[Ips-dsgr] ASWFC Daily Report - 22 August 25 issued 2330 UT on 22 Aug 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sat Aug 23 09:30:46 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 22 AUGUST AND FORECAST FOR 23 AUGUST - 25 AUGUST
STATUS INDICATORS SOL:GREEN   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 22 Aug:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.7    1851UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 22 Aug: 136/90


1B. SOLAR FORECAST
             23 Aug             24 Aug             25 Aug
Activity     R0, chance of R1   R0, chance of R1   R0, chance of R1
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   138/92             145/99             140/94

COMMENT: Solar activity on UT day 22-Aug was at the R1 level, 
due to an M1.7 flare at 22/1900UT from over the eastern limb. 
There are currently four numbered sunspot regions visible on 
the solar disk which are all magnetically simple and have no 
flaring history. AR4191 (N13E56, beta) is the largest region 
on the solar disk and appeared stable over the UT day. All other 
sunspot regions are either stable or in decay. Solar activity 
is expected to be at the R0 level over 23-25 Aug, with a chance 
of R1. Solar proton conditions were enhanced but well below the 
S1 level on UT day 22-Aug. S0 solar proton conditions are expected 
over 23-25 Aug. No significantly Earth-directed CMEs were observed 
on 22-Aug. A broad, east directed partial halo CME was observed 
from 22/0624UT in SOHO and STEREO-A imagery. This CME is associated 
with faint movement behind the southeast limb as observed in 
SDO imagery from 22/0540UT. Modelling indicates this CME presents 
the chance of a glancing impact with Earth late on 25-Aug. A 
broad, fast, east directed partial halo CME is visible from 22/1938UT 
in STEREO-A imagery only due to a current SOHO data gap. This 
CME is associated with an eruption off the eastern limb, visible 
from 22/1811UT in SDO imagery at around S17 and concurrent with 
the M1.7 flare at 22/1900UT. This CME appears to mostly be directed 
well to the east and thus is not expected to be significantly 
geoeffective. Further analysis will be performed when more coronagraph 
imagery becomes available. The solar wind speed on UT day 22-Aug 
was largely steady, ranging from 460 to 570 km/s and is currently 
near 500 km/s. The peak total interplanetary magnetic field strength 
(IMF, Bt) was 7 nT and the north-south IMF component (Bz) range 
was -5 to +5 nT. The solar wind speed is expected to decline 
gradually towards background levels as coronal hole high speed 
wind stream effects wane. An increase in wind speed is possible 
on 25-Aug due to a coronal hole in the northern hemisphere rotating 
towards a geoeffective position.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 22 Aug: G0

Estimated Indices 22 Aug : A   K           
   Australian Region       5   32101211
      Cocos Island         4   22111210
      Darwin               5   22101222
      Townsville           5   32101122
      Learmonth            6   32112221
      Alice Springs        4   32101111
      Gingin               5   32101220
      Canberra             3   22101111
      Kennaook Cape Grim   5   32101211
      Hobart               3   22101111    

Estimated Antarctic Regional K Indices 22 Aug :
      Macquarie Island     4   22102111
      Casey               11   44301222
      Mawson              24   64221253

Observed Regional daily pc3 Indices 22 Aug : 
      Darwin               8   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               8   (Quiet)
      Canberra            36   (Quiet to unsettled)
      Hobart              28   (Quiet to 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 Aug : A 
           Fredericksburg         8
           Planetary              8                         

Observed AFr/Ap Indices 21 Aug :  A   K
           Fredericksburg         8
           Planetary              8   3211 1122     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
23 Aug     6    G0
24 Aug     6    G0
25 Aug    10    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 22-Aug. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with isolated periods of G1 
and G2 observed at Mawson. G0 geomagnetic conditions are expected 
over 23-25 Aug.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
22 Aug      Normal         Normal         Normal-fair    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
23 Aug      Normal         Normal         Normal
24 Aug      Normal         Normal         Normal
25 Aug      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 22-Aug were 
mostly normal. HF radio propagation conditions are expected to 
be mostly normal over 23-25 Aug.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
22 Aug    94

Observed Australian Regional MUFs
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   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
Jul      88
Aug      96
Sep      93

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
23 Aug    98    Near predicted monthly values
24 Aug    98    Near predicted monthly values
25 Aug    98    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 23-Aug were near predicted monthly values. Spread 
F was observed at Hobart and Brisbane during local night hours. 
Sporadic E was observed at Brisbane and Learmonth. MUFs are expected 
to be near predicted monthly values over 23-25 Aug.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 21 Aug
       Daily Proton Fluence >1 MeV:   2.8E+05
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 3.90E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.9

DSCOVR Satellite Solar Wind Day Averaged Data for 21 Aug
Speed: 481 km/sec  Density:    2.2 p/cc  Temp:    76200 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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