Abstract
An investigation of ice fog in Alaska required a technique for the determination of the water content of the atmosphere at temperatures between −20 to −55C. No satisfactory method for direct field measurements at these low temperatures was available.
A field sampling-technique was developed which consisted of extracting the contained water by bubbling the air through absolute methanol, an aliquot of which was then titrated with Karl Fischer reagent. A visual end-point was applicable. The method permitted rapid titration, required simple apparatus, and measured the amount of moisture in the air directly to within 2 per cent of the absolute values.
A method of filtering the air in order to separate water vapor from precipitated water was also developed for sub-freezing temperatures.
Humidity observations were extended to levels above the surface by drawing a known volume of air into the bubbler through polyethylene tubing supported by captive balloons.
Results obtained with these techniques are included in a discussion of humidities determined at Eielson Air Force Base, Alaska, during the winter of 1952–1953.
