A typical British summer in the making

Monday 10 June 2013, 16:05

Paul Hudson Paul Hudson

An expected return to more changeable weather through this week reminded me of the work of one of our best known and most respected climatologists Professor Hubert Lamb.

 

Professor Lamb is credited with discovering an empirical relationship between low solar activity and an increased probability of higher pressure in winter across more northern latitudes – which leads to colder winters across the UK and Europe.

 

Another part of his work was to analyse weather patterns over 100 years to try and see if any repeat themselves across the UK, with some success.

 

One of his main findings was a change of pattern from around the middle of June, which, in his words, saw the ‘return of the westerlies’.

 

By looking at climate data he discovered, more often than not, the Atlantic would re-assert itself around or just after mid-June, bringing changeable weather once more across our shores.

 

This would follow a period when westerly winds were at their weakest.

 

Climatologically this period is now called the ‘European monsoon’ as areas of low pressure move in from the west.

If the jet stream is behaving normally, this would mean wettest conditions in the north and west, with the least rainfall in the south and east.

 

Most of the time, but not always and hence the difficulty of using this as a long range forecasting tool, this changeable spell of weather would last well into July.

 

Lamb then discovered a second period in the climate records which tended to assert itself from mid to late July, which he called ‘thundery and cyclonic’ – in other words, less windy, warmer but with a risk of heavy showers.

 

This type of weather would then last well into August.

 

Lamb’s work effectively describes a typical British summer; one in which long spells of fine settled weather are the exception rather than the rule.

 

Although it’s early days, there are already indications that this summer is starting to resemble one of Professor Lamb’s typical British summers.

 

Comments

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  • rate this
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    Comment number 1.

    drove up to Scotland on Saturday. weather was beautiful all the way but as we arrived it started to rain. temperature now about 12c. as you say Paul typical British summer

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    Comment number 2.

    What is the explanation of why the westerlies go away in late spring though?

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    Comment number 3.

    I'VE BEEN SAT IN THE SUN THIS LAST WEEK ON AND OFF AND HAVE NOTICED AS IN PREVIOUS YEARS THAT WHEN THE SUN GET COVERED WITH A CLOUD THE WIND GUSTS MORE.WHEN THE CLOUD PASSES THE WIND DROPS. I'VE BEEN MEANING TO ASK WHY THIS IS FOR AGES! WHATS THE REASON FOR IT PLEASE PAUL?

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    Comment number 4.

    All of Lambs books are still well worth reading if you can get hold of them.

    Off thread, but worth bringing to your attention, the presentation by Prof. Murray Salby on the relationship between temperature and CO2 is now available here:

    http://www.youtube.com/watch?v=2ROw_cDKwc0

    Only the intro in German!

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    Comment number 5.

    Keithb - your question about cloud and breeze. This is most likely due to the fact when passing clouds block the sun, solar radiation reduces temporarily and the ground cools slightly, so across a given area of country you have ground surfaces with different temperatures - some surfaces that are generating upward current of air as pockets of warm air rise from sunny areas and some that aren't because they are temporarily under cloud. I suspect that it is these differences that are generating the breezes.

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    Comment number 6.

    Hubert Lamb (1913-97) wrote this work in 1950. Unlike his later research, this article in the Quarterly Journal of the Royal Met Soc was highly subjective and empirical, not the be followed literally as a sequence of events that will happen year-in, year-out. He found his niche when he founded the University of East Anglia Climatic Research Unit in 1971. I was privileged to attend a Royal Met Soc lecture by him at Lincoln in 1979 or 1980, entitled: "Are the activities of man influencing the earth's climate?" or words to that effect. He convinced me that they were. More than 30 years later his foresight is continually confirmed.

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    Comment number 7.

    Re thesnowman. How can anyone believe there is a causal link between CO2 and temperature after seeing Prof. Salby's work? It completely refutes the UK's energy policy!

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    Comment number 8.

    I'm reasonably convinced that mankind is having an influence on climate. Primarily at a regional level but possibly and subsequently, at the global level. However, I'm not at all convinced it has anything to do with CO2.

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    Comment number 9.

    the work of one of our best known and most respected climatologists Professor Hubert Lamb.

    Paul

    He is the ONLY climatologist that I respect. At least he was totally honest.

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    Comment number 10.

    "He convinced me that they were. More than 30 years later his foresight is continually confirmed."

    In the books by Lamb that I have read "convinced " would not be accurate. He was never "convinced ". He always appeared to have reservations based on his acceptance that he did not know everything about how the climate system worked.

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    Comment number 11.

    #3.keithb

    "I'VE BEEN SAT IN THE SUN THIS LAST WEEK ON AND OFF AND HAVE NOTICED AS IN PREVIOUS YEARS THAT WHEN THE SUN GET COVERED WITH A CLOUD THE WIND GUSTS MORE.WHEN THE CLOUD PASSES THE WIND DROPS. I'VE BEEN MEANING TO ASK WHY THIS IS FOR AGES! WHATS THE REASON FOR IT PLEASE PAUL?"

    Unfortunately Paul Hudson doesn't normally answer specific questions in this blog. I don't claim to be an expert on weather, but I don't think that it is the cloud covering the sun which is affecting the wind. Rather the arrival of cloud and changes in wind speed are caused by the same thing, i.e. the passage of a weather front.
    When a weather front passes by, warm air is forced over colder air, causing the formation of cloud, precipitation and gusty winds.
    I await correction by someone more knowledgeable.
    If you google "weather fronts", you will get lots of references but here is the Wikipedia entry:
    http://en.wikipedia.org/wiki/Weather_front

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    Comment number 12.

