The proposed PhD studies are related to the Sea Ice Ecology consortium (SIE), which covers microbial biodiversity and metabolisms as well as physical and chemical processes in Baltic Sea ice. The consortium includes researchers from University of Helsinki; University of Lapland; Tvarminne Zoological Station; Finnish Institute of Marine Research (FIMR); University of Umea, Sweden; University of Wales, Bangor, UK; and National Environmental Research Institute, Denmark. SIE also coordinates a Nordic (NordForsk) network around sea ice research. The fieldwork of the announced PhD position is carried out primarily at the Tvarminne Zoological Station (Baltic Sea) and laboratory studies are performed in the Department of Biological and Environmental Sciences and FIMR.
In order to assess the nature and availability of photochemically borne nutrients and substrates in the ice ecosystem, the following five objectives will be addressed:
- Photochemical transformation of chromophoric dissolved organic matter;
- Photochemistry of nitrogen in sea ice;
- Photochemical mineralization of dissolved organic carbon to CO2;
- Impact of irradiance on the activity of phosphomonoesterase; and
- Photochemical changes in the bioavailability of dissolved organic
As part of the research strategy, controlled experimental studies concerning these objectives will be carried out in the laboratory with sea ice (natural or experimentally grown) and brine collected from sea ice and artificial brine solutions. Field studies will be conducted to compare the modeled outcomes to natural conditions and to reveal other underlying processes that affect the fate of the products of photochemical reactions in sea ice.

Applicants should have a good academic record, previous laboratory and field experience, and motivation to achieve a PhD from the described topic. The successful candidate will be selected according to his/her fit to the described PhD research.

To apply, please submit a curriculum vitae, excerpt of undergraduate studies and research interests, and contact details of two referees no
later than 15 October 2007 to:
Anssi Vahatalo
Department of Biological and Environmental Sciences
Viikinkaari 1
P.O. Box 65
FIN-00014 University of Helsinki
For further information about the Department of Biological and Environmental Sciences, please go to: