Wednesday 28 December 2022

Is this year’s tumultuous weather set to become the new ‘norm’ ?

 

The National Trust has warned that this year’s tumultuous weather is set to become the new ‘norm’ https://www.nationaltrust.org.uk/services/media/weather-and-wildlife-2022  The Stonehenge and Avebury WHS are thought to be at risk from climate change, so it is of interest here - http://www.stonehengeandaveburywhs.org/assets/Climate-Change-RA-for-web.pdf

We hear a lot about climate breakdown, that our climate is getting more unpredictable and tumultuous. We can survive and thrive in nearly any climate if we can plan and prepare for it from the arctic to the equator, from deserts to rainforests. But instability and uncertainty is dangerous. So is it getting more disorderly?

To check if any increasing instability was evident in England  I thought a simple, quick and dirty way would be to compare the annual, and each season’s, temperature and rainfall using the long running Hadley Centre Central England Temperature (HadCET) dataset and  HadUKP,  the UK regional precipitation series  available from https://www.metoffice.gov.uk/hadobs/index.html

My method was to compare the differences between years.

For instance the mean spring temperature in 2020 was 9.9°C, in 2021 8°C, and 2022 10.1° so the differences are  -1.9°C and 2.1°C.   I charted out the differences from 1963.

Wow, the swings are getting larger. English spring temperatures are getting less predictable.

So, I looked at more of the data.

Here’s the mean spring temperatures from 1904 – 1963:

 


Huh? That looks the same as the 1963 – 2022 chart.  Let’s overlay them to see:

 

So, spring temperature got more unpredictable from 1904 to 1963 and then the pattern repeated from 1964 to now.

What is going on? I don’t know but whatever it is it isn’t unprecedented.

 Just eyeballing the rest of the data graphs for the other seasons, years and annually I couldn’t spot any other repeating patterns either for temperature or rainfall. But torturing it with statistical analysis may reveal more. I hope someone with the skills does so.




  Another surprise to me from the series is how related the Min and Max series are. It appears that the temperature band is narrow, is it self-regulating?  A plot of spring temperatures shows: 



 A simple plot of Maximum temperature minus Minimum shows this over the whole period:


Sometimes very simple analysis is all that is needed to answer a question.

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