Over the past few years the weather in the UK appears to have gone a little haywire. The summers have been disappointingly wet and the winter’s surprisingly cold.
In an attempt to solve the riddle, many of the best experts of weather and climate joined forces for a brain-storming workshop.
It is already known that a shift in the jet stream, the fast-flowing ribbon of air that flows high up in the atmosphere, is responsible for the change in the weather. The question is, what causes the jet stream to shift in the first place?
There are several theories which may explain the shift, from changes in the sun’s energy, to the melting of the arctic.
The meeting concluded that the change in the jet streams in summer and winter was most likely to have been caused by different reasons.
In the winter, the melting of sea ice in the Arctic and the overall warming of the region, is thought to be the reason for the change. This heating has meant the difference in temperature between the Arctic and the Tropics has reduced dramatically.
This change in temperature could be the drive which has caused the alteration of the path of the jet stream. If this is the case, then the colder winters may well be a feature of the weather for the foreseeable future.
In the summer, the shift may be more transient. New research has revealed a link between warm surface temperatures in the North Atlantic Ocean and wet summers in Northern Europe.
Like the more famous temperature shift of the Pacific, the phenomenon of El Nino and La Nina, the Atlantic also has periodic changes in the sea surface temperatures.
Warm patterns, like the current one seen in the Atlantic, persisted between the 1930s and the 1950s, whereas cooler conditions prevailed between the 1960s and the 1980s.
If this theory holds, there could well be more wet summers in northwest Europe over the next few years, but at least the change isn’t thought to be permanent.