LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Birner, T.; Thompson, D. W. J.; Shepherd, T. G. (2013)
Publisher: American Geophysical Union
Languages: English
Types: Article
Subjects:

Classified by OpenAIRE into

arxiv: Physics::Atmospheric and Oceanic Physics, Physics::Fluid Dynamics
The role of eddy fluxes in the general circulation is\ud often approached by treating eddies as (macro)turbulence.\ud In this approach, the eddies act to diffuse certain quasiconservative quantities, such as potential vorticity (PV), along isentropic surfaces in the free atmosphere. The eddy fluxes are determined primarily by the eddy diffusivities and are necessarily down-gradient of the basic state PV field. Support for the (macro)turbulence approach stems from the fact that the eddy fluxes of PV in the free atmosphere are generally down-gradient in the long-term mean. Here we call attention to a pronounced and significant region of upgradient eddy PV fluxes on the poleward flank of the jet core in both hemispheres. The region of up-gradient (i.e., notionally “antidiffusive”) eddy PV fluxes is most pronounced during the winter and spring seasons and partially contradicts the turbulence approach described above. Analyses of the PV variance (potential enstrophy) budget suggest that the up-gradient PV fluxes represent local wave decay and are maintained by poleward fluxes of PV variance. Finite-amplitude effects thus represent leading order contributions to the PV variance budget, whereas dissipation is only of secondary importance locally. The appearance of up-gradient PV fluxes in the long-term mean is associated with the poleward shift of the jet—and thus the region of wave decay relative to wave growth—following wave-breaking events.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Andrews, D. G. (1983a), A conservation law for small-amplitude quasigeostrophic disturbances on a zonally asymmetric basic flow, J. Atmos. Sci., 40, 85-90.
    • Andrews, D. G. (1983b), A finite-amplitude Eliassen-Palm theorem in isentropic coordinates, J. Atmos. Sci., 40, 1877-1883.
    • Andrews, D. G., J. R. Holton, and C. B. Leovy (1987), Middle Atmosphere Dynamics, 489 pp., Academic Press, San Diego, Calif.
    • Bartels, J., D. Peters, and G. Schmitz (1998), Climatological Ertel's potential-vorticity flux and mean meridional circulation in the extratropical troposphere-Lower stratosphere, Ann. Geophys., 16, 250-265.
    • Butler, A. H., D. W. J. Thompson, and T. Birner (2011), Isentropic slopes, downgradient eddy fluxes, and the extratropical atmospheric circulation response to tropical tropospheric heating, J. Atmos. Sci., 68, 2292-2305.
    • Defant, A. (1921), Die Zirkulation der Atmosphäre in den gemässigten Breiten der Erde. Grundzüge einer Theorie der Klimaschwankungen, Geograf. Ann., 3, 209-266.
    • Edmon, H. J., B. J. Hoskins, and M. E. McIntyre (1980), Eliassen-Palm cross sections for the troposphere, J. Atmos. Sci., 37, 2600-2616.
    • Feldstein, S. B. (1998), An observational study of the intraseasonal poleward propagation of zonal mean flow anomalies, J. Atmos. Sci., 55, 2516-2529.
    • Green, J. S. A. (1970), Transfer properties of the large-scale eddies and the general circulation of the atmosphere, Q. J. R. Meteorol. Soc., 96, 157-185.
    • Haynes, P., J. Scinocca, and M. Greenslade (2001), Formation and maintenance of the extratropical tropopause by baroclinic eddies, Geophys. Res. Lett., 28, 4179-4182.
    • Held, I. M. (1999), The macroturbulence of the troposphere, Tellus, Ser. B, 51, 59-70.
