Climate model predictions, seasonal to decadal.

Posted: September 13, 2015 by Andrew in atmosphere, climate

imageCan climate models predict? A few months ago a lecture given by a senior member of the Met Office, describing where the models are at. What they can do, and more problematically, what they cannot.

Last June Dr Doug Smith of the Met Office gave the Walter Orr Roberts memorial lecture for the Apen Global Change Institute.

The title of the lecture “Seasonal to decadal climate prediction. Filling the gap between weather forecasts and climate projections”.

Begginning, and possibly playing to the crowd, with how humans “could be” tilting the climate Pin Table towards the possibility of more extreme weather. This obviously means that it is now vital to have accurate climate predictions.

Next comes the model based evidence that only GHGs can be the cause of the long term warming trend. However natural variability can cause the trend to wobble. So this variability is where models need to improve.

The main focus is the Atlantic SST variability and its effect on other regions of the northern hemisphere. Then some explanation of model hind and forecasts, with some brief but honest appraisal of their shortcomings, notably that some of the areas of greatest failure are Europe and North America.

As winter forecasts are also an area of difficulty for models he focuses in on the North Atlantic Oscillation (NAO). Looking at the myriad of factors that can influence the strength of the Polar Vortex, which in turn effects the NAO. In 2012 they had no skill at predicting the NAO. In 2014 we have reasonably high skill, however the model is very expensive, ten times more expensive.

The video at this point shows an animation of how the models now can represent ocean currents carrying differing water temperatures across the Atlantic.

With these improvements, the NAO and ENSO 3.4 stand out as the areas of the highest skill, with the rest lagging  behind.

After a forecast for this years El Niño and its impact on the global climate, the lecture finishes on the future of the Atlantic surface temperatures as the overturning circulation is clearly slowing. How this will impact the Sahel and Monsoon rainfall.

See the Lecture video Here

Comments
  1. hunter says:

    One problem is that the CO2 obsession has led to significant definitions of the issue.
    “Seasonal” is by definition weather, not climate. Daily, seasonal and even multi-year events are “weather”.
    I am not trying to parse. Quite the opposite, I want a full and useful conversation.
    That is something certainly not happening these past few years.
    Perhaps defining the terms of the discussion in clear objective ways would help enable a more productive conversation.
    Can anyone provide a clear definition of “climate” that is not circular or self-referential?

  2. linneamogren says:

    @Hunter

    Seems the AGW side believe or want to believe “seasonal extremes” are caused by increased C02. I agree, winter is influenced due to the earths axis thus weather conditions react. Is it climate? Well, southern Europe will be warmer and northern Europe cooler and when adding “C02 influence” they claim this to cause extremes. But is it climate? Good point.

  3. tchannon says:

    Climate:- the weather history of a place

  4. michael hart says:

    Haven’t had time to watch the whole video yet, but their short term forecasts seem to have converged to ‘best’ in 2004, and got worse since. Hmmm…🙂

  5. oosorio456 says:

    Climate change is a real issue in Western Hemisphere. it’s time to discuss this topic along with tax cuts and start thinking about it

  6. hunter says: September 13, 2015 at 8:32 pm

    “Can anyone provide a clear definition of “climate” that is not circular or self-referential?”

    Climate is a term used by realtors to close a sale!🙂

  7. Bryan says:

    So it seems that Ocean water perturbations mix the total water volume to a considerable extent.
    Ocean and sea water surface is 70% of total planet surface area.
    Assuming constant solar heating with conservative planetary heat losses factored in
    Its a simple calculation therefore to calculate the time taken to raise the water temperature volume by even one Kelvin unit.
    It takes thousands of years.
    The massive heat inertia of the Oceans shows that the CO2 driven global warming scare is pure fantasy.

  8. Doug Smith is the first author of the notorious 2007 paper that claimed there would be 0.3 degrees of warming from 2004-2014!
    Did he discuss the spectacular failure of his own prediction in his talk?

  9. oldbrew says:

    Everyone knows which way the Met Office winds are blowing…

    ‘The AVOID2 programme on avoiding ‘dangerous’ climate change’
    http://www.metoffice.gov.uk/climate-guide/science/uk/avoid

    ‘AVOID2 is a consortium comprising the Met Office, Grantham Institute at Imperial College, the Tyndall Centre for Climate Change Research, and the Walker Institute for Climate System Research.’

    (The Tyndall Centre was one of the 28 in the BBC’s ‘Twentyeightgate’ FOI legal case fiasco)

    Sample from the link: ‘Work Package A’

    ‘This Work Package is led by the Met Office and examines the link between emissions pathways and climate outcomes. This Work Package focuses on the feasibility of limiting climate change to a range of global average near surface warming levels ranging from 1.5°C to 4°C over this century.’

    Note: ‘This Work Package focuses on the feasibility of limiting climate change’

    Wasn’t the Met Office supposed to be a forecasting service? They should stick to 3-5 day forecasts IMO.

  10. hunter says:

    @oosorio456 says,
    Please define what you mean by a “real issue in the Western Hemisphere” a bit better. And do tell us what tax cuts are going to do about the real issue you are concerned with.

  11. ren says:

    SHOCK WEATHER WARNING: Coldest winter for 50 YEARS set to bring MONTHS of heavy snow to UK.
    http://www.express.co.uk/news/nature/604619/Long-range-weather-forecast-Britain-cold-winter-2015-arctic-snow-freeze

  12. ren says:

    New perspectives for long-term climate predictions?
    Long-term climate variability in the Northern Hemisphere linked to solar variations

    15. September 2015 / Kiel. The natural, 11-year cycle of solar activity is apparently influencing long-term climate fluctuations in the Northern Hemisphere. An international team of scientists led by GEOMAR Helmholtz Centre for Ocean Research Kiel showed that the so-called North Atlantic Oscillation, one of the dominant circulation patterns on the Northern Hemisphere, is phased-locked to the decadal solar activity with a delay of one or two years. The study appears today in the international journal Nature Communications.
    http://www.geomar.de/en/news/article/bessere-langfristprognosen-moeglich/

  13. catweazle666 says:

    Anyone who claims that a computer game simulation of an effectively infinitely large open-ended non-linear feedback-driven (where we don’t know all the feedbacks, and even the ones we do know, we are unsure of the signs of some critical ones) chaotic system – hence subject to inter alia extreme sensitivity to initial conditions – is capable of making meaningful predictions over any significant time period is either a charlatan or a computer salesman.

    Ironically, the first person to point this out was Edward Lorenz – a climate scientist.

    You can add as much computing power as you like, the result is purely to produce the wrong answer faster.

  14. oldbrew says:

    catweazle: it wouldn’t be realistic to expect accuracy from climate models any time soon.

    But the fact that they all seem to err on the side of too much warming – i.e. in excess of the observations – is more than a bit suspicious:/