Sea Ice

This Sea Ice experiment is a follow-up to the main weather@home 2014 UK Flooding experiment, which focuses especially on the link between sea-ice loss and the risk of heavy rainfall.

One of the most discussed features of the climate system is the potential for major Arctic sea-ice loss in a warming world to alter rainfall and storm patterns across the mid-latitudes. However, in simulations of climate change, it is not always possible to isolate any particular driver. Hence, how much of any predicted rainfall changes are directly due to sea-ice changes, rather than higher ocean temperature forcings for instance, may not be immediately apparent from estimates by Global Circulation Models.

Here we perform one of the first ever factorial experiments. We keep surface temperatures of the oceans as representative of present-day (period including Dec 2013 – Feb 2014, so through the time of major flooding in the UK), but allow the sea-ice cover to relax back to that of year 1985/6. That year corresponded to especially high cover, and a time when more accurate measurements were starting to become available. Year 1985 might be relatively near to pre-industrial conditions, after which the well-documented significant sea-ice loss started.

We are grateful for the citizen science contribution made by performing these simulations. This will then allow us to determine – in isolation – the extent to which sea-ice loss may be either preventing even heavier rainfall amounts, or the opposite of aggravating extreme storm and precipitation events.