Daily Report

(last updated 04 Oct 2024 23:31 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/04 OCTOBER 2024 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 04 OCTOBER AND FORECAST FOR 05 OCTOBER - 07 OCTOBER STATUS INDICATORS SOL:** RED ** MAG:** RED ** ION: ** YELLOW ** ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 04 Oct: R1 Flares Max Fadeout Freq. Sectors M1.1 03/2328UT possible lower West Pacific M4.0 0455UT possible lower E. Asia/Aust. M1.1 0521UT possible lower E. Asia/Aust. M1.2 1103UT possible lower European M1.2 2105UT possible lower East Pacific/ North American M1.2 2211UT possible lower East Pacific/ North American Observed 10.7 cm flux/Equivalent Sunspot Number for 04 Oct: 291/247 1B. SOLAR FORECAST 05 Oct 06 Oct 07 Oct Activity Moderate to high Moderate to high Moderate to high Fadeouts Probable Probable Probable 10.7cm/SSN 290/246 280/233 280/233 COMMENT: Solar activity on UT day 04-Oct was R1, with the strongest flare being M4 from AR3842. There are currently eight numbered sunspots on the disk. AR3842 (S15W19, beta-gamma) continues to grow and dominate as the largest and most complex sunspot. ARs 3841 (N13W34, beta), 3843 (S07W51, beta) and 3844 (S16W41, beta-gamma) have also grown in the past day. All other sunspots are stable. Solar activity is expected to be R-R3, with a very slight chance of R4 over 5-7 Oct. A CME was associated with the M4 flare from AR3843 and can be seen from 0448 UT; however, this region appeared to have a constant flow of material for most of the day. This CME may arrive from 07/1000 UT but may be earlier due to the solar wind preconditioning from earlier CMEs. A CME to the northeast can be seen from 04/2048 UT but this has been analysed as a a farside event. S0 solar radiation storm conditions were observed on 4-Oct. S0-S1 solar radiation storm conditions are expected over 5-7 Oct. The solar wind environment was generally near background levels on 4-Oct, possibly slightly enhanced, however the first of the CMEs from AR3842 has not yet arrived. The solar wind speed was on a slow incline, beginning near 300 km/s and ending the day near 400 km/s. The peak total interplanetary field strength (IMF, Bt) was 8 nT and the north-south IMF component range (Bz) was +7 to -7 nT. The solar wind environment is expected to become disturbed from 5-Oct and likely through to 7-Oct due to multiple expected CMEs. A small coronal hole may also contribute to increased solar wind speeds by 6-7 Oct. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 04 Oct: G0 Estimated Indices 04 Oct : A K Australian Region 5 22110123 Cocos Island 5 12111113 Darwin 7 23211113 Townsville 7 22111133 Learmonth 7 22221223 Alice Springs 5 22110123 Gingin 8 22120224 Canberra 5 22110123 Kennaook Cape Grim 6 21110133 Hobart 5 22110123 Estimated Antarctic Regional K Indices 04 Oct : Macquarie Island 2 11000112 Casey 19 44531233 Mawson 19 33221336 Observed Regional daily pc3 Indices 04 Oct : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 4 (Quiet) Canberra 2 (Quiet) Pc3 pulsations are high frequency (10-45 second period) variations of the Earths magnetic field. Daily pc3-indices are the daily sum of 20 minute pc3-indices for that station and have been shown to be well correlated with rejection of high resolution aeromagnetic survey flight-line data. NOTE: Indices may have been generated from data obtained in cooperation with the following organisations: Geoscience Australia, University of Newcastle Space Physics Group, Australian Government Antarctic Division and International Center for Space Weather Science and Education, Japan. Estimated AFr/Ap Indices 04 Oct : A Fredericksburg 12 Planetary 20 Observed AFr/Ap Indices 03 Oct : A K Fredericksburg 8 Planetary 7 1111 3222 2B. MAGNETIC FORECAST Date Ap Conditions 05 Oct 50 G3, chance of G4 06 Oct 60 G2-G3, chance of G4 07 Oct 30 G1-G2, chance G3 COMMENT: ASWFC Geomagnetic Warning 59 was issued on 4 October and is current for 4-6 Oct. G0 geomagnetic conditions were observed in the Australian and Antarctic regions on UT day 4-Oct, with an isolated period of G1 at Casey. Sunspot region AR3842 has produced several CMEs recently; one from 1-Oct and another from 4-Oct have failed to arrive by their predicted time, however are still expected on 5-Oct. AR3842 has produced several more CMEs with Earth-directed components since, but due to the large number of eruptions exact arrival times cannot be calculated with confidence as they may or may not interact in space. The result is that G3-G4 geomagnetic conditions are possible over 5-6 Oct, beginning to taper off by 7-Oct. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 04 Oct Normal Normal Normal PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 05 Oct Fair Fair-poor Fair-poor 06 Oct Fair Fair-poor Poor 07 Oct Fair Fair-poor Fair-poor COMMENT: HF radio communication conditions on UT day 4-Oct were normal. HF radio communication conditions are expected to become degraded at all latitudes on 5-Oct due to an anticipated CME arrival, followed by several other CMEs. Due to this, a prolonged geomagnetic storm is expected over 5-7 Oct, such that HF radio conditions are expected to be degraded for this whole period. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 04 Oct 156 Observed Australian Regional MUFs Cocos Island Region: Near predicted monthly values during local day. Enhanced by 15% during local night. Niue Island Region: Enhanced by 20% during local day. Near predicted monthly values during local night. Northern Australian Region: Near predicted monthly values during local day. Enhanced by 30% during local night. Southern Australian Region: Enhanced by 15% during local day. Enhanced by 25% during local night. Antarctic Region (Casey/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Sep 147 Oct 116 Nov 115 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 05 Oct 120 Near predicted monthly values/depressed 5 to 15% 06 Oct 100 Near predicted monthly values/depressed 10 to 25% 07 Oct 90 Near predicted monthly values/depressed 10 to 35% COMMENT: ASWFC SWF HF Communications Warning 111 was issued on 4 October and is current for 4-6 Oct. ASWFC Preliminary HF Communications Warning 112 was issued on 4 October and is current for 4-6 Oct. Maximum usable frequencies (MUFs) in the Australian region on UT day 4-Oct were near predicted values to 30% enhanced. Range spread was observed in Cocos Islands during local night hours. MUFs are expected to be near predicted values in the beginning of UT day 5-Oct, however are expected to become depressed by up to 15% upon the commencement of an expected geomagnetic storm. MUFs are likely to become progressively worse over 6-7 Oct due to expected prolonged geomagnetic storm conditions. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 03 Oct Daily Proton Fluence >1 MeV: 2.7E+05 Daily Proton Fluence >10 MeV: 1.5E+04 Daily Electron Fluence >2 MeV: 5.40E+06 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 1% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: C6.1 DSCOVR Satellite Solar Wind Day Averaged Data for 03 Oct Speed: 332 km/sec Density: 0.5 p/cc Temp: 49100 K Bz: 0 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------