Interactions between Shallow and Deep Convection under a Finite Departure from Convective Quasi Equilibrium

Jun-Ichi Yano GAME/CNRM, Météo-France and CNRS, Toulouse, France

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Robert Plant Department of Meteorology, University of Reading, Reading, United Kingdom

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Abstract

The present paper presents a simple theory for the transformation of nonprecipitating, shallow convection into precipitating, deep convective clouds. To make the pertinent point a much idealized system is considered, consisting only of shallow and deep convection without large-scale forcing. The transformation is described by an explicit coupling between these two types of convection. Shallow convection moistens and cools the atmosphere, whereas deep convection dries and warms the atmosphere, leading to destabilization and stabilization, respectively. Consequently, in their own stand-alone modes, shallow convection perpetually grows, whereas deep convection simply damps: the former never reaches equilibrium, and the latter is never spontaneously generated. Coupling the modes together is the only way to reconcile these undesirable separate tendencies, so that the convective system as a whole can remain in a stable periodic state under this idealized setting. Such coupling is a key missing element in current global atmospheric models. The energy cycle description used herein is fully consistent with the original formulation by Arakawa and Schubert, and is suitable for direct implementation into models using a mass flux parameterization. The coupling would alleviate current problems with the representation of these two types of convection in numerical models. The present theory also provides a pertinent framework for analyzing large-eddy simulations and cloud-resolving modeling.

Corresponding author address: Jun-Ichi Yano, CNRM, Météo-France, 42 Ave. Gaspard Coriolis, 31057 Toulouse CEDEX 1, France. E-mail: jun-ichi.yano@zmaw.de

Abstract

The present paper presents a simple theory for the transformation of nonprecipitating, shallow convection into precipitating, deep convective clouds. To make the pertinent point a much idealized system is considered, consisting only of shallow and deep convection without large-scale forcing. The transformation is described by an explicit coupling between these two types of convection. Shallow convection moistens and cools the atmosphere, whereas deep convection dries and warms the atmosphere, leading to destabilization and stabilization, respectively. Consequently, in their own stand-alone modes, shallow convection perpetually grows, whereas deep convection simply damps: the former never reaches equilibrium, and the latter is never spontaneously generated. Coupling the modes together is the only way to reconcile these undesirable separate tendencies, so that the convective system as a whole can remain in a stable periodic state under this idealized setting. Such coupling is a key missing element in current global atmospheric models. The energy cycle description used herein is fully consistent with the original formulation by Arakawa and Schubert, and is suitable for direct implementation into models using a mass flux parameterization. The coupling would alleviate current problems with the representation of these two types of convection in numerical models. The present theory also provides a pertinent framework for analyzing large-eddy simulations and cloud-resolving modeling.

Corresponding author address: Jun-Ichi Yano, CNRM, Météo-France, 42 Ave. Gaspard Coriolis, 31057 Toulouse CEDEX 1, France. E-mail: jun-ichi.yano@zmaw.de
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  • Arakawa, A., and W. H. Schubert, 1974: Interaction of a cumulus cloud ensemble with the large-scale environment, Part I. J. Atmos. Sci., 31, 674701.

    • Search Google Scholar
    • Export Citation
  • Benedict, J. J., and D. A. Randall, 2007: Observed characteristics of the MJO relative to maximum rainfall. J. Atmos. Sci., 64, 23322354.

    • Search Google Scholar
    • Export Citation
  • Bony, S., and J.-L. Dufresne, 2005: Marine boundary layer clouds at the heart of tropical cloud feedback uncertainties in climate models. Geophys. Res. Lett.,32, L20806, doi:10.1029/2005GL023851.

  • Bretherton, C. S., and Coauthors, 2004: The EPIC 2001 stratocumulus study. Bull. Amer. Meteor. Soc., 85, 967977.

  • Deardorff, J. W., 1980: Cloud top entrainment instability. J. Atmos. Sci., 37, 12111213.

  • Emanuel, K. A., 1989: The finite amplitude nature of tropical cyclogenesis. J. Atmos. Sci., 46, 34313456.

