• Ackerman, S. A., and G. L. Stephens, 1987: The absorption of solar radiation by cloud droplets: An application of anomalous diffraction theory. J. Atmos. Sci., 44 , 15741588.

    • Search Google Scholar
    • Export Citation
  • Anthes, R. A., 1977: A cumulus parameterization scheme utilizing a one-dimensional cloud model. Mon. Wea. Rev., 105 , 270286.

  • Anthes, R. A., 1983: Regional models of the atmosphere in middle latitudes. Mon. Wea. Rev., 111 , 13061335.

  • Arakawa, A., 1993: Closure assumptions in the cumulus parameterization problem. The Representation of Cumulus Convection in Numerical Models, Meteor. Monogr., No. 46, Amer. Meteor. Soc., 1–15.

    • Search Google Scholar
    • Export Citation
  • Bates, J. J., X. Wu, and D. L. Jackson, 1996: Interannual variability of upper-troposphere water vapor band brightness temperature. J. Climate, 9 , 427438.

    • Search Google Scholar
    • Export Citation
  • Black, T. L., 1994: The new NMC mesoscale Eta model: Description and forecast examples. Wea. Forecasting, 9 , 265278.

  • Del Genio, A. D., A. A. Lacis, and R. A. Ruedy, 1991: Simulation of the effect of a warmer climate on atmospheric humidity. Nature, 351 , 382385.

    • Search Google Scholar
    • Export Citation
  • Del Genio, A. D., W. Kovari, and M-S. Yao, 1994: Climatic implications of the seasonal variation of upper troposphere water vapour. Geophys. Res. Lett., 21 , 27012704.

    • Search Google Scholar
    • Export Citation
  • Diak, G. R., D. Kim, M. S. Whipple, and X. Wu, 1992: Preparing for the AMSU. Bull. Amer. Meteor. Soc., 73 , 19711984.

  • Eyre, J. R., 1991: A fast radiative transfer model for satellite sounding systems. ECMWF Tech Memo. 176, 28 pp. [Available online at http//www.ecmwf.int/library/homr.html.].

    • Search Google Scholar
    • Export Citation
  • Gregory, D., 1995: The representation of moist convection in atmospheric models. Proc. Seminar on Parameterization of Sub-grid Scale Physical Processes, Reading, United Kingdom, ECMWF, 77–113.

    • Search Google Scholar
    • Export Citation
  • Gregory, D., and M. J. Miller, 1989: A numerical study of the parameterization of deep tropical convection. Quart. J. Roy. Meteor. Soc., 115 , 12091242.

    • Search Google Scholar
    • Export Citation
  • Hanson, H. P., and V. E. Derr, 1987: Parameterization of radiative flux profiles within clouds. J. Climate Appl. Meteor., 26 , 15111521.

    • Search Google Scholar
    • Export Citation
  • Hayden, C. M., G. S. Wade, and T. J. Schmit, 1996: Derived product imagery from GOES-8. J. Appl. Meteor., 35 , 153162.

  • Johnson, R. H., 1976: The role of convective-scale precipitation downdrafts in cumulus and synoptic-scale interactions. J. Atmos. Sci., 33 , 18901910.

    • Search Google Scholar
    • Export Citation
  • Kondo, J., N. Saigusa, and S. Takeshi, 1990: A parameterization of evaporation from bare soil surfaces. J. Appl. Meteor., 29 , 385389.

    • Search Google Scholar
    • Export Citation
  • Krishnamurti, T. N., Y. Ramanathan, H-L. Pan, R. J. Pasch, and J. Molinari, 1980: Cumulus parameterization and rainfall rates I. Mon. Wea. Rev., 108 , 465472.

    • Search Google Scholar
    • Export Citation
  • Kuo, H. L., 1965: On formation and intensification of tropical cyclones through latent heat release by cumulus convection. J. Atmos. Sci., 22 , 4063.

    • Search Google Scholar
    • Export Citation
  • Kuo, H. L., 1974: Further studies of the parameterization of the influence of cumulus convection on large-scale flow. J. Atmos. Sci., 31 , 12321240.

    • Search Google Scholar
    • Export Citation
  • Kuo, H. L., and W. H. Raymond, 1980: A quasi-one-dimensional cumulus cloud model and parameterization of cumulus heating and mixing effects. Mon. Wea. Rev., 108 , 9911009.

    • Search Google Scholar
    • Export Citation
  • Lee, T. J., and R. A. Pielke, 1992: Estimating the soil surface specific humidity. J. Appl. Meteor., 31 , 480484.