    #6.4caster

    "I was privileged to attend a Royal Met Soc lecture by him at Lincoln in 1979 or 1980, entitled: "Are the activities of man influencing the earth's climate?" or words to that effect. He convinced me that they were. More than 30 years later his foresight is continually confirmed."

    What is it which convinced you at the time and now, that man's activities are influencing the climate?

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    Comment number 13.

    4. thesnowman

    Murry Salby's hypothesis appears to be that temperatures always drive CO2, and never vice versa. If this is the case, and if the MWP was as warm globally as it is today, then why didn't we see a similar spike in global CO2 levels during and after the MWP?

    According to the Law Dome ice core data, there was only a very modest overall rise in CO2 between 950 and 1350 CE There where also periods during which atmospheric CO2 declined within that time span. There are also previous phases within the past few hundred thousand years where global temperatures have been warmer than today, yet atmospheric CO2 has always, until recently, remained below 300ppm. Also, if the globe has now been cooling for 'x' number of years, as some maintain, why have atmospheric CO2 levels just reached a new record high (for the past few million years anyway) of ~400ppm?

    No one is suggesting that temperatures should rise in lock-step with increasing CO2 concentrations; at least no climate scientist is. For a start there is the thermal lag of the oceans; also the short term influence of natural variation, especially ENSO (which can be positive or negative).

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    Comment number 14.

    To "newdwr" at 13.
    You did not then see the part of the Salby presentation that explained why they think that the ice core proxy record of CO2 concentration was a factor of as much as 10 to 15 times less than reality.
    The Salby hypothesis, as you put it, was not only that temperature drives CO2, but that there is a natural and not a man-made signature to CO2 variation both in the proxy and the observed record. He finds the IPCC arguments, not just improbable, but "impossible".

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    Comment number 15.

    My daughter lives in central Spain where, she reports, it is cooler and wetter than normal, so a general cooling seems on the cards. The UK's temperatures are regulated by the Atlantic which is cooler than normal (Whatever that is).

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    Comment number 16.

    #14 Fudsdad,
    As the ice sheets age they become compressed by new snow annually. Entrapped gasses get squeezed out so the oldest ice shows a proxy low for real time CO2 concentrations at that age.
    If Saltby's arguments apply to CO2 then they also apply to other so called GHG's. The problem with his arguments is that his summing up showed the same model as the AR4 K&T flat earth abortion. He then continued to apply a quarter of total insolation to the whole earth thus making the error of earth being flat with 24/7 sunlight. Use of reality correctly puts 100% of flux over 10% of area and averages the rest over the hemisphere giving an average, outside the zenith position of 500W/m2. With reality figures the GHE is unnecessary as is Saltby's explanations.

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    Comment number 17.

    # 16 John Marshall,
    Thanks, but I wish I could say that I understand your criticism of Salby re the energy budget.
    What I took from a very technical presentation was that he demolished the case for man-made global warming through CO2. I simply cannot understand how this work can be out there, so to speak, without a detailed refutation from someone who represents the consensus position.

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    Comment number 18.

    @ newdwr54

    As Fudsdad has pointed out, Salby has an issue with the proxy record which he feels invalidates climate models which arguably are showing increasing variance with real world experience, therefore calling into question the theory of CO2 based AGW. My reading of Lamb is that he would have taken a similar sceptical view as to the validity of climate models had he been around today. I was also under the impression that he had become increasingly disillusioned with the direction that CRU had begun to take in the late 1990's.

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    Comment number 19.

    14. Fudsdad

    "You did not then see the part of the Salby presentation that explained why they think that the ice core proxy record of CO2 concentration was a factor of as much as 10 to 15 times less than reality."

    What observational evidence did he present to support his conclusion? I'm not aware of any study, either by Salby or anyone else, that is considered to seriously challenge the validity of the ice core CO2 record, which is obtained independently from several sites globally, including from both hemispheres.

    "The Salby hypothesis, as you put it, was not only that temperature drives CO2, but that there is a natural and not a man-made signature to CO2 variation both in the proxy and the observed record."

    No one doubts that there is a natural and long term carbon cycle and that atmospheric concentrations fluctuate over time due to volcanism, weathering of silicates, etc. The view that temperatures always drive CO2 levels, and that on average there has been a 10 month lag between rising temperature and rising CO2 of the past 50 years is contradicted by the observation that global CO2 levels have increased over the past 10 years, whereas global temperatures have fallen slightly.

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    Comment number 20.

    @newdwr54

    I would urge you to watch the presentation: Salby is the real deal - an actual atmospheric physicist of some standing. You will be pleased to know that he covers both of the points you raise. It is quite a technical talk (and he is presenting in rather deliberate English to a German audience) but he has an impressively cogent argument that has yet to be refuted.

 

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Hello, I’m Paul Hudson, weather presenter and climate correspondent for BBC Look North in Yorkshire and Lincolnshire. 

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I worked as a forecaster with the Met Office for nearly 15 years locally and at the international unit, after graduating with first class honours in Geophysics and Planetary physics at the University of Newcastle upon Tyne in 1992. I then joined the BBC in October 2007, where I divide my time between forecasting and reporting on stories about climate change and its implications for people's everyday lives.

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