Original scientific paper
HIGH OZONE EPISODE AT ZAVIŽAN, CROATIA DURING 17–19 JULY 1998
Zvjezdana Bencetić Klaić
; Andrija Mohorovičić Geophysical Institute, Department of Geophysics, Faculty of Science, University of Zagreb, Zagreb Croatia
Danijel Belušić
; Andrija Mohorovičić Geophysical Institute, Department of Geophysics, Faculty of Science, University of Zagreb, Zagreb Croatia
Amela Jeričević
; Croatian Meteorological and Hydrological Service, Zagreb, Croatia
Tomislav Cvitaš
; Department of Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia
Abstract
We investigated an unusual elevated-ozone episode that took place at a high altitude measuring site Zavižan (44.817°N,
14.983°E, 1594 m a.s.l.). The episode was characterized by three consecutive peaks. The first one was the highest (over 120 ppbv),
and it occurred at the late night on 17 July. Following two (both about 110 ppbv) appeared approximately 18 and 36 hours after the
first peak, respectively. The night-time maximum and the departure from the usual diurnal variation of ozone concentration during
investigated episode point to the non-local pollution sources, rather than to local photochemical production. Thus, recorded ozone
peaks might arise due to the long-range transport of photo-oxidants; 2) stratospheric ozone intrusion; or 3) they might be result of
both (1) and (2). In order to inspect which of above processes is responsible for the increased ozone concentrations we applied the
unified EMEP model, which among others, simulates atmospheric transport and deposition of photo-oxidants, and, a mesoscale
numerical weather prediction model WRF-ARW V2.2. Additionally, the larger scale atmospheric conditions were examined based
on the ECMWF ERA-40 reanalysis fields. Results suggest that the stratospheric ozone intrusion played an important role in the
occurrence of investigated episode.
Keywords
ozone episode; stratospheric ozone intrusion; long range transport; EMEP model
Hrčak ID:
64262
URI
Publication date:
12.12.2008.
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