Title A statistical approach to coastal upwelling in the Baltic Sea based on the analysis of satellite data for 1990-2009
Authors Lehmann, Andreas ; Myrberg, Kai ; Höflich, Katharina
DOI 10.5697/oc.54-3.369
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Is Part of Oceanologia.. Sopot : Polish Academy of Sciences. 2012, vol. 54, iss. 3, p. 369-393.. ISSN 0078-3234. eISSN 2300-7370
Keywords [eng] Baltic Sea ; upwelling ; sea surface temperature ; modelling
Abstract [eng] A statistical analysis of Baltic Sea upwelling has been carried out to cover, for the first time, the entire sea area for the period 1990–2009. Weekly composite SST maps based on NOAA/AVHRR satellite data were used to evaluate the location and frequency of upwelling. The results obtained were analysed and compared with earlier studies with excellent agreement. Our study enables the most intense upwelling areas in the entire Baltic Sea to be evaluated. According to the analysis of 443 SST maps, the most common upwelling regions are found off the Swedish south and east coasts (frequency 10–25%), the Swedish coast of the Bothnian Bay (16%), the southern tip of Gotland (up to 15%), and the Finnish coast of the Gulf of Finland (up to 15%). Pronounced upwelling also occurs off the Estonian coast and the Baltic east coast (up to 15%), the Polish coast and the west coast of R¨ugen (10–15%); otherwise the upwelling frequency was between 5 and 10%. Additionally, simulated SST distributions derived from a Baltic Sea numerical model were analysed for the same period. Furthermore, at specific positions close to the coastline, surface winds based on the SMHI meteorological data base were analysed for the same 20-year period. Wind components parallel to the coast were discriminated into favourable and unfavourable winds forcing upwelling. The obtained frequencies of upwelling-favourable winds fit very well the observed upwelling frequencies derived from satellite SST maps. A positive trend of upwelling frequencies along the Swedish east coast and the Finnish coast of the Gulf of Finland was calculated for the period 1990–2009.
Published Sopot : Polish Academy of Sciences
Type Journal article
Language English
Publication date 2012
CC license CC license description