Arctic ozone loss in threshold conditions: Match observations in 1997/1998 and 1998/1999

A. Schulz (1) , M. Rex (1) , N. R. P. Harris (2) , G. O. Braathen (3) , E. Reimer (4) , R. Alfier (4) , I. Kilbane-Dawe (2) , S. Eckermann (5) , M. Allaart (6) , M. Alpers (7) , B. Bojkov (3) , J. Cisneros (8) , H. Claude (9) , E. Cuevas (10) , J. Davies (11) , H. de Backer (12) , H. Dier (9) , V. Dorokhov (13) , H. Fast (11) , Sophie Godin (14) , B. Johnson (15) , B. Kois (16) , Y. Kondo (17) , E. Kosmidis (18) , E. Kyrö (19) , Z. Litynska (17) , I. S. Mikkelsen (20) , M. J. Molyneux (21) , G. Murphy (22) , T. Nagai (23) , H. Nakane (24) , F. O'Connor (25) , C. Parrondo (26) , F. J. Schmidlin (27) , P. Skrivankova (28) , C. Varotsos (29) , C. Vialle (14) , P. Viatte (30) , V. Yushkov (13) , C. Zerefos (18) , P. von Der Gathen (1)

1 AWI - Alfred Wegener Institute for Polar and Marine Research
2 EORCU - European Ozone Research Coordinating Unit [Cambridge]
3 NILU - Norwegian Institute for Air Research
4 Institut für Meteorologie [Berlin]
5 NRL - Naval Research Laboratory
6 KNMI - Royal Netherlands Meteorological Institute
7 AIP - Leibniz-Institute of Atmospheric Physics
8 INM - Instituto Nacional de Meteorologia [Madrid]
9 DWD - Deutscher Wetterdienst [Offenbach]
10 INM - Instituto Nacional de Meteorologia [Santa Cruz de Tenerife]
11 ECCC - Environment and Climate Change Canada
12 IRM - Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute of Belgium
13 CAO - Central Aerological Observatory
14 SA - Service d'aéronomie
15 NOAA - National Oceanic and Atmospheric Administration
16 IMGW - PIB - Institute of Meteorology and Water Management - National Research Institute
17 UTokyo - The University of Tokyo
18 Laboratory of Atmospheric Physics [Thessaloniki]
19 FMI - Finnish Meteorological Institute
20 DMI - Danish Meteorological Institute
21 Department of Meteorology [Reading]
22 MET ÉIREANN - Irish Meteorological Service
23 MRI - Meteorological Research Institute [Tsukuba]
24 NIES - National Institute for Environmental Studies
25 Centre for Atmospheric Science [Cambridge, UK]
26 INTA - Instituto Nacional de Técnica Aeroespacial
27 GSFC - NASA Goddard Space Flight Center
28 CHMI - Czech Hydrometeorological Institute
29 NKUA - National and Kapodistrian University of Athens
30 METAS - Swiss Federal Office of Metrology

Chemical ozone loss rates inside the Arctic polar vortex were determined in early 1998 and early 1999 by using the Match technique based on coordinated ozonesonde measurements. These two winters provide the only opportunities in recent years to investigate chemical ozone loss in a warm Arctic vortex under threshold conditions, i.e., where the preconditions for chlorine activation, and hence ozone destruction, only occurred occasionally. In 1998, results were obtained in January and February between 410 and 520 K. The overall ozone loss was observed to be largely insignificant, with the exception of late February, when those air parcels exposed to temperatures below 195 K were affected by chemical ozone loss. In 1999, results are confined to the 475 K isentropic level, where no significant ozone loss was observed. Average temperatures were some 8°-10° higher than those in 1995, 1996, and 1997, when substantial chemical ozone loss occurred. The results underline the strong dependence of the chemical ozone loss on the stratospheric temperatures. This study shows that enhanced chlorine alone does not provide a sufficient condition for ozone loss. The evolution of stratospheric temperatures over the next decade will be the determining factor for the amount of wintertime chemical ozone loss in the Arctic stratosphere.

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]

A. Schulz, M. Rex, N. R. P. Harris, G. O. Braathen, E. Reimer, et al.. Arctic ozone loss in threshold conditions: Match observations in 1997/1998 and 1998/1999. Journal of Geophysical Research: Atmospheres, 2001, 106 (D7), pp.7495-7503. ⟨10.1029/2000JD900653⟩. ⟨insu-03097721⟩