M1.6 solar flare erupted at western limb

M1.6 solar flare erupted at western limb

Impulsive M1.6 solar flare erupted from the Active Region 1692 on western limb. Moderate event started at 21:58 UTC and reached peak of M1.6 at 22:04 UTC.

SDO's EVE soft X-ray monitor on the left and SWPC's X-ray flux monitor on the right show M-class signature (Credit: NOAA/SWPC/SDO)

Active sunspots on western limb seen by SDO's HMI Intensitygram on March 21, 2013 (Credit: SDO/The Watchers)


Active Region 1692 erupted earlier on March 21, 2013, at 18:22 UTC with C3 solar flare. Solar flare activity has been low to moderate and was expected to decline as sunspot groups started to disappear behind the western limb of the sun. NOAA/SWPC forecasters estimated only 10% chances for M-class event today.

The solar wind speed was moderate and geomagnetic conditions reached unsettled levels. High-frequency radio communications are presently at normal background. NOAA/SWPC issued R1 or Minor Radio Blackout warning. Short-wave radio fadeouts are possible in the coming hours.

SDO's combined AIA 094, 335, 193 show some activity at western limb at 21:43 UTC on March 21, 2013 (Credit: SDO)

SDO's AIA 304 shows activity at 22:00 UTC on March 21, 2013 (Credit: SDO)

Current conditions

Solar wind
speed: 411.3 km/sec
density: 1.0 protons/cm3

Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 4 unsettled

Interplanetary Mag. Field
Btotal6.4 nT
Bz5.5 nT north


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