[Ips-dsgr] ASWFC Daily Report - 21 October 23 issued 2331 UT on 21 Oct 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Oct 22 10:31:06 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 OCTOBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 OCTOBER AND FORECAST FOR 22 OCTOBER - 24 OCTOBER
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 21 Oct: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Oct: 123/76
1B. SOLAR FORECAST
22 Oct 23 Oct 24 Oct
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 122/75 120/72 118/70
COMMENT: On UT day 21-Oct solar activity was R0. The most significant
solar flares of the period were two low level C class flares
at 20/2330 UT and 21/0030 UT from AR3467. There are currently
six numbered sunspot regions on the solar disk, although two
of these regions are near the western limb. Sunspot region AR3470
(N28E22, beta) has shown some very minor growth. but otherwise
all sunspot regions are either stable or in decay. There were
no large or magnetically complex sunspot regions on the solar
disk on 21-Oct. Solar activity is expected to be R0 over 22-24
Oct.
Associated with the C flares from AR3467 was a partial filament
eruption. A CME can be observed to the solar southwest from approximately
21/0030 UT, but due to the timing of events it is unlikely this
CME is associated with the filament eruption. In the event that
the filament was the source of the CME, it may have a weak impact
on 25-Oct, although this is unlikely. A narrow CME was observed
from 21/0817 on the southwest solar limb, but this CME is not
considered geoeffective. No other significant CMEs were observed.
The solar wind speed on UT day 21-Oct was on a general declining
trend and ranged between 289 to 351 km/s. The peak total interplanetary
field strength (IMF, Bt) was 10 nT and the north-south IMF component
range was -1 to -10 nT. A slight enhancement to solar wind parameters
was observed from 20/1230 UT, although it is unclear if this
was due to a recent CME. The solar wind parameter Bz was oriented
southward for the entire day, but weakened to near -1 to -3 nT
by 1300 UT. The solar wind is expected to be near background
levels over 22-24 Oct.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 21 Oct: G0
Estimated Indices 21 Oct : A K
Australian Region 8 12332311
Cocos Island 6 02212410
Darwin 7 02322311
Townsville 8 12332311
Learmonth 7 02222411
Alice Springs 12 33332411
Norfolk Island 7 11332211
Gingin 9 12232421
Canberra 11 33332311
Hobart 16 225323--
Estimated Antarctic Regional K Indices 21 Oct :
Macquarie Island 24 34644310
Casey 8 03232311
Mawson 38 36533644
Observed Regional daily pc3 Indices 21 Oct :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 0 (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 21 Oct : A
Fredericksburg 16
Planetary 21
Observed AFr/Ap Indices 20 Oct : A K
Fredericksburg 8
Planetary 8 1222 3133
2B. MAGNETIC FORECAST
Date Ap Conditions
22 Oct 10 G0
23 Oct 6 G0
24 Oct 6 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 21-Oct, although many Australian sites observed
a K-index of 4. G0-G2 geomagnetic conditions were observed in
the Antarctica region. The planetary K-index observed two periods
of 5 (G1). The source for this geomagnetic activity may have
been from a weak CME impact as was forecasted, but more significantly
the solar wind parameter Bz was oriented southward for the entire
24-hour day at an average of -7 to -8 nT for most of it. Solar
wind parameter Bz has since become near neutral and no further
geomagnetic activity is expected. G0 geomagnetic conditions are
expected over 22-24 Oct.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
21 Oct Normal-fair Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
22 Oct Normal-fair Normal-fair Normal-fair
23 Oct Normal Normal-fair Normal-fair
24 Oct Normal Normal Normal
COMMENT: HF radio propagation conditions were mostly normal to
mildly degraded on 21-Oct due to geomagnetic activity that occurred
throughout the day. Mild depressions are expected to continue
over 22-23 Oct, particularly during local night hours. HF conditions
are expected to return to normal by 24-Oct.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
21 Oct 138
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 25% during local night.
Northern Australian Region:
Mostly near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Sep 104
Oct 98
Nov 96
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
22 Oct 110 Near predicted monthly values to 15% depressed
23 Oct 115 Near predicted monthly values to 15% depressed
24 Oct 120 Near predicted monthly values to 15% enhanced
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 21-Oct were mostly near predicted monthly values
to 15% enhanced, particularly during local night hours. Sporadic-E
was observed in Brisbane, Canberra and Perth during local night
hours. MUFs are expected to be near monthly predicted values
over 22-23 Oct, with a chance to be depressed by 15% due to recent
geomagnetic activity. MUFs are expected to be near predicted
values to 15% enhanced by 24-Oct.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 20 Oct
Daily Proton Fluence >1 MeV: 3.4E+05
Daily Proton Fluence >10 MeV: 2.0E+04
Daily Electron Fluence >2 MeV: 1.90E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B4.4
DSCOVR Satellite Solar Wind Day Averaged Data for 20 Oct
Speed: 352 km/sec Density: 2.6 p/cc Temp: 28500 K Bz: -2 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