|
European Ozone
Upper atmospheric
conditions in The Northern Hemisphere are becoming similar to those of the
Antarctic. The result of this could be the formation of an "Arctic Ozone
Hole" or more correctly termed "low ozone event".
The alarming
difference is that there are millions of people that live in the area that will
be exposed to this deadly radiation. These conditions could expose large numbers
of people and animals to more ultraviolet radiation, which can cause skin cancer
and disrupt reproduction of some animals and destroy plant life. The
ozone layer, high up in the atmosphere, shields Earth from much of the sun's
harmful ultraviolet rays. A gradual thinning due to emissions of damaging
man-made chemicals has increased the occurrence of skin cancer and other
illnesses related to over-exposure to ultraviolet rays, scientists
say.
The continual
decline in ozone levels due to chemical depletion and the increase in frequency
of mini ozone holes over Europe is resulting in an increase in harmful
biologically active UV radiation.
Can
we explain the trends in European ozone levels?
J. E. Jonson1, D. Simpson1,
H. Fagerli1, and S. Solberg2
1Norwegian Meteorological
Institute, Oslo, Norway
2NILU, Kjeller, Norway
Abstract.
Ozone levels in Europe are changing. Emissions of ozone precursors from
Europe (NOx, CO and non-methane hydrocarbons) have been
substantially reduced over the last 10–15 years, but changes in ozone
levels cannot be explained by changes in European emissions alone. The
observed ozone trends at many European sites are only partially reproduced
by global or regional photochemistry models, and possible reasons for this
are discussed.
In
order to further explain the European trends in ozone since 1990, the EMEP
regional photochemistry model has been run for the years 1990 and
1995–2002. The EMEP model is a regional model centred over Europe but
the model domain also includes most of the North Atlantic and the polar
region. Climatological ozone data are used as initial and lateral boundary
concentrations. Model results are compared to measurements over this
timespan of 12 years. Possible causes for the measured trends in European
surface ozone have been investigated using model sensitivity runs
perturbing emissions and lateral boundary concentrations. The increase in
winter ozone partially, and the decrease in the magnitude of high ozone
episodes, is attributed to the decrease in ozone precursor emissions since
1990 by the model. Furthermore, the model calculations indicate that the
emission reductions have resulted in a marked decrease in summer ozone in
major parts of Europe, in particular in Germany. Such a trend in summer
ozone is likely to be difficult to identify from the measurements alone
because of large inter-annual variability.
http://www.atmos-chem-phys-discuss.net/5/5957/2005/acpd-5-5957-2005.html
11/11/2001-Low
Ozone Event In Europe
12/15/1999-European
Ozone Event Nov 20-Dec 2,1999: NASA images and report
http://www.ozone-sec.ch.cam.ac.uk/
The European Ozone Research
Coordinating Unit
|
