[HQRP] Fwd: New NOAA Solar Storm Scales

[Ed Manuel]

FYI.


>From: Paul Harden <pharden@aoc.nrao.edu>
>Subject: New NOAA Solar Storm Scales
>
>
>Gang,
>Recently, various organizations, most notably the National Oceonographic
>and Atmospheric Administration (NOAA), has adopted a "new" set of scales
>to better communicate to the public the anticipated effects of solar and
>geomagnetic storms.  Actually, there is nothing new about these scales
>at all, they have been around for years and on the NOAA websites, but have
>seldom been used.  As of April 1, 2002, most agencies are now using these
>scales, including NOAA solar alerts and the hourly WWV solar and
>geomagnetic updates.
>
>Here is a synopsis of the new scales.  The complete tables can be
>found at: http://www.sec.noaa.gov/NOAAscales
>
>GEOMAGNETIC STORMS
>==================
>CLASS Kp=   STORM     EFFECTS TO HF PROPAGATION   AURORA
>-------------------------------------------------------------------------
>   G1  Kp=5  Minor     Minor noise & fading        Extreme high latitudes
>   G2  Kp=6  Moderate  Fading at higher latitudes  Aurora US/VE border
>   G3  Kp=7  Strong    Intermittent                From Oregon to Illinois
>   G4  Kp=8  Severe    Very difficult & sporadic   From N. CA to AL
>                       & poss. power grid failures
>   G5  Kp=9  Extreme   Near or total HF blackout   To S. Tex. and Florida
>                       & poss. power grid failures
>-------------------------------------------------------------------------
>
>SOLAR(RADIO) STORMS
>===================
>CLASS FLARE STORM     EFFECTS TO HF PROPAGATION
>-------------------------------------------------------------------------
>   R1  M1    Minor     Weak degradation
>   R2  M5    Moderate  Limited blackouts on sunlit side of Earth
>   R3  X1    Strong    HF blackout on sunlit side; limited elsewhere
>   R4  X10   Severe    Global HF blackout, 24 hour duration
>   R5  X20   Extreme   Global HF blackout, 2-3 day duration
>-------------------------------------------------------------------------
>
>A few definitions:
>Kp = planetary K-index of geomagnetic disturbances.  The K-index is
>      measured every 3 hours and reported on WWV and www.sec.noaa.gov
>      The 24-hour average is called the A-index
>Flare = the approximate size of the solar flare triggering the solar and
>      radio storm.
>
>A reminder ...
>When a major flare occurs, it produces a solar/radio storm immediately
>and will persist from tens of minutes to 2-3 hours.  Then it's over.
>This is from the speed-of-light (relativistic) energy being released by
>the flare event.
>
>If the solar flare is located near the center of the sun and produces a
>CME (Coronal Mass Ejection), the shockwave from the CME will most likely
>hit the earth and trigger a geomagnetic storm.  This shockwave travels
>about 500-1200 km/sec., and takes 2-3 days to reach the earth.  Thus, a
>geomagnetic storm will occur 2-3 days AFTER the flare event, and this
>storm will last hours to a full day in duration.  This shockwave is what
>also triggers aurora.
>
>72, Paul NA5N


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