During the 1972 IFYGL 'alert' periods, the highly instrumented NOAA/RFF/DC-6 aircraft was used to record the time series of wind, temperature, and water vapor at heights ranging from 18 to 300 m above the surface of Lake Ontario. The aircraft was equipped with a gust probe system, a fast response thermistor, a microwave refractometer (for water vapor measurements), and a downward-pointing IR system; as well as the normal in-flight measurement of standard...