Parameterization of Wind Gustiness for the Computation of Ocean Surface Fluxes at Different Spatial Scales

Xubin Zeng Institute of Atmospheric Physics, The University of Arizona, Tucson, Arizona

Search for other papers by Xubin Zeng in
Current site
Google Scholar
PubMed
Close
,
Qiang Zhang Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China

Search for other papers by Qiang Zhang in
Current site
Google Scholar
PubMed
Close
,
D. Johnson Mesoscale Atmospheric Process Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland

Search for other papers by D. Johnson in
Current site
Google Scholar
PubMed
Close
, and
W-K. Tao Mesoscale Atmospheric Process Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland

Search for other papers by W-K. Tao in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Analysis of the Goddard cloud-ensemble (GCE) model output forced by observational data over the tropical western Pacific and eastern tropical North Atlantic has shown that ocean surface latent and sensible heat fluxes averaged in a typical global-model grid box are reproduced well using bulk algorithms with grid-box-average scalar wind speed but could be significantly underestimated under weak wind conditions using average vector wind speed. This is consistent with previous observational and modeling studies. The difference between scalar and vector wind speeds represents the subgrid wind variability (or wind gustiness) that is contributed by boundary layer large eddies, convective precipitation, and cloudiness. Based on the GCE data analysis for a case over the tropical western Pacific, a simple parameterization for wind gustiness has been developed that considers the above three factors. This scheme is found to fit well the GCE data for two other cases over the tropical western Pacific and eastern tropical North Atlantic. Its fit is also much better than that of the traditional approach that considers the contribution to wind gustiness by boundary layer large eddies alone. A simple formulation has also been developed to account for the dependence of the authors' parameterization on spatial scales (or model grid size). Together, the preliminary parameterization and formulation can be easily implemented into weather and climate models with various horizontal resolutions.

Corresponding author address: Xubin Zeng, Dept. of Atmospheric Sciences, The University of Arizona, P.O. Box 210081, Tucson, AZ 85721. Email: xubin@atmo.arizona.edu

Abstract

Analysis of the Goddard cloud-ensemble (GCE) model output forced by observational data over the tropical western Pacific and eastern tropical North Atlantic has shown that ocean surface latent and sensible heat fluxes averaged in a typical global-model grid box are reproduced well using bulk algorithms with grid-box-average scalar wind speed but could be significantly underestimated under weak wind conditions using average vector wind speed. This is consistent with previous observational and modeling studies. The difference between scalar and vector wind speeds represents the subgrid wind variability (or wind gustiness) that is contributed by boundary layer large eddies, convective precipitation, and cloudiness. Based on the GCE data analysis for a case over the tropical western Pacific, a simple parameterization for wind gustiness has been developed that considers the above three factors. This scheme is found to fit well the GCE data for two other cases over the tropical western Pacific and eastern tropical North Atlantic. Its fit is also much better than that of the traditional approach that considers the contribution to wind gustiness by boundary layer large eddies alone. A simple formulation has also been developed to account for the dependence of the authors' parameterization on spatial scales (or model grid size). Together, the preliminary parameterization and formulation can be easily implemented into weather and climate models with various horizontal resolutions.

Corresponding author address: Xubin Zeng, Dept. of Atmospheric Sciences, The University of Arizona, P.O. Box 210081, Tucson, AZ 85721. Email: xubin@atmo.arizona.edu

Save
  • Barnes, G. M., and M. Garstang, 1982: Subcloud layer energies of precipitating convection. Mon. Wea. Rev., 110 , 102117.

  • Beljaars, A. C. M., 1995: The parameterization of surface fluxes in large scale models under free convection. Quart. J. Roy. Meteor. Soc., 121 , 255270.

    • Search Google Scholar
    • Export Citation
  • Chen, M., R. E. Dickinson, X. Zeng, and A. Hahmann, 1996: Comparison of precipitation observed over the continental United States with that simulated by a climate model. J. Climate, 9 , 22332249.

    • Search Google Scholar
    • Export Citation
  • Chou, M. D., M. J. Suarez, C. H. Ho, M. M. H. Yan, and K. T. Lee, 1998: Parameterizations for cloud overlapping and shortwave single-scattering properties for use in general circulation and cloud ensemble models. J. Climate, 11 , 202214.

    • Search Google Scholar
    • Export Citation
  • Emanuel, K. A., and M. Zivkovic-Rothman, 1999: Development and evaluation of a convection scheme for use in climate models. J. Atmos. Sci., 56 , 17661782.

    • Search Google Scholar
    • Export Citation
  • Esbensen, S. K., and M. J. McPhaden, 1996: Enhancement of tropical ocean evaporation and sensible heat flux by atmospheric mesoscale systems. J. Climate, 9 , 23072325.

    • Search Google Scholar
    • Export Citation
  • Fairall, C. W., E. F. Bradley, D. P. Rogers, J. B. Edson, and G. S. Young, 1996: Bulk parameterization of air–sea fluxes for Tropical Ocean-Global Atmosphere Coupled-Ocean Atmosphere Response Experiment. J. Geophys. Res., 101 , 37473764.

    • Search Google Scholar
    • Export Citation
  • Ferrier, B. S., 1994: A double-moment multiple-phase four-class bulk ice scheme. Part I: Description. J. Atmos. Sci., 51 , 249280.

  • Gaynor, J. E., and C. F. Ropelewski, 1979: Analysis of the convectively modified GATE boundary layer using in situ and acoustic sounding data. Mon. Wea. Rev., 107 , 985993.

