Momentum Flux Spectrum of Convective Gravity Waves. Part I: An Update of a Parameterization Using Mesoscale Simulations

Hyun-Joo Choi Department of Atmospheric Sciences, Yonsei University, Seoul, South Korea

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Hye-Yeong Chun Department of Atmospheric Sciences, Yonsei University, Seoul, South Korea

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Abstract

The convective source and momentum flux spectra of a parameterization of convective gravity wave drag (GWDC) are validated in a three-dimensional spectral space using mesoscale numerical simulations for various ideal and real convective storms. From this, two important free parameters included in the GWDC parameterization—the moving speed of the convective source and the wave propagation direction—are determined. In the numerical simulations, the convective source spectrum shows nearly isotropic features in terms of magnitude, and its primary peak in any azimuthal direction occurs at a phase speed that equals the moving speed of the convective source in the same direction. It is found that the moving speed of the convective source is closely correlated with the basic-state wind averaged below 700 hPa (u700 and υ700). When the analytic convective source spectrum of the parameterization is calculated using the moving speed of the convective source as determined by u700 and υ700, its shape in all storm cases agrees with that from the simulation. The momentum flux spectrum at launch level (cloud top) is also calculated using the basic-state conditions and the moving speed of the convective source as determined by u700 and υ700. A comparison between the parameterization and simulation results shows that the parameterization reproduces the momentum flux spectrum from the simulation reasonably well. In the parameterization, two wave propagation directions of 45° (northeast and southwest) and 135° (northwest and southeast) best represent the momentum flux spectra from the simulations integrated over all directions when the minimum number of wave propagation directions is required for computational efficiency.

Corresponding author address: Hye-Yeong Chun, Department of Atmospheric Sciences, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, South Korea. E-mail: chunhy@yonsei.ac.kr

Abstract

The convective source and momentum flux spectra of a parameterization of convective gravity wave drag (GWDC) are validated in a three-dimensional spectral space using mesoscale numerical simulations for various ideal and real convective storms. From this, two important free parameters included in the GWDC parameterization—the moving speed of the convective source and the wave propagation direction—are determined. In the numerical simulations, the convective source spectrum shows nearly isotropic features in terms of magnitude, and its primary peak in any azimuthal direction occurs at a phase speed that equals the moving speed of the convective source in the same direction. It is found that the moving speed of the convective source is closely correlated with the basic-state wind averaged below 700 hPa (u700 and υ700). When the analytic convective source spectrum of the parameterization is calculated using the moving speed of the convective source as determined by u700 and υ700, its shape in all storm cases agrees with that from the simulation. The momentum flux spectrum at launch level (cloud top) is also calculated using the basic-state conditions and the moving speed of the convective source as determined by u700 and υ700. A comparison between the parameterization and simulation results shows that the parameterization reproduces the momentum flux spectrum from the simulation reasonably well. In the parameterization, two wave propagation directions of 45° (northeast and southwest) and 135° (northwest and southeast) best represent the momentum flux spectra from the simulations integrated over all directions when the minimum number of wave propagation directions is required for computational efficiency.

Corresponding author address: Hye-Yeong Chun, Department of Atmospheric Sciences, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, South Korea. E-mail: chunhy@yonsei.ac.kr
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  • Beres, J. H., 2004: Gravity wave generation by a three-dimensional thermal forcing. J. Atmos. Sci., 61, 18051815.

  • Beres, J. H., M. J. Alexander, and J. R. Holton, 2002: Effects of tropospheric wind shear on the spectrum of convectively generated gravity waves. J. Atmos. Sci., 59, 18051824.

    • Search Google Scholar
    • Export Citation
  • Bjorn, L. G., 1984: The cold summer mesopause. Adv. Space Res., 4, 145151, doi:10.1016/0273-1177(84)90277-1.

  • Booker, J. R., and F. P. Bretherton, 1967: The critical layer for internal gravity waves in a shear flow. J. Fluid Mech., 27, 513539.

    • Search Google Scholar
    • Export Citation
  • Choi, H.-J., H.-Y. Chun, and I.-S. Song, 2007: Characteristics and momentum flux spectrum of convectively forced internal gravity waves in ensemble numerical simulations. J. Atmos. Sci., 64, 37233734.

    • Search Google Scholar
    • Export Citation
  • Choi, H.-J., H.-Y. Chun, and I.-S. Song, 2009: Gravity wave temperature variance calculated using the ray-based spectral parameterization of convective gravity waves and its comparison with Microwave Limb Sounder observations. J. Geophys. Res., 114, D08111, doi:10.1029/2008JD011330.

    • Search Google Scholar
    • Export Citation
  • Chun, H.-Y., and J.-J. Baik, 1998: Momentum flux by thermally induced internal gravity waves and its approximation for large-scale models. J. Atmos. Sci., 55, 32993310.

    • Search Google Scholar
    • Export Citation
  • Chun, H.-Y., and J.-J. Baik, 2002: An updated parameterization of convectively forced gravity wave drag for use in large-scale models. J. Atmos. Sci., 59, 10061017.

    • Search Google Scholar
    • Export Citation
  • Chun, H.-Y., J.-J..Baik, and T. Horinouchi, 2005: Momentum flux spectrum of convectively forced gravity waves: Can diabatic forcing be a proxy for convective forcing? J. Atmos. Sci., 62, 41134120.

