Archive for the ‘weather’ Category

Standardised UK rainfall data, putting winter 2013/2014 into context

May 14, 2014 2 comments

This is a major work started during January. Results for the 17 Met Office areal time series from 1910 are presented standardised and ranked.

The only region of the 17 with remarkable rainfall was the data combination South East and Central Southern England with a Z-score of +3.2 based on de-annualised.

The primary plots and presentation is in PDF format where zoom can be used. Here is the file (2MB)

The objective was if possible Standardising the data with the intention of

  • revealing any data structure
  • allowing better regional comparison
  • producing a statistical measure for both dry and wet periods in spite of the wet/dry process being effectively non-linear, it does not rain dryness

The result is successful. A noise signal with no obvious structure appears. In common language it is called weather.

A calculation of Return Period for the most affected 2013 / 2014 area via GEV software gives a figure of 33 years. GEV is a huge subject where results need a contextual interpretation. See ref2

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Part 1, Central England Temperature timeseries and Manley papers

May 11, 2014 5 comments

This large article was composed some time ago, last edit Oct 2013 it seems but left unpublished, one of dozens.


There is a disturbing story behind the current CET dataset as will be revealed in Part 2. The above plot sets the scene, a straight illustration of the whole dataset with timeline.

This blog article is intended as a backgrounder covering a variety of information including links to official copies of the two historic Manley papers which are the basis of the CET dataset. In my opinion CET is misrepresented as more instrument based than it is in reality. More reasonably it is an expert opinion on weather.

The Met Office CET web page[1] mentions the whole data then plays pea and thimble silently showing a plot of the later subset. Reason to be revealed in part 2.

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Categories: History, temperature, weather

Lewin on two Lamb’s tales

March 5, 2014 Leave a comment

Bernie Lewin has written an excellent two part history about Hubert Lamb of CRU, with mention of Manley, Wigley and many more.

Such sentiments were not shared by many of Lamb’s colleagues and certainly not by the new director of the Met Office, B J Mason, appointed after Sutton retired in 1965. The new director was a vocal skeptic of cyclic natural climatic change across historical time, the nature of which Lamb was intent on establishing. Mason preferred to explain recent changes as evidence of only random fluctuations on different time scales [1, 2]. He made it clear that he did not value Lamb’s work and expressed concerns about Mr Lamb’s lack of qualifications as a climatologist. But there was more behind Mason’s dim view of Lambs efforts to glean climate data from historical archives.

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UK Winter 2013/2014 storms

February 17, 2014 2 comments

Figure 1

Figure 1 (click for larger) is showing surface level air movement from weather GCM. The stuck cold air mass over North America is part of a lack of rotation of the polar air mass leading to a stuck Atlantic circulation bringing repeated storms to Northern Europe where the energy is from the ocean circa Caribbean but with a back feed from the coast of Africa. Around and around. The parallel red arrows are showing where cyclone and anti-cyclone meet, to the left there is a sharp merge of three flows, an unstable region, the shear point is where the St Jude’s day storm formed.


Figure 2 (click for 2.3MB animation)


Figure 3 (click for 1.44MB animation)

Two GIF animations, figure 2 for wind including figure 1, figure 3 for rain. Click to open full size and activate.

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Categories: analysis, weather

Met Office reports of day extremes 2013

December 2, 2013 Leave a comment

Over much of 2013 I have been collecting the extremes for a day as reported by the UK Met Office. April up to 1st December.

Example as copied

24 hours ending 2100 on 1 Dec 2013:UK
Highest max 0900-2100 11.7 °C Gt Cumbrae Millport
Lowest max 0900-2100 5.1 °C Okehampton
Lowest min 2100-0900 -4.1 °C Exeter Airport
Highest rainfall 2100-2100 3.2 mm Cluanie Inn
Sunniest 2100-2100 6.8 hours Wittering
Last updated: 2302 on Sun 1 Dec 2013

This might be useful / of interest to a few people so I have processed the information into a flat field spreadsheet form. I considered full Normal form but lets keep things simple, I’ve done the hard part.

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Categories: Datasets, weather

Anders Angstrom: Nocturnal radiation at various altitudes

September 20, 2013 Leave a comment

The curves bring out some interesting facts that deserve special consideration.
For ordinary values of the humidity, the effective radiation has a maximum at 1 to 4 km. altitude. An increase of the humidity or a decrease of the temperature
gradient shifts this maximum to higher altitudes. The effective radiation gradient
is consequently positive at low altitudes and negative at high altitudes. — A. Angstrom

Fig. 14 from paper 100 years ago by Anders Angstrom on LWIR emission. This shows families of curves grouped by two different lapse rates.

Note: This Daedal Earth blog article was rapidly produced to make the PDF available for citation elsewhere. Content may change later.

Sub-extract from Smithsonian Miscellaneous Collections, Volume 65, Number 3, published 1915. is A study of the Radiation of the Atmosphere

Physicist Dr Anders Angstrom was the son of physicist Dr Knut Anstrom (radiation instrument inventor) the son of physicist Dr Anders Angstrom after whom the wavelength unit the Angstrom is named. Confusion is understandable.

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High altitude atmospheric pressure and ozone, south pole

September 12, 2013 Leave a comment


Overlay of south pole satellite measured Ozone and 1 hPa air pressure model. (note: 3 day difference of dates, data availability)

It’s spring in the southern hemisphere, sunlight is starting to buzz the atmosphere as the long night ends. Ozone is always low then.

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Categories: temperature, weather

Collated EUMETSAT European monthly weather videos

September 4, 2013 4 comments


Image from the cold March 2013.

If you are new to these videos expect a revealation, how air moves, clouds stream, bubble.

Clouds are sometimes on seveal levels moving in different directions: we are looking through circulation cells from above, warm air travelling to the Arctic to shed heat and cold air spilling back on it’s journey towards the equator.

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Categories: education, Satellites, weather