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Ann. Geophys., 21, 2175-2183, 2003
www.ann-geophys.net/21/2175/2003/
© European Geosciences Union 2003
Antarctic air over New Zealand following vortex breakdown in 1998
J. Ajtic1,2, B. J. Connor2, C. E. Randall3, B. N. Lawrence4, G. E. Bodeker2, J. E. Rosenfield5, and D. N. Heuff1
1Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020, New Zealand
2National Institute of Water and Atmospheric Research, Private Bag 50061, Omakau 9182, Central Otago, New Zealand
3Laboratory for Atmospheric and Space Physics, UCB 392, University of Colorado, Boulder, CO 80309-0392, USA
4British Atmospheric Data Centre, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
5Goddard Earth Sciences and Technology Center, NASA/Goddard Space Flight Center, Code 916, Greenbelt, MD 20771, USA
Abstract. An ozonesonde profile
over the Network for Detection of Stratospheric Change (NDSC) site at Lauder
(45.0° S, 169.7° E), New Zealand, for 24 December 1998 showed atypically low
ozone centered around 24 km altitude (600 K potential temperature). The origin
of the anomaly is explained using reverse domain filling (RDF) calculations
combined with a PV/O3 fitting technique applied to ozone
measurements from the Polar Ozone and Aerosol Measurement (POAM) III
instrument. The RDF calculations for two isentropic surfaces, 550 and 600 K,
show that ozone-poor air from the Antarctic polar vortex reached New Zealand on
24–26 December 1998. The vortex air on the 550 K isentrope originated in the
ozone hole region, unlike the air on 600 K where low ozone values were caused
by dynamical effects. High-resolution ozone maps were generated, and their
examination shows that a vortex remnant situated above New Zealand was the
cause of the altered ozone profile on 24 December. The maps also illustrate
mixing of the vortex filaments into southern midlatitudes, whereby the overall
mid-latitude ozone levels were decreased.
Key words. Atmospheric composition
and structure (middle atmosphere composition and chemistry) – Meteorology and
atmospheric dynamics (middle atmosphere dynamics)
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