Daily Report

(last updated 25 Sep 2020 23:31 UT)

SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/25 SEPTEMBER 2020 BY Space Weather Services FROM THE AUSTRALIAN SPACE FORECAST CENTRE SUMMARY FOR 25 SEPTEMBER AND FORECAST FOR 26 SEPTEMBER - 28 SEPTEMBER STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: GREEN ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 25 Sep: Very low Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Sep: 73/9 1B. SOLAR FORECAST 26 Sep 27 Sep 28 Sep Activity Very low Very low Very low Fadeouts None expected None expected None expected 10.7cm/SSN 73/9 73/9 73/9 COMMENT: Solar activity was very low on UT day 25 September. There is one numbered region on the visible disc, 2773 (currently at N30E32). No returning active regions are expected. No Earthbound CMEs were observed in the available coronagraph data. The solar wind speed ranged between 460 and 510 km/s, currently near 480 km/s. For the total IMF (Bt) and its north-south component (Bz) the ranges were 3-8 nT and +2/-6 nT, respectively; Bz was mostly negative. Very low levels of solar activity are expected for 26-28 September. Solar wind parameters are expected to be elevated during 26-28 September in response to coronal hole effects. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 25 Sep: Quiet to Active Estimated Indices 25 Sep : A K Australian Region 12 22332423 Cocos Island 6 11222312 Darwin 11 22332412 Townsville 12 22332423 Learmonth 14 21332523 Alice Springs 11 12332413 Gingin 11 21232423 Canberra 10 12232422 Hobart 12 12332423 Estimated Antarctic Regional K Indices 25 Sep : Macquarie Island 15 11343512 Casey 16 33432423 Mawson 59 65333667 Observed Regional daily pc3 Indices 25 Sep : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 6 (Quiet) Canberra 6 (Quiet) Melbourne NA 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 25 Sep : A Fredericksburg 15 Planetary 18 Observed AFr/Ap Indices 24 Sep : A K Fredericksburg 11 Planetary 18 3353 4402 2B. MAGNETIC FORECAST Date Ap Conditions 26 Sep 15 Unsettled to Active 27 Sep 20 Active 28 Sep 20 Active COMMENT: Quiet to active conditions were observed in the Australian region and mostly quiet to major storm levels in the Antarctic region on UT day 25 September. Global conditions are expected to be mostly unsettled with isolated active periods on 26 September and unsettled to active on 27-28 September due to coronal hole effects. There is a chance of isolated minor storm periods for all three days. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 25 Sep Normal Normal-fair Fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 26 Sep Normal Normal Normal-fair 27 Sep Normal Normal-fair Fair 28 Sep Normal Normal-fair Fair COMMENT: Normal to fair HF propagation conditions are expected for 26-28 September. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 25 Sep -6 Observed Australian Regional MUFs Cocos Island Region: Near predicted monthly values. Niue Island Region: No data available. Northern Australian Region: Near predicted monthly values during local day. Enhanced by 25% during local night. Southern Australian Region: Mostly near predicted monthly values. Antarctic Region (Casey/Scott Base/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Aug 6 Sep -13 Oct -14 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 26 Sep -10 Near predicted monthly values 27 Sep -5 Near predicted monthly values 28 Sep -5 Near predicted monthly values COMMENT: SWS HF Communications Warning 4 was issued on 25 September and is current for 25-26 Sep. MUFs in the Australian region were generally near predicted monthly values during daytime and enhanced through the night on UT day 25 September. Antarctic MUFs were mostly near predicted monthly values. MUFs in the Australian region are expected to be mostly near predicted monthly values on 26-28 September. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 24 Sep Daily Proton Fluence >1 MeV: 4.1E+05 Daily Proton Fluence >10 MeV: 4.6E+04 Daily Electron Fluence >2 MeV: 3.60E+07 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 5% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: A3.9 DSCOVR Satellite Solar Wind Day Averaged Data for 24 Sep Speed: 482 km/sec Density: 8.2 p/cc Temp: 257000 K Bz: -1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------