Daily Report

(last updated 18 May 2019 23:30 UT)

SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/18 MAY 2019 BY Space Weather Services FROM THE AUSTRALIAN SPACE FORECAST CENTRE SUMMARY FOR 18 MAY AND FORECAST FOR 19 MAY - 21 MAY STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 18 May: Very low Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 18 May: 71/6 1B. SOLAR FORECAST 19 May 20 May 21 May Activity Very low Very low Very low Fadeouts None expected None expected None expected 10.7cm/SSN 70/5 68/2 68/2 COMMENT: Solar activity was Very Low on UT day 18 May. There is currently one numbered sunspot region on the visible solar disk, AR2741, which is now located near the west limb of the visible solar disk. Very low solar activity is expected for the next 3 UT days, 19-21 May. No Earth-directed Coronal Mass Ejections (CMEs) were observed in available coronagraph imagery for UT day 18 May. During the last 24 hours, solar wind speed was mostly steady near 400 km/s. The observed weakly elevated speeds are in response to the recent CME activities. The total IMF (Bt) ranged from 4 nT to 6 nT. The north-south component of the IMF (Bz) ranged between +4 nT and -4 nT, without any significant periods of southward Bz. For the next 24 hours, the solar wind speed is expected to vary between the recently observed weakly elevated levels and background levels. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 18 May: Quiet Estimated Indices 18 May : A K Australian Region 2 01220000 Cocos Island 1 00120000 Darwin 2 11220001 Townsville 2 11220001 Learmonth 2 11220000 Culgoora 2 01220000 Gingin 2 01220000 Canberra 0 00110000 Launceston 3 11230000 Hobart 2 00230000 Estimated Antarctic Regional K Indices 18 May : Macquarie Island 5 00340000 Casey 6 13321110 Mawson 7 12232103 Davis 4 12321000 Observed Regional daily pc3 Indices 18 May : Darwin 0 (Quiet) Townsville NA 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 18 May : A Fredericksburg 5 Planetary 6 Observed AFr/Ap Indices 17 May : A K Fredericksburg 7 Planetary 5 3111 2101 2B. MAGNETIC FORECAST Date Ap Conditions 19 May 5 Quiet 20 May 5 Quiet 21 May 5 Quiet COMMENT: Geomagnetic activity was at Quiet levels across the Australian region on UT day 18 May. Mostly Quiet levels were observed in Antarctica. The global geomagnetic activity is expected to be mostly at Quiet levels during the next 3 UT days, 19-21 May. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 18 May Normal Normal Normal PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 19 May Normal Normal Normal 20 May Normal Normal Normal 21 May Normal Normal Normal COMMENT: Maximum usable frequencies (MUFs) were mostly near predicted monthly values during the last 24 hours; moderate depressions were observed mostly at high latitudes in the Northern Hemisphere. Mostly normal MUFs with possible minor to moderate depressions and degradations in HF conditions are expected for the next 3 UT days, 19-21 May. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 18 May 7 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 60% during local day. Enhanced by 15% during local night. Niue Island Region: Enhanced by 15% during local day. Enhanced by 70% during local night. Northern Australian Region: Near predicted monthly values during local day. Enhanced by 40% during local night. Southern Australian Region: Near predicted monthly values during local day. Enhanced by 20% during local night. Enhanced by 20% after local dawn. Antarctic Region (Casey/Scott Base/Davis/Mawson): Enhanced by 30% over the UT day. Monthly T index: Month T index Apr 1 May -12 Jun -12 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 19 May 0 Near predicted monthly values 20 May 0 Near predicted monthly values 21 May 0 Near predicted monthly values COMMENT: Maximum usable frequencies (MUFs) ranged from near predicted monthly values to moderately enhanced levels during the last 24 hours in the Aus/NZ regions. Similar HF propagation conditions in the Australian region are expected for the next 3 UT days, 19-21 May. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 17 May Daily Proton Fluence >1 MeV: 5.4E+05 Daily Proton Fluence >10 MeV: 1.9E+04 Daily Electron Fluence >2 MeV: 1.80E+07 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 3% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: A8.0 DSCOVR Satellite Solar Wind Day Averaged Data for 17 May Speed: 448 km/sec Density: 11.8 p/cc Temp: 176000 K Bz: 2 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------