51.806588 -0.360175 Met Office Assessed CIMO Class 1 Installed 1853
Quite possibly the Met Office’s finest station against which others should be judged. Rothamsted Research runs this and other Met Office weather stations at North Wyke, Brooms Barn and Woburn.
“In 2018, the World Meteorological Organisation (WMO) officially designated Rothamsted as a Centennial Station, joining a global network of sites recognised by the WMO for recording reliable observations for over 100 years.”
Needless to say that if the Met Office had national coverage of stations as well sited and maintained as Rothamsted there would still be those who would argue that it would not be good enough. However, given there are no significant buildings, roadways or problematic extraneous heat sources in the immediate vicinity, the only possible queries could be the changing vegetation – not a failure issue in my humble opinion. A wider area map really does not indicate any more Urban Heat Island Effect than anywhere else that could likely be found in south east England.
To demonstrate just how much difference good sites make, Rothamsted is included in the world’s longest continually running weather dataset – the Central England Temperature series. It took over from Cambridge Botanic Gardens currently rated CIMO Class 5.
” We replaced the Cambridge station by Rothamsted Observatory in 1931 because of evidence of urban warming at the former by that time”
Way back in 1931 the Cambridge Botanical Gardens site was deemed unacceptable for the temperature record due to Urban Heat Island effect with a population of just over 69,000. In 2019, with the population having more than doubled to over 146,000, the same Class 5 site was deemed by the modern day Met Office as acceptable to record the all time national highest temperature of 38.7°C. Meanwhile over at Class 1 Rothamsted a maximum of only 36.2°C was being recorded that day.
On 10th august 2003 whilst CIMO Class 4 Faversham allegedly recorded (disputed by Royal Meteorological Society) 38.5°C, Rothamsted only reached 36°C.
On 19th July 2022 whilst aviation site RAF Coningsby ( highly debatable CIMO Class 3 site with major extraneous heat sources officially identified) was recording a further record breaking 40.3°C, Rothamsted only registered a lower 38.5°C.
On 4th August 1990 when Montpelier Gardens Weather Station, Cheltenham (by the bandstand whilst a fair was on) recorded the record of 37.1°C, Rothamstead only reached 33.8°C.
The above examples are not 100% definitive of problems elsewhere but it is quite obvious that there are significant differences in temperatures being recorded between different classes of stations with poorer sites regularly exaggerating records.
My personal contention is that the temperature record should (like the original CET aspirations) only include well sited and maintained stations. Rothamsted is the benchmark of such quality against which others should be measured. Perfection should not be the enemy of the good…..but please feel free to disagree
via Tallbloke’s Talkshop
September 8, 2024 at 05:30AM
Iowa Climate Science Education 