The Relationship of Satellite-Inferred Stratospheric Aerosol Extinction to the Position of the 50-mb North Polar Jet Stream

Abstract

Particulate extinction profiles measured by the satellite-borne SAM II and SAGE I sensors have been used to investigate the relationship between stratospheric aerosols (between 15 and 30 km) and the location of the north polar night stratospheric jet stream during selected periods of the winters of 1979?1982. Mean profiles of aerosol extinction mixing ratio (the ratio of particulate to molecule extinction) and temperature across the jet axis have been constructed by determining the location and the distance of individual SAM II profiles relative to the position of the jet axis on the 50-mb isobaric surface, and averaging all profiles located at similar distances on the same side (cyclonic or anticyclonic) of the jet. Variations in aerosol extinction mixing ratio patterns among winters and during major stratospheric warming events within separate winters have been examined. The analyses show a well-defined positive gradient in extinction mixing ratio and temperature across the jet stream from the cyclonic side to the anticyclonic side at altitudes between 20 and 30 km during each winter period. During major stratospheric warming events, this relationship between the distribution of aerosols and the jet stream axis remained intact, even though the dynamic meteorological structure underwent major changes that typically included the breakdown of an elongated, intense polar vortex into two separate, smaller, and less intense vortices. Time-averaged estimates of extinction mixing ratio profiles measured at locations near the center of the polar vortex suggest that a gradual subsidence took place within the polar vortex during at least three of the four winter periods.