title: Nitric acid trihydrate (NAT) in polar stratospheric clouds.
abstract: A comprehensive investigation of polar stratospheric clouds was performed on 25 January 2000 with instruments onboard a balloon gondola flown from Kiruna, Sweden. Cloud layers were repeatedly encountered at altitudes between 20 and 24 kilometers over a wide range of atmospheric temperatures (185 to 197 kelvin). Particle composition analysis showed that a large fraction of the cloud layers was composed of nitric acid trihydrate (NAT) particles, containing water and nitric acid at a molar ratio of 3:1; this confirmed that these long-sought solid crystals exist well above ice formation temperatures. The presence of NAT particles enhances the potential for chlorine activation with subsequent ozone destruction in polar regions, particularly in early and late winter.
authors: Max-Planck-Institut für Kernphysik, Division of Atmospheric Physics, Post Office Box 103 980, D-69029 Heidelberg, Germany.
authors: C
authors: C
authors: Voigt
authors: J
authors: J
authors: Schreiner
authors: A
authors: A
authors: Kohlmann
authors: P
authors: P
authors: Zink
authors: K
authors: K
authors: Mauersberger
authors: N
authors: N
authors: Larsen
authors: T
authors: T
authors: Deshler
authors: C
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authors: Kröger
authors: J
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authors: Rosen
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authors: Adriani
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authors: Cairo
authors: G
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authors: Di Donfrancesco
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authors: Viterbini
authors: J
authors: J
authors: Ovarlez
authors: H
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authors: Ovarlez
authors: C
authors: C
authors: David
authors: A
authors: A
authors: Dörnbrack