    • Search Google Scholar
    • Export Citation
  • Gleckler, P. J., and Coauthors. 1995: Interpretation of ocean energy transports implied by atmospheric general circulation models. Geophys. Res. Lett., 22 , 791794.

    • Search Google Scholar
    • Export Citation
  • Jabouille, P., J. L. Redelsperger, and J. P. Lafore, 1996: Modification of surface fluxes by atmospheric convection in the TOGA COARE region. Mon. Wea. Rev., 124 , 816837.

    • Search Google Scholar
    • Export Citation
  • Johnson, R. H., and M. E. Nicholls, 1983: A composite analysis of the boundary layer accompanying a tropical squall line. Mon. Wea. Rev., 111 , 308319.

    • Search Google Scholar
    • Export Citation
  • Ledvina, D., G. S. Young, R. A. Miller, and C. W. Fairall, 1993: The effect of averaging on bulk estimates of heat and momentum fluxes for the tropical western Pacific Ocean. J. Geophys. Res., 98 , 2022120217.

    • Search Google Scholar
    • Export Citation
  • Lynn, B. H., W-K. Tao, and P. Wetzel, 1998: A study of landscape-generated deep moist convection. Mon. Wea. Rev., 126 , 928942.

  • Mahrt, L., and J. Sun, 1995: The subgrid velocity scale in the bulk aerodynamic relationship for spatially averaged scalar fluxes. Mon. Wea. Rev., 123 , 30323041.

    • Search Google Scholar
    • Export Citation
  • Miller, M. J., A. C. M. Beljaars, and T. N. Palmer, 1992: The sensitivity of the ECMWF model to the parameterization of evaporation from the tropical oceans. J. Climate, 5 , 418434.

    • Search Google Scholar
    • Export Citation
  • Redelsperger, J. L., F. Guichard, and S. Mondon, 2000: A parameterization of mesoscale enhancement of surface fluxes for large-scale models. J. Climate, 13 , 402421.

    • Search Google Scholar
    • Export Citation
  • Roberts, C. M., C. Gordon, and C. Cooper, 1997: The origin of flux adjustments in a coupled model. Mon. Wea. Rev., 125 , 909925.

  • Saxen, T. R., and S. A. Rutledge, 1998: Surface fluxes and boundary layer recovery in TOGA COARE: Sensitivity to convective organization. J. Atmos. Sci., 55 , 27632781.

    • Search Google Scholar
    • Export Citation
  • Simpson, J., and W-K. Tao, 1993: The Goddard cumulus ensemble model. Part II: Applications for studying cloud precipitating processes and for NASA TRMM. Terr. Atmos. Oceanic Sci., 4 , 73116.

    • Search Google Scholar
    • Export Citation
  • Sun, J., J. F. Howell, S. K. Esbensen, L. Mahrt, C. M. Greb, R. Grossman, and M. A. LeMone, 1996: Scale dependence of air–sea fluxes over the western equatorial Pacific. J. Atmos. Sci., 53 , 29973012.

    • Search Google Scholar
    • Export Citation
  • Tao, W-K., and J. Simpson, 1993: The Goddard cumulus ensemble model. Part I: Model description. Terr. Atmos. Oceanic Sci., 4 , 3572.

  • Tao, W-K., S. Lang, J. Simpson, W. S. Olson, D. Johnson, B. Ferrier, C. Kummerow, and R. Adler, 2000: Vertical profiles of latent heat release and their retrieval for TOGA COARE convective systems using a cloud resolving model, SSM/I, and ship-borne radar data. J. Meteor. Soc. Japan, 78 , 333355.

    • Search Google Scholar
    • Export Citation
  • Vickers, D., and S. K. Esbensen, 1998: Subgrid surface fluxes in fair weather conditions during TOGA COARE: Observational estimates and parameterization. Mon. Wea. Rev., 126 , 620633.

    • Search Google Scholar
    • Export Citation
  • Wang, Y., W-K. Tao, and J. Simpson, 1996: The impact of ocean surface fluxes on a TOGA COARE convective system. Mon. Wea. Rev., 124 , 27532763.

    • Search Google Scholar
    • Export Citation
  • Webster, P. J., and R. Lukas, 1992: TOGA COARE: The Coupled Ocean–Atmosphere Response Experiment. Bull. Amer. Meteor. Soc., 73 , 13771416.

    • Search Google Scholar
    • Export Citation
  • Wilks, D. S., 1995: Statistical Methods in the Atmospheric Sciences: An Introduction. Academic Press, 467 pp.

  • Williams, A. G., 2001: A physically based parameterization for surface flux enhancement by gustiness effects in dry and precipitating convection. Quart. J. Roy. Meteor. Soc., 127 , 469491.

    • Search Google Scholar
    • Export Citation
  • Young, G. S., S. M. Perugini, and C. W. Fairall, 1995: Convective wakes in the equatorial western Pacific during TOGA. Mon. Wea. Rev., 123 , 110123.

    • Search Google Scholar
    • Export Citation
  • Zeng, X., M. Zhao, and R. E. Dickinson, 1998: Intercomparison of bulk aerodynamic algorithms for sea surface fluxes using the TOGA COARE and TAO data. J. Climate, 11 , 26282644.

    • Search Google Scholar
    • Export Citation
  • Zulauf, M., and S. K. Krueger, 1997: Parameterization of mesoscale enhancement of large-scale surface fluxes over tropical oceans. Preprints, 22d Conf. on Hurricanes and Tropical Meteorology, Fort Collins, CO, Amer. Meteor. Soc., 164–165.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 395 108 5
PDF Downloads 332 129 3