The Use of Cloud-Resolving Simulations of Mesoscale Convective Systems to Build a Mesoscale Parameterization Scheme

G. David Alexander Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado

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William R. Cotton Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado

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Abstract

A method is described for parameterizing thermodynamic forcing by the mesoscale updrafts and downdrafts of mesoscale convective systems (MCSs) in models with resolution too coarse to resolve these drafts. The parameterization contains improvements over previous schemes, including a more sophisticated convective driver and inclusion of the vertical distribution of various physical processes obtained through conditional sampling of two cloud-resolving MCS simulations. The mesoscale parameterization is tied to a version of the Arakawa–Schubert convective parameterization scheme that is modified to employ a prognostic closure. The parameterized Arakawa–Schubert cumulus convection provides condensed water, ice, and water vapor, which drives the parameterization for the large-scale effects of mesoscale circulations associated with the convection. In the mesoscale parameterization, determining thermodynamic forcing of the large scale depends on knowing the vertically integrated values and the vertical distributions of phase transformation rates and mesoscale eddy fluxes of entropy and water vapor in mesoscale updrafts and downdrafts. The relative magnitudes of these quantities are constrained by assumptions made about the relationships between various quantities in an MCS’s water budget deduced from the cloud-resolving MCS simulations. The MCS simulations include one of a tropical MCS observed during the 1987 Australian monsoon season (EMEX9) and one of a midlatitude MCS observed during a 1985 field experiment in the Central Plains of the United States (PRE-STORM 23–24 June).

Corresponding author address: William R. Cotton, Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523.

Abstract

A method is described for parameterizing thermodynamic forcing by the mesoscale updrafts and downdrafts of mesoscale convective systems (MCSs) in models with resolution too coarse to resolve these drafts. The parameterization contains improvements over previous schemes, including a more sophisticated convective driver and inclusion of the vertical distribution of various physical processes obtained through conditional sampling of two cloud-resolving MCS simulations. The mesoscale parameterization is tied to a version of the Arakawa–Schubert convective parameterization scheme that is modified to employ a prognostic closure. The parameterized Arakawa–Schubert cumulus convection provides condensed water, ice, and water vapor, which drives the parameterization for the large-scale effects of mesoscale circulations associated with the convection. In the mesoscale parameterization, determining thermodynamic forcing of the large scale depends on knowing the vertically integrated values and the vertical distributions of phase transformation rates and mesoscale eddy fluxes of entropy and water vapor in mesoscale updrafts and downdrafts. The relative magnitudes of these quantities are constrained by assumptions made about the relationships between various quantities in an MCS’s water budget deduced from the cloud-resolving MCS simulations. The MCS simulations include one of a tropical MCS observed during the 1987 Australian monsoon season (EMEX9) and one of a midlatitude MCS observed during a 1985 field experiment in the Central Plains of the United States (PRE-STORM 23–24 June).

Corresponding author address: William R. Cotton, Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523.

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  • Alexander, G. D., and G. S. Young, 1992: The relationship between EMEX mesoscale precipitation feature properties and their environmental characteristics. Mon. Wea. Rev.,120, 554–564.

  • Arakawa, A., and M.-D. Cheng, 1993: The Arakawa–Schubert cumulus parameterization. The Representation of Cumulus Convection in Numerical Models, Meteor. Monogr., No. 46, Amer. Meteor. Soc., 123–136.

  • Avissar, R., and F. Chen, 1993: Development and analysis of prognostic equations for mesoscale kinetic energy and mesoscale (subgrid scale) fluxes for large-scale atmospheric models. J. Atmos. Sci.,50, 3751–3774.

  • Barnes, S. L., 1973: Mesoscale objective map analysis using weighted time-series observations. NOAA Tech. Memo. ERL NSSL-62, 60 pp. [NTIS COM-73-10781.].

  • Bernstein, B. C., and R. H. Johnson, 1994: A dual-Doppler radar study of an OK PRE-STORM heat burst event. Mon. Wea. Rev.,122, 259–273.

  • Bograd, S. J., 1989: The mesoscale structure of precipitation in EMEX cloud clusters. M.S. thesis, Dept. of Atmospheric Sciences, University of Washington, 143 pp.

  • Browning, K. A., A. Betts, P. R. Jonas, R. Kershaw, M. Manton, P. J. Mason, M. Miller, M. W. Moncrieff, H. Sundqvist, W. K. Tao, M. Tiedtke, P. V. Hobbs, J. Mitchell, E. Raschke, R. E. Stewart, and J. Simpson, 1993: The GEWEX Cloud System Study (GCSS). Bull. Amer. Meteor. Soc.,74, 387–399.

