Daily Report

(last updated 19 May 2024 23:30 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/19 MAY 2024 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 19 MAY AND FORECAST FOR 20 MAY - 22 MAY STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 19 May: R1 Flares Max Fadeout Freq. Sectors M1.9 1344UT possible lower European M2.5 1756UT possible lower South American/ Atlantic M1.6 2159UT possible lower East Pacific/ North American Observed 10.7 cm flux/Equivalent Sunspot Number for 19 May: 201/153 1B. SOLAR FORECAST 20 May 21 May 22 May Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 200/152 200/152 200/152 COMMENT: Solar activity on UT day 19-May was at the R1 level due to three low level M-class flares, the largest of which was an M2.5 flare at 19/1756UT produced by AR3685 (S14E31, beta-delta). There are currently nine numbered sunspot regions visible on the solar disk. AR3685 is the largest and most magnetically complex region on the disk and has exhibited spot development over the UT day, particularly in its intermediate spots. AR3679 (S12W19, beta-gamma) has shown growth in its trailer spots. AR3683 (S23W56, beta) and AR3684 (S06E13, beta) have both shown growth in their leader spots. AR3686 (S08E43, beta) has exhibited spot development in its trailer spots. All other sunspot regions are either stable or in decay. Solar activity is expected to be at R0-R1 levels over 20-22 May. Several CMEs were observed, but none are considered geoeffective. A low velocity southward CME was observed, visible in STEREO-A coronagraph imagery at 19/0123UT. This CME is associated with a filament eruption first observed at 18/2048UT. Modelling indicates this CME is not geoeffective. Two filament eruptions were observed on UT day 19-May, the first at 19/1408UT near N31W27, the second at 19/1530UT near N24W60. A northeast-directed CME was observed, visible in LASCO C2 coronagraph imagery from 19/1709UT, likely associated with the first filament eruption. Modelling indicates this CME does not contain an Earth-directed component. No CME was observed in association with the second filament eruption. The solar wind speed on UT day 19-May was mostly stable, ranging from 365 to 430 km/s and is currently near 405 km/s. The peak total interplanetary field strength (IMF, Bt) was 10 nT and the north-south IMF component (Bz) range was +6 to -9 nT. A sustained interval of southward IMF conditions was observed from 19/1200-1800UT. The solar wind speed is expected to remain near background levels over 20-22 May. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 19 May: G0 Estimated Indices 19 May : A K Australian Region 4 12122120 Cocos Island 3 12111120 Darwin 5 12122121 Townsville 7 12223221 Learmonth 5 12122220 Alice Springs 3 11122110 Gingin 5 12113220 Canberra 3 01122111 Kennaook Cape Grim 4 01123120 Estimated Antarctic Regional K Indices 19 May : Macquarie Island 6 01133220 Casey 6 22222121 Mawson 15 24322252 Observed Regional daily pc3 Indices 19 May : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 4 (Quiet) Canberra 4 (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 19 May : A Fredericksburg 9 Planetary 12 Observed AFr/Ap Indices 18 May : A K Fredericksburg 14 Planetary 15 3434 4322 2B. MAGNETIC FORECAST Date Ap Conditions 20 May 8 G0 21 May 8 G0 22 May 6 G0 COMMENT: G0 geomagnetic conditions were observed in the Australian region on UT day 19-May. Mostly G0 geomagnetic conditions were observed in the Antarctic region, with an isolated period of G1 observed at Mawson. G0 geomagnetic conditions are expected over 20-22 May. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 19 May Normal Normal Normal PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 20 May Normal Normal Normal-fair 21 May Normal Normal Normal-fair 22 May Normal Normal Normal COMMENT: HF radio communication conditions on UT day 19-May were mostly normal. Mostly normal HF conditions are expected over 20-22 May. Shortwave fadeouts are possible. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 19 May 149 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 20% during local day. Enhanced by 65% during local night. Niue Island Region: Enhanced by 20% during local day. Near predicted monthly values during local night. Northern Australian Region: Near predicted monthly values during local day. Enhanced by 25% during local night. Southern Australian Region: Enhanced by 15% during local day. Near predicted monthly values during local night. Antarctic Region (Casey/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Apr 125 May 114 Jun 116 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 20 May 145 Near to 15% above predicted monthly values 21 May 145 Near to 15% above predicted monthly values 22 May 145 Near to 15% above predicted monthly values COMMENT: ASWFC SWF HF Communications Warning 54 was issued on 19 May and is current for 20-22 May. Maximum usable frequencies (MUFs) on UT day 19-May were near predicted monthly values to 25% enhanced in Northern Australia. Spread F was observed at Hobart during local night hours. Ionospheric scintillation was observed at Darwin and Weipa from 19/1142-1610UT. MUFs are expected to be near predicted monthly values to 15% enhanced over 20-22 May. Shortwave fadeouts are possible. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 18 May Daily Proton Fluence >1 MeV: 1.5E+07 Daily Proton Fluence >10 MeV: 6.6E+04 Daily Electron Fluence >2 MeV: 2.90E+06 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 1% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: C1.5 DSCOVR Satellite Solar Wind Day Averaged Data for 18 May Speed: 412 km/sec Density: 2.3 p/cc Temp: 48000 K Bz: -2 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------