    • Search Google Scholar
    • Export Citation
  • Chun, H.-Y., H.-J. Choi, and I.-S. Song, 2008: Effects of nonlinearity on convectively forced internal gravity waves: Application to a gravity wave drag parameterization. J. Atmos. Sci., 65, 557575.

    • Search Google Scholar
    • Export Citation
  • Corfidi, S. F., 2003: Cold pools and MCS propagation: Forecasting the motion of downwind-developing MCSs. Wea. Forecasting, 18, 9971017.

    • Search Google Scholar
    • Export Citation
  • Corfidi, S. F., J. H. Merritt, and J. M. Fritsch, 1996: Predicting the movement of mesoscale convective complexes. Wea. Forecasting, 11, 4146.

    • Search Google Scholar
    • Export Citation
  • Dhaka, S. K., M. K. Yamamoto, Y. Shibagaki, H. Hashiguchi, M. Yamamoto, and S. Fukao, 2005: Convection-induced gravity waves observed by the Equatorial Atmosphere Radar (0.20°S, 100.32°E) in Indonesia. Geophys. Res. Lett., 32, L14820, doi:10.1029/2005GL022907.

    • Search Google Scholar
    • Export Citation
  • Dunkerton, T. J., 1997: The role of gravity waves in the quasi-biennial oscillation. J. Geophys. Res., 102(D22)26 05326 076.

  • Garcia, R. R., and B. A. Boville, 1994: “Downward control” of the mean meridional circulation and temperature distribution of the polar winter stratosphere. J. Atmos. Sci., 51, 22382245.

    • Search Google Scholar
    • Export Citation
  • Garcia, R. R., T. J. Dunkerton, R. S. Lieberman, and R. A. Vincent, 1997: Climatology of the semiannual oscillation of the tropical middle atmosphere. J. Geophys. Res., 102, 26 01926 032

    • Search Google Scholar
    • Export Citation
  • Kessler, E., 1969: On the Distribution and Continuity of Water Substance in Atmospheric Circulation. Meteor. Monogr., No. 32, Amer. Meteor. Soc., 84 pp.

    • Search Google Scholar
    • Export Citation
  • Klemp, J. B., and D. K. Lilly, 1978: Numerical simulation of hydrostatic mountain waves. J. Atmos. Sci., 35, 78107.

  • Klemp, J. B., and R. Wilhelmson, 1978: The simulation of three-dimensional convective storm dynamics. J. Atmos. Sci., 35, 10701096.

  • Lane, T. P., M. J. Reeder, and T. L. Clark, 2001: Numerical modeling of gravity wave generation by deep tropical convection. J. Atmos. Sci., 58, 12491274.

    • Search Google Scholar
    • Export Citation
  • Lin, Y.-L., and H.-Y. Chun, 1991: Effects of diabatic cooling in a shear flow with a critical level. J. Atmos. Sci., 48, 24762491.

  • Lindzen, R. S., 1981: Turbulence and stress owing to gravity wave and tidal breakdown. J. Geophys. Res., 86, 97079714.

  • Matsuno, T., 1982: A quasi one-dimensional model of the middle atmosphere circulation interacting with internal gravity waves. J. Meteor. Soc. Japan, 60, 215221.

    • Search Google Scholar
    • Export Citation
  • Skamarock, W. C., and Coauthors, 2008: A description of the Advanced Research WRF version 3. NCAR Tech. Note NCAR/TN-475+STR, 113 pp.

  • Song, I.-S., and H.-Y. Chun, 2005: Momentum flux spectrum of convectively forced internal gravity waves and its application to gravity wave drag parameterization. Part I: Theory. J. Atmos. Sci., 62, 107124.

    • Search Google Scholar
    • Export Citation
  • Song, I.-S., and H.-Y. Chun, 2006: A spectral parameterization of convectively forced internal gravity waves and estimation of gravity-wave momentum forcing to the middle atmosphere. J. Korean Meteor. Soc., 42, 339359.

    • Search Google Scholar
    • Export Citation
  • Song, I.-S., and H.-Y. Chun, 2008: A Lagrangian spectral parameterization of gravity wave drag induced by cumulus convection. J. Atmos. Sci., 65, 12041224.

    • Search Google Scholar
    • Export Citation
  • Song, I.-S., H.-Y. Chun, and T. P. Lane, 2003: Generation mechanisms of convectively forced internal gravity waves and their propagation to the stratosphere. J. Atmos. Sci., 60, 19601980.

    • Search Google Scholar
    • Export Citation
  • Song, I.-S., H.-Y. Chun, R. R. Garcia, and B. A. Boville, 2007: Momentum flux spectrum of convectively forced internal gravity waves and its application to gravity wave drag parameterization. Part II: Impacts in a GCM (WACCM). J. Atmos. Sci., 64, 22862308.

    • Search Google Scholar
    • Export Citation
  • Trier, S. B., W. C. Skamarock, M. A. LeMone, D. B. Parsons, and D. P. Jorgensen, 1996: Structure and evolution of the 22 February 1993 TOGA COARE squall line: Numerical simulations. J. Atmos. Sci., 53, 28612886.

    • Search Google Scholar
    • Export Citation
  • Uppala, S. M., and Coauthors, 2005: The ERA-40 Re-Analysis. Quart. J. Roy. Meteor. Soc., 131, 29613012.

  • Weisman, M. L., and J. B. Klemp, 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev., 110, 504520.

    • Search Google Scholar
    • Export Citation
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