Wireless Optical Communication Links (OCL), or Free Space Optics (FSO) links involving optical ground stations (OGS) are highly influenced by the earth atmosphere due to the interaction of the optical wave with particles of different size and shape. Fog, clouds, rain and snow cause significant signal attenuation thus limiting the performance of OCL. In this paper, we consider the behavior of OC...

This paper describes some of the microphysical and kinematic properties of precipitating systems associated with a typhoon using Chug-Li VHF radar. In order to gain a better understanding of these mechanisms and the vertical structure of the precipitation associated with a typhoon at different stages of development, an analysis has been carried out of the radar back-scattered signal in order to...

Using a matrix of drop size distributions (DSDs), measured by a microscale array of disdrometers, a method of spatial and temporal DSD interpolation is presented. The goal of this interpolation technique is to estimate the DSD above the disdrometer array as a function of three spatial coordinates, time and drop diameter. This interpolation algorithm assumes simpliŽ ed drop dynamics, based on cl...

The rate of production of secondary ice particles during the growth of rime in a supercooled cloud at about -5 "C is known to depend mainly upon the rate of accretion of large drops (diameter 325 pm). New experiments have defined more clearly how 'splinter' production is affected by the rate of accretion of small drops (diameter ~ 1 2 Fm). The relationship between secondary ice production and r...

Motivated by recent experiments involving the acoustic levitation of foam drops, we develop a model for nonlinear oscillations of a spherical drop composed of monodisperse aqueous foam with void fraction below 0.1. The model conceptually divides a foam drop into many cells, each cell consisting of a spherical volume of liquid with a bubble at its center. By treating the liquid as incompressible...

This work represents a continuation in the investigation of techniques to estimate the parameters for raindrop-size-distribution (DSD) functions. Although moment estimators are often used to estimate these parameters, our previous work (Smith and Kliche, 2005; Smith et al., 2005) showed that the method of moments produces biased results that can lead to misleading extrapolations, and that the r...

EXPERIMENTAL INVESTIGATION OF X-BAND POLARIMETRIC ALGORITHM FOR DROP SIZE DISTRIBUTION RETRIEVAL Marios N. Anagnostou (1), Emmanouil N. Anagnostou (1), Jothiram Vivekanandan (2) (1) University of Connecticut, Department of Civil and Environmental Engineering, Storrs, CT 06269, USA ([email protected], [email protected]), (2) National Center for Atmospheric Research, 3450 Mitchell Lane, Bui...

[1] Idealized simulations of tornadogenesis in supercell storms are performed using a grid of 100 m spacing. The cold pool intensity and low-level storm dynamics are found to be very sensitive to the intercept parameters of rain and hail drop size distributions (DSD). DSDs favoring smaller (larger) hydrometeors result in stronger (weaker) cold pools due to enhanced (reduced) evaporative cooling...

This study proposes a Bayesian approach to retrieve raindrop size distributions (DSDs) and to estimate rainfall rates from radar reflectivity in horizontal polarization ZH and differential reflectivity ZDR. With this approach, the authors apply a constrained-gamma model with an updated constraining relation to retrieve DSD parameters. Long-term DSD measurements made in central Oklahoma by the t...