Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 15 Topics in modern geophysical fluid dynamics 2009 10.5194/adgeo-15-65-2009 http://www.adv-geosci.net/15/65/2009/ http://www.adv-geosci.net/15/65/2009/adgeo-15-65-2009.html http://www.adv-geosci.net/15/65/2009/adgeo-15-65-2009.pdf 65 69 2009-03-26 Time development of the upper cloud edge in one-dimensional approximation based on moist thermodynamics P. B. Rutkevich peter@d902.iki.rssi.ru B. P. Rutkevych G. S. Golitsyn Space Research Institute (IKI), Moscow, Russia Institute of Radio Astronomy of Academy of Sciences of Ukraine, Kharkov, Ukraine A. M. Obukhov Institute of Atmospheric Physics, Moscow, Russia It is commonly accepted, that cloud formation is caused by the humidity flux directed from the warm bottom atmospheric layers towards the cold dry heights, and the transportation mechanism in stable stratification is due to development of so-called turbulent boundary layer. The transportation of vapor can be described by buoyancy profile, and requires two significant characteristics of the atmosphere. The first is the heat and water vapor fluxes from the underlying surface which has been investigated by Smith (1988). The second is the temperature profile in the atmosphere, which is usually approximated and parameterized in various ways, because the exact solution is complicated and difficult to use. In this paper we construct a theory of three-component gas mixture, containing air, vapor, and water droplets. This model can be applied for the internal cloud region. Later we use buoyancy to investigate the dynamics of cloud formation, taking into account condensation of the water vapor inside the cloud. The obtained results suggest a typical time of 10 h required for development of intense cloud layer over a sea surface. %G.S.Golitsyn. An analytical model for Marine Planetary Boundary layer %Development with Cloudness. Surface Fluxes in Climate Systems (SFINCS), %First Annual Report December 1997 - November 1998. Bolton, D.: The computation of equivalent potential temperature, Mon. Weather Rev., 108, 1046–1053, 1980. Bretherton, C. S.: Convection in stratocumulus-topped atmospheric boundary layers, in: The physics and Parameterization of Moist Atmospheric convection, edited by: Smith, R. K., Kluwer Acad. Pub., 127–142, 1997. Emanuel, K. A. : Atmospheric convection, Oxford University Press, Oxford, 1994. % %A. Henderson-Sellers, %A new formula for latent-heat of vaporization of water as a function of %temperature. Quarterly Journal of the Royal Meteorological Society. %\bf 110 (466), p. 1186-1190, (1984). % %L.T. Matveev, \it Physics of atmospere, %St. Petersburg, Hydrometeoizdat, 375 p. (2000). Smith, S. D.: Coefficients for Sea Surface Wind Stress, Heat Flux, and Wind Profiles as a Function of Wind Speed and Temperature, J. Geophys. Res., 93(C12), 15467–15472, 1988. Zilitinkevich, S. S.: Theoretical model of turbulent penetrative convection, Izvestia AN SSSR, FAO, 23, 6, 593–610, 1987.