Scales for Stormy Space Weather
NOAAs New Richter-Like Scales Predict
Impact of Upcoming Solar Max Space Storms
By Sareen R.
what the National Weather Service forecasts: earth weather.
But how many of us are aware of space weather? You can track
geomagnetic storms, solar flares, and other space weather alerts
on the Space Environment Centers
website but why bother, unless youre an astronaut?
Fact is, space
weather, influenced largely by the sun, affects daily life on earth
far more than most people imagine. Especially during a Solar Maximum,
the peak of every 11-year solar cycle (were in Cycle 23 right
now), solar winds buffeting the earths magnetosphere generate
huge and sometimes very severe geomagnetic storms that can and do
cause power outages, radio and satellite malfunctions, and pager
and cell phone failures. With communications, these days, depending
so heavily on satellites, and the numbers of satellites increasing,
space weather can no longer be considered a concern only for scientists.
the solar max effects, however, has just been improved. The National
Oceanic and Atmospheric Administration (NOAA) has reinvented
the communication of methods used to present data on the effects
of geomagnetic storms, making them far more accessible to the public
and to companies and industries that need the information.
At the Commerce
Department in Washington on November 9, NOAA officials announced
a new set of scales for characterizing the effects of the upcoming
space storms. The various strengths of the storms are rated, G1
for a minor storm, up to G5 for one that is extreme -- much as earthquakes
are measured on the Richter scale. Descriptions of the effects on
power systems, spacecraft, pipelines, radio, etc., accompany each
rating. The NOAA Space Weather Scales also include scales, with
accompanying descriptions of the effects, for radio blackouts (R1,
minor, to R5, extreme), and for solar radiation storms (S1, minor,
to S5, extreme).
All of the
scales are being made available to the general public. And they
are, indeed, easy -- and a little scary -- to read. According to
the S1-S5 scale, for example, an extreme solar radiation storm can
cause radiation doses equivalent to a chest X-ray to passengers
in highflying aircraft at high latitudes, and high radiation hazards
to astronauts working outside a spaceship. But for the first time,
said Dr. D. James Baker, under secretary for oceans and atmosphere
at Commerce, and NOAA administrator, "We can predict the impact
of solar storms." Dr. Baker said that the space storms may
be a real problem in 2001.
upcoming solar maximum, the peak of Solar Cycle 23, scientists believe
there is a potential for public safety problems. Customers for space
weather information in the 50s were mostly people interested in
short-wave radio. Now, say the experts at the Space Environment
Center (run by NOAA and the U. S. Air Force) urgent queries are
increasing concerning weather satellites, GPS navigation, ozone
measurements, aircraft radiation hazards, and of course relays for
commercial TV. Pipelines for gas and oil can be corroded by induced
ground currents reaching hundreds of amps. Radio blackouts would
mean that low-frequency navigation signals used by maritimne and
general aviation systems would experience outages on the sunlit
side of the earth, causing loss in positioning. All of these effects
are brought on by the turbulence far above.
In March, 1989,
during the last solar maximum, major solar flares and the resulting
space storm knocked out the electrical system throughout Quebec
and destroyed a large power transformer in New Jersey. Ten years
ago, computers could not cope quickly enough with scientific observations
to provide alerts. Now that high tech capabilities have vastly increased,
warnings, watches and forecasts can be issued, albeit not so far
in advance as might be hoped. But at least the general public can
be made more aware of the impact on their daily lives as well as
on navigation, power distribution, and radio communications systems.
of sunspots is an indicator of the increasingly turbulent solar
activity which includes the ejection of clouds of hot solar gases
and proton jets, causing gusty solar winds. You can track
the "Sunspot Number" daily; it is being published by NOAA
and is also on a special NASA website, http://www.sunspotcycle.com.
On 9 November, for example, it was 232. It had been only 194 on
1 November. Sunspots, which long ago were thought to be satellites
of the sun, but are known now to be gaseous, have been recorded
since the 17th century, by the early scientists Galileo, Thomas
Harriot, Johannes and David Fabricius, and Christoph Scheiner. (For
some printable images of their 17th century sunspot drawings, go
to the Rice
But -- a cautionary
-- best leave direct sunspot counting and observing to the scientists
who have special equipment: no one should ever look directly
at the sun, or through a telescope, binoculars, or any other viewing
device, as serious retinal damage and blindness can result.
Spot: the Northern Lights
For those who
have never had a chance to view the beautiful Aurora Borealis, which
is usually visible only in the northern latitudes, theres
one small bonus ahead. During the solar maximum, these shimmering
curtains of red and green light in the sky will be visible much
further south. As a matter of fact, the southward tour of the aurorae
is also charted on the NOAA scale: Minor space storm? The aurora
will be visible at high latitudes (60 degrees); moderate, 50 degrees;
strong, as low as mid-latitudes; severe, as low as the tropics,
and -- believe it or not -- during an extreme geomagnetic storm
(G5 on the NOAA scale), the aurora will be seen as low as the equator.
Gerson from the Occupational Safety and Health Administration is
a member of the Federal Communicators
Network. You may write her at Sareen.Gerson@osha-no.osha.gov.