What
is "space weather", and why should I care?
The
term "space weather" was coined to describe conditions in outer
space. Just like "atmospheric weather" that we experience every
day, space weather is driven by the Sun. The most visible space weather
effect is the aurora borealis, also known as the Northern Lights.
Space
weather occurs because the Sun is a magnetically-variable star and, for
planets with atmospheres or magnetic fields, the variable Sun can have
profound effects. Since Earth has both an atmosphere and a magnetic field,
we experience many space weather effects, even on the ground.
Most
people have heard about "solar flares" which is one of the more
violent ways the Sun varies as magnetic energy is transformed into heat
and energized atomic particles. But the Sun also blows off plasma and
strong magnetic fields into the heliosphere. When Earth runs into one
of these magnetic fields, then a geomagnetic storm can occur.
Solar
flares...geomagnetic storms...so what, and who cares?!
Do
you ever use electricity? Have you ever flown in a jet airplane? Do you
watch television? Do you use a telephone? Does anyone you know rely on
GPS (Global Positioning System)? The societal infrastructure that we all
expect to be there 24x7 -- power systems, as well as our communication
and navigation systems, can be temporarily put out of commission by space
weather storms.
In
upcoming months we will explore some space weather causes and effects
through this Q & A column, so be on the lookout. In the meantime,
one of the web sites with information about space weather is:
http://spaceweather.com/
In
the United States, NOAA is the official agency in charge of making space
weather forecasts. You can see the present space weather conditions at
their web site:
http://www.sec.noaa.gov/
This
week's question comes from Dr. Chris St. Cyr. Dr.
St. Cyr is a researcher in the Solar Physics Branch, and
he is the Senior Project Scientist for NASA's Living With a Star Program.
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