• Ait-Chaalal, F., and T. Schneider, 2015: Why eddy momentum fluxes are concentrated in the upper troposphere. J. Atmos. Sci., 72, 15851604, doi:10.1175/JAS-D-14-0243.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Andrews, D. G., 1987: On the interpretation of the Eliassen–Palm flux divergence. Quart. J. Roy. Meteor. Soc., 113, 323338, doi:10.1002/qj.49711347518.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Andrews, D. G., and M. E. McIntyre, 1976: Planetary waves in horizontal and vertical shear: The generalized Eliassen–Palm relation and the mean zonal acceleration. J. Atmos. Sci., 33, 20312048, doi:10.1175/1520-0469(1976)033<2031:PWIHAV>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Andrews, D. G., and M. E. McIntyre, 1978: Generalized Eliassen–Palm and Charney–Drazin theorems for waves on axismmetric mean flows in compressible atmospheres. J. Atmos. Sci., 35, 509512, doi:10.1175/1520-0469(1978)035<0509:ESPBSG>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 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, doi:10.1175/1520-0469(1983)040<2768:ETWATM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 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, 250265, doi:10.1007/s00585-998-0250-3.

    • Search Google Scholar
    • Export Citation
  • Birner, T., D. W. J. Thompson, and T. G. Shepherd, 2013: Up-gradient eddy fluxes of potential vorticity near the subtropical jet. Geophys. Res. Lett., 40, 59885993, doi:10.1002/2013GL057728.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bolton, D., 1980: The computation of equivalent potential temperature. Mon. Wea. Rev., 108, 10461053, doi:10.1175/1520-0493(1980)108<1046:TCOEPT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ceppi, P., and D. L. Hartmann, 2016: Clouds and the atmospheric circulation response to warming. J. Climate, 29, 783799, doi:10.1175/JCLI-D-15-0394.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, G., 2013: The mean meridional circulation of the atmosphere using the mass above isentropes as the vertical coordinate. J. Atmos. Sci., 70, 21972213, doi:10.1175/JAS-D-12-0239.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dee, D. P., and et al. , 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quart. J. Roy. Meteor. Soc., 137, 553597, doi:10.1002/qj.828.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Donner, L. J., and et al. , 2011: The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component AM3 of the GFDL global coupled model CM3. J. Climate, 24, 34843519, doi:10.1175/2011JCLI3955.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Donohoe, A., D. W. Frierson, and D. Battisti, 2014: The effect of ocean mixed layer depth on climate in slab ocean aquaplanet experiments. Climate Dyn., 43, 10411055, doi:10.1007/s00382-013-1843-4.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Edmon, H. J., Jr., B. J. Hoskins, and M. E. McIntyre, 1980: Eliassen–Palm cross sections for the troposphere. J. Atmos. Sci., 37, 26002616, doi:10.1175/1520-0469(1980)037<2600:EPCSFT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Eliassen, A., and E. Palm, 1961: On the transfer of energy in stationary mountain waves. Geofys. Publ., 22 (3), 123.

  • Emanuel, K. A., M. Fantini, and A. J. Thorpe, 1987: Baroclinic instability in an environment of small stability to slantwise moist convection. Part I: Two-dimensional models. J. Atmos. Sci., 44, 15591573, doi:10.1175/1520-0469(1987)044<1559:BIIAEO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Frierson, D. M. W., 2007: The dynamics of idealized convection schemes and their effect on the zonally averaged tropical circulation. J. Atmos. Sci., 64, 19591976, doi:10.1175/JAS3935.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Frierson, D. M. W., I. M. Held, and P. Zurita-Gotor, 2006: A gray-radiation aquaplanet moist GCM. Part I: Static stability and eddy scale. J. Atmos. Sci., 63, 25482566, doi:10.1175/JAS3753.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Haynes, P. H., M. E. McIntyre, T. G. Shepherd, C. J. Marks, and K. P. Shine, 1991: On the “downward control” of extratropical diabatic circulations by eddy-induced mean zonal forces. J. Atmos. Sci., 48, 651678, doi:10.1175/1520-0469(1991)048<0651:OTCOED>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Held, I. M., and B. J. Hoskins, 1985: Large-scale eddies and the general circulation of the troposphere. Advances in Geophysics, Vol. 28, Academic Press, 3–31, doi:10.1016/S0065-2687(08)60218-6.

