Thursday, October 30, 2014

Comment on Mcleans Paper " Late Twentieth-Century Warming and Variations in Cloud Cover"

This comment was posted on WUWT on10/30/14

The post and cooling forecast at
has this to say about the sun and climate.
"NOTE!!  The connection between solar "activity" and climate is poorly understood and highly controversial. Solar "activity" encompasses changes in solar magnetic field strength, IMF, CRF, TSI, EUV, solar wind density and velocity, CMEs, proton events etc. The idea of using the neutron count and the 10Be record as the most useful proxy for changing solar activity and temperature forecasting is agnostic as to the  physical mechanisms involved.
Having said that, however, it is reasonable to suggest that the three main solar activity related climate drivers are:
a) the changing GCR flux - via the changes in cloud cover and natural aerosols (optical depth)
b) the changing EUV radiation - top down effects via the Ozone layer
 c) the changing TSI - especially on millennial and centennial scales.
 The effect on climate of the combination of these solar drivers will vary non-linearly depending on the particular phases of the eccentricity, obliquity and precession orbital cycles at any particular time.
 Of particular interest is whether the perihelion of the precession falls in the northern or southern summer at times of higher or lower obliquity."
I am gratified to note that the McLean paper provides strong support for a) above. Closer investigation into the exact processes involved in the solar magnetic field strength -GCR -cloud connection should prove fruitful.
It highly significant that the sharp decline  in the 0-30 N and 0-30 S cloud cover (Fig 10) ends at about the same time as global warming stops.
It is also of interest to note the almost coincident drop to what looks like a new baseline in the Magnetic Plage Strength Index.see p34 in Leif Svalgaard's
1610  Solar-Activity-Past-Present-and-Future.ppt (TIEMS Conference, Oslo, Norway, 2012) pdf pdf with notes
The McLean paper is at


  1. The cause of global cloudiness changes appears to be an opposite sign ozone response to solar variations in the mesosphere as compared to the response in the stratosphere.

    The mesosphere response then descends through the true polar vortex (not the circumpolar vortex)which is a column of descending air in the stratosphere above each pole which brings the mesosphere ozone response down into the stratosphere and alters tropopause heights above the poles.

    A quiet sun increases ozone in the mesosphere, warms the stratosphere above the poles and forces tropopause height down above the poles.

    It is the fall in tropopause height above the poles when the sun is quiet that pushes polar air outweards in a negative AO and AAO to make the climate zones shift equatorward and cause more meridional jets.

    That in turn changes global cloudiness which affects the proportion of solar energy entering the oceans to drive the climate system.

  2. Stephen - sounds very plausible - thanks for the comment Norman

  3. The models are wrong because of the initial assumption that without GH gases the troposphere would have been isothermal. We know this assumption is made because we know the 255K temperature is at about 5Km altitude, and yet they say the surface would have been the same 255K. From there they get their sensitivity by assuming water vapor makes rain forests about 30 to 40 degrees hotter than dry regions and carbon dioxide adds a bit of warming also. In fact none of that happens.

    The assumption regarding isothermal conditions is inherently applying the Clausius "hot to cold" statement which is just a corollary of the Second Law which only applies in a horizontal plane. That we know because it is clearly specified (as here) that the entropy equation is derived by assuming that changes in molecular gravitational potential energy can be ignored. It is those changes which actually cause the temperature gradient to evolve, so we must always remember that sensible heat transfers are not always from warmer to cooler regions in a vertical plane in a gravitational field
    So they cannot prove that the Clausius statement they use to get their assumed isothermal conditions is correct in a vertical column of a planet's troposphere, and so they cannot prove the fundamental building block upon which they built the GH conjecture.

    Any questions are probably already answered here: