[Ips-dsgr] ASWFC Daily Report - 18 October 23 issued 2330 UT on 18 Oct 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Thu Oct 19 10:30:11 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 OCTOBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 OCTOBER AND FORECAST FOR 19 OCTOBER - 21 OCTOBER
STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 18 Oct: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Oct: 135/89
1B. SOLAR FORECAST
19 Oct 20 Oct 21 Oct
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 135/89 135/89 140/94
COMMENT: Solar activity on UT day 18-Oct was at the R0 level.
There are currently four numbered sunspot regions visible on
the solar disk and one unnumbered region. AR3465 (N10W22, beta)
is the most significant sunspot region on the solar disk, but
is magnetically simple and displayed decay in its trailer spots
over the UT day. A small, unnumbered region is visible at around
N28E60 with beta magnetic characteristics, it appears stable.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be at the R0 level over 19-21 Oct. A
southeast directed CME is visible in SOHO and STEREO-A imagery
from 18/0612UT. An associated eruption is visible on the solar
disk at around S20E40, visible from 18/0608UT in SDO, GOES SUVI
and H-alpha imagery. Modelling of this CME is currently low confidence
with any impact likely to be glancing at most on 21-Oct. A partial
halo CME is visible directed to the north-northwest in SOHO and
STEREO-A imagery from 18/0236UT. This CME is associated with
coronal dimming off the northwest limb in GOES SUVI and SDO imagery
from 18/0221UT. This CME is not considered geoeffective. A faint,
east directed, CME is visible in SOHO and STEREO-A imagery from
18/0412UT. This CME is associated with a filament eruption off
the east limb at around S10, visible in SDO, GOES SUVI and H-alpha
imagery. This CME is not currently considered geoeffective. The
solar wind speed on UT day 18-Oct increased, ranging from 284
to 473 km/s and is currently near 410 km/s. The peak total interplanetary
field strength (IMF, Bt) was 13 nT and the north-south IMF component
(Bz) range was +6 to -11 nT. A sustained period of mostly negative
Bz is visible from 18/1012UT to 18/1800UT. The enhancement in
solar wind speed and IMF conditions suggests the Earth has entered
a coronal hole high speed wind stream, possibly along with a
glancing CME impact. The solar wind is expected to remain moderately
elevated over 19-Oct. Further mild increases are possible on
20-21 Oct due to impacts from slow CMEs first observed on 16-17
Oct.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 18 Oct: Quiet to Unsettled
Estimated Indices 18 Oct : A K
Australian Region 9 02233322
Cocos Island 4 02122211
Darwin 8 03232312
Townsville 10 13233322
Learmonth 8 03132322
Alice Springs 8 02133321
Gingin 7 02133222
Canberra 7 02232222
Hobart 9 02233322
Estimated Antarctic Regional K Indices 18 Oct :
Macquarie Island 10 02125311
Casey 11 14323222
Mawson 18 23224444
Observed Regional daily pc3 Indices 18 Oct :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 9 (Quiet)
Hobart 10 (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 Oct : A
Fredericksburg 7
Planetary 8
Observed AFr/Ap Indices 17 Oct : A K
Fredericksburg 2
Planetary 2 0000 0002
2B. MAGNETIC FORECAST
Date Ap Conditions
19 Oct 12 G0
20 Oct 20 G0, chance of G1
21 Oct 20 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 18-Oct. G0 conditions were mostly observed in
the Antarctic region, with an isolated period of G1 at Macquarie
Island. G0 geomagnetic conditions are expected on 19-Oct. G0
conditions, with a chance of G1 are expected on 20-21 Oct due
to predicted impacts from slow CMEs first observed on 16-17 Oct.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
18 Oct Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
19 Oct Normal Normal Normal-fair
20 Oct Normal Normal-fair Fair
21 Oct Normal Normal-fair Fair
COMMENT: HF radio propagation conditions were mostly normal on
18-Oct. Mostly normal HF propagation conditions are expected
over 19-21 Oct, with mild degradations possible over 20-21 Oct
at high latitudes.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
18 Oct 144
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Enhanced by 45% 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 20% after local dawn.
Southern Australian Region:
Enhanced by 20% during local day.
Enhanced by 30% during local night.
Antarctic Region (Casey/Davis/Mawson):
Enhanced by 30% 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
19 Oct 140 Near to 15% above predicted monthly values
20 Oct 140 Near to 15% above predicted monthly values
21 Oct 140 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 18-Oct were
enhanced by up to 30% in the southern Australian region, with
the strongest enhancements being during local night. MUFs were
at near predicted monthly values during daylight hours in the
northern Australian region, with enhancements of up to 20% observed
during local night. MUFs are expected to be near predicted monthly
values to 15% enhanced over 19-21 Oct.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 17 Oct
Daily Proton Fluence >1 MeV: 4.1E+05
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 2.10E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.8
DSCOVR Satellite Solar Wind Day Averaged Data for 17 Oct
Speed: 299 km/sec Density: 1.6 p/cc Temp: 13400 K Bz: 0 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
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Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
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