INCREASING CHANCE OF GEOMAGNETIC STORMS: NOAA forecasters have boosted the odds of geomagnetic storms this week to 75% as a series of CMEs approaches Earth. The action begins on May 15th when the first CME is expected to arrive and could continue through May 17th as additional CMEs follow. Storms levels will almost certainly reach category G1 (minor) with isolated periods of G2 (moderate) storming as well. Auroras could cross the US-Canadian border in the nights ahead. Aurora Alerts: SMS Text.
BE ALERT FOR STEVE! There's more to geomagnetic storms than auroras. Sometimes a completely different phenomenon appears: STEVE. Steve Zhu (no relation) photographed the strange mauve ribbon arcing over Chilliwack BC on May 14th:
"It was so big I had to stitch together three shots to capture the whole thing," says Zhu. "I could see it even in bright moonlight."
STEVE is a hot (3000 degrees C) ribbon of ionized gas slicing through Earth's upper atmosphere some 300 km above the ground. It appears unpredictably during some, but not all, geomagnetic storms. Originally thought to be a type of aurora borealis, new research shows that it is not an aurora at all.
The soft purple color of STEVE may be caused by emissions from nitrogen, according to a new study just published in the Geophysical Research Letters. Its color and narrow ribbon-like structure distinguish it from regular auroras, which tend to be green and wide. Residents of Canada and northern-tier US states should look for STEVE this week after the CMEs hit. Aurora Alerts: SMS Text.
SURPRISE STORM SPARKS AURORAS IN THE USA: A surprise geomagnetic storm erupted during the early hours of May 14th when a crack opened in Earth's magnetic field. Solar wind poured through the gap, igniting auroras over northern-tier US states. Paul Nelson photographed the display from the shore of Lake Superior near Marquette, Michigan:
"The auroras were bright enough to see reflected in the still waters of Lake Superior," says Nelson. "The ISS made a visible pass during the best part of the show, right across and above the Northern Lights."
Auroras were also sighted in Ohio, the Dakotas, and Wyoming.
At its peak, the storm reached category G3--one of the strongest in years. NOAA analysts think the instigating crack may have been opened by an early-arriving CME. If you missed the show, good news: More CMEs are coming. Subscribers to the Space Weather Alert service can receive text messages when the storm clouds arrive. Stay tuned! Aurora Alerts: SMS Text.
COSMIC RAY BALLOON: When CMEs are coming, there's only one thing to do: Launch a cosmic ray balloon. Spaceweather.com and the students of Earth to Sky Calculus launched this one on May 13th:
The balloon carried an array of X-ray/gamma-ray sensors to the stratosphere more than 100,000 feet above Earth's surface. The students have been launching these balloons almost once a week for the past 4 years. They find that cosmic rays are increasing--a trend that might temporarily reverse this week.
CMEs sweep aside cosmic rays, causing atmospheric radiation levels to drop. The phenomenon is called a "Forbush Decrease," named after physicist Scott E. Forbush who first described it. The May 13th launch established a baseline by measuring levels before the CMEs arrived. During- and after-CME launches will take place in the days ahead. Stay tuned for results.
CRYSTAL MOON BALL IN THE STRATOSPHERE: On Star Wars Day ("May the 4th be with you"), the students of Earth to Sky Calculus launched an array of cosmic ray sensors to the stratosphere. They do this every week or so to monitor increasing levels of atmospheric radiation. This crystal Moon ball went along for the ride:
You can have it for $129.95. The students are selling these far-out balls to support their cosmic ray ballooning program.
Each one comes with an LED base that turns the laser-etched crystaline Moon a beautiful shade of purple, blue, green or yellow. It makes a great night light. Also included is a greeting card showing the crystal ball in flight and telling the story of its journey to the edge of space and back again.
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