52.61189 -0.46793 Met Office Assessed CIMO Class 1 Installed 1/1/1955
This is a typical UK military airfield site – there are surprisingly over 120 such locations. The above circle delineates a 100 metre radius from the Stevenson Screen. If it comes down to pernickety measurements this possibly should be more correctly defined as Class 2. However, it would still be accurate enough for good quality data recording and the site, as with all military sites, is impeccably maintained. The historic data record from such a site should be equally impeccable, however………
Tim Channon reviewed the site back in 2012 arriving at a completely different assessment
Obviously Tim was reviewing a different site so the question is had he misidentified the location? That seems highly unlikely as he would have used the Met Office location co-ordinates given at the time and the image above is certainly a weather station site.
What has now become apparent is that there are two separately WMO numbered sites and both of them still seem to be operational in one way or another. WMO03461 appears to have been superseded for historic temperature recording but understandably continued for immediate aviation purposes. The footpath to it is well worn indicating continued regular use.
The headlined Class 1 (2?) WMO03462 is providing recordings to the historic record though this only appears to be from around 1994/5/6 as indicated in the CEDA archived data.
Prior to this archives suggest WMO03461 (different location & different elevation) was the primary source of data.
But there was a not entirely explained relocation in the 1970s
20th Century Met Office protocol regarding identification numbering of sites was stipulated as follows:
“Over time certain instruments, or the whole enclosure, may be relocated some distance away from the original site. Where the distance moved is small, the observations obtained from the new site may have exactly the same climatological characteristics as previously and it makes sense to regard them as coming from the same source or station distinguished by certain identifiers. Where the distance moved is large, or, where the exposure at the new site is sufficiently different that a detectable impact on the measured climatology is judged likely, it is appropriate that observations from the new site are labelled by a different set of identifiers.”
Conclusions that can be drawn from this site review are:
1. The current recording is now from a good quality site.
2. Unfortunately this good site does not have a particularly long term record with its comparative data record under 30 years i.e. less than a climate averaging period.
3. Longer term comparison would not be reliable due to significant location/elevation differences sufficient to require re-identification numbering of sites where ” a detectable impact on the measured climatology is judged likely”.
I would hope these above conclusions were similarly accepted by the current Met Office regime from their own historic guidance though, sadly, I suspect not.
via Tallbloke’s Talkshop
November 19, 2024 at 08:47AM
Iowa Climate Science Education 