Daily Report

(last updated 26 Feb 2021 23:30 UT)

SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/26 FEBRUARY 2021 BY Space Weather Services FROM THE AUSTRALIAN SPACE FORECAST CENTRE SUMMARY FOR 26 FEBRUARY AND FORECAST FOR 27 FEBRUARY - 01 MARCH STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 26 Feb: Very low Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Feb: 80/20 1B. SOLAR FORECAST 27 Feb 28 Feb 01 Mar Activity Very low to low Very low to low Very low to low Fadeouts None expected None expected None expected 10.7cm/SSN 80/20 80/20 78/17 COMMENT: Solar activity was very low on UT day 26 February. Currently there are three numbered regions on the visible solar disk: AR2803, AR2804, and AR2805. The region AR2805 has produced a B9.5 flare peaking at 26/0725 UT. Solar activity is expected to be very low to low for the next three UT days, 27 February to 1 March. A CME associated with the above-mentioned flare was observed in LASCO and STEREO imagery. Preliminary modelling results show that a glancing blow may occur on 2 March (low confidence). There were no other Earth-directed CMEs in the available coronagraph imagery. On 26 February, the solar wind speed was gradually decreasing from 430 km/s to 400 km/s up to ~1100 UT; the total IMF (Bt) and the north-south component of the IMF (Bz) ranges were 3-5 nT and +3/-3 nT, respectively. Then the solar wind speed increased abruptly to 450-460 km/s; Bt and Bz reached 6 nT and -6 nT, respectively. Probably, this disturbance happened due to a westward CME observed on 22 Feb/2300 UT. The solar wind speed is expected to remain elevated on 27 February. On 1 March another increase in the solar wind speed is expected due to coronal hole effects. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 26 Feb: Quiet to Unsettled Estimated Indices 26 Feb : A K Australian Region 8 21122332 Cocos Island 7 21122331 Darwin 7 11122331 Townsville 9 21122342 Learmonth 10 21123342 Alice Springs 6 10122331 Gingin 7 21022332 Canberra 6 11022232 Hobart 6 11122232 Estimated Antarctic Regional K Indices 26 Feb : Macquarie Island 9 21143221 Casey 13 34332232 Mawson 29 54333246 Observed Regional daily pc3 Indices 26 Feb : 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 26 Feb : A Fredericksburg 9 Planetary 8 Observed AFr/Ap Indices 25 Feb : A K Fredericksburg 13 Planetary 15 5423 1323 2B. MAGNETIC FORECAST Date Ap Conditions 27 Feb 9 Quiet to Unsettled 28 Feb 7 Quiet 01 Mar 15 Unsettled to Active COMMENT: On UT day 26 February, mostly quiet to unsettled conditions were observed in the Australian region. Quiet to storm levels were observed in the Antarctic region. Global geomagnetic conditions are expected to be quiet to unsettled on UT day 27 February and mostly quiet on 28 February. On 1 March geomagnetic activity is expected to reach active levels with possible minor storm periods due to coronal hole effects. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 26 Feb Normal Normal Normal-fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 27 Feb Normal Normal Normal-fair 28 Feb Normal Normal Normal-fair 01 Mar Normal Normal Normal-fair COMMENT: Mostly normal HF propagation conditions are expected on UT days 27 February to 1 March. Mildly degraded conditions are possible on 1 March due to expected increase in geomagnetic activity. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 26 Feb 1 Observed Australian Regional MUFs Cocos Island Region: Near predicted monthly values. Niue Island Region: No data available. Northern Australian Region: Near predicted monthly values. Southern Australian Region: 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 Jan 2 Feb 12 Mar 15 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 27 Feb 5 Near predicted monthly values 28 Feb 5 Near predicted monthly values 01 Mar 5 Near predicted monthly values COMMENT: On UT day 26 February, MUFs in the Australian region were mostly near predicted monthly values. Sporadic E layers were observed, strong at times. MUFs in the Australian region are expected to be mostly near predicted monthly values on UT days 27 February to 1 March. Mildly degraded HF propagation conditions are possible on 1 March due to expected increase in geomagnetic activity. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 25 Feb Daily Proton Fluence >1 MeV: 5.6E+04 Daily Proton Fluence >10 MeV: 4.3E+04 Daily Electron Fluence >2 MeV: 2.00E+07 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 3% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: A7.3 DSCOVR Satellite Solar Wind Day Averaged Data for 25 Feb Speed: 458 km/sec Density: 6.1 p/cc Temp: 126000 K Bz: -2 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------