[Ips-dsgr] ASWFC Daily Report - 22 April 25 issued 2330 UT on 22 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Apr 23 09:30:50 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 22 APRIL AND FORECAST FOR 23 APRIL - 25 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 22 Apr: R1
Flares Max Fadeout Freq. Sectors
M1.3 1049UT possible lower European
Observed 10.7 cm flux/Equivalent Sunspot Number for 22 Apr: 163/117
1B. SOLAR FORECAST
23 Apr 24 Apr 25 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 160/114 160/114 165/119
COMMENT: Solar activity on UT day 22-Apr was R1, with an isolated
M1 solar flare from off the western limb, due to two contributing
regions: a region not in view but has been relatively active
recently, and also AR4065 (S30W01, beta). There are currently
eight numbered sunspot regions on the solar disk. AR4064 (N11W05,
beta), AR4067 (S03E01, beta) and AR4070 (s13E40, beta) have all
shown some minor growth over the past day, with AR6064's polarities
diverging away from one another. Solar activity is expected to
be R0-R1 over 23-25 Apr.
Several CMEs were observed on UT day 22-Apr. Associated with the flare
event from AR4065 was a southward directed CME from 1012 UT. Modelling
indicates this may graze the Earth late on 24-Apr UT day. No other
CMEs were considered to be geoeffective.
S0 solar radiation storm conditions were observed on UT day 22-Apr.
S0 solar radiation storm conditions are expected over 23-25 Apr.
The solar wind environment on UT day 22-Apr was mostly steady.
The solar wind speed remained high and ranged from 700 km/s near
the start of the day, trending to near 600 km/s. The peak total
interplanetary field strength (IMF, Bt) dereased from yesterday's
co-rotating interaction region (CIR), reaching 9 nT. The north-south
IMF component range (Bz) was +6 to -5 nT. The large coronal hole in the
southern solar hemisphere, responsible for the CIR, may fluctuate in
its connection to Earth over the next few days due to its latitude possibly
being slightly too high. The solar wind speed is still expected
to remain mostly elevated over 23-25 Apr, with a small CME impact
om late 24-Apr.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 22 Apr: G0
Estimated Indices 22 Apr : A K
Australian Region 6 22211222
Cocos Island 5 22210221
Darwin 6 22211222
Townsville 6 2--12222
Learmonth 7 32212222
Alice Springs 5 22201222
Gingin 7 32211222
Canberra 5 22201222
Kennaook Cape Grim 7 22311222
Hobart 7 22311222
Estimated Antarctic Regional K Indices 22 Apr :
Macquarie Island 8 32321212
Casey 11 34321222
Mawson 30 34542436
Observed Regional daily pc3 Indices 22 Apr :
Darwin 11 (Quiet)
Townsville 48 (Unsettled)
Learmonth 12 (Quiet)
Alice Springs 2 (Quiet)
Gingin 73 (Active)
Canberra 69 (Active)
Hobart 55 (Unsettled)
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 22 Apr : A
Fredericksburg 16
Planetary 22
Observed AFr/Ap Indices 21 Apr : A K
Fredericksburg 0
Planetary 0 4544 5442
2B. MAGNETIC FORECAST
Date Ap Conditions
23 Apr 16 G0-G1, chance G2
24 Apr 16 G0-G1, chance G2
25 Apr 16 G0-G1, chance G2
COMMENT: G0 Geomagnetic conditions were observed in the Australian
region on UT day 22-Apr. G0-G1 geomagnetic conditions were observed
in the Antarctic region. G0-G1 geomagnetic conditions are expected
over 23-25 Apr with a chance of G2. The large coronal hole in
the southern solar hemisphere may fluctuate in its connection
with Earth over this period. A weak glancing blow from a CME
first seen on 22-Apr may arrive late on 24-Apr.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
22 Apr Normal-fair Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
23 Apr Normal-fair Normal-fair Fair
24 Apr Normal-fair Normal-fair Fair
25 Apr Normal-fair Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 22-Apr were
normal to fair, with some degradations in high latitudes. Mid
latitudes were generally normal with isolated bouts of degradations
throughout the day. HF radio propagation conditions are expected
to be normal to fair over 23-25 Apr, with the worst conditions
being at high latitudes.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
22 Apr 113
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 75% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Monthly T index:
Month T index
Mar 126
Apr 115
May 113
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
23 Apr 100 Depressed 10 to 20%/near predicted monthly values
24 Apr 105 Depressed 10 to 20%/near predicted monthly values
25 Apr 100 Depressed 10 to 20%/near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 41 was issued on
22 April and is current for 22-23 Apr. Maximum usable frequencies
(MUFs) in the Australian region on UT day 22-Apr were near predicted
values to 15% depressed. Conditions were a little degraded with
spread-F being present in Hobart and sporadic-E in Learmonth
during local night hours. MUFs are expected to be near predicted
values to 10-20% depressed over 23-25 Apr, however may fluctuate
through out the period.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 21 Apr
Daily Proton Fluence >1 MeV: 1.5E+06
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 1.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 21 Apr
Speed: 632 km/sec Density: 2.4 p/cc Temp: 348000 K Bz: 0 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