Daily Report

(last updated 09 Dec 2018 23:30 UT)

SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/09 DECEMBER 2018 BY Space Weather Services FROM THE AUSTRALIAN SPACE FORECAST CENTRE SUMMARY FOR 09 DECEMBER AND FORECAST FOR 10 DECEMBER - 12 DECEMBER STATUS INDICATORS SOL:GREEN MAG:GREEN ION: ** YELLOW ** ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 09 Dec: Very low Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 09 Dec: 72/8 1B. SOLAR FORECAST 10 Dec 11 Dec 12 Dec Activity Very low Very low Very low Fadeouts None expected None expected None expected 10.7cm/SSN 68/2 68/2 68/2 COMMENT: Solar activity remained Very Low on UT day 9 December. There is one sunspot group (AR2729, currently at S06W88) on the solar disc visible from the Earth. Solar activity is expected to stay Very Low for the next three UT days, 10-12 December. No Earth directed CMEs were observed in the available coronagraph imagery. On UT day 9 December, the solar wind speed was high, varying between 520 km/s and 630 km/s, currently at 630 km/s. This is due to high-speed solar wind streams associated with a large recurrent coronal hole. During the last 24 hours, the total IMF (Bt) varied between 5 nT and 11 nT and the north-south component of IMF (Bz) fluctuated between -6 and +10 nT and was mostly positive. The solar wind speed is expected to be enhanced during the next 2 UT days, 10-11 December, as the effects of the coronal hole persist. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 09 Dec: Quiet Estimated Indices 09 Dec : A K Australian Region 6 22112222 Cocos Island 5 21112212 Darwin 5 22112212 Townsville 7 22123222 Learmonth 9 22123323 Alice Springs 6 02113222 Culgoora 6 22112222 Gingin 9 22222323 Canberra 6 22112222 Launceston 8 23212322 Hobart 5 22112212 Estimated Antarctic Regional K Indices 09 Dec : Macquarie Island 3 21011211 Casey 34 56543334 Mawson 22 33323355 Davis 23 34433345 Observed Regional daily pc3 Indices 09 Dec : Darwin 0 (Quiet) Townsville 0 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 20 (Quiet) Canberra 25 (Quiet to unsettled) 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 09 Dec : A Fredericksburg 5 Planetary 8 Observed AFr/Ap Indices 08 Dec : A K Fredericksburg 10 Planetary 7 2232 1311 2B. MAGNETIC FORECAST Date Ap Conditions 10 Dec 10 Quiet to Unsettled 11 Dec 8 Quiet to Unsettled 12 Dec 7 Quiet COMMENT: Mostly quiet geomagnetic conditions were observed in the Australian region on UT day 9 December. Quiet to minor storm levels were observed in Antarctica. This was in response to high-speed solar wind streams associated with a large recurrent coronal hole. During the next two UT days, 10-11 December, the global geomagnetic activity is expected to be at quiet to unsettled levels as the effects of the coronal hole persist. There is a chance for isolated active periods to occur on 10 December because the solar wind speed is still high. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 09 Dec Normal-fair Normal-fair Normal-fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 10 Dec Normal-fair Normal-fair Normal-fair 11 Dec Normal-fair Normal-fair Normal-fair 12 Dec Normal-fair Normal-fair Normal-fair COMMENT: On UT day 9 December, a combination of very low levels of ionising radiation from the Sun and geomagnetic disturbance associated with the coronal hole caused significant MUF depressions over the mid and high latitude regions in Southern Hemisphere as compared to the monthly predicted levels. Similar depressions are possible on 10 December as the solar and geomagnetic effects persist. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 09 Dec -46 Observed Australian Regional MUFs Cocos Island Region: No data available. Niue Island Region: Depressed by 15% during local day. Depressed by 15% during local night. Northern Australian Region: Depressed by 15% during local day. Depressed by 20% during local night. Southern Australian Region: Depressed by 15% during local day. Depressed by 15% during local night. Antarctic Region (Casey/Scott Base/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Nov -32 Dec -8 Jan -9 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 10 Dec -35 Depressed 20%/near predicted monthly values 11 Dec -40 Depressed 25%/near predicted monthly values 12 Dec -35 Depressed 20%/near predicted monthly values COMMENT: SWS HF Communications Warning 24 was issued on 9 December and is current for 10 Dec only. On UT day 9 December, a combination of very low levels of ionising radiation from the Sun and geomagnetic disturbance associated with the coronal hole caused significant MUF depressions across the Australian region as compared to the monthly predicted levels. Sporadic E layers were seen across the Australian region and in Antarctica. Depressions are expected to continue on 10-12 December as a consequence of the continued very low levels of ionising radiation from the Sun and recent increase in geomagnetic activity. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 08 Dec Daily Proton Fluence >1 MeV: 7.2E+05 Daily Proton Fluence >10 MeV: 1.6E+04 Daily Electron Fluence >2 MeV: 1.30E+07 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability: 2% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: A2.3 DSCOVR Satellite Solar Wind Day Averaged Data for 08 Dec Speed: 548 km/sec Density: 6.4 p/cc Temp: 225000 K Bz: 0 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------