Oxford DCNN 4522 – Not improving with age.

51. 76126 -1.26401 Met Office assessed CIMO Class 4S Records exist from 1767

“Oxford University’s Radcliffe Meteorological Station is the longest running weather station in the UK. On 15 May, the Met Office will present an award to the University ‘in recognition of 200 years of continuous climate observations at the Radcliffe Observatory, Oxford’. 

Whilst I accept this site has a long standing record, I do not equate longevity with accuracy nor wish to treat the site with the same sort of reverence that the Met Office does. It is assessed as Class 4 indicating inaccuracy up to 2°C plus suffering effects of shading rendering some data effectively unreliable. Surely such a venerable site should be well cared for …. but how does regularly parking a long term marquee with full catering equipment alongside it improve the quality of readings?

Several things are evident from the above image. To address each in turn…..

SHADING. The site regularly falls into deep shadow from the large adjacent Observatory Dome as is obvious from this 2014 aerial imagery. The contrast from deep shade to bright sun indicates daytime effects and not just low sun times of early morning/late evening. And of course that recurring marquee.

WALLED GARDEN. As is common for many Met office stations, Oxford Radcliffe is located in an environment deliberately constructed to artificially elevate temperatures and create a micro climate. Simply rotating the street view around from the headline image reveals the garden walls as below. Clearly an unnatural environment

Urban Heat Island. Oxford is a large city now of over 165,000 but when this site was originally established the population of Oxford was under 12,000. In recent times the entire south to west quadrant of the site around the Observatory has been heavily re-developed completely changing the character of the area. The addition of AirCon to new construction mirrors the development around the Cambridge Botanic Gardens site. UHI is acknowledged to elevate area local temperatures by several degrees.

Extraneous Heat sources. The Marquee is a long term annual visitor to the site – long enough to cause an effect on the grass visible several months after the Marquee has gone. The majority of the many historic aerial images on Google Earth Pro either show the Marquee or its after effects on the grass. It is inconceivable that Met Office inspectors are unaware of this siting regularity. It is not only the presence of such a structure that compromises the site but also what it is used for. Many images clearly show catering equipment which can only contribute artificial heat to the surroundings. Subjectively, I would suggest that, as screen site security is minimal, the screen is liable to “high jinx” effects at times.

In conclusion the Met office class this station as Class 4, I find that implausible given all the elements compromising the temperature readings representation of a wider area. In the same way as Cambridge Botanic Gardens I feel this site is more properly assessed as Class 5 and its readings worthless for the historic climate record. Probably time to retire this old station.