The F-type radio-meteorograph as an instrument to measure vertical currents in the atmosphere

Abstract

The paper describes the chief features of the fan used in the Indian F-type radio-meteorograph and how it enables one to know from the radiosonde data whether the balloon is descending due to accumulation of snow or strong vertical currents. Instances when the balloon went up and down due to accumulation and melting of snow have been described. The decrease in the rate of ascent and even the descent of the balloon due to strong downward currents in a thunderstorm on the 26th April 1950, have been estimated. The paper also shows how the F-type radiosonde data can be used to identify regions of clear air turbulence.