HR: 0830h
AN: NG51A-0832    [PDF]
TI: Fluctuations of Cloud Properties and Application of Nonextensive Statistical Physics
AU: * Liu, Y
EM: lyg@bnl.gov
AF: Brookhaven National Laboratory, Bldg. 815E, Upton, NY 11973-5000 United States
AU: Daum, P H
EM: phdaum@bnl.gov
AF: Brookhaven National Laboratory, Bldg. 815E, Upton, NY 11973-5000 United States
AB: Microphysical properties of clouds in a turbulent atmosphere fluctuate over a wide range of scales. Knowledge of the probability density function (PDF) of the climatically important variables (e.g., liquid water content, cloud droplet number concentration and relative dispersion of the cloud droplet size distribution) is crucial for treating subgrid cloud variability in various models such as global climate models (GCMs) and for understanding the role of fluctuations in the formation and development of clouds. A Gaussian-type PDF has been traditionally applied to describe the fluctuation of cloud properties. A number of studies have recently shown that turbulent fluctuations often deviate from the "norm", exhibiting heavy-tailed PDFs, and that the PDF is scale-dependent. In this work we examine the fatness of the PDF tail and the scale-dependence of cloud microphysical data collected under different dynamical conditions. We also apply the theory of the Tallis nonextensive statistical physics to the characterization of the fluctuation PDF, and integrate the results with the systems theory that we have proposed for describing cloud droplet size distributions.. The results of this research have applications for representations of clouds in GCMs and for validation of remote sensing with in-situ measurements.
DE: 1800 HYDROLOGY
DE: 3240 Chaos
DE: 3250 Fractals and multifractals
DE: 3300 METEOROLOGY AND ATMOSPHERIC DYNAMICS
DE: 4500 OCEANOGRAPHY: PHYSICAL
SC: Nonlinear Geophysics [NG]
MN: 2003 Fall Meeting