INTENSE SOLAR FLARE OBSERVED BY NOAA

April 3, 2001 — NOAA's Space Environment Center in Boulder, Colo., observed an extreme solar flare late Monday afternoon, with an estimated x-ray intensity of X-22, plus or minus 2. X-flares are the highest category of flares possible and are usually measured on a scale from 1 to 20. The flare occurred at 5:52 EDT. According to forecasters at the SEC, a flare of this intensity is off the charts. This is the first time during this solar cycle that a flare with this intensity has been measured. Forecasters had to estimate the intensity at X-22 because sensors on NOAA's GOES satellite that measure these type of events were saturated by the flare at an X-18 level. (Click image from the NASA/European Space Agency SOHO satellite for larger view.)

Extreme radio blackouts on the sunlit side of the Earth have occurred in the Pacific, reaching the R-5 level, which is the top of the NOAA Space Weather Scales. Radio blackouts cause outages in low-frequency communication and navigation signals used by maritime and general aviation users. A solar radiation storm at the S-1 level has already started, and there is a potential for a strong geomagnetic storm in 48 to 72 hours. NOAA space weather forecaster Alex Hilton said that "Even if we get hit by the edge of this storm, it could be quite an event, although it may also be a fairly short-lived event due to the high speed of the Coronal Mass Ejection we observed on the sun." CME's are large explosions on the sun that send billions of tons of highly energized particles towards Earth.

The flare occurred in Region 9393, the active sunspot region that is the largest observed in more than 10 years. That region has been exploding periodically over the last few days.

NOAA's Space Environment Center is the nation's official source of space weather alerts and warnings and continually monitors and forecasts Earth's space environment.

Relevant Web Sites
NOAA's Space Environment Center — Click "Space Weather Now" for the latest information on solar activity.

NOAA's Space Weather Scales

NOAA Space Weather Advisories

Today's Space Weather Forecast — Includes the latest image of the sun from Earth-based telescopes positioned around the world.

Real-time images of the Sun from NASA's SOHO Satellite

SPACE WEATHER - WHAT IS IT AND WHY DO WE WANT TO KNOW ABOUT IT?

NEW NOAA SPACE WEATHER SCALES MAKE SOLAR MAX EFFECTS MORE PREDICTABLE

Media Contact:
Barbara McGehan, NOAA Space Environment Center, Boulder, Colo., at (303) 497-6288

 

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