100 years of atmospheric and marine observations at Utö Island


Utö Atmospheric and Marine Research Station
Utö Atmospheric and Marine Research Station

Measurements generate data on Finnish sea areas. In a fresh publication, a digitized long data series both reflects observed changes in the Baltic Sea and supports new research projects that assess interactions between the sea and the atmosphere.

Meteorological observations began on the island of Utö in 1881, with the systematic recording of seawater temperature and salinity starting in 1900. The new publication reviews the magnitude of long-term changes in the sea and atmosphere and the factors influencing these.

As the ice cover has decreased significantly, the annual average temperature at Utö has only increased since 1980. This is different from the trend on mainland Finland.  Based on results, it appears that earlier the ice has slowed down warming by reflecting sunlight better than open water. The ice also functioned as an insulator between the sea and atmosphere.

Long-term variation in seawater salinity is also seen in the observations made at Utö and this is clearly connected to both Baltic Sea salt pulses and to the flow of Baltic Sea rivers. The results also indicate that the sea bottom has been cooler during periods of greater salinity than in those where the salt concentration has been low. This, in turn, points to slowed stratification and vertical mixing.

The long observation time series digitized for the purposes of the research functions as a basis for new research projects at the Utö Atmospheric and Marine Research Station.  For example, the dynamics of the sea ecosystem, interactions between the atmosphere and the sea, and atmospheric properties in marine areas will be investigated in these projects. The new observations may be used to understand climate changes related to positive feedbacks, to support shipping and official supervision and to facilitate the investigation of the reasons for changes happening in the Baltic Sea.

The publication has been produced jointly by the Finnish Meteorological Institute and the University of Eastern Finland.

The Utö Atmospheric and Marine Research Station is part of the Finnish Marine Research Infrastructure FINMARI. The latest observations from Utö can be seen on the following webpage:

Further information:

Head of Group Lauri Laakso, Finnish Meteorological Institute, lauri.laakso@fmi.fi, tel. +358 50 525 7488

Senior Researcher Santtu Mikkonen, University of Eastern Finland, Department of Applied Physics, santtu.mikkonen@uef.fi, tel. +358 40 355 2319

Laakso, L., Mikkonen, S., Drebs, A., Karjalainen, A., Pirinen, P., and Alenius, P.: 100 years of atmospheric and marine observations at the Finnish Utö Island in the Baltic Sea, Ocean Sci., 14, 617-632, https://doi.org/10.5194/os-14-617-2018, 2018.