Convective cells of internal gravity waves in the mesopause region
Category: 16-3UDC 550.348.098.45; 551.511
O. G. Onishchenko(1,2), O. A. Pokhotelov(1), N. M. Astafieva(2)
(1) Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
(2) Space Research Institute of RAS, Moscow, Russia
Abstract. The influence of the shear wind on the formation of vortex (roll type) structure of the internal gravity waves (IGWs) in atmosphere is investigated. A closed system of equations is derived for the nonlinear dynamics of the IGWs in the presence of vertical gradients of temperature and wind. The obtained set of non-linear equations in the quasi-stationary case can be reduced to the equation which yields a vortex solution. The dependence of spatial scale and horizontal velocity of rolls on parameters of atmosphere and shear wind is studied. It is found that roll type vortex structures of the IGWs can exist in the dynamic unstable mesopause. These structures play a crucial role in mesosphere convection and generation of atmospheric turbulence and may affect global circulation.
Keywords: internal gravitational waves, mesopause, stability, nonlinear structures.
References
Dunkerton T.J. Shear instability of internal inertia-gravity waves, J. Atmosp. Sci., 1987, vol. 54, pp. 1628–1641.
Fritts D.C. and Alexander M.J. Gravity wave dynamics and effects in the middle atmosphere, Rev. Geophys., 2003, vol. 41, no 1, doi:10.1029/2001RG000106.
Gardner C.S., Zhao Y., and Liu A. Atmospheric stability and gravity wave dissipation in the mesopause refgion, J. Atmos. Solar Terr. Phys., 2002, vol. 64, pp. 923 – 929.
Horton W., Kaladze T.D., and Van Dam J.W. Zonal flow generation by internal gravity waves in the atmosphere, J. Geophys. Res., 2008, vol. 113, A08312, doi:10.1029/2007JA012952.
Larichev V.D. and Reznik G.M. On 2D solitary Rossby waves, Sov. Phys. Doklady, 1976, vol. 21, pp. 581.
Mikhailovskii A.B., Lakhin V.P., Mikhailovskaya L.A., and Onishchenko O.G. On the theory of vortices in a plasma, Sov. Phys. JETP, 1984, vol. 59, pp. 1198 – 1205.
Onishchenko O.G., Pokhotelov O.A., and Astaf'eva N.M. Generatsiya krupnomasshtabnykh vikhrei i zonal'nykh vetrov v atmosferakh planet (Generation of large-scale eddies and zonal winds in planetary atmospheres), Uspekhi fizicheskih nauk, 2008, vol. 178, no 6, pp. 605–616.
Onishchenko O.G. and Pokhotelov O.A. Generation of zonal structures by internal gravity waves in the Earth’s atmosphere, Doklady Earth Sci., 2012, vol. 445, no 1, pp. 845–848.
Onishchenko O.G., Pokhotelov O.A., and Fedun V.N. Convective cells of internal gravity waves in the Earth's atmosphere with finite temperature gradient, Ann. Geophys., 2013, vol. 31, pp. 459–462.
Petviashvili V.I. and Pokhotelov O.A. Uedinennye Volny v Plazme I Atmosfere (Solitary Waves in Plasmas and in the Atmosphere), Moscow: Energoatomizdat, 1989 [Translated into English (Philadelphia: Gordon and Breach Sci. Publ., 1992)].
Sherman J.P. and Che C.Y. Seasonal variation of mesopause region wind shears, convective and dynamic instabilities above Fort Collins, CO: A statistical study, J. Atmos. Solar Terr. Phys., 2006, vol. 68, pp. 1061–1074.
Stenflo L. and Shukla P.K. Nonlinear acoustic gravity waves, J. Plasma Phys., 2009, vol. 75, No 6, pp. 841–847.
Yuan L. and Fritts D. Influence of mean shear on the dynamical instability of an inertio-gravity wave, J. Atmos. Sci., 1989, vol. 46, pp. 2562–2568.
Zhao Y., Liu A., and Gardner C.S. Measuremants of atmospheric stability in the mesopause region at Starfire Optical Range, NM, J. Atmos. Solar Terr. Phys., 2003, vol. 65, pp. 219–232.