Topband: VANISHING SUNSPOTS (http://spaceweather.com/)

Bill Tippett btippett at alum.mit.edu
Sun Jun 5 08:47:12 EDT 2016


Something interesting is happening on the sun. Yesterday, June 3rd, the
sunspot number dropped to 0, and the solar disk is still blank on June 5th.
Latest images from NASA's Solar Dynamics Observatory reveal no significant
dark cores.

What does this mean? The solar cycle is like a pendulum, swinging back and
forth between periods of high and low sunspot number every 11 years.
Today's blank sun is a sign that the pendulum is swinging toward low
sunspot numbers. In other words, Solar Minimum is coming.

The spotless state of today's sun is just temporary. Underneath the visible
surface of the sun, the solar dynamo is still churning out knots of
magnetism that will soon bob to the surface to make new sunspots. The
current solar cycle is not finished. It is, however, rapidly waning
<http://www.swpc.noaa.gov/products/solar-cycle-progression>.

http://www.swpc.noaa.gov/products/solar-cycle-progression

Forecasters expect the next Solar Minimum to arrive in 2019-2020. Between
now and then, there will be lots of spotless suns. At first, the blank
stretches will be measured in days; later in weeks and months. Don't expect
space weather to grow quiet, however. Solar Minimum brings many interesting
changes. For instance, as the extreme ultraviolet output of the sun
decreases, the upper atmosphere of Earth cools and collapses. This allows
space junk to accumulate around our planet. Also, the heliosphere shrinks,
bringing interstellar space closer to Earth. Galactic cosmic rays penetrate
the inner solar system with relative ease. Indeed, a cosmic ray surge
<http://news.spaceweather.com/cosmic-rays-continue-to-intensify-feb-2016/> is
already underway. Goodbye sunspots, hello deep-space radiation!

http://news.spaceweather.com/cosmic-rays-continue-to-intensify-feb-2016/


More information about the Topband mailing list