Daily Report

(last updated 12 May 2021 23:30 UT)

SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/12 MAY 2021 BY Space Weather Services FROM THE AUSTRALIAN SPACE FORECAST CENTRE SUMMARY FOR 12 MAY AND FORECAST FOR 13 MAY - 15 MAY STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: ** YELLOW ** ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 12 May: Low Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 12 May: 75/13 1B. SOLAR FORECAST 13 May 14 May 15 May Activity Low to moderate Low to moderate Low to moderate Fadeouts Possible Possible Possible 10.7cm/SSN 76/14 78/17 80/20 COMMENT: Solar activity was low on UT day 12 May with a C1.5 flare at 0935 UT from region 2822. There are currently two active regions on the visible disk of the Sun, AR2822 (Cai-BetaGamma) and AR2823 (Hax-Alpha). There were no Earth directed CMEs in the available coronagraph images. Solar activity is expected to be low to moderate with a chance of more C-class flares and a small chance of M-class flares for the next three UT days 13-15 May. This is due to the flaring potential of AR2822 which is currently situated near CMD at N17E10. On UT day 12 May, the solar wind speed increased suddenly from background levels up to 440 km/s at 0548 UT and then continued increasing up to 525 km/s. This elevation of solar wind speed to moderately enhanced levels was most likely caused by the arrival of the 9 May CME from a DSF. The IMF (Bt) peaked at 23 nT and the north-south component of IMF (Bz) range was +23/-20 nT and was mostly southwards during 1022-1429 UT. The solar wind speed is expected to remain moderately enhanced on UT day 13 May and then gradually decrease back to nominal levels on UT days 14-15 May. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 12 May: Quiet to Major Storm Estimated Indices 12 May : A K Australian Region 25 01446523 Cocos Island 18 02435423 Darwin 20 11445512 Townsville 25 02446513 Learmonth 35 11556623 Alice Springs 25 02446522 Gingin 27 11435634 Canberra 22 01436512 Hobart 22 01436512 Estimated Antarctic Regional K Indices 12 May : Macquarie Island 41 00347711 Casey 18 12544323 Mawson 31 41544436 Observed Regional daily pc3 Indices 12 May : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 21 (Quiet to unsettled) Canberra 9 (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 12 May : A Fredericksburg 25 Planetary 53 Observed AFr/Ap Indices 11 May : A K Fredericksburg 4 Planetary 4 2100 1111 2B. MAGNETIC FORECAST Date Ap Conditions 13 May 15 Unsettled to Active 14 May 7 Quiet 15 May 5 Quiet COMMENT: SWS Geomagnetic Warning 17 was issued on 12 May and is current for 12-13 May. Geomagnetic conditions in the Australian region on UT day 12 May were quiet initially but then suddenly became disturbed, rising from unsettled to active levels with minor storms and a major storm period at about 14 UT. In the Antarctic region quiet to active levels were also observed with storm periods. This disturbance was most likely caused by the 9 May CME from a DSF. Global geomagnetic conditions are expected to be mostly unsettled to active on UT day 13 May, as CME effects fade. Then mostly quiet levels are expected on UT days 14-15 May. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 12 May Normal-fair Normal-fair Normal-fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 13 May Normal-fair Normal-fair Fair 14 May Normal Normal-fair Normal-fair 15 May Normal Normal Normal-fair COMMENT: Mild to moderate depressions in HF propagation conditions are possible on UT days 13-14 May. This disturbance will be more prominent in the Northern Hemisphere mid and high latitude regions. Mostly normal HF propagation conditions are expected on UT day 15 May. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 12 May 10 Observed Australian Regional MUFs Cocos Island Region: No data available. Niue Island Region: Depressed by 20% during local day. Near predicted monthly values during local night. Northern Australian Region: Depressed by 20% during local day. Near predicted monthly values during local night. Southern Australian Region: Depressed by 15% during local day. Enhanced by 30% during local night. Antarctic Region (Casey/Scott Base/Davis/Mawson): Enhanced by 30% over the UT day. Monthly T index: Month T index Apr 12 May 21 Jun 24 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 13 May 0 Depressed 15%/near predicted monthly values 14 May 5 Near predicted monthly values 15 May 10 Near predicted monthly values COMMENT: MUFs in the Australian region on UT day 12 May were mostly near predicted monthly values with some mild to moderate depressions during the local day. There were also some moderate enhancements in the South Australian during the local night and Antarctic regions. In the Australian region, MUFs on UT day 13 May are expected to be mostly near predicted monthly values during the local day, with some mild to moderate depressions expected during the local night. The forecast depressions are in response to the recent disturbed conditions associated with the 9 May CME. Then mostly normal HF propagation conditions are expected on UT days 14-15 May. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 11 May Daily Proton Fluence >1 MeV: 8.4E+04 Daily Proton Fluence >10 MeV: 4.3E+04 Daily Electron Fluence >2 MeV: 2.20E+06 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 1% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: A4.6 DSCOVR Satellite Solar Wind Day Averaged Data for 11 May Speed: 333 km/sec Density: 6.9 p/cc Temp: 40700 K Bz: 1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------