Перегляд архіву понеділок, 22 вересня 2014

Daily bulletin on solar and geomagnetic activity from the SIDC

Випущено: 2014 Sep 22 1307 UTC

SIDC Forecast

Сонячні спалахи

Eruptive (C-class flares expected, probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Сонячні протони

Quiet

	10cm flux	Ap
22 Sep 2014	126	007
23 Sep 2014	126	011
24 Sep 2014	126	011

Bulletin

Solar X-ray flaring activity was very low with no flares detected over the last 24 hours. The potential flaring source regions are all located at the eastern hemisphere. C flaring with a chance for M-flares is expected in the next 24 hours with especially AR 2172 (beta-delta) as potential source region. Two significant partial halo CME's were recorded (reported as one event by Cactus). Both are assessed to be related to backside activity and will therefore not be geo-effective. The onset of the first was missed in SOHO/LASCO C2 images due to a data gap. In SOHO/LASCO C3 it becomes visible at 6:54UT. It is, however, well recorded by STEREO B where it is first visible in COR2 images around 6:25 UT onwards. The mass is expelled predominantly in north-eastern direction from the Sun-STEREO B line i.e. North-Western direction as seen from Earth. In STEREO B/EUVI 193 it can be seen to originate from AR 2158, currently at about 150 degrees west (with respect to the Sun-Earth line), and hence backsided. This event is believed to be responsible for the rise in >10 MeV proton levels starting at around 8:00 UT, and which currently seems to reach its peak at about an order of magnitude below the event threshold. The second event is first visible in SOHO/LASCO C2 data at 8:48 UT and as seen from the Sun-Earth line it is directed predominantly in eastern direction. It can be related to flaring activity at the centre of the disc as seen from STEREO B, and CME is hence judged to be backsided. STEREO B EUVI 193 images capture it just after suffering a data gap and the most important activity is probably missed. Being directed towards STEREO B and rather faint, it is only very weakly visible in STEREO B COR2 coronagraph data. Solar wind conditions are returning to nominal. Solar wind speed decreased from around 540 km/s at the start of the reporting period to around 440 km/s at the end. Total magnetic field is just over 5 nT with the Bz component changing from predominantly positive to predominantly negative after a sector boundary crossing from a negative (towards) into a positive (away) sector after 2:00 UT. Geomagnetic conditions were quiet to unsettled (NOAA Kp 1-3, local K Dourbes 0-3). Nominal solar wind conditions and quiet to unsettled geomagnetic conditions are expected to first continue, with later increased activity possible from September 23 onwards due to the influence of a corotating interaction region and a coronal hole high speed stream.

Today's estimated international sunspot number (ISN): 067, based on 20 stations.

Solar indices for 21 Sep 2014

Wolf number Catania	///
10cm solar flux	124
AK Chambon La Forêt	008
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	066 - Based on 23 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

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