MIPAS detects Antarctic stratospheric belt of NAT PSCs caused by mountain waves

• Main Authors: Höpfner, M., Larsen, N., Spang, R., Luo, B. P., Ma, J., Svendsen, S. H., Eckermann, S. D., Knudsen, B., Massoli, P., Cairo, F., Stiller, G., V. Clarmann, T., Fischer, H.
• Other Authors: Forschungszentrum Karlsruhe, Danish Meteorological Institute (DMI), Forschungszentrum Jülich GmbH, Helmholtz-Gemeinschaft = Helmholtz Association, Institut für Atmosphäre und Klima Zürich, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Computational Physics, Inc., E. O. Hulburt Center for Space Research, Naval Research Laboratory (NRL), Consiglio Nazionale delle Ricerche Roma (CNR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarctic; The Antarctic; Antarctic Peninsula; Ellsworth Mountains; Antarc*; Antarctica
• Online Access: https://hal.archives-ouvertes.fr/hal-00295881; https://hal.archives-ouvertes.fr/hal-00295881/document; https://hal.archives-ouvertes.fr/hal-00295881/file/acp-6-1221-2006.pdf

International audience Space borne infrared limb emission measurements by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) reveal the formation of a belt of polar stratospheric clouds (PSCs) of nitric acid trihydrate (NAT) particles over Antarctica in mid-June 2003. By mesoscale microphysical simulations we show that this sudden onset of NAT PSCs was caused by heterogeneous nucleation on ice in the cooling phases of large-amplitude stratospheric mountain waves over the Antarctic Peninsula and the Ellsworth Mountains. MIPAS observations of PSCs before this event show no indication for the presence of NAT clouds with volume densities larger than about 0.3 µm 3 /cm 3 and radii smaller than 3 µm, but are consistent with supercooled droplets of ternary H 2 SO 4 /HNO 3 /H 2 O solution (STS). Simulations indicate that homogeneous surface nucleation rates have to be reduced by three orders of magnitude to comply with the observations.