Solar Wind Drop Means More Cosmic Rays

NASA photo showing charged particles bursting from the sun’s surface. Temperatures are 1.8 million degrees Fahrenheit. The blue color enables the human eye to perceive the solar activity’s ultraviolet light.

It sounds like the plot of a sci-fi movie, but it could be serious: The sun’s solar wind is now blowing with less intensity than at any time since the mid-20th Century, exposing Earth to more cosmic rays.

According to an article today on Discovery News:

The sun is presently at the lowest point in its 11-year cycle of sunspot activity, but it's also 20 percent cooler and less windy than the last solar minimum in 1994-95, explained Karine Issautier, the Ulysses radio wave lead investigator at the Observatoire de Paris, Meudon, France. In other words, the sun is showing signs of other, much longer cycles which also affect its power output.

The sun is also hitting an all-time low for its wind speed and pressure, blowing at 25 percent less than at the last solar minimum, Southwest Research Institute's David McComas told Discovery News.

The bubble of charged solar particles that fills the solar system is shrinking, exposing Earth and other planets to the onslaught of needling galactic cosmic rays normally held at bay by the solar wind. Inside Earth's magnetic field the main effect of the cooler, less windy sun is the cooling and lowering of the outermost part of the atmosphere. 

Click here for the Discovery News article.