During the past years several kinds of extreme events in the total ozone content of the atmosphere (TOC) could be observed:

As well as the TOC changes the UV-B radiation does. Since its high photobiological impact the changes in the UV radiation effect significant all ecosystems.

While high levels of UV-B radiation enhances damage, low levels of UV-B may leed to deficiences or to secondary damage. Socondary damge is the disturbtion of an established photoequilibrium. An example for this the detrimendation due to enhanced viral, bacterial or fungal spreadness. Extreme Day-To-Day Changes force additional stress.

1. Photobiological Impact of Extreme Ozone Mini-Holes

We define a Extreme Ozone Mini-Hole as a synoptic scale phenomena during that the TOC undergoes a level of 200DU (Note the threshold value for the Antarctic Ozone Hole is 220DU).
EOMH occur over Europe during late autumn and early spring (Nov. to Jan.). The following gives the chronology of EOMH over Europe.

1.1 Extreme Ozone Mini-Holes

1.1.1 EOMHs between 1978 and 1993 over Eruope
1.1.2 EOMHs between 1996 and 2004 over Europe
1.1.3 Temporal courses during of selected EOMH over Europe
1.2 Biologically effective UV Radiation during EMOH
1.2.1 Biologically effective UV Radiation during EMOH
1.3 References
1.3.1 References for OMH
1.3.2 References for UV during OMH

2. Photobiological Impact of Extreme Day-To-Day Changes

We define a Extreme Day-To-Day Change as a change in TOC by more then 40% within 24 hours.

3. Photobiological Impact of Extreme High TOC levles

Extreme high TOC may also inluence the ecosysteme as it decreases the UV reaching the earth's surface.

4. Call for Cooperation

We welcome everybody who would like to contribute
to this webpage.
or to contribute in answering the many open scientific questions.
Contact: alois.schmalwieser()