The Climatology Of The Polar Aerosol From The Poam Instruments

Abstract

We present a climatology of the high-latitude stratospheric aerosol derived from the multiwavelength extinction data of the POAM (Polar Ozone and Aerosol Measurement) II and III instruments from 1993 to 2003. Stratospheric aerosols north of 54°N and south of 63°S were continually monitored by POAM II between September 1993 and November 1996. These data clearly show the decay of the volcanic aerosol from the Pinatubo eruption which was still evident when the spacecraft ceased operation at the end of 1996. POAM III was launched into a similar orbit in March 1998 and has monitored the seasonal variation in the aerosol layer since its recovery to background levels. Extinction data from these two instruments at six wavelengths from the ultraviolet to near-infrared are combined through principal component analysis to yield total aerosol surface-area and volume densities. The temporal and spatial evolution of these physical parameters, which can be employed in chemistry and climate models, are presented and analyzed.