    • Held, I. M. (2000), The general circulation of the atmosphere, Lecture Notes, Woods Hole GFD Summer School.
    • Held, I. M., and B. J. Hoskins (1985), Large-scale eddies and the general circulation of the troposphere, in Advances in Geophysics, vol. 28, edited by B. Saltzman, pp. 3-31, Academic Press, New York.
    • Held, I. M., and P. J. Phillips (1990), A barotropic model of the interaction between the Hadley cell and a Rossby wave, J. Atmos. Sci., 47, 856-869.
    • Hoskins, B. J. (1983), Modelling of the transient eddies and their feedback on the mean flow, in Large-Scale Dynamical Processes in the Atmosphere, edited by B. Hoskins and R. Pearce, pp. 169-199, Academic Press, New York.
    • Hoskins, B. J., M. E. McIntyre, and A. W. Robertson (1985), On the use and significance of isentropic potential vorticity maps, Q. J. R. Meteorol. Soc., 111, 877-946.
    • Jansen, M., and R. Ferrari (2013), The vertical structure of the eddy diffusivity and the equilibration of the extratropical atmosphere, J. Atmos. Sci., 70, 1456-1469.
    • Jeffreys, H. (1926), On the dynamics of geostrophic winds, Q. J. R. Meteorol. Soc., 51, 85-101.
    • Karoly, D. J. (1982), Eliassen-Palm cross sections for the northern and southern hemispheres, J. Atmos. Sci., 39, 178-182.
    • Lee, S., S.-W. Son, K. Grise, and S. B. Feldstein (2007), A mechanism for the poleward propagation of zonal mean flow anomalies, J. Atmos. Sci., 64, 849-868.
    • Lorenz, D. J., and D. L. Hartmann (2001), Eddy-zonal flow feedback in the southern hemisphere, J. Atmos. Sci., 58, 3312-3327.
    • McIntyre, M. E. (2000), On global-scale atmospheric circulations, in Perspectives in Fluid Dynamics, edited by G. K. Batchelor, H. K. Moffatt, and M. G. Worster, pp. 557-624, Cambridge Univ. Press, Cambridge, U. K.
    • McIntyre, M. E. (2008), Potential-vorticity inversion and the waveturbulence jigsaw: Some recent clarifications, Adv. Geosci., 15, 47-56.
    • Nakamura, N., and D. Zhu (2010), Finite-amplitude wave activity and diffusive flux of potential vorticity in eddy-mean flow interaction, J. Atmos. Sci., 67, 2701-2716.
    • Plumb, R. A. (1979), Eddy fluxes of conserved quantities by smallamplitude waves, J. Atmos. Sci., 36, 1699-1704.
    • Randel, W. J., and I. M. Held (1991), Phase speed spectra of transient eddy fluxes and critical layer absorption, J. Atmos. Sci., 48, 688-697.
    • Rhines, P. B., and W. R. Young (1982), Homogenization of potential vorticity in planetary gyres, J. Fluid Mech., 122, 347-367.
    • Robinson, W. A. (2000), A baroclinic mechanism for the eddy feedback on the zonal index, J. Atmos. Sci., 57, 415-422.
    • Schneider, T. (2004), The tropopause and the thermal stratification in the extratropics of a dry atmosphere, J. Atmos. Sci., 61, 1317-1340.
    • Sobel, A. H. (1999), Diffusion versus nonlocal models of stratospheric mixing, in theory and practice, J. Atmos. Sci., 56, 2571-2584.
    • Swanson, K. L. (2001), Upper-tropospheric potential vorticity fluctuations and the dynamical relevance of the time mean, J. Atmos. Sci., 58, 1815-1826.
    • Taylor, G. I. (1914), Eddy motion in the atmosphere, Proc. London Math. Soc., 2, 196-211.
    • Thompson, D. W. J., and T. Birner (2012), On the linkages between the tropospheric isentropic slope and eddy fluxes of heat during northern hemisphere winter, J. Atmos. Sci., 69, 1811-1823.
    • Vallis, G. K. (2006), Atmospheric and Oceanic Fluid Dynamics, 745 pp., Cambridge Univ. Press, Cambridge, U. K.
  • No related research data.
  • Discovered through pilot similarity algorithms. Send us your feedback.

Share - Bookmark

Cite this article