[Inertia gravity waves characteristics within a baroclinic cavity]
High-resolution direct numerical simulations have shown the occurrence of inertia gravity waves simultaneously with baroclinic instabilities within a differentially heated rotating annulus, the “baroclinic cavity”. The working fluid is characterised by a Prandtl number . A decomposition technique applied to the dependent variables has allowed us to separate in space and in time the contributions of the large-scale baroclinic structures from that of the small-scale fluctuations. These latter have been identified as inertia gravity waves from their dispersion relation. The present work is particularly focused on the mechanism responsible for the spontaneous generation of these waves.
Des simulations numériques directes de haute résolution ont mis en évidence la présence simultanée dʼondes dʼinertie gravité avec des instabilités baroclines dans un domaine annulaire tournant différentiellement chauffé, la « cavité barocline ». Elle est remplie dʼun liquide caractérisé par un nombre de Prandtl . Une technique de décomposition des variables a permis de séparer dans lʼespace et dans le temps les contributions des vagues baroclines de celles de fluctuations de petite échelle. Ces dernières ont été identifiées comme des ondes dʼinertie gravité à partir de leur relation de dispersion. Nous nous intéressons en particulier au mécanisme responsable de la génération spontanée de ces ondes.
Accepted:
Published online:
Keywords: Fluid mechanics, Inertia gravity waves, Baroclinic instability
Anthony Randriamampianina 1
@article{CRMECA_2013__341_6_547_0, author = {Anthony Randriamampianina}, title = {Caract\'eristiques d'ondes d'inertie gravit\'e dans une cavit\'e barocline}, journal = {Comptes Rendus. M\'ecanique}, pages = {547--552}, publisher = {Elsevier}, volume = {341}, number = {6}, year = {2013}, doi = {10.1016/j.crme.2013.01.006}, language = {fr}, }
Anthony Randriamampianina. Caractéristiques dʼondes dʼinertie gravité dans une cavité barocline. Comptes Rendus. Mécanique, Volume 341 (2013) no. 6, pp. 547-552. doi : 10.1016/j.crme.2013.01.006. https://comptes-rendus.academie-sciences.fr/mecanique/articles/10.1016/j.crme.2013.01.006/
[1] Gravity wave dynamics and effects in the middle atmosphere, Rev. Geophys., Volume 41 (2003), p. 1003
[2] Generation of inertia-gravity waves in the rotating thermal annulus by a localised boundary layer instability, Geophys. Astrophys. Fluid Dyn., Volume 105 (2011), pp. 161-181
[3] Instabilities of a buoyancy-driven system, J. Fluid Mech., Volume 35 (1969), pp. 775-798
[4] R.D. Wordsworth, Theoretical and experimental investigations of turbulent jet formation in planetary fluid dynamics, PhD thesis, Linacre College, Oxford University, UK, 2009.
[5] Direct numerical simulations of bifurcations in an air-filled rotating baroclinic cavity, J. Fluid Mech., Volume 561 (2006), pp. 359-389
[6] The mechanics of an organized wave in turbulent shear flow, J. Fluid Mech., Volume 41 (1970), pp. 241-258
[7] Generation of inertia-gravity waves in a simulated life cycle of baroclinic instability, J. Atmos. Sci., Volume 52 (1995), pp. 3695-3716
[8] Inertia-gravity waves spontaneously generated by jets and fronts. Part I: Different baroclinic life cycles, J. Atmos. Sci., Volume 64 (2007), pp. 2502-2520
Cited by Sources:
Comments - Policy