[Ips-dsgr] ASWFC Daily Report - 18 September 24 issued 2330 UT on 18 Sep 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Sep 19 09:30:48 AEST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 SEPTEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 SEPTEMBER AND FORECAST FOR 19 SEPTEMBER - 21 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 18 Sep: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Sep: 163/117
1B. SOLAR FORECAST
19 Sep 20 Sep 21 Sep
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible Possible Possible
10.7cm/SSN 162/116 155/109 155/109
COMMENT: Solar activity on UT day 18-Sep was at the R0 level,
with several C-class flares observed. There are currently six
numbered sunspot regions visible on the solar disk. AR3825 (S15W00,
gamma) is the largest and most magnetically complex region on
the disk but showed decay in its trailer spots over the UT day.
AR3824 (S04W61, beta) and AR3828 (S12E47, beta) both showed trailer
development on 18-Sep. All other sunspot regions are either stable
or in decay. Solar activity is expected to be at the R0 level,
with a chance of R1 over 19-21 Sep. S0 solar proton storm conditions
were observed on 18-Sep. The solar proton flux was elevated but
declined to background levels over the UT day. S0 conditions
are expected over 19-21 Sep. No Earth-directed CMEs have been
observed. A south directed CME was observed from 18/0624UT in
SOHO and STEREO-A imagery. This is considered a farside event.
A southwest directed CME was observed from 18/1236UT in SOHO
and STEREO-A imagery associated with an eruption off the eastern
limb at around S20 from 18/1215UT in SDO and GOES SUVI imagery.
This CME is not considered geoeffective. A small filament eruption
was observed in H-Alpha, SDO and GOES SUVI imagery from 18/1735UT
at around N15W60. No associated CME is visible in currently available
coronagraph imagery. Further analysis will be performed once
more imagery is available. The solar wind speed on UT day 18-Sep
decreased, ranging from 390 to 526 km/s and is currently near
470 km/s. The peak total interplanetary field strength (IMF,
Bt) was 9 nT and the north-south IMF component (Bz) range was
+6 to -7 nT. A sustained period of -Bz began at 18/2100UT and
is ongoing. The solar wind speed is expected to slowly decline
towards background levels over 19-21 Sep as CME and coronal hole
high speed wind stream effects wane.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 18 Sep: G0
Estimated Indices 18 Sep : A K
Australian Region 8 31112313
Cocos Island 5 31111202
Darwin 8 32112303
Townsville 7 32112213
Learmonth 8 31112313
Alice Springs 5 21012203
Gingin 6 31011303
Canberra 4 21001312
Kennaook Cape Grim 5 2111231-
Hobart 5 2111231-
Estimated Antarctic Regional K Indices 18 Sep :
Macquarie Island 8 22123321
Casey 15 34332224
Mawson 17 43233334
Observed Regional daily pc3 Indices 18 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 4 (Quiet)
Canberra 13 (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 18 Sep : A
Fredericksburg 9
Planetary 10
Observed AFr/Ap Indices 17 Sep : A K
Fredericksburg 39
Planetary 64 7756 6434
2B. MAGNETIC FORECAST
Date Ap Conditions
19 Sep 12 G0, chance of G1
20 Sep 8 G0
21 Sep 5 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 18-Sep. G0 geomagnetic conditions,
with a chance of G1 are expected on 19-Sep as CME and coronal
hole high speed wind stream effects wane. G0 geomagnetic conditions
are expected over 20-21 Sep.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
18 Sep Poor-fair Normal-poor Normal-poor
PCA Event : 10MeV Proton/PCA Event Began at 0735UT 17/09, Ended at 1425UT 17/09
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
19 Sep Normal Normal Normal-fair
20 Sep Normal Normal Normal-fair
21 Sep Normal Normal Normal
COMMENT: HF radio communication conditions on UT day 18-Sep were
poor at all latitudes for the first third of the UT day due to
recent geomagnetic activity, for the remainder of the day conditions
recovered to mostly normal at low and mid latitudes and poor
to fair at high latitudes. Mostly normal HF conditions are expected
over 19-21 Sep.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
18 Sep 147
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 50% during local day.
Enhanced by 30% during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Mostly near predicted monthly values.
Northern Australian Region:
Enhanced by 25% during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Monthly T index:
Month T index
Aug 159
Sep 117
Oct 116
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
19 Sep 155 Near to 15% above predicted monthly values
20 Sep 155 Near to 15% above predicted monthly values
21 Sep 155 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 18-Sep were generally near predicted monthly
values to 15-25% enhanced, with the strongest enhancements observed
during local day. Spread F was observed at Hobart during local
night hours. MUFs are expected to be near predicted monthly values
to 15% enhanced over 19-21 Sep.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 17 Sep
Daily Proton Fluence >1 MeV: 9.5E+07
Daily Proton Fluence >10 MeV: 8.4E+05
Daily Electron Fluence >2 MeV: 1.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.1
DSCOVR Satellite Solar Wind Day Averaged Data for 17 Sep
Speed: 512 km/sec Density: 4.3 p/cc Temp: 197000 K Bz: -5 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list