Daily Report

(last updated 25 Mar 2023 23:31 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/25 MARCH 2023 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 25 MARCH AND FORECAST FOR 26 MARCH - 28 MARCH STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 25 Mar: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Mar: 160/114 1B. SOLAR FORECAST 26 Mar 27 Mar 28 Mar Activity R0, chance R1 R0, chance R1 R0, chance R1 Fadeouts Possible Possible Possible 10.7cm/SSN 165/119 160/114 155/109 COMMENT: Solar activity on UT day 25-Mar was at the R0 level, with no significant flaring activity. There are currently eight numbered sunspot regions visible on the solar disk and one unnumbered region. AR3258 (N20W46, beta) and AR3263 (N17W11, beta) have both shown growth in their trailer spots over the 24-hour period. An unnumbered region recently appeared at ~N20E12 and is stable. All other sunspot regions are either stable or in decay. The background X-ray flux is at high B-class levels. Solar activity is expected to be at the R0 level, with a chance of R1. A northwest CME was observed, visible in LASCO C2 coronagraph imagery from 24/2212UT. Modelling indicates this CME is not geoeffective. No other Earth-directed CMEs have been observed. The solar wind speed on UT day 25-Mar increased, ranging from 460 to 550 km/s, and is currently near 550 km/s. The peak total interplanetary field strength (IMF, Bt) was 10 nT and the north-south IMF component (Bz) range was +8 to -8 nT. The solar wind speed is expected to remain elevated over 26-28 Mar due to coronal hole high speed wind stream effects from a broad southern hemisphere coronal hole. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 25 Mar: G0 Estimated Indices 25 Mar : A K Australian Region 9 22233222 Cocos Island 7 22231221 Darwin 7 22223122 Townsville 10 22333222 Learmonth 10 32233222 Alice Springs 9 22233222 Gingin 10 32223232 Canberra 9 22333122 Hobart 10 22333222 Estimated Antarctic Regional K Indices 25 Mar : Macquarie Island 22 23455332 Casey 22 45443233 Mawson 30 43453355 Observed Regional daily pc3 Indices 25 Mar : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 4 (Quiet) Canberra 13 (Quiet) Hobart 26 (Quiet to unsettled) 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 Mar : A Fredericksburg 16 Planetary 21 Observed AFr/Ap Indices 24 Mar : A K Fredericksburg 40 Planetary 72 6874 2344 2B. MAGNETIC FORECAST Date Ap Conditions 26 Mar 18 G0-G1 27 Mar 16 G0, chance G1 28 Mar 8 G0 COMMENT: G0 geomagnetic conditions were observed in the Australian region on UT day 25-Mar. G0-G1 geomagnetic conditions were observed in the Antarctic region. G0-G1 geomagnetic conditions are expected on 26-Mar due to coronal hole high speed wind stream effects from a broad southern hemisphere coronal hole. G0 geomagnetic conditions are expected on 27-Mar, with a chance of G1. G0 geomagnetic conditions are expected on 28-Mar. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 25 Mar Normal Normal Normal PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 26 Mar Normal Normal-fair Fair 27 Mar Normal Normal-fair Fair 28 Mar Normal Normal Normal-fair COMMENT: Normal HF propagation conditions were observed on 25-Mar. An extended period of mildly degraded HF conditions for middle to high latitudes is possible due to a broad solar coronal hole wind stream over 26-27 Mar. Middle to low latitude HF conditions are expected to remain normal. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 25 Mar 139 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 35% during local day. Near predicted monthly values during local night. Enhanced by 20% after local dawn. Niue Island Region: Enhanced by 25% during local day. Enhanced by 35% during local night. Northern Australian Region: Enhanced by 35% during local day and after local dawn. Enhanced by 25% during local night. Southern Australian Region: Enhanced by 35% during local day. Near predicted monthly values during local night. Enhanced by 20% after local dawn. Antarctic Region (Casey/Scott Base/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Feb 117 Mar 80 Apr 80 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 26 Mar 130 Near to 20% above predicted monthly values 27 Mar 130 Near to 20% above predicted monthly values 28 Mar 130 Near to 20% above predicted monthly values COMMENT: Maximum usable frequencies (MUFs) on UT day 25-Mar in the Australian region were enhanced by 25-35% in Northern Australia and 35% enhanced in Southern Australia during local day. Spread F was observed at Hobart. Degraded HF conditions during local night hours are possible for southern Australia over 26-27 Mar due to a mild increase in geomagnetic activity from a broad solar coronal hole. MUFs are expected to be near predicted monthly values to 20% enhanced over 26-28 Mar. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 24 Mar Daily Proton Fluence >1 MeV: 1.4E+06 Daily Proton Fluence >10 MeV: 2.1E+04 Daily Electron Fluence >2 MeV: 1.50E+06 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 1% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: B6.8 DSCOVR Satellite Solar Wind Day Averaged Data for 24 Mar Speed: 438 km/sec Density: 9.9 p/cc Temp: 93000 K Bz: -5 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------