Been away for a variety of reasons, has been a horrible few weeks including frenetic work on software workarounds. Several personal matters were far worse. Lets hope that is the end of it, more stuff keeps on dumping on me.
The weather is a tad chilly in England, went down to -6.8C at Katesbridge Northern Ireland last night (27th into 28th) [UPDATE] and what happened next? See comments and link to another blog article with data, went off the bottom of plot shown here –Tim][UPDATE 2, -8.8C ]
It might drop further tonight, flat anti-cyclone calm over the UK, unusually clear skies but there is still humidity to freeze out.
We had a remarkable day today in southern England, clear sunny all day with flat calm, just right to look at insolation and radiation balance.
Benson, south Oxfordshire tends to be the coldest weather station in the south of England, up to midnight [UPDATE: some cloud was arriving warmied slightly –Tim]
During the sunny day here an IR reading on the sky zenith read < -40C, at 20 hours it read -42C, concrete paving -2C and roof of my car -12C. A shaded thermometer near the house -1.8C
Humidity will keep air temperature up.
Chilbolton yesterday shows the clear conditions
As you can see close to the winter solstice there isn’t much insolation. Temperature is falling noisy as presumably frost sparkles out.
I’ve computed the radiation balance where assuming this is correct is around negative 40 Watts sqm. (various details not mentioned about errors in quick plots etc., all I can do quickly)
The estimate of a universal fudge factor to do with clear air insolation is wrong in this case, low by about 10%. This an ongoing work, early days. Next month the official data should be available so I could do some checking. (archive is updated monthly)
Post by Tim