Notes on upper air hygrometry.—II. On The Humidity in the Stratosphere

Abstract

Abstract The meteorograph records of the almost daily ascents over England during the months of April, 1939, and September, 1930, have been evaluated according to a method described in an earlier paper. ( Q.J. 70 , 1944, p. 293). The humidities so obtained indicate (1) that supersaturation with respect to ice is very frequently found in the upper troposphere; (2) that, within the stratosphere, dry air of a humidity mixing ratio of about 10 −5 sometimes does occur, which can only be explained as tropical stratosphere air; (3) that, on one occasion, very dry air from the stratosphere appears to have been drawn into the uppermost regions of the troposphere.