  • Emanuel, K. A., and M. Bister, 1996: Moist convective velocity and buoyancy scales. J. Atmos. Sci., 53, 32763285.

  • Emanuel, K. A., J. D. Neelin, and C. S. Bretherton, 1994: On large-scale circulation in convective atmospheres. Quart. J. Roy. Meteor. Soc., 120, 11111143.

    • Search Google Scholar
    • Export Citation
  • Fuchs, Z., and D. J. Raymond, 2005: Large-scale modes in a rotating atmosphere with radiative–convective instability and WISHE. J. Atmos. Sci., 62, 40844094.

    • Search Google Scholar
    • Export Citation
  • Fuchs, Z., and D. J. Raymond, 2007: A simple, vertically resolved model of tropical disturbances with a humidity closure. Tellus, 59A, 344354.

    • Search Google Scholar
    • Export Citation
  • Guichard, F., and Coauthors, 2004: Modelling the diurnal cycle of deep precipitating convection over land with cloud-resolving models and single-column models. Quart. J. Roy. Meteor. Soc., 130, 31393172.

    • Search Google Scholar
    • Export Citation
  • Holland, J. Z., and E. M. Rasmusson, 1973: Measurements of the atmospheric mass, energy, and momentum budgets over a 500-km square of tropical ocean. Mon. Wea. Rev., 101, 4455.

    • Search Google Scholar
    • Export Citation
  • Johnson, R. H., T. M. Rickenbach, S. A. Rutledge, P. E. Ciesielski, and W. H. Schubert, 1999: Trimodal characteristics of tropical convection. J. Climate, 12, 23972418.

    • Search Google Scholar
    • Export Citation
  • Khairoutdinov, M., and D. Randall, 2006: High-resolution simulation of shallow-to-deep convection transition over land. J. Atmos. Sci., 63, 34213436.

    • Search Google Scholar
    • Export Citation
  • Lin, J.-L., and Coauthors, 2006: Tropical intraseasonal variability in 14 IPCC AR4 climate models. Part I: Convective signals. J. Climate, 13, 26652690.

    • Search Google Scholar
    • Export Citation
  • Lord, S. J., and A. Arakawa, 1980: Interaction of a cumulus cloud ensemble with the large-scale environment. Part II. J. Atmos. Sci., 37, 26772692.

    • Search Google Scholar
    • Export Citation
  • Majda, A. J., and M. G. Shefter, 2001: Models for stratiform instability and convectively coupled waves. J. Atmos. Sci., 58, 15671584.

    • Search Google Scholar
    • Export Citation
  • Mapes, B. E., 2000: Convective inhibition, subgrid-scale triggering energy, and stratiform instability in a toy tropical wave model. J. Atmos. Sci., 57, 15151535.

    • Search Google Scholar
    • Export Citation
  • Moeng, C.-H., 1998: Stratocumulus-topped atmospheric planetary boundary layer. Buoyant Convection in Geophysical Flows, E. J. Plate, Eds., Kulwer Academic, 421–440.

  • Moncrieff, M. W., 2010: The multiscale organization of convection at the interaction of weather and climate. Why Climate Vary? Geophys. Monogr., Vol. 189, Amer. Geophys. Union, 3–26.

  • Nitta, T., and S. Esbensen, 1974: Heat and moisture budget analyses using BOMEX data. Mon. Wea. Rev., 102, 1728.

  • Pan, D.-M., and D. A. Randall, 1998: A cumulus parameterization with prognostic closure. Quart. J. Roy. Meteor. Soc., 124, 949981.

  • Parodi, A., and K. Emanuel, 2009: A theory for buoyancy and velocity scales in deep moist convection. J. Atmos. Sci., 66, 34493463.

  • Parsons, D. B., K. Yoneyama, and J.-L. Redelsperger, 2000: The evolution of the tropical western Pacific atmosphere–ocean system following the arrival of a dry intrusion. Quart. J. Roy. Meteor. Soc., 126, 517548.

    • Search Google Scholar
    • Export Citation
  • Peters, O., and J. D. Neelin, 2006: Critical phenomena in atmospheric precipitation. Nat. Phys., 2, 393396.

  • Plant, R. S., 2010: A review of the theoretical basis for bulk mass flux convective parameterization. Atmos. Chem. Phys., 10, 35293544.

    • Search Google Scholar
    • Export Citation
  • Randall, D. A., 1980: Conditional instability of the first kind upside-down. J. Atmos. Sci., 37, 125130.

  • Randall, D. A., and Coauthors, 2007: Climate models and their evaluation. Climate Change2007 : The Physical Basis, S. Solomon et al., Eds., Cambridge University Press, 589–662.

  • Raymond, D. J., and Z. Fuchs, 2007: Convectively coupled gravity and moisture modes in a simple atmospheric model. Tellus, 59A, 627640.

    • Search Google Scholar
    • Export Citation
  • Shutts, G. J., and M. E. B. Gray, 1999: Numerical simulations of convective equilibrium under prescribed forcing. Quart. J. Roy. Meteor. Soc., 125, 27672787.

    • Search Google Scholar
    • Export Citation
  • Stevens, B., 2005: Atmospheric moist convection. Annu. Rev. Earth Planet. Sci., 33, 605643.

  • Stevens, B., and Coauthors, 2003: On entrainment rates in nocturnal marine stratocumulus. Quart. J. Roy. Meteor. Soc., 129, 34693493.

    • Search Google Scholar
    • Export Citation
  • Tiedtke, M., 1989: A comprehensive mass flux scheme of cumulus parameterization in large-scale models. Mon. Wea. Rev., 117, 17791800.

    • Search Google Scholar
    • Export Citation
  • Wu, C. M., B. Stevens, and A. Arakawa, 2009: What controls the transition from shallow to deep convection? J. Atmos. Sci., 66, 17931806.

    • Search Google Scholar
    • Export Citation
  • Yano, J.-I., 2011: Mass-flux subgrid-scale parameterization in analogy with multi-component flows: A formulation towards scale independence. Geosci. Model Dev. Discuss., 4, 31273160.

    • Search Google Scholar
    • Export Citation
  • Yano, J.-I., and R. S. Plant, 2012: Finite departure from convective quasi-equilibrium: Periodic cycle and discharge-recharge mechanism. Quart. J. Roy. Meteor. Soc., 138, 626637.

    • Search Google Scholar
    • Export Citation
  • Yano, J.-I., K. Fraedrich, and R. Blender, 2001: Tropical convective variability as 1/f–noise. J. Climate, 14, 36083616.

  • Yano, J.-I., J.-P. Chaboureau, and F. Guichard, 2005a: A generalization of CAPE into potential-energy convertibility. Quart. J. Roy. Meteor. Soc., 131, 861875.

    • Search Google Scholar
    • Export Citation
  • Yano, J.-I., J.-L. Redelsperger, F. Guichard, and P. Bechtold, 2005b: Mode decomposition as a methodology for developing convective-scale representations in global models. Quart. J. Roy. Meteor. Soc., 131, 23132336.

    • Search Google Scholar
    • Export Citation
  • Yano, J.-I., P. Bénard, F. Couvreux, and A. Lahellec, 2010: NAM–SCA: A nonhydrostatic anelastic model with segmentally constant approximations. Mon. Wea. Rev., 138, 19571974.

    • Search Google Scholar
    • Export Citation
  • Zhang, M. H., and Coauthors, 2005: Comparing clouds and their seasonal variations in 10 atmospheric general circulation models with satellite measurements. J. Geophys. Res., 110, D15S02, doi:10.1029/2004JD005021.

    • Search Google Scholar
    • Export Citation
  • Zipser, E. J., 1969: The role of organized unsaturated convective downdrafts in the structure and rapid decay of an equatorial disturbance. J. Appl. Meteor., 8, 799814.

    • Search Google Scholar
    • Export Citation
  • Zipser, E. J., 1977: Mesoscale and convective-scale downdrafts as distinct components of squall-line structure. Mon. Wea. Rev., 105, 15681589.

    • Search Google Scholar
    • Export Citation
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