Seasonal Change and Chemical State of Polar Stratospheric Aerosols

• Main Authors: Iwasaka, Y., Hayashi, M., Nomura, A., Kondoh, Y., Koga, S.
• Other Authors: NAGOYA UNIV (JAPAN)
• Format: Text
• Language: English
• Published: 1992
• Subjects: Geography; Atmospheric Physics; Geology; Geochemistry and Mineralogy; *AEROSOLS; *DEPLETION; *OZONE; *SEASONS; *STRATOSPHERE; ACIDS; AUGMENTATION; BALLOONS; ELECTRON MICROSCOPES; ELECTRONS; MEASUREMENT; MICROSCOPES; NITRIC ACID; OBSERVATION; PARTICLES; REGIONS; SEDIMENTATION; STATIONS; SULFATES; WINTER; Arctic; Syowa Station; Antarc*; Antarctica
• Online Access: http://www.dtic.mil/docs/citations/ADP007362; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP007362

Winter enhancement of stratospheric aerosols was measured at Syowa Station, Antarctica by a lidar. Electron microscope observation of individual particles collected in the winter Arctic stratosphere with a balloon-borne impactor suggested that particles containing nitric acid were formed during the cold winter season, and the appearance of such particles was an important process causing the winter enhancement of polar stratospheric aerosols. An externally mixed state of nitric acid and sulfate particles was observed in the region of 18.8-19.6 km (the upper region of the sulfate particle layer) during the measurements of January 31, 1990. One possible explanation of this is nitric acid particle sedimentation, which has been speculated as being an important process causing denitrification of the polar stratosphere and polar ozone depletion.