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<br />5. VERTICAL DISTRIBUTION OF SUPERCOOLED LIQUID WATER <br /> <br />An important aspect of the distribution of supercooled water in winter <br /> <br />st6rms'is' the altitude, depth~ and temperature of the superc601ed'~ater bearing <br /> <br />layers. In order to investigate this relationship, rawinsonde data was paired <br /> <br />with radiometer liquid water data averaged over the first 20 minutes of balloon <br /> <br />ascent. <br /> <br />Initially, the rawinsonde relative humidity had to be adjusted to account <br /> <br />for water-saturated conditions when such conditions were indicated by the <br /> <br />measurement of supercooled water by the radiometer. The source of this problem <br /> <br />stems from the inability of the ra\~insonde hygristor to report 100 percent <br /> <br />humidity as discussed by Brousaides (1975) and Shaffer (1982). The hygristor <br /> <br />problem results in an underestimation of relative humidity, therefore, water- <br /> <br />saturated conditions are rarely measured. The problem was rectified by raising <br /> <br />the maximum measured relative humidity to 100 percent when the radiometer <br /> <br />detected supercooled water greater than 0.05 mm. The increase in relative <br /> <br />humidity required to attain saturation was then added to all levels of the <br /> <br />sounding. Usually this increase was not greater than 5 percent. <br /> <br />.. <br />A saturated <br /> <br />layer was then defined if the dewpoint temperature was within 0.2 oC of the <br /> <br />ambient (free air) temperature. The height and temperature measurements at <br />saturated levels were then used in the following analyses. There were 158 <br />soundings launched in clouds during periods when radiometric measurements of <br /> <br />liquid water exceeded 0.05 mm. These soundings form the basis of the following <br /> <br />discussion. <br /> <br />Figure 19 shows a frequency distribution histogram of the height of water <br /> <br />saturated layers. The curve indicates the percentage of soundings in which <br /> <br />25 <br /> <br />I <br />.._---=-~ <br />