Solar System Slammed by Unprecedented Cosmic Rays

Earth and the solar system are experiencing a bombardment of cosmic rays higher than ever recorded. This unprecedented onslaught of high energy cosmic particles is allowed to happen by the weakening sun. Since cosmic rays seed cloud formation in Earth's atmosphere, climatic cooling can be anticipated over this period of weak sun.

"In 2009, cosmic ray intensities have increased 19% beyond anything we've seen in the past 50 years," says Richard Mewaldt of Caltech.

...The cause of the surge is solar minimum, a deep lull in solar activity that began around 2007 and continues today. Researchers have long known that cosmic rays go up when solar activity goes down. Right now solar activity is as weak as it has been in modern times, setting the stage for what Mewaldt calls "a perfect storm of cosmic rays."..."We're experiencing the deepest solar minimum in nearly a century," says Dean Pesnell of the Goddard Space Flight Center...

Galactic cosmic rays come from outside the solar system. They are subatomic particles--mainly protons but also some heavy nuclei--accelerated to almost light speed by distant supernova explosions....The sun's magnetic field is our first line of defense against these highly-charged, energetic particles. The entire solar system from Mercury to Pluto and beyond is surrounded by a bubble of solar magnetism called "the heliosphere." It springs from the sun's inner magnetic dynamo and is inflated to gargantuan proportions by the solar wind. When a cosmic ray tries to enter the solar system, it must fight through the heliosphere's outer layers; and if it makes it inside, there is a thicket of magnetic fields waiting to scatter and deflect the intruder.

"At times of low solar activity, this natural shielding is weakened, and more cosmic rays are able to reach the inner solar system," explains Pesnell. _SD

Henrik Svensmark and colleagues continue to elaborate the connection between cosmic rays and cloud formation in Earth's atmosphere.

Other connections between cyclic solar activity and Earth's climate are likely. As the infant science of climatology matures into a form that will finally deserve the respect of scientists, we will learn more of the myriad factors that play into cyclic climate activity.