Terms 

K-index: Used to characterize the magnitude of geomagnetic storms.

G-Scale: The geometric scale

Solar Radiation Storms 

Radio Blackouts 

Electron Flux Alert 


The total number of lines of force passing through the unit area of a surface held perpendicularly. They follow a strong diurnal (daily) cycle due to the geometry of Earth's magnetic field. Maximum values generally occur near local noon locations on the daytime side of the Earth. 


Plaque-forming unit (PFU) is a measure of the number of particles capable of forming plaques per unit volume, such as virus particles. 



MeV- million electron volts 

• 10 MeV Warning: Issued when flux levels above 10 pfu are predicted.

• 10 MeV ALERTS: Issued when flux level exceeding 10, 100, 1,000, 10,000, or 100,000 pfu confirmed.

•  10 MeV Proton Event Summary: Issued when 10 MeV flux levels make a confirmed drop below S-Scale . Includes date/times for begining and end. 

• 100 MeV Flux ALERT: Issued when flux level exceeding 1 pfu.

• 100 MeV Proton Event Summary: Issued when 100 MeV flux level makes confirmed drop below 1 pfu threshold.

World Map with latitude and longitude lines 

ftp://ftp.swpc.noaa.gov/pub/alerts/current_month.html