• Andrews, D. G., J. D. Mahlman, and R. W. Sinclair, 1983: Eliassen-Palm diagnostics of wave–mean flow interaction in the GFDL “SKYHI” general circulation model. J. Atmos. Sci., 40, 27682784, https://doi.org/10.1175/1520-0469(1983)040<2768:ETWATM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Brayshaw, D. J., B. Hoskins, and M. Blackburn, 2008: The storm-track response to idealized SST perturbations in an aquaplanet GCM. J. Atmos. Sci., 65, 28422860, https://doi.org/10.1175/2008JAS2657.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chang, E. K. M., 2006: An idealized nonlinear model of the Northern Hemisphere winter storm tracks. J. Atmos. Sci., 63, 18181839, https://doi.org/10.1175/JAS3726.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Charney, J. G., and M. E. Stern, 1962: On the stability of internal baroclinic jets in a rotating atmosphere. J. Atmos. Sci., 19, 159172, https://doi.org/10.1175/1520-0469(1962)019<0159:OTSOIB>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Eady, E. T., 1949: Long waves and cyclonic waves. Tellus, 1 (3), 3352, https://doi.org/10.3402/tellusa.v1i3.8507.

  • Eichelberger, S. J., and D. L. Hartmann, 2007: Zonal jet structure and the leading mode of variability. J. Climate, 20, 51495163, https://doi.org/10.1175/JCLI4279.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Held, I. M., 1975: Momentum transport by quasi-geostrophic eddies. J. Atmos. Sci., 32, 14941497, https://doi.org/10.1175/1520-0469(1975)032<1494:MTBQGE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Held, I. M., and A. Y. Hou, 1980: Nonlinear axially symmetric circulations in a nearly inviscid atmosphere. J. Atmos. Sci., 37, 515533, https://doi.org/10.1175/1520-0469(1980)037<0515:NASCIA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Held, I. M., and M. J. Suarez, 1994: A proposal for the intercomparison of the dynamical cores of atmospheric general circulation models. Bull. Amer. Meteor. Soc., 75, 18251830, https://doi.org/10.1175/1520-0477(1994)075<1825:APFTIO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hoskins, B. J., and P. J. Valdes, 1990: On the existence of storm-tracks. J. Atmos. Sci., 47, 18541864, https://doi.org/10.1175/1520-0469(1990)047<1854:OTEOST>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • James, I. N., 1987: Suppression of baroclinic instability in horizontally sheared flows. J. Atmos. Sci., 44, 37103720, https://doi.org/10.1175/1520-0469(1987)044<3710:SOBIIH>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • James, I. N., and L. J. Gray, 1986: Concerning the effect of surface drag on the circulation of a baroclinic planetary atmosphere. Quart. J. Roy. Meteor. Soc., 112, 12311250, https://doi.org/10.1002/qj.49711247417.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lachmy, O., and N. Harnik, 2014: The transition to a subtropical jet regime and its maintenance. J. Atmos. Sci., 71, 13891409, https://doi.org/10.1175/JAS-D-13-0125.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lee, S., and H. Kim, 2003: The dynamical relationship between subtropical and eddy-driven jets. J. Atmos. Sci., 60, 14901503, https://doi.org/10.1175/1520-0469(2003)060<1490:TDRBSA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lunkeit, F., L. Fraedrich, and S. E. Bauer, 1998: Storm tracks in warmer climate: Sensitivity studies with a simplified global circulation model. Climate Dyn., 14, 813826, https://doi.org/10.1007/s003820050257.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nakamura, H., 1992: Midwinter suppression of baroclinic wave activity in the Pacific. J. Atmos. Sci., 49, 16291642, https://doi.org/10.1175/1520-0469(1992)049<1629:MSOBWA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nakamura, H., and T. Sampe, 2002: Trapping of synoptic-scale disturbances into the North-Pacific subtropical jet core in midwinter. Geophys. Res. Lett., 29, 1761, https://doi.org/10.1029/2002GL015535.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nakamura, H., and A. Shimpo, 2004: Seasonal variations in the Southern Hemisphere storm tracks and jet streams as revealed in a reanalysis dataset. J. Climate, 17, 18281844, https://doi.org/10.1175/1520-0442(2004)017<1828:SVITSH>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Panetta, R. L., 1993: Zonal jets in wide baroclinically unstable regions: Persistence and scale selection. J. Atmos. Sci., 50, 20732106, https://doi.org/10.1175/1520-0469(1993)050<2073:ZJIWBU>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rhines, P. B., 1975: Waves and turbulence on a beta plane. J. Fluid Mech., 69, 417443, https://doi.org/10.1017/S0022112075001504.

