag maxima correspond to constructive interference of the upward- and downward-propagating waves in the region z < z(1), while drag minima correspond to destructive interference. The reflection coefficient at the interface z = z(1) increases as Ri decreases. The critical level, z(c), plays no role in the drag amplification. A preliminary numerical treatment of nonlinear effects is presented, where z(c) appears to become more relevant, and flow over a 2D ridge qualitatively changes its character. But these effects, and their connection with linear theory, still need to be better understood.
dc.description.sponsorshipBULET/33980/99
dc.description.versioninfo:eu-repo/semantics/publishedVersion
dc.identifier.doihttps://doi.org/10.1256/qj.04.154
dc.identifier.issn0035-9009
dc.identifier.urihttp://hdl.handle.net/10400.1/11483
dc.language.isoeng
dc.peerreviewedyes
dc.publisherRoyal Meteorological Society
dc.relationEFEITOS DE CAMADA-LIMITE E TURBULÊNCIA EM TERRENO COMPLEXO
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/
dc.subjectSevere downslope windstorms
dc.subject3 spatial dimensions
dc.subject2 dimensional mountain
dc.subjectHydrostatic flow
dc.subjectSurface pressure
dc.subjectShear flow
dc.subjectTopography
dc.subjectStability
dc.subjectStates
dc.subjectHigh-drag states
dc.subjectLinear theory
dc.subjectMountain waves
dc.titleResonant gravity-wave drag enhancement in linear stratified flow over mountains
dc.typejournal article
dspace.entity.typePublication
oaire.awardTitleEFEITOS DE CAMADA-LIMITE E TURBULÊNCIA EM TERRENO COMPLEXO
oaire.awardURIinfo:eu-repo/grantAgreement/FCT//SFRH%2FBPD%2F3533%2F2000/PT
oaire.citation.endPage1814
oaire.citation.issue609
oaire.citation.startPage1795
oaire.citation.titleQuarterly Journal of the Royal Meteorological Society
oaire.citation.volume131
person.familyNameArgain
person.givenNameJose Luis
person.identifier.ciencia-id0814-FF4B-8E43
person.identifier.orcid0000-0001-9140-0867
person.identifier.ridM-5296-2013
person.identifier.scopus-author-id11941013900
project.funder.identifierhttp://doi.org/10.13039/501100001871
project.funder.nameFundação para a Ciência e a Tecnologia
rcaap.rightsopenAccess
rcaap.typearticle
relation.isAuthorOfPublication46a57ed8-c4e0-49e8-84e0-5a03276a34a1
relation.isAuthorOfPublication.latestForDiscovery46a57ed8-c4e0-49e8-84e0-5a03276a34a1
relation.isProjectOfPublicationf4b028b9-d61c-4a56-b9bd-a374923244dc
relation.isProjectOfPublication.latestForDiscoveryf4b028b9-d61c-4a56-b9bd-a374923244dc

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Resonant gravity-wave drag enhancement in linear stratified flow over mountains.pdf
Size:
1.66 MB
Format:
Adobe Portable Document Format
Download

Collections

FCT2-Artigos (em revistas ou actas indexadas)