In an interview with the BBC Science Editor David Shukman, research at ECMWF was described regarding the role of Arctic sea-ice anomalies on summer weather in north-west Europe.
We suspect that declining Arctic sea-ice cover in summer has an association with lower pressure over the UK if there are also higher than normal sea-surface temperatures in the north-west Atlantic. In these circumstances we expect there to be an increased risk of the north- having relatively poor summer weather - wet, cool and windy. This is part of a long-term and large-scale pattern called the Arctic Oscillation that means the UK’s weather can be affected by events far remote from our shores.
The Arctic Oscillation is associated with changes to the position of the jet stream such that during this summer the UK and was in the path of a series of storms. However, there are many other factors that determine our summer weather and the year-to-year and decade-to-decade variability is large. This is why at ECMWF we use what is called ensemble prediction where the range of possibilities is explored by performing 51 parallel forecasts starting from slightly different conditions.
The interview with Professor Alan Thorpe, Director-General of ECMWF, can be watched here.
Research published: Impact of 2007 and 2008 Arctic ice anomalies on Atmospheric Circulation, by Balmaseda et al, Q. J. R. Meteorol. Soc., 136, 1655-1664 (2010)