M3 solar flare took place on Sun’s western limb

This morning at 1145 UT, an active region on the sun’s western limb unleashed an M3-class solar flare. NASA’s Solar Dynamics Observatory recorded the flash of extreme UV radiation:

Although the blast site was not directly facing Earth, radiation from the explosion nevertheless ionized Earth’s upper atmosphere. This altered the propagation of radio signals around Europe, where it was high-noon at the time of the flare.

In addition to the UV flash, the explosion also hurled a CME into space: SOHO movie. The cloud is not heading for Earth, so no auroras will result from this particular event. (SpaceWeather)

 

Solar wind
speed: 400.6 km/sec
density: 1.8 protons/cm³

The Radio Sun
10.7 cm flux: 119 sfu

Interplanetary Mag. Field
B_total: 5.2 nT
B_z: 2.9 nT north

A C8.3 Solar Flare took place near the western limb at 01:13 UTC Sunday morning. This was followed by a C9.0 Flare at 04:53 UTC and a stronger M3.2 at 11:45 UTC. All flares were centered around new Sunspot 1286. Because of its location, any further activity around this region may not be earth directed. Solar activity has increased with several C-Class flares and now one M-Class event. All flares appear to be around Sunspot 1286 which is rotating onto the western limb.

Sunspot 1283 continues to transit the northern hemisphere and remains a large Sunspot group. It does not appear to be magnetically complex however. (SolarHam)

 

Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z (NOAA/SWPC):
Solar activity was at moderate levels due to an M3 x-ray event observed on the west limb at 04/1145Z. This event originated from the west limb spot group complex consisting of Regions 1280 (N13W91) and 1286 (N20W75). Close proximity to the limb made precise analysis of the flare location difficult. Associated with the M3 event was a west limb CME, first observed in LASCO C2 imagery at 04/1212Z. A plane-of-sky speed was estimated at about 400 km/s. Preceding this event was another west limb CME, first observed in LASCO C2 imagery at 04/0912Z.

A plane-of-sky speed was estimated at about 150 km/s. Analysis of the potential geoeffectiveness of these CMEs is ongoing. Numerous C-class flares were also observed during the period from this area of the west limb. Region 1287 (S32E51) produced a C1 x-ray event early in the period at 03/2212Z. This region showed minor growth in area while the remaining regions on the disk indicated a slight decay in area coupled with loss of spots.

Solar activity is expected to be low for the next three days (05 – 07 September). A chance for additional M-class activity exists through 06 September.

The geomagnetic field was at quiet to unsettled levels. Observations from the ACE spacecraft indicated wind speeds varied predominately
between 350 to 400 km/s. The Bz component of the interplanetary magnetic field did not vary much beyond +/- 5 nT during the period.

The geomagnetic field is expected to be at quiet to unsettled levels for day one (05 September) due to continuing effects from a coronal hole high speed stream (CH HSS). By days two and three (06 – 07 September), the field is expected to be at mostly quiet levels as the CH HSS moves out of a geoeffective position.