This is the Arctic Research Centre in Sodankylä.
ARC provides several meteorological measurements and satellite data reception and processing.
For visitors we offer measurement infrastructure, workshop and accomodation facilities.
The bars show the maximum 30 minute average of UV index on each day.
The black line shows total ozone values measured by the Brewer spectrophotometer, if available.
The cyan line is the average ozone column measured by the TOMS satellite 1979-1992.
The standard deviation is indicated by vertical lines.
From mid October to the end of February the sun is too low for Brewer measurements, and lunar measurements or data from SAOZ spectrometer are shown. For the same reason also TOMS mean is missing during midwinter.
Daily total ozone values of Sodankyla expressed in Dobson Units (DU) yellow dots) are mainly
data.The data gap during the winter when the sun is not high enough for Brewer is filled by
mainly data from SAOZ
(Systeme d'Analyse par Observation Zenithale)
but some points are obtained from Brewer focused moon observations.
The direct sun measurements are used ranking first. When this is not possible due to clouds measurements are taken from zenith sky.
Focused sun method is used during
the beginning and end of winter.
The black line presents the long time mean of
satellite instrument observations for comparison. Also these data are missing for the mid-winter months (dotted line).
Latest total ozone map of the Northern Hemisphere is available at