  • Sampe, T., H. Nakamura, A. Goto, and W. Ohfuchi, 2010: Significance of a midlatitude SST frontal zone in the formation of a storm track and an eddy-driven westerly jet. J. Climate, 23, 17931814, https://doi.org/10.1175/2009JCLI3163.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Son, S.-W., and S. Lee, 2005: The response of westerly jets to thermal driving in a primitive equation model. J. Atmos. Sci., 62, 37413757, https://doi.org/10.1175/JAS3571.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Vallis, G. K., 2006: Atmospheric and Oceanic Fluid Dynamics. Cambridge University Press, 770 pp.

    • Crossref
    • Export Citation
  • Walker, C. C., and T. Schneider, 2006: Eddy influences on Hadley circulations: Simulations with an idealized GCM. J. Atmos. Sci., 63, 33333350, https://doi.org/10.1175/JAS3821.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yuval, J., and Y. Kaspi, 2016: Eddy activity sensitivity to changes in the vertical structure of baroclinicity. J. Atmos. Sci., 73, 17091726, https://doi.org/10.1175/JAS-D-15-0128.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yuval, J., and Y. Kaspi, 2017: The effect of vertical baroclinicity concentration on atmospheric macroturbulence scaling relations. J. Atmos. Sci., 74, 16511667, https://doi.org/10.1175/JAS-D-16-0277.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zurita-Gotor, P., 2007: The relation between baroclinic adjustment and turbulent diffusion in the two-layer model. J. Atmos. Sci., 64, 12841300, https://doi.org/10.1175/JAS3886.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
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Eddy Sensitivity to Jet Characteristics

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  • 1 Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
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Abstract

The atmosphere exhibits two distinct types of jets: the thermally driven subtropical jet and the more poleward eddy-driven jet. Depending on location and season, these jets are often merged or separated, and their position, structure, and intensity strongly influence the eddy fields. Here, the authors study the sensitivity of eddies to changes in the jets’ amplitudes and positions in an idealized general circulation model. A modified Newtonian relaxation scheme that has a very short relaxation time for the mean state and a long relaxation time for eddies is used. This scheme makes it possible to obtain any zonally symmetric temperature distribution and is used to systematically modify the jets’ amplitudes and locations. It is found that eddies are more sensitive to changes in the amplitude of the eddy-driven jet than to changes in the amplitude of the subtropical jet. Furthermore, when the eddy-driven jet is shifted poleward, eddies tend to intensify. These results are tested for robustness in two different reference simulations: one resembling a situation where the subtropical and eddy-driven jets are nearly merged and one when they are separated.

© 2018 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Janni Yuval, yaniyuval@gmail.com

Abstract

The atmosphere exhibits two distinct types of jets: the thermally driven subtropical jet and the more poleward eddy-driven jet. Depending on location and season, these jets are often merged or separated, and their position, structure, and intensity strongly influence the eddy fields. Here, the authors study the sensitivity of eddies to changes in the jets’ amplitudes and positions in an idealized general circulation model. A modified Newtonian relaxation scheme that has a very short relaxation time for the mean state and a long relaxation time for eddies is used. This scheme makes it possible to obtain any zonally symmetric temperature distribution and is used to systematically modify the jets’ amplitudes and locations. It is found that eddies are more sensitive to changes in the amplitude of the eddy-driven jet than to changes in the amplitude of the subtropical jet. Furthermore, when the eddy-driven jet is shifted poleward, eddies tend to intensify. These results are tested for robustness in two different reference simulations: one resembling a situation where the subtropical and eddy-driven jets are nearly merged and one when they are separated.

© 2018 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Janni Yuval, yaniyuval@gmail.com
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