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Solar Maximum
Every
11 years the sun undergoes a period of activity called the "solar
maximum", followed by a period of quiet called the "solar
minimum". During the solar maximum there are many sunspots, solar flares,
and coronal mass ejections, all of which can affect communications and weather
here on Earth.
Solar
maximum or solar max is the period of greatest solar activity in the solar cycle
of the sun. During solar maximum, sunspots appear. Solar maximum is contrasted
with solar minimum. Solar maximum is the period when the suns magnetic field
lines are the most distorted due to the magnetic field on the solar equator
rotating at a slightly faster pace than at the solar poles. The sun takes about
11 years to go from one solar maximum to another and 22 years to complete a full
cycle (where the magnetic charge on the poles is the same).
The Sun, a roiling ball of
plasma, occupies its place in space approximately 93 million miles from Earth.
Though it seems simple to inhabitants of this planet -- the Sun shines, giving
light and heat -- the processes occurring in the Sun are so complex that many
scientists devote their careers to just one aspect of solar activity.
Changes in the activity of the
Sun particularly engage solar scientists. Whether fluctuations in the solar
magnetic field, expulsions of plasma called coronal mass ejections, emissions of
high-energy flares, or changes in the sunspot number, variations in solar
activity can be dramatic and therefore highly interesting.
Through careful study of solar
activity (particularly sunspots, visible from Earth through telescopes) over
hundreds of years, scientists have found a consistent cycle of activity: every
eleven years, activity rises to a maximum, then falls to a minimum. To track the
solar cycle, scientists plot the average of Wolf numbers (values from a method
of counting sunspots devised by Johann Rudolf Wolf in 1848) from various
observatories daily to get a sunspot number graph.
The sunspot or solar cycle does
not have the same magnitude every eleven years, however. Entire cycles can have
lower activity levels than usual, as during the Maunder Minimum from 1645 to
1700, or the upcoming maximum might have more activity than ever.
First official sunspot
belonging to the new Solar Cycle 24
Credit:
NASA , European Space Agency |
