Extended Abstract (164K)P13.6
Comparison of analytical approximations of the shapes of the cloud dropsize distributions, utilized for the interpretation of remote sensing data
Oleg A. Krasnov, Delft Univ. of Technology, Delft, Netherlands; and H. W. J. Russchenberg
The interpretation of radar data of clouds often requires parametrizations of the dropsize distributions. Most frequently utilized are the three-parameters gamma or log-normal distributions. However, a detailed statistical analysis of in-situ aircraft data shows that the shapes of dropsize distributions are more complicated than these parametrization suggest: only multi-parameters family distributions (like Pearson or Johnson) or mixture of some distributions are sufficient to statically describe the real dropsize spectrums and their variations. Nonetheless, the methods of the radar remote sensing allow (and aim at) the estimation of some statistical moments of the drops spectrum (effective particle size (2-nd moment), liquid water content (3-rd moment), reflectivity (6-th moment)) and their interdependence. In such situation it seems to be interesting to analyze the influence of the actual complicated shape of the cloud drop size spectrum to the interdependencies of statistical moments as measured using the remote sensing methods. Examples of real dropsize distributions, obtained with in-situ FSSP and 2DC probe during the CLARA (the Netherlands, 1996) and the CLARE'98 (UK, 1998) campaigns, were used. The results of this analysis show the limits of possible errors of interpretation of cloud radar data and allow to estimate the need for taking into account more complicated approximations of the drop size distributions.
Poster Session 13, Quantitative Rainfall—Microphysics II
Monday, 23 July 2001, 2:00 PM-3:30 PM
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