Daily Report

(last updated 29 Sep 2016 23:30 UT)

SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/29 SEPTEMBER 2016 BY Space Weather Services FROM THE AUSTRALIAN SPACE FORECAST CENTRE SUMMARY FOR 29 SEPTEMBER AND FORECAST FOR 30 SEPTEMBER - 02 OCTOBER STATUS INDICATORS SOL:GREEN MAG:** RED ** ION: ** YELLOW ** ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 29 Sep: Very low Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 29 Sep: 83/24 1B. SOLAR FORECAST 30 Sep 01 Oct 02 Oct Activity Very low to low Very low to low Very low to low Fadeouts None expected None expected None expected 10.7cm/SSN 81/22 78/17 80/20 COMMENT: The solar activity was at very low levels for the UT day, 29 September. The only active sunspot region (Region 2597) will soon rotate to the rearward side of the sun. Thus, the two day outlook (30 September and 1 October) is for very low solar activity with only slight chance of C-class flares. No Earth-directed CMEs were observed in the available coronagraph imagery. The solar wind speeds were steady at very high levels of near 700 km/s throughout the UT day. These enhanced solar wind speeds are due to high speed streams emanating from the large positive polarity coronal hole. The north-south component of the Interplanetary Magnetic Field (IMF) fluctuated between -8 and +8 nT, and was predominately southwards from 29/0500 UT to 29/1500 UT. Bt ranged between 5 and 9 nT, and had been exhibited a gradual declining trend starting from 29/0600 UT. The current Bt magnitude is near 5 nT. The two day outlook (30 September and 1 October) is for the solar winds to remain at these enhanced levels as the coronal effects persist. Expect a slow declining trend in solar wind speeds from 2 October as the coronal effects begin to wane. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 29 Sep: Unsettled to Major Storm Estimated Indices 29 Sep : A K Australian Region 25 33464422 Darwin 20 23454422 Townsville 22 33454432 Learmonth 27 33455532 Alice Springs 21 33454422 Norfolk Island 17 33353322 Gingin 26 33355532 Camden 27 34464422 Canberra 16 23353322 Launceston 36 34474433 Hobart 34 34474422 Estimated Antarctic Regional K Indices 29 Sep : Macquarie Island 53 34675642 Casey 23 45443333 Mawson 70 46664576 Observed Regional daily pc3 Indices 29 Sep : Darwin 2 (Quiet) Townsville 3 (Quiet) Learmonth 12 (Quiet) Alice Springs 3 (Quiet) Gingin 114 (Major storm) Canberra 99 (Minor storm) 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 29 Sep : A Fredericksburg 28 Planetary 46 Observed AFr/Ap Indices 28 Sep : A K Fredericksburg 24 Planetary 39 5535 4564 2B. MAGNETIC FORECAST Date Ap Conditions 30 Sep 40 Minor Storm 01 Oct 30 Active to Minor Storm 02 Oct 20 Active COMMENT: SWS Geomagnetic Warning 38 was issued on 29 September and is current for 29 Sep to 1 Oct. The geomagnetic activity over the Australian region were mostly at active to minor storm levels, and briefly reached major storm levels between 29/0800 UT and 29/1000 UT. The Australian region Dst index dipped to a low of -120 nT at near 29/0920 UT. These fluctuations in geomagnetic conditions are associated with very strong solar wind speeds in excess of 700 km/s emanating from a large positive polarity coronal hole and predominate southwards Bz from 29/0500 UT to 29/1500 UT. The two day outlook (30 September and 1 October) is for the geomagnetic activity to reach minor storm levels and at times even reach major storm levels associated with the persisting very strong solar wind speeds from the coronal hole. The storm intensities are expected to be slightly stronger than that observed in the previous two rotations (previous rotation Ap was 32) associated with this coronal hole because the earth-sun coupling efficiency is highest during the equinox periods. Thus there is again chance that aurora may be visible on the local nights of 30 September from Tasmania and some parts of Victoria, Australia. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 29 Sep Normal Fair Fair-poor PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 30 Sep Fair Fair-poor Poor 01 Oct Normal Fair Fair-poor 02 Oct Normal Normal-fair Poor COMMENT: Observed MUF's were near predicted monthly values over the equatorial regions and strongly depressed in the mid and high latitudes regions. Similar HF conditions are expected today, 30 September, with chance that the MUF depressions can extend even into the equatorial regions due to the persistant prolonged heating of the high latitude ionosphere during this storm. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 29 Sep 6 Observed Australian Regional MUFs Cocos Island Region: Near predicted monthly values during local day. Depressed by 30% during local night. Depressed by 20% after local dawn. Niue Island Region: No data available. Northern Australian Region: Depressed by 20% during local day. Near predicted monthly values during local night. Southern Australian Region: Depressed by 25% throughout the day. Antarctic Region (Casey/Scott Base/Davis/Mawson): Depressed by 20% over the UT day. Monthly T index: Month T index Aug 29 Sep 35 Oct 34 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 30 Sep 0 15 to 20% below predicted monthly values 01 Oct 5 Depressed 15%/near predicted monthly values 02 Oct 10 Depressed 15%/near predicted monthly values COMMENT: SWS HF Communications Warning 42 was issued on 29 September and is current for 29 Sep to 1 Oct. Observed MUF's were strongly depressed over most Australian regions throughout the UT day 29 September except on the day side for the equatorial Australian regions. These depression are associated with the observed disturbed geomagnetic conditions driven by a very large positive polarity coronal hole. Similar MUF depressions are expected for the next three days (30 September to 2 October) as active conditions associated with the coronal hole are expected to persist for few days. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 28 Sep Daily Proton Fluence >1 MeV: 5.9E+06 Daily Proton Fluence >10 MeV: 1.3E+04 Daily Electron Fluence >2 MeV: 3.80E+08 (moderate fluence) Electron Fluence Daily Deep Dielectric Discharge Probability:21% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: A8.5 ACE Satellite Solar Wind Day Averaged Data for 28 Sep Speed: 669 km/sec Density: 8.3 p/cc Temp: 674000 K Bz: -1 nT (Courtesy Space Weather Prediction Center, Boulder USA) ACE data can be incorrect during strong proton events. -----------------------------------------------------------