[Ips-dsgr] ASWFC Daily Report - 28 July 24 issued 2335 UT on 28 Jul 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Jul 29 09:35:57 AEST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 JULY 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 JULY AND FORECAST FOR 29 JULY - 31 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 Jul: R2
Flares Max Fadeout Freq. Sectors
M7.8 0151UT probable lower West Pacific
M9.9 0157UT probable lower West Pacific
M1.0 1009UT possible lower European
M7.7 1042UT probable lower European
M1.3 1826UT possible lower East Pacific/
North American
M1.9 2036UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Jul: 214/165
1B. SOLAR FORECAST
29 Jul 30 Jul 31 Jul
Activity R1-R2 R1-R2 R1-R2
Fadeouts Probable Probable Probable
10.7cm/SSN 210/161 210/161 200/152
COMMENT: Solar activity on UT day 28-Jul was R2. Solar region
AR3766(S07E01, beta-gamma-delta) produced the M7.8, M9.9 and
M2.6 flares. These flares were short in duration. Solar region
AR3762(S10W45, beta-gamma-delta) produced the M1.5 and M7.7 flares.
The M1.3 flare is most likely from AR3765(S11E09, beta-gamma)
or possibly AR3762 due to near simultaneous optical emission
at the time of the X-ray flare. Solar region AR3762 which was
recently the most significant region on the disk is now is rapid
decay. A nearby smaller region AR3768(S16W28,beta-gamma) is currently
developing in size and complexity. Solar region AR3765 has shown
significant rapid growth of its intermediate spots and is now
the largest region on the solar disk. Nearby solar region AR3766
is showing growth in its leader spots. New smaller region AR3770(N07E09,
beta-gamma) has rapidly developed. There are currently nine numbered
solar regions on the visible solar disk with a small unnumbered
region emerging near S03W26. Solar flare activity is expected
to be R1-R2 over 29-31 Jul. Earth-directed CMEs were observed
on 28-Jul. The M7.8 and M9.9 twin flares were followed by a halo
CME which appears to be a mix of shock and plasma ejecta. Event
modelling shows an arrival 31-Jul at 1400UT +/- 12 hours. Whilst
the more central location of this event gives high confidence
of a shock arrival, the flare parameters and the CME structure
suggests that it is possible that any induced geomagnetic activity
from this event may be shorter in duration. The M7.7 flare at
28/1042UT appears to be followed by a narrow northwest CME first
visible from 28/1248UT. Event modelling shows an Earth miss,
with a possible slight graze on 01-Aug at 1900UT +/- 12 hours.
>From 28/1505UT in LASCO C2 either simultaneous northeast and
southeast directed CMEs or possibly a halo CME was observed.
Assessment is difficult due to CME overlap with the earlier northwest
directed CME. The CME activity visible from 28/1505UT is currently
considered far side. A bright northeast directed CME was observed
earlier in the UT day from 28/0536UT and is considered non Earth
directed and could not be associated with on disk activity. S0
solar radiation storm conditions were observed on 28-Jul. S0,
slight chance S1 solar radiation storm conditions are expected
over 29-31 Jul. The solar wind speed on UT day 28-Jul was steady,
ranging from 375 to 430 km/sec and is currently at 384 km/sec.
The peak total interplanetary field strength (IMF, Bt) was 6
nT and the north-south IMF component range (Bz) was +5 to -5
nT. A sequence of CME arrivals is expected over the next few
days. A glancing blow CME is expected late in the UT day on 29-Jul
followed by CME arrivals near middle of the UT day on 30-Jul
and on 31-Jul.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 28 Jul: G0
Estimated Indices 28 Jul : A K
Australian Region 4 22112111
Cocos Island 3 21111120
Darwin 4 22111112
Townsville 5 22112112
Learmonth 7 32212122
Alice Springs 3 21111012
Gingin 5 22112122
Canberra 3 11112111
Kennaook Cape Grim 4 12112111
Hobart 5 12113111
Estimated Antarctic Regional K Indices 28 Jul :
Macquarie Island 4 01013121
Casey 9 33322122
Mawson 21 43232255
Observed Regional daily pc3 Indices 28 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 4 (Quiet)
Canberra 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 28 Jul : A
Fredericksburg 6
Planetary 7
Observed AFr/Ap Indices 27 Jul : A K
Fredericksburg 14
Planetary 16 2334 4332
2B. MAGNETIC FORECAST
Date Ap Conditions
29 Jul 18 G0-G1, chance G2 late in UT day
30 Jul 50 G2
31 Jul 45 G2
COMMENT: ASWFC Geomagnetic Warning 36 was issued on 28 July and
is current for 29-31 Jul. G0 geomagnetic conditions were observed
in the Australian region on UT day 28-Jul. Mostly G0 conditions
were observed in Antarctica, with isolated period of G1 observed
at Mawson. Geomagnetic storm activity is expected over the next
few days, with G1, chance G2 conditions expected from late in
the UT day on 29-Jul, increasing to G2 conditions on 30-Jul and
on 31-Jul due to a sequence of anticipated CME arrivals. There
is a chance for an isolated G3 period during the interval
30 and 31-Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
28 Jul Normal Normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
29 Jul Normal Normal-fair Fair
30 Jul Normal Fair-poor Poor
31 Jul Normal Fair-poor Poor
COMMENT: HF radio communication conditions on UT day 28-Jul were
mostly fair to normal. HF radio communication conditions are
expected to be become degraded for middle to high latitudes from
late 29-Jul and on 30-31 Jul due to anticipated CME arrivals. Isolated
fadeouts are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
28 Jul 117
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jun 120
Jul 118
Aug 117
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
29 Jul 120 Near predicted monthly values
30 Jul 90 Depressed 10 to 15%/near predicted monthly values
31 Jul 80 Depressed 10 to 20%/near predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 80 was issued
on 28 July and is current for 31 Jul to 1 Aug. ASWFC SWF HF Communications
Warning 81 was issued on 28 July and is current for 28-30 Jul.
Maximum usable frequencies (MUFs) on UT day 28-Jul were near
predicted values in the Australian region, with 15% depressions
during local night hours in the northern Australian region. Spread
F was observed at Hobart during local night hours. A fadeout
was observed 28/0146-0237UT. MUFs are expected to be near predicted
values on 29-Jul. MUFs may become 15% depressed after local dawn
on 30-Jul and on 31-Jul due to anticipated geomagnetic activity
induced from recent CMEs. Isolated fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 27 Jul
Daily Proton Fluence >1 MeV: 1.0E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 3.40E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.8
DSCOVR Satellite Solar Wind Day Averaged Data for 27 Jul
Speed: 433 km/sec Density: 0.1 p/cc Temp: 73000 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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