WORLD METEOROLOGICAL ORGANIZATION

UNITED NATIONS ENVIRONMENT PROGRAMME

FINLAND

Ozone monitoring was started in Finland in 1988 with Brewer spectrometer and in 1990 with a SAOZ spectrometer. Finland started routine ozone soundings in 1988 at Sodankylä. That record is the longest in the European Arctic. Today also special soundings like aerosol and water vapour soundings, as well as aerosol lidar observations are made at Sodankylä.

The first UV observations were made in Finland during the 1920's by professor Lunelund. The modern UV monitoring programme in Finland was started in 1990. Today the network consists of a double monochromator Brewer instrument (Jokioinen). a single monochromator Brewer (Sodankylä) and seven Solar Light 501 erythema radiometers. Besides UV observations large amount of various

Figure 1. The location of Finnish ozone and UV radiation stations.

OZONE MONITORING AT ANTARCTICA
Finland (FMI) and Argentina (SMN) have been performing routine ozone soundings at Marambio. Antarctica (64 °S) since 1988, and total ozone measurements with a Dobson spectrometer since 1987.

STRATOSPHERIC CLIMATOLOGY
Finland has long history in developing radiosounding equipment and in performing pTU soundings. The records back to 1940 s hare been reanalysed. A pronounced wintertime cooling in the lower stratosphere has been detected with enhanced occurrence of cold temperatures needed for PSC formation.

The ECMWF analysis data has been used for studies of stratospheric temperature, potential vorticity and 3-d trajectories.

MODELLING OF STRATOSPHERIC CHEMISTRY AND DYNAMICS
FMI has performed cooperation with NCAR and Univ. of Oslo in the field of stratospheric modelling. Today three different models are used in Finland.

RADIATIVE TRANSFER MODELLING
Radiative transfer models are used as a part of UV research in Finland. UV process studies as based on observations of UV and several ancillary measurements are used for improving model parametrization.

EU OZONE RESEARCH PROJECTS
FMI is coordinating two EU Environment and Climate programme's (1996- 99) stratospheric and tropospheric ozone research projects, and participates as contractor to two other projects.

EU UV RESEARCH PROJECTS
FMI is coordinating EU Environment and Climate programme's (1996-99) UV radiation research project, and participates as contractor to two other projects. In a project called "UV Radiation in the Arctic; Past. Present and Future" e.g. scenarios for the future development of UV radiation in the Arctic are developed. In those scenarios the future chlorine and bromine loading and the possible effect of CO' increase on Arctic polar vortex dynamics are taken in to account. An example of an Arctic UV scenario is shown in Fig. 2.

PLANNED FUTURE ACTIVITIES

FUTURE SATELLITE MISSION PLANNING
Finland has participated in planning of ESA ENVISAT-1 GOMOS (launch 1999) and SSC ODIN (launch 1997) instrument design, algorithms and data centre activities These instruments are expected to give new information of stratospheric chemistry of relevance for ozone.

EUMETSAT 03 SAF
Finland has coordinated the planning of EUMETSAT Satellite Application Facility for Atmospheric Ozone. The 03 SAF will serve as a science centre and developer of facilities for the new generation of EUMETSAT-ESA instruments to monitor atmospheric ozone. These operational instruments will fly onboard MSG and METOP-1 satellites.

IGBP-IGAC ITOY
Finland has been chairing a IGAC-GLONET lTOY committee to implement 24 additional ozone sounding stations to be operated in Latin America. Africa and Asia besides the existing ozone sounding stations. The International Tropospheric Ozone Year is planned to be realised in 1998.

Figure 2. An example of a UV-B scenario to be expected as an outcome of the UVRAPPF project. Here the Arctic ozone hole scenario be Austin et al., 1999 (Nature 360, 221-225) and clear-sky radiative transfer calculations for 67 N latitude. In the sear 9040 case the expected doubling of atmospheric CO2 content has led to a more stable and cold Arctic polar vortex lasting until early May. Absolute (a) and relative (b) changes of UV-B irradiances in a CO2- doubled atmosphere are shown.