Daily Report

(last updated 20 Sep 2020 23:31 UT)

SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/20 SEPTEMBER 2020 BY Space Weather Services FROM THE AUSTRALIAN SPACE FORECAST CENTRE SUMMARY FOR 20 SEPTEMBER AND FORECAST FOR 21 SEPTEMBER - 23 SEPTEMBER STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 20 Sep: Very low Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Sep: 70/5 1B. SOLAR FORECAST 21 Sep 22 Sep 23 Sep Activity Very low Very low Very low Fadeouts None expected None expected None expected 10.7cm/SSN 70/5 70/5 70/5 COMMENT: Solar activity was Very Low on UT day 20 September. The Sun is currently spotless with no numbered regions on the visible disc. No returning regions are expected. No earthward directed CMEs were visible in the available coronagraph images. Very Low levels of solar activity are expected for the next three UT days, 21-23 September. On UT day 20 September, the solar wind speed varied between 270-300 km/s for most of the day until it started to increase after 20/2200 UT and is currently around 320 km/s. The total IMF (Bt) started the day varying between 1-2 nT, then started increasing after 20/0800 UT, currently around 9 nT. The north-south component of IMF (Bz) varied between +6 and -5 nT. For the next three UT days, 21-23 September, the solar wind parameters are expected to be mostly near background levels but may become weakly enhanced at times due to a few small and weak equatorial coronal holes. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 20 Sep: Quiet Estimated Indices 20 Sep : A K Australian Region 2 01022101 Cocos Island 1 00111001 Darwin 3 01122102 Townsville 5 11132111 Learmonth 4 01032102 Alice Springs 2 00022101 Gingin 3 00022102 Canberra 2 00021101 Hobart 2 01022101 Estimated Antarctic Regional K Indices 20 Sep : Macquarie Island 0 00001000 Casey 5 12221112 Mawson 10 01121135 Observed Regional daily pc3 Indices 20 Sep : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 0 (Quiet) Canberra 0 (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 20 Sep : A Fredericksburg 3 Planetary 4 Observed AFr/Ap Indices 19 Sep : A K Fredericksburg 4 Planetary 3 0111 0100 2B. MAGNETIC FORECAST Date Ap Conditions 21 Sep 6 Quiet, with a chance of isolated Unsettled periods 22 Sep 6 Quiet, with a chance of isolated Unsettled periods 23 Sep 6 Quiet, with a chance of isolated Unsettled periods COMMENT: Mainly Quiet geomagnetic conditions were observed in the Australian region on UT day 20 September, with an isolated Unsettled period observed at some sites. The Antarctic region observed mainly Quiet conditions, with Mawson station observing an Unsettled to Minor Storm period late in the UT day. Global geomagnetic conditions are expected to be mostly Quiet, with a chance of isolated Unsettled periods, during the next three UT days, 21-23 September. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 20 Sep Normal Normal Normal PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 21 Sep Normal Normal Normal 22 Sep Normal Normal Normal 23 Sep Normal Normal Normal COMMENT: Normal HF propagation conditions are expected for the next three UT days, 21-23 September. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 20 Sep -4 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 15% during local day. Depressed by 25% during local night. Niue Island Region: No data available. Northern Australian Region: Mostly near predicted monthly values. Southern Australian Region: Mostly near predicted monthly values. Antarctic Region (Casey/Scott Base/Davis/Mawson): Enhanced by 20% 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 21 Sep -5 Near predicted monthly values 22 Sep -5 Near predicted monthly values 23 Sep -5 Near predicted monthly values COMMENT: MUFs in the Australian and Antarctic regions were mostly near predicted monthly values to mildly enhanced on UT day 20 September. MUFs in the Cocos Island Region were mildly enhanced during the local day and mildly depressed during the local night. MUFs in the Australian region are expected to be mostly near predicted monthly values on UT days 21-23 September. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 19 Sep Daily Proton Fluence >1 MeV: 7.2E+04 Daily Proton Fluence >10 MeV: 4.6E+04 Daily Electron Fluence >2 MeV: 2.00E+06 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 1% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: <A1.0 DSCOVR Satellite Solar Wind Day Averaged Data for 19 Sep Speed: 314 km/sec Density: 3.3 p/cc Temp: 19200 K Bz: -1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------