    • Crossref
    • Export Citation
  • Jansen, M., and R. Ferrari, 2013: The vertical structure of the eddy diffusivity and the equilibration of the extratropical atmosphere. J. Atmos. Sci., 70, 14561469, doi:10.1175/JAS-D-12-086.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Karoly, D. J., 1982: Eliassen–Palm cross sections for the Northern and Southern Hemispheres. J. Atmos. Sci., 39, 178182, doi:10.1175/1520-0469(1982)039<0178:EPCSFT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kidston, J., and E. P. Gerber, 2010: Intermodel variability of the poleward shift of the austral jet stream in the CMIP3 integrations linked to biases in 20th century climatology. Geophys. Res. Lett., 37, L09708, doi:10.1029/2010GL042873.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kushner, P. J., I. M. Held, and T. L. Delworth, 2001: Southern Hemisphere atmospheric circulation response to global warming. J. Climate, 14, 22382249, doi:10.1175/1520-0442(2001)014<0001:SHACRT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Laîné, A., G. Lapeyre, and G. Rivière, 2011: A quasigeostrophic model for moist storm tracks. J. Atmos. Sci., 68, 13061322, doi:10.1175/2011JAS3618.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lorenz, D. J., 2014: Understanding midlatitude jet variability and change using Rossby wave chromatography: Poleward-shifted jets in response to external forcing. J. Atmos. Sci., 71, 23702389, doi:10.1175/JAS-D-13-0200.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lu, J., G. Chen, and D. M. W. Frierson, 2010: The position of the midlatitude storm track and eddy-driven westerlies in aquaplanet AGCMs. J. Atmos. Sci., 67, 39844000, doi:10.1175/2010JAS3477.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 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, 27012716, doi:10.1175/2010JAS3432.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nie, Y., Y. Zhang, G. Chen, and X.-Q. Yang, 2016: Delineating the barotropic and baroclinic mechanisms in the midlatitude eddy-driven jet response to lower-tropospheric thermal forcing. J. Atmos. Sci., 73, 429448, doi:10.1175/JAS-D-15-0090.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • O’Gorman, P. A., 2011: The effective static stability experienced by eddies in a moist atmosphere. J. Atmos. Sci., 68, 7590, doi:10.1175/2010JAS3537.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • O’Gorman, P. A., and T. Schneider, 2008a: Energy of midlatitude transient eddies in idealized simulations of changed climates. J. Climate, 21, 57975806, doi:10.1175/2008JCLI2099.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • O’Gorman, P. A., and T. Schneider, 2008b: The hydrological cycle over a wide range of climates simulated with an idealized GCM. J. Climate, 21, 38153832, doi:10.1175/2007JCLI2065.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Orlanski, I., 2003: Bifurcation in eddy life cycles: Implications for storm track variability. J. Atmos. Sci., 60, 9931023, doi:10.1175/1520-0469(2003)60<993:BIELCI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pauluis, O., A. Czaja, and R. Korty, 2008: The global atmospheric circulation on moist isentropes. Science, 321, 10751078, doi:10.1126/science.1159649.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pauluis, O., T. Shaw, and F. Laliberté, 2011: A statistical generalization of the transformed Eulerian-mean circulation for an arbitrary vertical coordinate system. J. Atmos. Sci., 68, 17661783, doi:10.1175/2011JAS3711.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pfahl, S., P. A. O’Gorman, and M. S. Singh, 2015: Extratropical cyclones in idealized simulations of changed climates. J. Climate, 28, 93739392, doi:10.1175/JCLI-D-14-00816.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pfeffer, R. L., 1992: A study of eddy-induced fluctuations of the zonal-mean wind using conventional and transformed Eulerian diagnostics. J. Atmos. Sci., 49, 10361050, doi:10.1175/1520-0469(1992)049<1036:ASOEIF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schneider, T., P. A. O’Gorman, and X. J. Levine, 2010: Water vapor and the dynamics of climate changes. Rev. Geophys., 48, RG3001, doi:10.1029/2009RG000302.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schubert, W., 2004: A generalization of Ertel’s potential vorticity to a cloudy, precipitating atmosphere. Meteor. Z., 13, 465471, doi:10.1127/0941-2948/2004/0013-0465.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Shaw, T. A., and O. Pauluis, 2012: Tropical and subtropical meridional latent heat transports by disturbances to the zonal mean and their role in the general circulation. J. Atmos. Sci., 69, 18721889, doi:10.1175/JAS-D-11-0236.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Simmons, A. J., and D. M. Burridge, 1981: An energy and angular-momentum conserving vertical finite-difference scheme and hybrid vertical coordinates. Mon. Wea. Rev., 109, 758766, doi:10.1175/1520-0493(1981)109<0758:AEAAMC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Simpson, I. R., T. A. Shaw, and R. Seager, 2014: A diagnosis of the seasonally and longitudinally varying midlatitude circulation response to global warming. J. Atmos. Sci., 71, 24892515, doi:10.1175/JAS-D-13-0325.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Singh, M. S., and P. A. O’Gorman, 2012: Upward shift of the atmospheric general circulation under global warming: Theory and simulations. J. Climate, 25, 82598276, doi:10.1175/JCLI-D-11-00699.1.

