Michele Casati: Stratospheric Warming events and Solar Cycles

Posted: January 2, 2013 by tchannon in Astrophysics, atmosphere, climate, Solar physics, weather


Michele kindly sent me a link to a new article on his Italian language blog, article entitled “Il collegamento fra i Mayor Midwinter stratospheric warming e il ciclo solare”


Google translation (new link, for Bing translate see menu at top of page here)

SST are fascinating entities of considerable importance. Erl Happ has written about these on a number of occasions.

  1. Verity Jones says:

    The full paper discussed by the linked article is in English, other than a bilingual abstract: http://strat-www.met.fu-berlin.de/labitzke/moreqbo/MZ-Labitzke-et-al-2006.pdf

  2. Back in time…
    An example disorder

    Transition solar cycle SC18-19
    Italy big cold !

    January-February 1956
    Jump SF a 250-300
    disorder vortex

    [mod: above image http://modeles.meteociel.fr/modeles/reana/1956/archivesnh-1956-2-1-12-0.png ]


  3. Stephen Wilde says:

    I consider the observed effects of such events at the surface to be an indication that we need to see a warmer stratosphere at a time of inactive sun and a cooler stratosphere at a time of active sun in order to achieve the observed atmospheric response.

    It is becoming clearer that more meridional jets need a warmer stratosphere and meridionality increases when the sun is less active.

  4. Stephen Wilde says:

    “Here we extend our first study (Labitzke 1987) by using additional data.
    Instead of 30 years of data, we now have 65 years. Results for the entire
    data set fully conirm the early findings and suggest a significant effect of
    the SSC on the strength of the stratospheric polar vortex and the mean
    meridional circulation.”

    Interesting that this has been going on in the background yet Leif Svalgaard completely ignores it.

    I have been saying just this for a few years now without knowing of this research.

    I think one can go a step further by proposing that the circulation changes then affect climate zone positions, jet stream meridionality, global cloudiness and the amount of energy entering the oceans to fuel the climate system.

  5. Paul Vaughan says:

    Stephen Wilde, the aggregate generalization depends on time of year:

    As you can clearly see, departures from normal do the opposite thing at different times of the year. Maybe have a look at some of Harry van Loon’s work on the semi-annual oscillation to work towards wrapping your thinking around this. He has done some very, very tedious work. If you would like links to some of his papers, let me know. Climatologists have superior awareness of Earth’s circulation; whatever Svalgaard may know about the sun, he simply does not have a handle on terrestrial circulation and the statistics of aggregation in the presence of globally constrained turbulence.

    Thanks for sharing stimulating material Michele!

  6. adolfogiurfa says:

    We have shown in earlier studies the size of the changes in the lower stratosphere which can be attributed to the 11-year sunspot cycle (SSC). We showed further that in order to detect the solar signal it is necessary to group the data according to the phase of the Quasi-Biennial Oscillation (QBO). Although this is valid throughout the year it was always obvious that the effect of the SSC and the QBO on the stratosphere was largest during the northern winters (January/February).
    Here we extend our first study (Labitzke 1987) by using additional data. Instead of 30 years of data, we now have 65 years. Results for the entire data set fully confirm the early findings and suggest a significant effect of the SSC on the strenght of the stratospheric polar vortex and the mean meridional circulation.

    This reminds me Birkeland´s “Terrella experiments and William Gilbert’s terrella´s ( a very obvious electrical interaction):

  7. Stephen Wilde says:


    Thanks for that. I accept the annual variations but am more interested on net variability over decades and centuries.

  8. Paul Vaughan says:

    When there is differential change in annual cycles between 2 locations (e.g. continents & oceans), that affects gradients and hence flows (including jet streams & circumpolar currents).

    There’s no avoiding the semi-annual & annual variations if decadal and longer timescale variations are to be understood. (For example, see van Loon’s work on the southern hemisphere.)

    The advantage of looking at clusters of annual & semi-annual spikes is that this makes it possible to see right past ENSO, something which cannot be done with plain averages.

    (The northern hemisphere may seem a good deal more simple. I suspect that may be where Stephen’s attention is focused.)

    For readers interested in how circulation changes when annual cycles change differentially in adjacent areas, here are a few papers with which to ease into the subject:

    Meehl, G.A.; Hurrell, J.W.; & van Loon, H. (1998). A modulation of the mechanism of the semiannual oscillation in the southern hemisphere. Tellus 50A, 442-450.

    Chen, G.; Qian, C.; Zhang, C. (2012). New insights into annual and semiannual cycles of sea level pressure. Monthly Weather Review 140, 1347-1355.

    (Tip: There’s a connection with geomagnetic aa index & sunspot numbers.)


  9. A new stratospheric warming event in the 2014 ?

  10. tchannon says:

    384 hours is at the limit. Need to keep watch.

  11. @ tim

    Yes Tim, but you observe the trend 200hours to 300hours.
    We must see next days

  12. Wrestling mania for stratospheric vortex