[Ips-dsgr] ASWFC Daily Report - 29 July 23 issued 2330 UT on 29 Jul 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Jul 30 09:30:10 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 JULY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 JULY AND FORECAST FOR 30 JULY - 01 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 29 Jul: R1
Flares Max Fadeout Freq. Sectors
M1.4 1624UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 29 Jul: 179/132
1B. SOLAR FORECAST
30 Jul 31 Jul 01 Aug
Activity R0-R1, chance R2 R0-R1, chance R2 R0-R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 175/129 170/124 165/119
COMMENT: Solar activity on UT day 29-Jul was R1, with an M1.4
flare at 1624 UT from AR3380 (S21E36, beta). There are currently
11 numbered sunspot regions on the solar disk. AR3380 and AR3390
(S18E64, beta) have shown some growth over the period. New region
AR3391 region currently on the east limb near N22 has been producing
high level C-class flares and CMEs. All other sunspot regions
are either stable or in decay. Solar activity is expected to
be R0-R1 with a chance for R2 over 30-31 Jul and 01-Aug. A filament
that erupted from 28/2110 UT that produced a partial halo CME
has now been assessed. The CME is expected to have an Earth-directed
component that will arrive from 0000 UT on 01-Aug ± 10 hours.
A long duration C6 flare at 29/0734 UT from the AR3391 on the
eastern limb was associated with a CME but is not expected to
be geoeffective. No other significant CMEs were observed. The
solar wind speed on UT day 30-Jul was mostly steady and ranged
from 333 to 430 km/s. The peak total planetary field strength
(IMF, Bt) was 8 nT and the north-south IMF component (Bz) range
was +7 to -6 nT. The solar wind is expected to remain at background
levels over 30-31 Jul, but is expected to increase on 01-Aug
due to the arrival of a recent CME. The 10 MeV proton flux was
enhanced on 29-Jul due to events from ex-region AR3376, which
is now behind the western solar limb out of sight. S1 solar radiation
storm conditions were reached at 29/2350 UT and then reached
S2 solar radiation storm conditions over 0525 to 1205 UT. The
proton flux dropped back to S1 by this time, but has remained
enhanced. S1 solar radiation storm conditions are expected to
continue over 30-Jul, with a chance for low-level S2 conditions.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 29 Jul: G0
Estimated Indices 29 Jul : A K
Australian Region 5 22112221
Cocos Island 4 22111111
Darwin 5 11112222
Townsville 7 22113222
Learmonth 6 22112231
Alice Springs 4 21012221
Gingin 5 11112231
Canberra 5 12013221
Hobart 5 11013221
Estimated Antarctic Regional K Indices 29 Jul :
Macquarie Island 8 01015221
Casey 9 232321--
Mawson 18 45323332
Observed Regional daily pc3 Indices 29 Jul :
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 29 Jul : A
Fredericksburg 9
Planetary 10
Observed AFr/Ap Indices 28 Jul : A K
Fredericksburg 5
Planetary 6 1001 2233
2B. MAGNETIC FORECAST
Date Ap Conditions
30 Jul 10 G0
31 Jul 5 G0
01 Aug 30 G1-G2
COMMENT: Geomagnetic conditions in the Australian region on UT
day 29-Jul were G0. Geomagnetic conditions in the Antarctica
region reached G1 in Macquarie Island and Mawson. G0 geomagnetic
conditions are expected over 30-31 Jul. G1-G2 geomagnetic conditions
are expected on 01-Aug from 0000 UT ± 10 hours due to a CME first
observed from 28/2312 UT.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
29 Jul Fair Normal-fair Poor(PCA)
PCA Event : 10MeV Proton/PCA Event Began 29 07 2023 0035UT and is in progress
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
30 Jul Normal-fair Normal-fair Poor(PCA)
31 Jul Normal-fair Normal-fair Fair
01 Aug Normal-fair Normal-fair Fair
COMMENT: HF propagation conditions on UT day 29-Jul were mostly
normal with some degradations at low and high latitudes. Increased
absorption from a polar cap absorption (PCA) event that began
from 28/2350 UT led to degraded conditions in high latitudes.
Further degraded conditions in high latitudes are expected on
30-Jul, likely returning to normal by 31-Jul. Degraded conditions
are then expected to commence on 01-Aug due to anticipated geomagnetic
activity. Isolated shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
29 Jul 111
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Enhanced by 25% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
Proton event in progress, increased absorption observed.
Monthly T index:
Month T index
Jun 98
Jul 91
Aug 88
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
30 Jul 105 Near predicted monthly values
31 Jul 105 Near predicted monthly values
01 Aug 80 Near predicted monthly values to 15% depressed
COMMENT: ASWFC SWF HF Communications Warning 72 was issued on
29 July and is current for 28-30 Jul. Maximum usable frequencies
(MUFs) on UT day 29-Jul were mostly near predicted values. Spread-F
was observed at Canberra, Hobart and Perth during local night
hours. Sporadic-E was observed at Brisbane during local dawn.
MUFs are expected to remain near predicted values over 30-31
Jul, then experience some mild depressions of 15-20% over 01-Aug
due to expected geomagnetic activity from a CME first observed
on 28-Jul. Polar cap absorption (PCA) began from 28/2350 UT and
is currently in progress, causing degraded HF conditions, particularly
in high latitudes. The PCA is expected to continue over 30-Jul.
Isolated shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 28 Jul
Daily Proton Fluence >1 MeV: 4.7E+05
Daily Proton Fluence >10 MeV: 1.3E+05
Daily Electron Fluence >2 MeV: 2.80E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.6
DSCOVR Satellite Solar Wind Day Averaged Data for 28 Jul
Speed: 394 km/sec Density: 3.3 p/cc Temp: 60900 K Bz: 1 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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