Any hope for sea ice this winter?
Top figure: Map of hydrography stations in Isfjorden, sampled by UNIS and the Murmansk Marine Biological Institute.
If you are longing for sea ice, the development so far is indeed depressing. This winter is unusually warm in Svalbard and we may face the largest failure in sea ice formation in West-Spitsbergen ever.
Researchers and students at UNIS are monthly checking the sea temperature in Isfjorden, more exact the ~280 m deep Karlskronadypet (Station 48, KKD; top figure). The development from last autumn until now is depressing if you are longing for sea ice. In mid-February the entire water column from surface to bottom were close to +2 degrees Celsius (top figure). Warm sea temperatures were particularly prevalent in December and January, with up to 5 degrees Celsius in December. In comparison, sea temperatures between zero and -1 degrees Celsius were measured in May and partly in June 2015 (top figure). Even in the otherwise cold Billefjorden, rather warm surface temperatures were recorded in December (0.6°C), but gladly these were reduced to -1°C in mid-January.
In Tempelfjorden, another fjord arm that partly freezes in winter, sea ice was only found the last 600-1000 m in front of the glacier 19 of February. However, the sea temperatures are getting colder here (see plot from Feb 19 and March 4), but we will need cold and calm weather for an extended period before this fjord can be crossed on sea ice this winter. Sea water firsts starts to freeze when reaching -1.6 to -1.9°C depending on the salt content. At the time when sea ice has just started to form, minimum 10 days of calm weather and temperatures below -10 C is needed before the sea ice grows to roughly 30 cm thickness.
In cooperation with Murmansk Marine Biological Institute (MMBI), which has a small marine biological station in Barentsburg, UNIS conduct hydrography and plankton surveys in Isfjorden in spring, summer, autumn and winter. This joint Norwegian-Russian project named IMOS (Isfjorden Marine Observatory System) is funded by the Research Council in Norway for three years, but the aim is to establish a long-term data series that not only cover annual variability, but also seasonal variability.
Need long time series
In the Arctic we are lacking long time series, which are crucial to be able to detect climate change impacts. Longyearbyen and Barentsburg with permanent settlements can easily maintain such time series with relatively low costs. If UNIS also manage to establish an online “weather station” in sea, then all who are interested can follow the development in temperature, salinity, currents and tides, light and algal biomass continuously.
UNIS has a pending Svalbard Environmental Fund proposal for such an online ocean weather station and if we get it funded, it will be a very important tool helping us to conduct sampling campaigns when the largest changes occur and to perform better predictions on sea ice formation in Isfjorden.
Grave consequences for the ringed seal
Sea ice is currently largely absent on the west coast in Spitsbergen. Even Van Mijenfjorden, which normally is considered a safe fjord when it comes to proper sea ice, is still mostly open water (see web cam: https://kappamsterdam.kystnor.no/).
If relative high air temperatures continues, a record-low fjord-ice minimum will be a fact in 2016. The last minimum was in 2014. How this will impact the fjord ecosystem, especially at the primary- and secondary producer level (i.e. smaller organisms which makes up the fundament for higher trophic levels such as fish, sea birds and marine mammals) is poorly known, but is studied at UNIS. The ring seal, however, which are dependent on sea ice for giving birth and nursing their pups, will for sure be impacted in a strong negative way.