STRATOSPHERIC EVOLUTION OF SUDDEN WARMINGS IN 1969-74 DETERMINED FROM MEASURED INFRARED RADIATION FIELDS.

Abstract

Radiance measurements made by the Satellite Infrared Spectrometers (SIRS A and B) and Vertical Temperature Profile Radiometers (VTPR) in 1969-74 comprise a basically uniform observational data source, in view of the similarity of the transmittance weighting functions for the stratospheric channels of these instruments. Hemispheric radiance maps of measurements in the 669 and 678 cm** minus **1 channels are used to depict the evolution of major stratospheric warmings in the 1969-70, 1970-71 and 1972-73 winters. These warmings are indicated to have arisen from the interaction of eastward-traveling thermal waves with a standing wave in eastern Siberia. Sudden warming in the Arctic was related to the poleward migration of the resultant thermal systems. A preliminary description of a late winter warming in 1973-74 is also given.