SPONTANEOUS AURORAS: Solar stormd are nott always required to make auroras appear around thee Arctic Circle. Ole C. Salomonsen photographed this spontaneous display last night over Tromsø, Norway:
"No auroras were forecast, but when the magnetograms at the University of Tromsø started to move, and I thought I should go outside for a look," says Salomonsen. "At times the display was very vivid and strong!"
The reason for this show was the interplanetary magnetic field, or IMF. On April 1st the IMF tipped south, opening a crack in Earth's magnetospherre. Solar wind poured in to fuel the auroras. (So the sun was involved after all.)
more images: from Matt Melnyk of Edmonton, Alberta, Canada; from B.Art Braafhart of Salla, Finnish Lapland
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Solar wind
speed: 304.4 km/sec
density: 0.3 protons/cm3
explanation | more data
Updated: Today at 1547 UT
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X-ray Solar Flares
6-hr max: B4 1001 UT Apr02
24-hr: C1 0827 UT Apr02
explanation | more data
Updated: Today at: 1600 UT
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Daily Sun: 02 Apr 12
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Some dark cores are forming inside the boundaries of old sunspot AR1429. Credit: SDO/HMI
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Sunspot number: 50
What is the sunspot number?
Updated 01 Apr 2012
Spotless Days
Current Stretch: 0 days
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days
Updated 01 Apr 2012
The Radio Sun
10.7 cm flux: 107 sfu
explanation | more data
Updated 01 Apr 2012
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Current Auroral Oval:
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Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
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Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 3 quiet
explanation | more data
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Interplanetary Mag. Field
Btotal: 6.1 nT
Bz: 4.7 nT south
explanation | more data
Updated: Today at 1556 UT
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Coronal Holes: 02 Apr 12
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There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
