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Drop size distributions and related properties of fog for five locations measured from aircraftFog drop size distributions were collected from aircraft as part of the Synthetic Vision Technology Demonstration Program. Three west coast marine advection fogs, one frontal fog, and a radiation fog were sampled from the top of the cloud to the bottom as the aircraft descended on a 3-degree glideslope. Drop size versus altitude versus concentration are shown in three dimensional plots for each 10-meter altitude interval from 1-minute samples. Also shown are median volume radius and liquid water content. Advection fogs contained the largest drops with median volume radius of 5-8 micrometers, although the drop sizes in the radiation fog were also large just above the runway surface. Liquid water content increased with height, and the total number of drops generally increased with time. Multimodal variations in number density and particle size were noted in most samples where there was a peak concentration of small drops (2-5 micrometers) at low altitudes, midaltitude peak of drops 5-11 micrometers, and high-altitude peak of the larger drops (11-15 micrometers and above). These observations are compared with others and corroborate previous results in fog gross properties, although there is considerable variation with time and altitude even in the same type of fog.
Document ID
Document Type
Contractor Report (CR)
Zak, J. Allen
(Vigyan Research Associates, Inc. Hampton, VA, United States)
Date Acquired
September 6, 2013
Publication Date
April 1, 1994
Subject Category
Meteorology And Climatology
Report/Patent Number
NAS 1.26:4585
Accession Number
Funding Number(s)
PROJECT: RTOP 505-64-13-67
Distribution Limits
Work of the US Gov. Public Use Permitted.
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