Skip to main content
Log in

Inversions, and fog, stratus and cumulus formation in warm air over cooler water

  • Published:
Boundary-Layer Meteorology Aims and scope Submit manuscript

Abstract

Two aspects of convection over oceans are discussed and the following conclusions are derived from theoretical considerations.

  1. (1)

    The air layer over the sea will usually convect even when the water surface is ten degrees or more colder than the initial air temperature.

  2. (2)

    An inversion at stratus cloud tops is created by the stratus, and is not a necessary preexisting condition. Such inversions persist after subsidence evaporates the cloud.

  3. (3)

    Radiation heat exchange does not play an essential role in stratus formation or maintenance, and can either heat or cool the cloud.

  4. (4)

    Dry air convection does not erode inversions at the top of the convecting layer. Examples of soundings are discussed.

  5. (5)

    Fogs are most likely to form at sea where the water is coolest, and need no radiation effects to initiate cooling, or a boost from patches of warmer water, to begin convection.

  6. (6)

    Both stratus cloud growth, and the evaporation of clouds by cloud top entrainment, readjust the vertical structure of the air to leave a constant wet-bulb potential temperature with height.

These conclusions are supported by, firstly, a convective model which has been developed and which shows that vapor-driven convection over the ocean will proceed with zero or negative heat fluxes, at rates which saturate the lowest layer of the atmosphere in a few hours to altitudes of many tens of meters. Secondly, the availability of condensed moisture at the top of the surface layer cools the warmer entrained overlying dry air parcels so that when they descend they are no warmer than the sea surface temperature, and this induces downward moving plumes. This occurs if the wet-bulb potential temperature of the overlying air is less than the sea surface temperature, even if it is ten degrees C, or more, warmer in actual temperature.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Ball, F. K.: 1960, ‘Control of Inversion Height by Surface Heating’, Quart. J. Roy. Meteorol. Soc. 86, 483–494.

    Google Scholar 

  • Chai, S. K.: 1978, ‘Lowering Stratus Cloud in Surface Driven Convection over the Sea’, Ph.D. Dissertation, Univ., of Nevada, Reno, 146 pp.

    Google Scholar 

  • Chai, S. K. and Telford, J. W.: 1983, ‘Convection Model for Stratus Cloud over a Warm Water Surface’, Boundary-Layer Meteorol. 26, 25–49.

    Google Scholar 

  • Deardorff, J. W.: 1980, ‘Cloud Top Entrainment Instability’, J. Atmos. Sci. 37, 131–147.

    Google Scholar 

  • Deardorff, J. W.: 1983, ‘A Multi-Limit Mixed-Layer Entrainment Formulation’, Jour. Phys. Ocean. 13, 988–1002.

    Google Scholar 

  • Guldberg, C. M. and Mohn, H.: 1876, ‘Etudes sur les mouvements de l'atmosphére’, Pt. 1 Christiania. 39 pp.

  • Lilly, D. K.: 1968, ‘Models of Cloud-Topped Mixed Layers Under a Strong Inversion’, Quart. J. R. Meteorol. Soc., 94, 292–309.

    Google Scholar 

  • Manton, M. J.: 1980, ‘On the Modelling of Mixed Layers and Entrainment in Cumulus Clouds’, Boundary-Layer Meteorol. 19, 337–358.

    Google Scholar 

  • Presley, J. D.: 1976, ‘Free Convective Plumes in the Atmosphere’, Ph.D. Dissertation, Univ. of Nevada-Reno, 162 pp.

  • Randall, D. A.: 1980a, ‘Entrainment into a Stratocumulus Layer with Distributed Radiative Cooling’, J. Atmos. Sci. 37, 148–159.

    Google Scholar 

  • Randall, D. A.: 1980b, ‘Conditional Instability of the First Kind Upside-Down’, J. Atmos. Sci. 37, 125–130.

    Google Scholar 

  • Saunders, P. M.: 1964, ‘Sea Smoke and Steam Fog’, Quart. J. Roy. Meteorol. Soc. 90, 156–165.

