Rare solar cycle has cold implications for UK climate
NASA last week confirmed their prediction that the current solar cycle 24 is likely to be the weakest since 1906.
Intriguingly, the current solar cycle shows a striking similarity with solar cycle 5 which was also very weak, with the same double peak as the current cycle, and ran from approximately the mid 1790s to around 1810.
Solar cycle 6 was weaker still and stretched from around 1810 to the early 1820s.
Solar cycles 5 and 6 were so unusual that they were named the Dalton solar minimum after meteorologist John Dalton and coincided with a period of increasingly cold winters and poor summers.
This type of climate is a result of a jet stream that’s positioned further south than normal – caused, it’s thought at least in part, by the behaviour of the sun.
The mechanism as to why weak solar cycles may affect the position of the jet stream is poorly understood.
But a more southerly positioned jet stream is the reason why the UK has recently seen a return of cold snowy winters and a run of poor summers.
Should solar activity continue to mirror that which was observed from 1795 to 1820 then it’s possible that our weather could be similar too.
The Central England Temperature (CET) record, which began in 1659, gives an intriguing insight into what might lie ahead.
The period was littered with examples of cold, wet summers and cold winters – indeed the decade from 1810-1819 was the coldest since the 1690s.
There were exceptions, for example the very warm summer of 1818; and not every winter was harsh.
It’s worth noting that the year 1816 was complicated by a huge volcanic eruption in Indonesia the year before, which depressed temperatures worldwide.
But despite some temporary warmer interludes, historical weather records give a good indication of the type of weather the UK could experience should current solar activity continue to mirror that which was observed during the Dalton minimum over 200 years ago.
And it’s sobering to remember that the Dalton solar minimum lasted for 25 years.
My guest on this weekends weather show is former BBC weather forecaster John Kettley, who offers interesting opinions on climate past, present and future. It will be available on the BBC iplayer later on sunday, click HERE