Analysis of the physical state of one Arctic polar stratospheric cloud based on observations

• Main Authors: K. Drdla, A. Tabazadeh, R. P. Turco, M. Z. Jacobson, J. E. Dye, C. Twohy, D. Baumgardner
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1994
• Subjects: Arctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.453.6420; http://web.stanford.edu/group/efmh/jacobson/Articles/Others/94GL02405.pdf

Abstract. During the Arctic Airborne Stratospheric Expe-dition, simultaneous measurements of aerosol size distribution and NOy (HNO 3+ NO + NO 2 + 2.N20 5) were made along ER-2 flight paths. The flow characteristics of the NOy instrument allow us to derive the condensed NOy amount (assumed tobe HNO3) present during polar stratospheric cloud (PSC) events. Analysis of the January 24th flight indicates that this condensed HNO 3 amount does not agree well with the aerosol volume if the observed PSCs are composed of solid nitric acid trihydrate (NAT), as is generally assumed. However, the composition agrees well with that predicted for liquid H2SO4/I-INO3/I-I2 ¸ solution droplets using a new Aerosol Physical Chemistry Model (APCM). The agreement corresponds in detail to variations intemperature and humidity. The weight percentages of H2SO 4, HNO 3, and H20 derived from the measurements all correspond to those predicted for ternary, liquid solutions.