  • Chen, S., and W. R. Cotton, 1983: A one-dimensional simulation of the stratocumulus-capped mixed layer. Bound.-Layer Meteor.,25, 289–321.

  • Chong, M., and D. Hauser, 1989: A tropical squall line observed during the COPT81 experiment in West Africa. Part II: Water budget. Mon. Wea. Rev.,117, 728–744.

  • Churchill, D. D., and R. A. Houze Jr., 1984: Development and structure of winter monsoon cloud clusters on 10 December 1978. J. Atmos. Sci.,41, 933–960.

  • Cotton, W. R., G. Tripoli, R. M. Rauber, and E. A. Mulvihill, 1986:Numerical simulation of the effects of varying ice crystal nucleation rates and aggregation processes on orographic snowfall. J. Climate Appl. Meteor.,25, 1658–1680.

  • Cunning, J. B., 1986: The Oklahoma–Kansas Preliminary Regional Experiment for STORM-Central. Bull. Amer. Meteor. Soc.,67, 1478–1486.

  • Donner, L. J., 1993: A cumulus parameterization including mass fluxes, vertical momentum dynamics, and mesoscale effects. J. Atmos. Sci.,50, 889–906.

  • Flatau, P. J., G. J. Tripoli, J. Verlinde, and W. R. Cotton, 1989: The CSU-RAMS cloud microphysics module: General theory and code documentation. CSU Dept. of Atmos. Sci. Research Paper 451, 88 pp. [Available from Dept. of Atmos. Sci., Colorado State University, Fort Collins, CO 80523.].

  • Gallus, W. A., Jr., and R. H. Johnson, 1991: Heat and moisture budgets of an intense midlatitude squall line. J. Atmos. Sci.,48, 122–146.

  • Gamache, J. F., and R. A. Houze Jr., 1983: Water budget of a mesoscale convective system in the tropics. J. Atmos. Sci.,40, 1835–1850.

  • ——, F. Marks Jr., and R. W. Burpee, 1987: EMEX data report: The Equatorial Mesoscale Experiment. AOML/HRD Rep. [Available from National Oceanic and Atmospheric Administration, Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division, Miami, FL 33149.].

  • Houze, R. A., Jr., 1977: Structure and dynamics of a tropical squall line system. Mon. Wea. Rev.,105, 1540–1567.

  • Johnson, R. H., 1976: The role of convective-scale precipitation downdrafts in cumulus and synoptic-scale interactions. J. Atmos. Sci.,33, 1890–1910.

  • ——, and P. J. Hamilton, 1988: The relationship of surface pressure features to the precipitation and airflow structure of an intense midlatitude squall line. Mon. Wea. Rev.,116, 1444–1471.

  • ——, and D. L. Bartels, 1992: Circulations associated with a mature-to-decaying midlatitude mesoscale convective system. Part II: Upper-level features. Mon. Wea. Rev.,120, 1301–1320.

  • ——, S. Chen, and J. J. Toth, 1989: Circulations associated with a mature-to-decaying midlatitude mesoscale convective system. Part I: Surface features—Heat bursts and mesolow development. Mon. Wea. Rev.,117, 942–959.

  • Klemp, J. B., and R. B. Wilhelmson, 1978a: The simulation of three-dimensional convective storm dynamics. J. Atmos. Sci.,35, 1070–1096.

  • ——, and ——, 1978b: Simulations of right- and left-moving storms produced through storm splitting. J. Atmos. Sci.,35, 1097–1110.

  • Leary, C. A., and R. A. Houze Jr., 1980: The contribution of mesoscale motions to the mass and heat fluxes of an intense tropical convective system. J. Atmos. Sci.,37, 784–796.

  • Lee, T. J., 1992: The impact of vegetation on the atmospheric boundary layer and convective storms. Ph.D. dissertation, Colorado State University, 137 pp.

  • Lord, S. J., and A. Arakawa, 1980: Interaction of a cumulus ensemble with the large-scale environment. Part II. J. Atmos. Sci.,37, 2677–2692.

  • Louis, J. F., 1979: A parametric model of vertical eddy fluxes in the atmosphere. Bound.-Layer Meteor.,17, 309–322.

  • Lucas, C., E. J. Zipser, and M. A. LeMone, 1994: Vertical velocity in oceanic tropical convection off tropical Australia. J. Atmos. Sci.,51, 3183–3193.

