[Ips-dsgr] ASWFC Daily Report - 21 August 24 issued 2334 UT on 21 Aug 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Aug 22 09:34:57 AEST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 AUGUST 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 AUGUST AND FORECAST FOR 22 AUGUST - 24 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 21 Aug: R2
Flares Max Fadeout Freq. Sectors
M1.1 0602UT possible lower Mid East/Indian
M5.1 2208UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Aug: 239/188
1B. SOLAR FORECAST
22 Aug 23 Aug 24 Aug
Activity R1-R2 R1-R2 R1-R2
Fadeouts Possible Possible Possible
10.7cm/SSN 240/189 240/189 245/195
COMMENT: Solar activity on UT day 21-Aug was at the R2 level
due an M5.1 flare from solar region AR3796 (N04E30, beta-delta).
This region also produced the M1 class flare. Solar region AR3790
(S13W07, beta) is the largest region on the solar disk though
is currently a more magnetically simple bipolar group and has
produced little activity in the past 24 hours. Solar region AR3796
is showing rapid growth in its trailer spots. Solar region AR3790
has shown decline in its intermediate spots with penumbral growth
in its leader and trailer spots. Solar region AR3792 (S17E09,
beta) which has been a large single monopole spot now has small
trailer spots. Solar region AR3794 (N17W20, beta) showed initial
decay in its trailers then redevelopment. There are currently
eleven numbered sunspot regions visible on the solar disk. All
other sunspot regions are either stable or in decay. Solar activity
is expected to be at the R1-R2 level over 22-24 Aug, Small localised
plasma diming was observed south of solar region AR3794 in SDO193
imagery from 21/0547UT. A small 5 degree long solar filament
in the neutral line of AR3793 erupted from 21/1244-1305UT followed
by a dark surge/spray southward visible in GONG H-alpha imagery.
An area of plasma diming formed during the interval 21/1717-2108UT
in SDO193 imagery. The small filament then subsequently reformed.
No significantly Earth directed CME was observed. Two northwest
directed CMEs were observed from 21/0549 and 21/1505UT. It is
possible that the on disk activity observed in SDO imagery is
related to these CMEs. However the use of STEREOA imagery suggests
that they are possibly farside CMEs due to longitude mismatch.
A model run was conducted using LASCO imagery assuming front
side activity and showed a minor arrival is possible 24/1800UT.
A narrow westward CME was observed from 21/0304UT. A very narrow
east directed CME was observed from 21/0436UT which was associated
with solar spray activity on the eastern solar limb visible in
GOES SUVI. The solar wind speed on UT day 21-Aug declined, ranging
from 295 to 353 km/s and is currently near 304 km/s. The peak
total interplanetary field strength (IMF, Bt) was 7 nT and the
north-south IMF component (Bz) range was +4 to -6 nT. The solar
wind speed may mildly increase over 22-23 Aug due to weak coronal
hole high speed wind stream effects.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 21 Aug: G0
Estimated Indices 21 Aug : A K
Australian Region 4 21212111
Cocos Island 3 22111100
Darwin 4 21211112
Townsville 6 22222112
Learmonth 6 31222111
Alice Springs 4 21212111
Gingin 6 31212121
Canberra 4 21211111
Kennaook Cape Grim 5 21212211
Hobart 4 21212111
Estimated Antarctic Regional K Indices 21 Aug :
Macquarie Island 6 11233210
Casey 8 33321111
Mawson 20 53223443
Observed Regional daily pc3 Indices 21 Aug :
Darwin 0 (Quiet)
Townsville 2 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 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 Aug : A
Fredericksburg 8
Planetary 8
Observed AFr/Ap Indices 20 Aug : A K
Fredericksburg 9
Planetary 11 3222 2332
2B. MAGNETIC FORECAST
Date Ap Conditions
22 Aug 6 G0
23 Aug 6 G0
24 Aug 12 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 21-Aug. Mostly G0 geomagnetic conditions were
observed in the Antarctic region, with an isolated period of
G1 observed at Mawson. G0 geomagnetic conditions are expected
over 22-24 Aug. There is a chnace for a slight increase in geomagnetic
activity on 24-Aug.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
21 Aug Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
22 Aug Normal Normal Normal
23 Aug Normal Normal Normal
24 Aug Normal Normal Normal-fair
COMMENT: HF radio communication conditions on UT day 21-Aug were
normal. HF radio communication conditions are expected to be
generally normal over 22-24 Aug. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
21 Aug 162
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 40% during local day.
Enhanced by 55% during local night.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 65% during local night.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 25% during local night.
Southern Australian Region:
Enhanced by 15% during local day.
Enhanced by 20% during local night.
Enhanced by 20% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jul 131
Aug 119
Sep 119
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
22 Aug 160 15 to 25% above predicted monthly values
23 Aug 160 15 to 25% above predicted monthly values
24 Aug 160 15 to 25% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 21-Aug were 15-25% enhanced. Ionospheric scintillation
was observed at Niue during the interval 21/0720-1040UT. Strong
range spread was observed at Niue 21/0800UT and 1000UT. MUFs
were strongly enhanced at Niue and Cocos Island during local
night hours. MUFs are expected to be 15-25% enhanced over 22-24
Aug. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 20 Aug
Daily Proton Fluence >1 MeV: 3.5E+04
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 1.10E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C3.0
DSCOVR Satellite Solar Wind Day Averaged Data for 20 Aug
Speed: 337 km/sec Density: 1.7 p/cc Temp: 43900 K Bz: -3 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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