Cosmic Rays Continue Increasing: Global Cooling Ahead!
Clouds: What cosmic rays help create      Photo Credit: Wikimedia Commons/Fir0002
The latest measurements of cosmic ray intensity in the stratosphere from Spaceweather.com and the students of Earth to Sky Calculus have been made available, and when added to previous measurements, show a continuing increase. The data record so far is shown plotted versus time below. Â Â
Image Credit: spaceweather.com/Earth to Sky Calculus
The instruments making the measurements were carried into the stratosphere by helium balloons launched by the student group. Cosmic ray intensity is plotted in units of microsieverts per hour (uSv/hr), where a microsievert is one millionth of a Sievert, and a Sievert is a derived unit of ionizing radiation dose.
It has long been known that as the sun grows more active, the solar wind from the sun (which is a plasma mostly composed of electrons, protons, and alpha particles) becomes more intense. The more intense it is, the more it blows cosmic rays away from the interior solar system. Cosmic rays are very high energy radiation, composed primarily of protons and atomic nuclei, that originate mostly outside the solar system.
Image Credit: National Aeronautics and Space Administration
Therefore, the less active the sun is, the less intense the solar wind is, and the higher the intensity of cosmic rays that penetrate our atmosphere. The intensely high energy charged particles in the cosmic rays then ionize multiple particulates suspended in the atmosphere, as represented in the figure below.
Image Credit: NASA/Simon Swordy, U. of Chicago
Such ionized particulates then act as nucleation centers that attract water suspended in the atmosphere to form clouds. As I wrote in Clouds and Global Warming, the primary effect of clouds is to reflect both visible and infrared incident radiation back into space. In this way the Earth is cooled by cloud cover generated by incident cosmic rays. This model and the evidence supporting it are described in detail in the posts of the Global Warming theme, and is summarized in the post Global Warming:A Summation.
As you can see from the data on the Solar Activity page, mostly from the decreasing sun spot count over time, the Sun’s activity has been declining since about the year 2000. What you will see on that page are scatter plots of sunspot numbers. These plots show a number of periodic peaks that display the well-known 11 year solar-cycle. However, since roughly the year 2000, the amplitude of the peaks have been declining, and solar activity and solar wind have been declining in intensity. This is consistent with the pause in global warming that has been observed since then. Because of our model we expect cosmic ray intensity to have been continuously increasing in that period. The Spaceweather.com and the Earth to Sky Calculus data shown above is consistent with the model. As long as it shows increases, we can expect the pause and perhaps some global cooling to continue.
From now on I will be including the latest cosmic ray intensity plots in the Solar Activity page.
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