ASIBIA: Polar Bear Free Sea-Ice Research | James France
The University of East Anglia is currently building a brand new facility to grow sea-ice under realistic Arctic or Antarctic conditions. The role of sea-ice in the Earth’s climate is important for many reasons, including acting as an insulating layer for the oceans, reflecting sunlight back into space and providing a valuable habitat to species such as microscopic algae to polar bears. However, conducting experiments on sea-ice is difficult (sampling sea-ice nearly always involves removing the sea-ice and storing for analysis back in a lab), relatively dangerous - reference those polars bears mentioned earlier - and usually very expensive. The running costs for an icebreaking ship, such as the Norwegian’s Polarstern Vessel is around £50,000 per day. The idea of creating a miniature version of the Arctic in the laboratory not only reduces the day to day costs of sea-ice research but also entirely removes the dangers posed by polar bears! The Science Background The UEA sea-ice chamber (or to give its full name: The ASIBIA, Arctic Sea Ice, snow, Biogeochemistry and Impacts on the Atmosphere Chamber 1) aims to be a little different from previously constructed sea-ice chambers by creating an enclosed ocean-sea-ice-atmosphere system which can be temperature controlled and each of the ocean, sea-ice and atmosphere continuously monitored and sampled from. Some systems which require the large scale of the Arctic, such as how sea-ice breaks up and how large mammals interact with their environment cannot be replicated in a lab – but some; such as how sea-ice forms under different turbulence conditions, how gases are transferred from the ocean through sea-ice to the atmosphere or how microbiology responds to changing sea-ice conditions are ideally suited to experiments where all the environmental conditions can be controlled. One of the major scientific problems of working in the Arctic on sea-ice is the uncertainty of the conditions and trying to understand which variables are the important factors. In a laboratory set up, factors such as wind speed and temperature can be controlled. So what will the facility be able to do? Well when complete… it’ll look something similar to the sketch below. The ocean will be heated and insulated to recreate the ocean heat flux, and to prevent cooling from any direction but at the top of the ocean. The air above the ocean is cooled in the same way an air-conditioning system works and can be as low at -55°C.
The atmosphere is made from a Teflon film which is unreactive so that any chemistry we want to observe isn’t affected by the materials used. Another advantage to using this type of Teflon is that it is nearly completely transparent to Ultra-violet light and visible light, so the lighting can easily illuminate the sea-ice and ocean. The lighting rack above the chamber will consist of a combination of solar replication LED bulbs and ultraviolet bulbs (the ultra-violets are normally used in tanning salons and skin therapy treatments) so that the effects of UV photochemistry can be observed and light required for biological experiments can be tuned. There will be a range of sensors in the chamber measuring ocean temperatures and salinity; ice measurements sensors for light transmission, salinity, temperature and pressure and atmospheric measurements of temperature, light, humidity and wind speed. There are also small pipes which can be used to sample gas concentrations in the atmosphere. We have also got underwater video to allow us to see how the ice forms (such as in this test experiments below):
What have we achieved so far? The environmental room in which the sea-ice facility is housed is built and fully tested, the tank for the ocean and sea-ice is built and some of the ocean and sea-ice instruments have been tested in an initial proof of concept experiment.
Part of the Sensor Array Present in the Sea-Ice Chamber
So far so good, but what’s the plan going forward? The next stage is to make sure the whole system works with an atmosphere and appropriate lighting, and then we can start to run a whole suite of experiments looking at a wide range of scientific questions. We have a lot of people in the school of environmental sciences who would like to use it for a variety of experiments including air-sea-ice gas exchange, algal growth under sea-ice and the effect of photochemistry in sea-ice on the atmosphere. There’s lots more interest from scientists outside the UEA with diverging interests such as snow on sea-ice, the effect of oil slicks under sea-ice and how melt ponds form at the base of sea-ice, to include just a few. Many of these are almost impossible to gain access to in the field without great time and cost due to the requirements to sample below the ice or be waiting for perfect sampling conditions. We’re hoping that the facility here will be well used by the community and become a useful tool for sea-ice research in the years to come. 1 ASIBIA was the brainchild of the late Prof Roland von Glasow, who sadly passed away earlier this year. The European Research Council have funded the project.