  • Leslie, L. M., G. A. Mills, L. W. Logan, D. J. Gauntlett, G. A. Kelly, J. L. McGregor, and M. J. Manton, 1985: A high resolution primitive equation NWP model for operations and research. Aust. Meteor. Mag., 33 , 1135.

    • Search Google Scholar
    • Export Citation
  • Lindzen, R. S., 1990a: Response. Bull. Amer. Meteor. Soc., 71 , 14651467.

  • Lindzen, R. S., 1990b: Some coolness concerning global warming. Bull. Amer. Meteor. Soc., 71 , 288299.

  • Lindzen, R. S., 1991: Response to AMS policy statement on global climate change. Bull. Amer. Meteor. Soc., 72 , 515.

  • McGregor, J. L., L. M. Leslie, and D. J. Gauntlett, 1978: The ANMRC limited-area model: Consolidated formulation and operational results. Mon. Wea. Rev., 106 , 427438.

    • Search Google Scholar
    • Export Citation
  • McMillin, L. M., and H. E. Fleming, 1976: Atmospheric transmittance of an absorbing gas: A computational fast and accurate model for absorbing gases with constant mixing ratios in inhomogeneous atmospheres. Appl. Opt., 15 , 358363.

    • Search Google Scholar
    • Export Citation
  • Menzel, W. P., D. P. Wylie, and K. I. Strabala, 1992: Seasonal and diurnal changes in cirrus clouds as seen in four years of observations with the VAS. J. Appl. Meteor., 31 , 370385.

    • Search Google Scholar
    • Export Citation
  • Mills, G. A., and R. S. Seaman, 1990: The BMRC regional data assimilation system. Mon. Wea. Rev., 118 , 12171237.

  • Molinari, J., 1982: A method for calculating the effects of deep cumulus convection in numerical models. Mon. Wea. Rev., 110 , 15271534.

    • Search Google Scholar
    • Export Citation
  • Molinari, J., and T. Corsetti, 1985: Incorporation of cloud-scale and mesoscale downdrafts into a cumulus parameterization: Results of one- and three-dimensional integrations. Mon. Wea. Rev., 113 , 485501.

    • Search Google Scholar
    • Export Citation
  • Molinari, J., and M. Dudek, 1992: Parameterization of convective precipitation in mesoscale numerical models: A critical review. Mon. Wea. Rev., 120 , 326344.

    • Search Google Scholar
    • Export Citation
  • Naidu, P. S., 1996: Modern Spectrum Analysis of Time Series. CRC Press, 399 pp.

  • Orlanski, I., 1981: The quasi-hydrostatic approximation. J. Atmos. Sci., 38 , 572582.

  • Perry, K. D., and P. V. Hobbs, 1996: Influence of isolated cumulus clouds on the humidity of their surroundings. J. Atmos. Sci., 53 , 159174.

    • Search Google Scholar
    • Export Citation
  • Raymond, D. J., and K. A. Emanuel, 1993: The Kuo cumulus parameterization. The Representation of Cumulus Convection in Numerical Models, Meteor. Monogr., No. 46, Amer. Meteor. Soc., 145–147.

    • Search Google Scholar
    • Export Citation
  • Raymond, W. H., 1988: High-order low-pass implicit tangent filters for use in finite area calculations. Mon. Wea. Rev., 116 , 21322141.

    • Search Google Scholar
    • Export Citation
  • Raymond, W. H., 1999: Nonlocal turbulent mixing based on convective adjustment concepts (NTAC). Bound.-Layer Meteor., 92 , 263291.

  • Raymond, W. H., 2000: Moisture advection using relative humidity. J. Appl. Meteor., 39 , 23972408.

  • Raymond, W. H., and R. B. Stull, 1990: Application of transilient turbulence theory to mesoscale numerical weather forecasting. Mon. Wea. Rev., 118 , 24712499.

    • Search Google Scholar
    • Export Citation
  • Raymond, W. H., and R. M. Aune, 1998: Improved precipitation forecasts using parameterized feedbacks in a hydrostatic forecast model. Mon. Wea. Rev., 126 , 693710.

    • Search Google Scholar
    • Export Citation
  • Raymond, W. H., W. S. Olson, and G. Callan, 1995: Diabatic forcing and initialization with assimilation of cloud and rainwater in a forecast model. Mon. Wea. Rev., 123 , 366382.

    • Search Google Scholar
    • Export Citation
  • Schneider, E. K., B. P. Kirtman, and R. S. Lindzen, 1999: Tropospheric water vapor and climate sensitively. J. Atmos. Sci., 56 , 16491658.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., 2000: Enlightening water vapor. Nature, 406 , 247248.

  • Soden, B. J., and R. Fu, 1995: A satellite analysis of deep convection, upper-tropospheric humidity, and the greenhouse effect. J. Climate, 8 , 23332351.

    • Search Google Scholar
    • Export Citation
  • Stephens, G. L., D. L. Jackson, and I. Wittmeyer, 1996: Global observations of upper-tropospheric water vapor derived from TOVS radiance data. J. Climate, 9 , 305326.

    • Search Google Scholar
    • Export Citation
  • Sun, D-Z., and R. S. Lindzen, 1993: Distribution of tropospheric water vapor. J. Atmos. Sci., 50 , 16431660.

  • Sundqvist, H., E. Berge, and J. E. Kristjansson, 1989: Condensation and cloud parameterization studies with a mesoscale numerical weather prediction model. Mon. Wea. Rev., 117 , 16411659.

    • Search Google Scholar
    • Export Citation
  • Treadon, R., 1993: The NMC Eta Model post processor: A documentation. NOAA Office Note 394, National Oceanic and Atmospheric Administration, 42 pp. [Available from NASA Goddard Space Flight Center, Wallops Flight Facility, Wallops Island, VA 23337.].

    • Search Google Scholar
    • Export Citation
  • Udelhofen, P. M., and D. L. Hartmann, 1995: Influence of tropical cloud systems on the relative humidity in the upper troposphere. J. Geophys. Res., 100 , 74237440.

    • Search Google Scholar
    • Export Citation
  • Weinreb, M. P., H. E. Fleming, L. M. McMillin, and A. C. Neuendorffer, 1981: Transmittance for the TIROS Operational Vertical Sounder. NOAA Tech. Rep. NESS 85, 60 pp. [Available from National Technical Information Service, 5285 Port Royal Rd., Springfield, VA 22161.].

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 93 42 4
PDF Downloads 20 12 0

Conservation of Moisture in a Hybrid Kuo-Type Cumulus Parameterization

View More View Less
  • 1 Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin—Madison, Madison, Wisconsin
  • | 2 NOAA/National Environmental Satellite, Data, and Information Service, Madison, Wisconsin
Restricted access

Abstract

The conservation of moisture requirement used in a hybrid Kuo-type cumulus parameterization scheme is generalized so that the source of moisture for the cumulus process originates from all layers below the level of condensation, including the subcloud layer(s). This conservation scheme is distinctly different than those used with the traditional Kuo-type cumulus parameterizations, which do not include convective-scale vertical transport involving the subcloud layer(s). Numerical forecasts with the modified conservation scheme are compared with those obtained using the conventional approach that extracts the moisture from the grid-scale moisture field at the level of condensation. Radiosonde observations and Geostationary Operational Environmental Satellite (GOES) observed brightness temperatures for water vapor channel 3 (6.7 μm) are used to verify the lower- and upper-tropospheric moisture fields, respectively.

Forecast statistics, including precipitation as measured against rain gauge reports, are all improved by using the generalized moisture conservation approach. Removing moisture from the subcloud layer(s) helps stabilize the sounding and promotes self-regulation of the convection. Including the subcloud layer(s) also alters the evolution and duration of some moist convective events. In contrast, an unregulated subcloud layer encourages the moist parameterization to produce excessive precipitation.

Corresponding author address: Dr. William H. Raymond, Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin—Madison, 1225 West Dayton St., Madison, WI 53706. Email: wraymond@mail.ssec.wisc.edu

Abstract

The conservation of moisture requirement used in a hybrid Kuo-type cumulus parameterization scheme is generalized so that the source of moisture for the cumulus process originates from all layers below the level of condensation, including the subcloud layer(s). This conservation scheme is distinctly different than those used with the traditional Kuo-type cumulus parameterizations, which do not include convective-scale vertical transport involving the subcloud layer(s). Numerical forecasts with the modified conservation scheme are compared with those obtained using the conventional approach that extracts the moisture from the grid-scale moisture field at the level of condensation. Radiosonde observations and Geostationary Operational Environmental Satellite (GOES) observed brightness temperatures for water vapor channel 3 (6.7 μm) are used to verify the lower- and upper-tropospheric moisture fields, respectively.

Forecast statistics, including precipitation as measured against rain gauge reports, are all improved by using the generalized moisture conservation approach. Removing moisture from the subcloud layer(s) helps stabilize the sounding and promotes self-regulation of the convection. Including the subcloud layer(s) also alters the evolution and duration of some moist convective events. In contrast, an unregulated subcloud layer encourages the moist parameterization to produce excessive precipitation.

Corresponding author address: Dr. William H. Raymond, Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin—Madison, 1225 West Dayton St., Madison, WI 53706. Email: wraymond@mail.ssec.wisc.edu

Save