Daily Report

(last updated 07 Dec 2022 23:31 UT)

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT ISSUED AT 2330UT/07 DECEMBER 2022 FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE SUMMARY FOR 07 DECEMBER AND FORECAST FOR 08 DECEMBER - 10 DECEMBER STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx ----------------------------------------------------------- 1A. SOLAR SUMMARY Activity 07 Dec: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 07 Dec: 148/102 1B. SOLAR FORECAST 08 Dec 09 Dec 10 Dec Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 150/105 150/105 150/105 COMMENT: Solar activity on UT day 07-Dec was at the R0 level. There are currently 7 numbered sunspot regions on the solar disk. Solar region AR3157 (N18E20, beta) produced three C class flares, the largest a C5.8 at 07/1304UT. This region has shown some development in its trailer spots and may be showing a slight increase in magnetic complexity. The largest region currently on the solar disk AR3153(S17W03, beta), initially showed a decline in its intermediate spots, later in the UT day some minor redevelopment of intermediate spots was evident in an arc around the large leader spot, with perhaps a slight increase in magnetic complexity evident, though this region has yet to produce any significant flare activity. Other sunspot regions were relatively stable. Solar activity is expected to be at the R0-R1 levels over 08-10 Dec. No Earth directed CMEs were observed. An apparent very slow moving narrow CME was observed over an extended period 06/2100-07/1400UT in LASCO C2 and in STEREO-A imagery from 07/0423UT, directed predominately southward and slightly to the east, steeply out of the ecliptic plane. The CME could not be correlated to any on disk activity. The solar wind speed on 07-Dec increased from 311 to 497 km/s, and is currently near 488 km/s. The peak total interplanetary field strength (IMF, Bt) was 21 nT, and the north-south IMF component (Bz) range was +17 to -14 nT. An interval of southward IMF conditions was observed 07/0920-1550UT. Solar wind conditions are elevated due to a solar coronal hole and the wind speed is expected to be elevated over the interval 08-09 Dec. ----------------------------------------------------------- 2A. MAGNETIC SUMMARY Geomagnetic field for Australian Region 07 Dec: G0 Estimated Indices 07 Dec : A K Australian Region 10 10024333 Cocos Island 8 01123332 Darwin - -------- Townsville 10 21033333 Learmonth 11 11034333 Alice Springs 7 00023332 Gingin 10 10024333 Canberra 11 10034333 Hobart 8 00024332 Estimated Antarctic Regional K Indices 07 Dec : Macquarie Island 22 00045632 Casey 15 13334333 Mawson 22 32243535 Observed Regional daily pc3 Indices 07 Dec : Darwin NA Townsville 2 (Quiet) Learmonth 0 (Quiet) Alice Springs 0 (Quiet) Gingin 0 (Quiet) Canberra 0 (Quiet) Hobart 2 (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 07 Dec : A Fredericksburg 11 Planetary 19 Observed AFr/Ap Indices 06 Dec : A K Fredericksburg 2 Planetary 2 0100 1101 2B. MAGNETIC FORECAST Date Ap Conditions 08 Dec 18 G0, isolated G1 periods possible 09 Dec 16 G0, isolated G1 periods possible 10 Dec 10 G0 COMMENT: ASWFC Geomagnetic Warning 57 was issued on 3 December and is current for 7-9 Dec. G0 geomagnetic conditions were observed in the Australian region on 07-Dec, with mildly elevated geomagnetic activity associated with the Earth's entry into a coronal hole wind stream. Mostly G0 conditions were observed in the Antarctic region on 07-Dec, with a period of G1 and G2 observed at Macquarie Island and two isolated periods of G1 at Mawson. G0 geomagnetic conditions are generally expected over 08-09 Dec, with isolated G1 periods possible due to continuing high speed wind stream effects. ----------------------------------------------------------- 3A. GLOBAL HF PROPAGATION SUMMARY Latitude Band Date Low Middle High 07 Dec Normal Normal-fair Fair PCA Event : No event. 3B. GLOBAL HF PROPAGATION FORECAST Latitude Band Date Low Middle High 08 Dec Normal Normal-fair Fair 09 Dec Normal Normal-fair Fair 10 Dec Normal Normal Normal-fair COMMENT: Mildly degraded conditions are expected during 08-09 Dec for middle to high latitudes particularly during local night hours, due to coronal hole high speed wind stream effects. Isolated shortwave fadeouts are possible. ----------------------------------------------------------- 4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY Date T index 07 Dec 101 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 15% during local day. Enhanced by 65% during local night. Niue Island Region: Near predicted monthly values. Northern Australian Region: Near predicted monthly values during local day. Enhanced by 20% during local night. Enhanced by 15-20% after local dawn. Southern Australian Region: Mostly near predicted monthly values. Depressed 20% to enhanced by 25% after local dawn. Antarctic Region (Casey/Scott Base/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Nov 77 Dec 70 Jan 70 4B. AUSTRALIAN REGION IONOSPHERIC FORECAST Date T index MUFs 08 Dec 70 Depressed 10 to 15%/near predicted monthly values 09 Dec 70 Depressed 10 to 15%/near predicted monthly values 10 Dec 70 Near predicted monthly values COMMENT: ASWFC Preliminary HF Communications Warning 97 was issued on 6 December and is current for 7-9 Dec. Maximum usable frequencies (MUFs) in the Australian region on UT day 07-Dec were generally near predicted monthly values to 25% enhanced, with strong enhancements observed at Cocos Island. MUFs have been quite variable after local dawn this morning with some sites 20% enhanced whilst others 15% depressed. The regional ionosphere appears to have shown an unexpected positive response to the onset of mild geomagnetic activity associated with the Earth's entry into a coronal hole wind stream. Spread F was observed at Hobart during local night hours. Occasional blanketing sporadic E was observed at some sites. The ionosphere at Darwin and Townsville appeared briefly disturbed after local dawn this morning. MUFs are expected to be generally near predicted monthly values with depressions of 15% possible over 08-09 Dec for the southern Australian region due to a mild increase in geomagnetic activity expected during this period. ----------------------------------------------------------- 5. SPACE ENVIRONMENT SUMMARY GOES satellite data for 06 Dec Daily Proton Fluence >1 MeV: 6.7E+04 Daily Proton Fluence >10 MeV: 3.3E+04 Daily Electron Fluence >2 MeV: 8.80E+07 (normal fluence) Electron Fluence Daily Deep Dielectric Discharge Probability:10% Fluence (flux accumulation over 24hrs)/ cm2-ster-day. X-ray background: B5.1 DSCOVR Satellite Solar Wind Day Averaged Data for 06 Dec Speed: 396 km/sec Density: 3.0 p/cc Temp: 100000 K Bz: -1 nT (Courtesy Space Weather Prediction Center, Boulder USA) -----------------------------------------------------------