  • Mapes, B. E., and R. A. Houze Jr., 1992: An integrated view of the 1987 Australian monsoon and its mesoscale convective systems. I: Horizontal structure. Quart. J. Roy. Meteor. Soc.,118, 927–963.

  • McCumber, M. C., and R. A. Pielke, 1981: Simulation of the effects of surface fluxes of heat and moisture in a mesoscale numerical model. Part I: Soil layer. J. Geophys. Res.,86, 9929–9938.

  • Olsson, P. Q., and W. R. Cotton, 1997: Balanced and unbalanced circulations in a primitive equation simulation of a midlatitude MCC. Part I: The numerical simulation. J. Atmos. Sci.,54, 457–478.

  • Pielke, R. A., W. R. Cotton, R. L. Walko, C. J. Tremback, W. A. Lyons, L. D. Grasso, M. E. Nicholls, M. D. Moran, D. A. Wesley, T. J. Lee, and J. H. Copeland, 1992: A comprehensive meteorological modeling system—RAMS. Meteor. Atmos. Phys,49, 69–91.

  • Randall, D. A., and D.-M. Pan, 1993: Implementation of the Arakawa–Schubert cumulus parameterization with a prognostic closure. The Representation of Cumulus Convection in Numerical Models, Meteor. Monogr., No. 46, Amer. Meteor. Soc., 137–144.

  • Roux, F., and S. Ju, 1990: Single-Doppler observations of a west African squall line on 27–28 May 1981 during COPT 81: Kinematics, thermodynamics, and water budget. Mon. Wea. Rev., 118, 1826–1854.

  • Stensrud, D. J., and R. A. Maddox, 1988: Opposing mesoscale circulations, a case study. Wea. Forecasting,3, 189–204.

  • Tao, W.-K., J. Simpson, C.-H. Sui, B. Ferrier, S. Lang, J. Scala, M.-D. Chou, and K. Pickering, 1993: Heating, moisture, and water budgets of tropical and midlatitude squall lines: Comparisons and sensitivity to longwave radiation. J. Atmos. Sci.,50, 673–690.

  • Tremback, C. J., and R. Kessler, 1985: A surface temperature and moisture parameterization for use in mesoscale numerical models. Preprints, Seventh Conf. on Numerical Weather Prediction, Montreal, PQ, Canada, Amer. Meteor. Soc., 355–358.

  • Tripoli, G. J., and W. R. Cotton, 1982: The Colorado State University three-dimensional cloud/mesoscale model—1982. Part I: General theoretical framework and sensitivity experiments. J. Rech. Atmos.,16, 185–220.

  • Webster, P. J., and R. A. Houze Jr., 1991: The Equatorial Mesoscale Experiment (EMEX): An overview. Bull. Amer. Meteor. Soc.,72, 1481–1505.

  • 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, 504–520.

  • Weissbluth, M. J., and W. R. Cotton, 1993: The representation of convection in mesoscale models. Part I: Scheme fabrication and calibration. J. Atmos. Sci.,50, 3852–3872.

  • Wilson, M. F., and A. Henderson-Sellers, 1985: A global archive of land cover and soils data for use in general circulation climate models. J. Climatol., 5, 119–143.

  • Wong, T., G. L. Stephens, P. W. Stackhouse Jr., and F. P. J. Valero, 1993: The radiative budgets of a tropical mesoscale convective system during EMEX-STEP-AMEX Experiment. II: Model results. J. Geophys. Res.,98, 8695–8711.

  • Wu, X., 1993: Effects of cumulus ensemble and mesoscale stratiform clouds in midlatitude convective systems. J. Atmos. Sci.,50, 2496–2518.

  • Xu, K.-M., 1995: Partitioning mass, heat, and moisture budgets of explicitly simulated cumulus ensembles into convective and stratiform components. J. Atmos. Sci.,52, 551–573.

  • Yanai, M., S. Esbensen, and J.-H. Chu, 1973: Determination of bulk properties of tropical cloud clusters from large-scale heat and moisture budgets. J. Atmos. Sci.,30, 611–627.

  • Zipser, E. J., 1982: Use of a conceptual model of the life cycle of mesoscale convective systems to improve very-short-range forecasts. Nowcasting, Academic Press, 191–204.

  • ——, R. J. Meitin, and M. A. LeMone, 1981: Mesoscale motion fields associated with a slowly moving GATE convective band. J. Atmos. Sci.,38, 1725–1750.

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