Daily Report

(last updated 04 Dec 2022 23:30 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/04 DECEMBER 2022 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 04 DECEMBER AND FORECAST FOR 05 DECEMBER - 07 DECEMBER STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 04 Dec: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 04 Dec: 144/98 1B. SOLAR FORECAST 05 Dec 06 Dec 07 Dec Activity R0 R0 R0 Fadeouts Possible Possible Possible 10.7cm/SSN 145/99 145/99 143/97 COMMENT: Solar activity on UT day 4-Dec was at the R0 level with several C-class flares. There are currently 5 numbered sunspot regions on the solar disk. AR3155 (N22W21, beta) and AR3158 (N26E11. alpha) showed spot development over the 24-hour period whilst AR3153 (S17E31, beta) showed some trailer spot development. All other sunspot regions were stable. Solar activity is expected to be at the R0-R1 levels over 5-7 Dec. An east directed CME was observed in LASCO C2 imagery from 4/0125UT. This CME is possibly associated with a filament eruption visible on the disk from 3/2357UT in H-alpha and SDO imagery at around N35E27. Modelling indicates there is a chance that this CME will impact Earth with a glancing blow at 7/0300UT (+/- 12 hours). The solar wind speed on 4-Dec remained elevated varying between 544 to 482 km/s, and is currently near 510 km/s. The peak total interplanetary field strength (IMF, Bt) was 8 nT, and the north-south IMF component (Bz) range was +5 to -7. A sustained period of -Bz was observed from 4/1230UT to 4/1645UT. The elevated solar wind speed and sustained -Bz period may be due to a glancing blow from a CME first observed on 1-Dec. The solar wind speed is expected to decline over 5-Dec due to waning coronal hole high speed wind stream effects. An increase is expected over 6-7 Dec due to high speed wind stream effects from an equatorial coronal hole rotating towards a geoeffective position. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 04 Dec: G0 Estimated Indices 04 Dec : A K Australian Region 9 22123332 Cocos Island 7 12112332 Darwin 4 -1121--- Townsville 10 22123333 Learmonth 12 22223433 Alice Springs 9 22123332 Gingin 13 22123443 Canberra 8 22122332 Hobart 9 12223332 Estimated Antarctic Regional K Indices 04 Dec : Macquarie Island 22 22135632 Casey 22 35333443 Mawson 62 43234874 Observed Regional daily pc3 Indices 04 Dec : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 2 (Quiet) Canberra 13 (Quiet) Hobart 20 (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 Dec : A Fredericksburg 11 Planetary 13 Observed AFr/Ap Indices 03 Dec : A K Fredericksburg 7 Planetary 8 2322 1211 2B. MAGNETIC FORECAST Date Ap Conditions 05 Dec 5 G0 06 Dec 10 G0, chance of G1 07 Dec 15 G0-G1 COMMENT: ASWFC Geomagnetic Warning 57 was issued on 3 December and is current for 7-9 Dec. G0 geomagnetic conditions were observed in the Australian region on UT day 4-Dec. Isolated periods of G1 were observed at Casey and Macquarie Island, with a period of G2 also observed at Macquarie Island. Periods of G3 and G4 geomagnetic conditions were observed at Mawson. G0 geomagnetic conditions are expected on 5 Dec. G0 conditions are expected on 6-Dec with a chance of G1, due to high speed wind stream effects from a coronal hole rotating towards a geoeffective position. G0-G1 conditions are expected on 7-Dec due to a combination of coronal hole high speed wind stream effects and a possible glancing blow from a CME first observed on 4-Dec. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 04 Dec Normal Normal Normal PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 05 Dec Normal Normal Normal 06 Dec Normal Normal Normal-fair 07 Dec Normal Normal Normal-fair COMMENT: Normal HF propagation conditions are expected over 5-6 Dec although there is a chance of mild degradations on 6-Dec due to coronal hole high speed wind stream effects. Normal to mildly degraded conditions are expected on 7-Dec due to a combination of coronal hole high speed wind stream effects and a possible glancing blow from a CME first observed on 4-Dec. Shortwave fadeouts are possible. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 04 Dec 86 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 15% during local day. Enhanced by 40% during local night. Niue Island Region: Near predicted monthly values during local day. Enhanced by 15% during local night. Northern Australian Region: Near predicted monthly values during local day. Enhanced by 15% 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 Nov 77 Dec 70 Jan 70 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 05 Dec 80 Near predicted monthly values 06 Dec 80 Near predicted monthly values 07 Dec 70 Near predicted monthly values COMMENT: Maximum usable frequencies (MUFs) in the northern Australian region on UT day 4-Dec were near predicted monthly values to 15% enhanced and near predicted monthly values in the southern Australian region. Significant amounts of sporadic E were observed across the Australian region during local night. MUFs are expected to be near predicted monthly values over 5-7 Dec, with a chance of mild depressions on 6-Dec due to coronal hole high speed wind streams effects and a a chance of mild depressions on 7-Dec due to a combination of coronal hole high speed wind stream effects and a possible glancing blow from a CME first observed on 4-Dec. Further significant sporadic E can be expected across the Australian region, particularly during local night. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 03 Dec Daily Proton Fluence >1 MeV: 7.9E+05 Daily Proton Fluence >10 MeV: 3.3E+04 Daily Electron Fluence >2 MeV: 5.70E+08 (high fluence) Electron Fluence Daily Deep Dielectric Discharge Probability:24% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: B6.8 DSCOVR Satellite Solar Wind Day Averaged Data for 03 Dec Speed: 565 km/sec Density: 7.5 p/cc Temp: 173000 K Bz: -1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------