History of Baltic Sea Ice Climate Workshops 
15 
History of Baltic Sea Ice Climate Workshops 
Matti Lepparanta 
Division of Geophysics, University of Helsinki, Helsinki, Finland, 
Email matti.lepparanta@helsinki.fi 
Abstract 
The first Baltic Sea Ice Climate Workshop was held in Tvarminne, Finland in 1993. The 
motivation was to collect sea ice scientists around the Baltic Sea together to exchange data, 
information and results, to start up a data base for sea ice modelling needs in the Baltic Sea. 
This workshop then grew into series at three-year time interval, the number of participants 
being in the range 20-40. 
Introduction 
Ice occurs in the Baltic Sea annually for seven months, from November to June. In normal 
winters the Gulf of Bothnia, Gulf of Finland, and Gulf of Riga are mostly ice covered, while 
further south only shallow bays and coastal areas freeze over. In cold winters the whole Baltic 
Sea is frozen; the most recent case is from 1947 but, however, in 1987 the coverage reached 
up to 96% of the total area of the Baltic Sea. The ice season has a major role in the annual 
cycle of the Baltic Sea via its influence on the air - sea momentum, heat and gas transfer, 
salinity budget of the sea, light conditions, and storage and transport of pollutants. The 
hydrographic and illumination conditions have further a strong influence on the ecological 
conditions in the basin. 
In spite of the importance of the ice season in the Baltic Sea, many research programmes have 
overlooked the ice problems in the past. In particular this has led into serious biases in the 
research programmes in the northern and eastern large gulfs. Also it is well known that ice and 
ice-related presentations in the “Baltic Oceanographers” conference series has amounted to 
less than 5% of the total. Baltic Sea Ice Services have held meetings since early 20th century 
but these meetings have focused on practical questions such as ice codes, chart formats, and 
information exchange and transfer. 
In the beginning of the 1990s, along with the increase of climate research in the Baltic Sea 
region, a workshop “Baltic Sea Ice Climate” was organised by the Department of Geophysics of 
the University of Helsinki. The objective was to collect sea ice scientists together on topics 
related to climate variability and Baltic Sea ice conditions. The workshop collected 36 
participants, and in fact initiated a series of conferences on this topic, at three-year interval 
reaching to the 5th workshop in 2005.