There has been a lot of media coverage today following a science workshop held at the Met Office HQ in Exeter yesterday.
Most of the articles go some way to capturing the science as it was delivered in the press briefing following the event – such as this article on the BBC News website. However, some stories, and particularly some headlines, do not.
The key point revolves around discussion of Atlantic ocean cycles, specifically one known as the Atlantic Multidecadal Oscillation (AMO), which can have an influence on UK summer weather.
Professor Stephen Belcher, Head of the Met Office Hadley Centre, and Dr James Screen, a NERC Research Fellow at the University of Exeter, were careful in their messaging about the AMO.
They talked about initial research which suggests this cycle, which can last for 10-20 years, can ‘load the dice’ to mean we may see a higher frequency of wetter than average summers before switching to its opposite phase, where we may see the opposite effect.
Currently, they said, it appears we are well into the ‘wet’ phase of this cycle, so it may continue to have an influence for a few more years to come.
That does not mean every summer will be a ‘washout’ for the next decade and shouldn’t be taken as a deterministic forecast for what we will see in the years to come.
First of all, we’ve seen five summers of higher than average rainfall in the last six years (with 2010 being the exception, which had average levels of rainfall). Even within each of those years we have seen periods of decent weather – so there’s no expectation of total washouts for the whole summer.
Secondly, the research suggests there is a tendency towards a higher frequency of wetter than average summers – so we could still see summers which buck this trend.
And finally, this research is still at an early phase and more work needs to be done to see exactly how this process works and how we can predict its influence on future seasons.
So, much like a blog we recently wrote about this year’s summer, it’s fair to say that you shouldn’t write off summers for the next decade or so.
We expect to be publishing a guest blog from scientists at the University of Reading on the science they presented to the workshop yesterday, so look out for that in the coming days.
You can now see video of the Professor Stephen Belcher speaking at the press conference which followed the science workshop on 18 June on our Youtube channel.
For English Farmers -what would be their perfect summer?
Mmmm. Dear Met, to quote,
“The key point revolves around discussion of Atlantic ocean cycles, specifically one known as the Atlantic Multidecadal Oscillation (AMO),”
“They talked about initial research which suggests this cycle, which can last for 10-20 years”
Now here is AMO raw data,
Now, forgive me for being pedantic, but if you use the word ‘cycle’ with respect to a periodic function then that includes the ‘positive’ and the ‘negative’ phase. The raw data suggests a cyclic ‘period’ of 60 to 70 years for the AMO. A negative ‘phase’ like we are entering now is then one half of a cycle, or 30 to 35 years. If we have been negative for a ‘few years’, as you suggest, we are ‘unlikely’ to go back to a positive phase ‘in a few years’ again as you suggest. Where do you get, “10 to 20” years from?
Also the AMO shows very similar patterns to the PDO including cycle length and strong phase relationship. Both are in similar phase to the solar cycle modulation with the PDO, the AMO, and solar cycle strength all in negative phase.
Often, the Met Office can’t even get the weather forecast right for tomorrow, so how do they expect to predict ten years? Even the ,about events past, are wrong. 2012 was said to have had no Summer (Or a wet Summer); in South Wales, include 2007 – 2011! As it happens, the “Winter” of 2006 – 13 did at least end this year and the Summer since, although no 1976, made a mockery of the prediction of a “Decade of wet Summers”.