The bulk properties of tropical cloud clusters, such as the vertical mass flux, the excess temperature, and moisture and the liquid water content of the clouds, are determined from a combination of 1) the observed large-scale heat and moisture budgets over an area covering the cloud cluster, and 2) a model of a cumulus ensemble which exchanges mass, heat, water vapor and liquid water with the environment through entrainment and detrainment The method also provides an understanding of how the environmental air is heated and moistened by the cumulus convection An estimate of the average cloud cluster properties and the heat and moisture balance of the environment, obtained from 1956 Marshall Islands data, is presented

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Determination of Bulk Properties of Tropical Cloud Clusters from Large-Scale Heat and Moisture Budgets

Surface layer coefficients for wind profiles, wind stress, and heat flux in typical open sea conditions are briefly reviewed. Businger-Dyer flux-gradient relationships and a Charnock wind stress formula fit the empirical data and are dimensionally consistent. These have been solved by an iterative method, and the results are presented in a tabular form suitable for climatological calculations from marine wind and temperature data.

Coefficients for sea surface wind stress, heat flux, and wind profiles as a function of wind speed and temperature

On the basis of recent data for the roughness Reynolds number of the sea surface, and using the Owen-Thomson theory on the transfers of heat and mass between a rough surface and the flow above it, the bulk transfer coefficients of the sea surface have been estimated. For a reference height of 10 m, the neutral-lapse transfer coefficient for water vapor is larger by only a few percent than that for sensible heat. When the wind speed at the 10-m height is u10>3 m s−1, the coefficient for sensible heat CH is larger by about 10% than that for momentum CD. For u10<5 m s−1, however, the value of CD exceeds the value of CH, and for u10=15 m s−1 it is shown that CH≈0.8CD. It may be also proposed that 103CD=1.11 to 1.70, 103CE=1.18 to 1.30, and 103CH=1.15 to 1.26 for a range of u10=4 to 20 m s−1. A plot of diabatic transfer coefficients versus wind speed is obtained by using a parameter of the sea-air temperature difference. For practical purposes, the coefficients are approximated by empirical formulae.

Air-sea bulk transfer coefficients in diabatic conditions

To test the local-isotropy predictions of Kolmogorov's universal equilibrium theory, we have taken hot-wire measurements of the velocity fluctuations in the test-section-ceiling boundary layer of the 80×120 foot Full-Scale Aerodynamics Facility at NASA Ames Research Center, the world's largest wind tunnel. The maximum Reynolds numbers based on momentum thickness, R θ , and on Taylor microscale, R λ , were approximately 370 000 and 1450 respectively. These are the largest ever attained in laboratory boundary-layer flows. The boundary layer develops over a rough surface, but the Reynolds-stress profiles agree with canonical data sufficiently well for present purposes

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Local isotropy in turbulent boundary layers at high Reynolds number

Sea salt aerosol (SSA) exerts a major influence over a broad reach of geophysics. It is important to the physics and chemistry of the marine atmosphere and to marine geochemistry and biogeochemistry generally. It affects visibility, remote sensing, atmospheric chemistry, and air quality. Sea salt aerosol particles interact with other atmospheric gaseous and aerosol constituents by acting as sinks for condensable gases and suppressing new particle formation, thus influencing the size distribution of these other aerosols and more broadly influencing the geochemical cycles of substances with which they interact. As the key aerosol constituent over much of Earth's surface at present, and all the more so in pre-industrial times, SSA is central to description of Earth's aerosol burden.

Sea Salt Aerosol Production: Mechanisms, Methods, Measurements, and Models - A Critical Review

This paper describes results of measurements of the fluxes of momentum, moisture and sensible heat by both the eddy correlation and “dissipation” techniques. The data were collected on the R/V Flip during BOMEX (Barbados Oceanographic and Meteorological Experiment) and during a pre-BOMEX trial cruise near San Diego in February 1969. The results are mainly based on data collected by personnel from Oregon State University and the University of British Columbia. We are grateful to the University of Washington personnel who have made their data and results available to us to check some of our results and allowed us to use their temperature fluctuation data from the San Diego cruise when our equipment failed to provide such data. The methods of determining the fluxes are discussed. The instrumentation and methods of data analysis are described. The effects of Flip's interference on the flow are described and the method of removing the interference from the results is given. The spectra of the three co...

J. E. Paquin

Papers

Measurements of the Turbulent Fluxes of Momentum, Moisture and Sensible Heat Over the Ocean,