    • 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, doi:10.1175/JAS3571.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Stone, P. H., and G. Salustri, 1984: Generalization of the quasi-geostrophic Eliassen–Palm flux to include eddy forcing of condensation heating. J. Atmos. Sci., 41, 35273536, doi:10.1175/1520-0469(1984)041<3527:GOTQGE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Taylor, K. E., R. J. Stouffer, and G. A. Meehl, 2012: An overview of CMIP5 and the experiment design. Bull. Amer. Meteor. Soc., 93, 485498, doi:10.1175/BAMS-D-11-00094.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Thorncroft, C. D., B. J. Hoskins, and M. E. McIntyre, 1993: Two paradigms of baroclinic-wave life-cycle behaviour. Quart. J. Roy. Meteor. Soc., 119, 1755, doi:10.1002/qj.49711950903.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., and D. P. Stepaniak, 2003: Covariability of components of poleward atmospheric energy transports on seasonal and interannual timescales. J. Climate, 16, 36913705, doi:10.1175/1520-0442(2003)016<3691:COCOPA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tung, K. K., 1986: Nongeostrophic theory of zonally averaged circulation. Part I: Formulation. J. Atmos. Sci., 43, 26002618, doi:10.1175/1520-0469(1986)043<2600:NTOZAC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Voigt, A., and T. A. Shaw, 2015: Circulation response to warming shaped by radiative changes of clouds and water vapour. Nat. Geosci., 8, 102106, doi:10.1038/ngeo2345.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yamada, R., and O. Pauluis, 2016: Momentum balance and Eliassen–Palm flux on moist isentropic surfaces. J. Atmos. Sci., 73, 12931314, doi:10.1175/JAS-D-15-0229.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yin, J. H., 2005: A consistent poleward shift of the storm tracks in simulations of 21st century climate. Geophys. Res. Lett., 32, L18701, doi:10.1029/2005GL023684.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 333 332 32
PDF Downloads 195 195 38

Moist Formulations of the Eliassen–Palm Flux and Their Connection to the Surface Westerlies

View More View Less
  • 1 Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
© Get Permissions
Restricted access

Abstract

The Eliassen–Palm (EP) flux is an important diagnostic for wave propagation and wave–mean flow interaction in the atmosphere. Here, two moist formulations of the EP flux are compared with the traditional dry EP flux, and their links to the surface westerlies are analyzed using reanalysis data and simulations with GCMs. The first moist formulation of the EP flux modifies only the static stability to account for latent heat release by eddies, while the second moist formulation simply replaces all potential temperatures with equivalent potential temperatures. For reanalysis data, the peak upward EP flux in the lower troposphere is farther equatorward and stronger when the moist formulations are used, with greater changes for the second moist formulation. The moist formulations have the advantage of giving a closer relationship over the seasonal cycle between the latitudes of the peak surface westerlies and the peak upward EP flux. In simulations with a comprehensive GCM, the dry and moist upward EP fluxes shift poleward by a similar amount as the climate warms. In simulations over a wider range of climates with an idealized GCM, the surface westerlies can shift both poleward and equatorward with warming, and they are influenced by an anomalous region of dry EP flux divergence near the subtropical jet. Using moist EP fluxes weakens this anomalous divergence in the idealized GCM simulations, and the shifts in the surface westerlies can then be understood through changes in the preference for equatorward or poleward wave propagation.

© 2017 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 e-mail: John G. Dwyer, jgdwyer@mit.edu

Abstract

The Eliassen–Palm (EP) flux is an important diagnostic for wave propagation and wave–mean flow interaction in the atmosphere. Here, two moist formulations of the EP flux are compared with the traditional dry EP flux, and their links to the surface westerlies are analyzed using reanalysis data and simulations with GCMs. The first moist formulation of the EP flux modifies only the static stability to account for latent heat release by eddies, while the second moist formulation simply replaces all potential temperatures with equivalent potential temperatures. For reanalysis data, the peak upward EP flux in the lower troposphere is farther equatorward and stronger when the moist formulations are used, with greater changes for the second moist formulation. The moist formulations have the advantage of giving a closer relationship over the seasonal cycle between the latitudes of the peak surface westerlies and the peak upward EP flux. In simulations with a comprehensive GCM, the dry and moist upward EP fluxes shift poleward by a similar amount as the climate warms. In simulations over a wider range of climates with an idealized GCM, the surface westerlies can shift both poleward and equatorward with warming, and they are influenced by an anomalous region of dry EP flux divergence near the subtropical jet. Using moist EP fluxes weakens this anomalous divergence in the idealized GCM simulations, and the shifts in the surface westerlies can then be understood through changes in the preference for equatorward or poleward wave propagation.

© 2017 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 e-mail: John G. Dwyer, jgdwyer@mit.edu
Save