Analysis of Solar Active Regions and latest solar flare activity august 23 2013from 22/2100Z to 23/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 22/2207Z from Region 1828 (N14E26). There are currently 9 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on day one (24 Aug) and expected to be low on days two and three (25 Aug, 26 Aug). IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 593 km/s at 22/2215Z. Total IMF reached 7 nT at 22/2100Z. The maximum southward component of Bz reached -5 nT at 22/2205Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1857 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (24 Aug), quiet to minor storm levels on day two (25 Aug) and quiet to unsettled levels on day three (26 Aug).
Solar activity was low. Region 1820 (S12W73, Cao/beta) produced a C1 at 23/1557 UTC, which was the largest event of the period. Region 1830 (S05W64, Dao/beta) showed minor growth while the other regions on the disk were either stable or decaying. A narrow coronal mass ejection (CME) from Region 1820 was observed on LASCO C2 coronagraph imagery at 23/0048 UTC, but was not Earth-directed. .Forecast... Solar activity is expected to be low with a slight chance for M-class flares on day one (24 Aug). Solar activity is expected to be low for days two and three (25 - 26 Aug). Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit was at normal to high levels, reaching a maximum value of 1,860 pfu at 23/1710 UTC. The greater than 10 MeV proton flux at geosynchronous orbit was at background levels. .Forecast... The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to high levels for the next three days (24 - 26 Aug). The greater than 10 MeV proton flux at geosynchronous orbit is expected to remain at background levels for the next three days (24 - 26 Aug). Solar Wind .24 hr Summary... Solar wind parameters, measured at ACE, were indicative of waning coronal hole high speed stream (CH HSS) influence. Solar wind speed steadily decreased from initial values near 560 km/s to end-of-period values near 475 km/s. The total field strength ranged from 6 nT to 2 nT while the Bz component ranged from +4 nT to -5 nT. The phi angle remained in a predominately positive (away) sector throughout the period. .Forecast... Solar wind speed is expected to increase on day one (24 Aug) and remain enhanced for days two and three (25 - 26 Aug) with arrival of the 21 Aug CME and onset of a CH HSS late on day three. Geospace .24 hr Summary... The geomagnetic field was at quiet to active levels. .Forecast... With arrival of the 21 Aug CME, the geomagnetic field is expected to be at unsettled to G1 (Minor) geomagnetic storm levels on day one (24 Aug), decreasing to quiet to G1 (Minor) geomagnetic storm levels on day two (25 Aug). Predominately quiet to unsettled conditions are expected on day three (26 Aug) with waning CME effects and the onset of a CH HSS.
