The Sun Has Gone Quiet

Details at theSI Weather, where I have selected a segment which may be of interest blog readers.

solar-stuff-gifConsequences of a weak solar cycle

First, the weak solar cycle has resulted in rather benign “space weather” in recent times with generally weaker-than-normal geomagnetic storms. By all Earth-based measures of geomagnetic and geoeffective solar activity, this cycle has been extremely quiet. However, there is some evidence that most large events such as strong solar flares and significant geomagnetic storms tend to occur in the declining phase of the solar cycle. In other words, there is still a chance for significant solar activity in the months and years ahead.

Second, it is pretty well understood that solar activity has a direct impact on temperatures at very high altitudes in a part of the Earth’s atmosphere called the thermosphere. This is the biggest layer of the Earth’s atmosphere which lies directly above the mesosphere and below the exosphere. Thermospheric temperatures increase with altitude due to absorption of highly energetic solar radiation and are highly dependent on solar activity.

Finally, if history is a guide, it is safe to say that weak solar activity for a prolonged period of time can have a negative impact on global temperatures in the troposphere which is the bottom-most layer of Earth’s atmosphere – and where we all live. There have been two notable historical periods with decades-long episodes of low solar activity. The first period is known as the “Maunder Minimum”, named after the solar astronomer Edward Maunder, and it lasted from around 1645 to 1715. The second one is referred to as the “Dalton Minimum”, named for the English meteorologist John Dalton, and it lasted from about 1790 to 1830. Both of these historical periods coincided with below-normal global temperatures in an era now referred to by many as the “Little Ice Age”. In addition, research studies in just the past couple of decades have found a complicated relationship between solar activity, cosmic rays, and clouds on Earth. This research suggests that in times of low solar activity where solar winds are typically weak; more cosmic rays reach the Earth’s atmosphere which, in turn, has been found to lead to an increase in certain types of clouds that can act to cool the Earth.

5 thoughts on “The Sun Has Gone Quiet

  1. Russ Steele July 21, 2014 / 7:23 am

    Reblogged this on Sierra Foothill Commentary and commented:

    This is cross posted from the Next Grand Minimum. A quiet sun has historically resulted in cooler temperatures on the Planet. Un fortunately cooler temperatures have also brought long term droughts to the Southwest US. The global warming pause maybe mu,ch longer then the current 17 years.

  2. Professor Xavier LaMBSBOTTLE July 21, 2014 / 7:36 am

    Yes, the sun is quiet and will remain so for an extended period. Unfortunately the warming will continue coupled with erratic weather. Climates due not turn on a dime. Sea level will rise by 25 feet by 2040, which will spell the end of modern civilization. Sorry about that, but you did it to yourselves.

  3. Dave Cranfield July 21, 2014 / 3:20 pm

    On the down side of low solar activity is amateur radio. This past weekend I was in a 6 meter CW contest. This low solar activity resulted in me making a paltry 11 contacts. 10 in California and one in Kentucky. The latter being a sporadic bounce off the E layer of the atmosphere.

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