    Google Scholar 

  • Smithsonian Meteorological Tables: 1966, Sixth Revised Edition, Smithsonian Miscellaneous Collections, Vol. 114, The Smithsonian Institution, 527 pp.

  • Squires, P.: 1958, ‘Penetrative Downdraughts in Cumuli’, Tellus 10, 381–389.

    Google Scholar 

  • Telford, J. W.: 1966, ‘The Convective Mechanism in Clear Air’, J. Atmos. Sci. 23, 652–666.

    Google Scholar 

  • Telford, J. W.: 1970, ‘Convective Plumes in a Convective Field’, J. Atmos. Sci. 27, 347–358.

    Google Scholar 

  • Telford, J. W.: 1972, ‘A Plume Theory for the Convective Field in Clear Air’, J. Atmos. Sci. 29, 128–134.

    Google Scholar 

  • Telford, J. W.: 1975, ‘The Effects of Compressibility and Dissipation Heating on Boundary Layer Plumes’, J. Atmos. Sci. 32, 108–115.

    Google Scholar 

  • Telford, J. W.: 1981, ‘The Surface Roughness and Planetary Boundary Layer’, Pure Appl. Geophys. 119, 278–293.

    Google Scholar 

  • Telford, J. W.: 1982, ‘A Theoretical Value for von Karman's Constant’, Pure Appl. Geophys. 120, 648–661.

    Google Scholar 

  • Telford, J. W. and Warner, J.: 1962, ‘On the Measurement from an Aircraft of Buoyancy and Vertical Air Velocity in Cloud’, J. Atmos. Sci. 19, 415–423.

    Google Scholar 

  • Telford, J. W. and Warner, J.: 1964, ‘Fluxes of Heat and Vapor in the Lower Atmosphere Derived from Aircraft Observations’, J. Atmos. Sci. 21, 539–548.

    Google Scholar 

  • Telford, J. W. and Presley, J. D.: 1978, ‘The Surface Boundary Layer as a Part of the Overlying Convective Layer’, Pure Appl. Geophys. 117, 664–689.

    Google Scholar 

  • Telford, J. W. and Wagner, P. B.: 1981, ‘Observations of Condensation Growth Determined by Entity Type Mixing’, Pure Appl. Geophys. 119, 934–965.

    Google Scholar 

  • Telford, J. W. and Chai, S. K.: 1982, ‘Fog, Stratus and Cumulus Formation in Warm Air over Cooler Water’, Preprints of the Conference on Cloud Physics, November 15–18, 1982, Chicago, Illinois, 7–8.

  • Telford, J. W. and Keck, T. S.: 1984, ‘Inversions, Entrainment into Clouds, and Invariance of the Wet Bulb Potential Temperature with Height’, submitted for publication.

  • Telford, J. W., Vaziri, A., and Wagner, P. B.: 1976, ‘Aircraft Observations in the Planetary Boundary Layer under Stable Conditions’, Boundary-Layer Meteorol. 10, 353–377.

    Google Scholar 

  • Twomey, S.: 1983, ‘Radiative Effects in California Stratus’, Contrib. Atmos. Phys. 56, 429–439.

    Google Scholar 

  • Warner, J. and Telford, J. W.: 1963, ‘Some Patterns of Convection in the Lower Atmosphere’, J. Atmos. Sci. 20, 313–318.

    Google Scholar 

  • Warner, J. and Telford, J. W.: 1967, ‘Convection Below Cloud Base’, J. Atmos. Sci. 24, 374–382.

    Google Scholar 

  • Woodcock, A. H.: 1982, ‘Fog, and Tidal Current Connection at Cape Cod Canal — Early Recognition and Recent Measurements’, Bull. Am. Meteorol. Soc. 63, 161–166.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Telford, J.W., Chai, S.K. Inversions, and fog, stratus and cumulus formation in warm air over cooler water. Boundary-Layer Meteorol 29, 109–137 (1984). https://doi.org/10.1007/BF00206826

Download citation

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00206826

Keywords

Navigation