[Ips-dsgr] ASWFC Daily Report - 31 July 25 issued 2332 UT on 31 Jul 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Aug 1 09:32:28 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 JULY AND FORECAST FOR 01 AUGUST - 03 AUGUST
STATUS INDICATORS SOL:GREEN   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Jul:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Jul: 145/99


1B. SOLAR FORECAST
             01 Aug             02 Aug             03 Aug
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   145/99             145/99             145/99

COMMENT: Solar activity on UT day 31-Jul was at the R0 level, 
with no significant flaring activity. There are currently nine 
numbered sunspot regions visible on the solar disk. Newly numbered 
AR4167 (N07W09, beta) is currently the most notable sunspot region 
due to its recent growth on the solar disk. AR4166 (N20W39, beta) 
has also shown slight growth 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 01-03 Aug. S0 solar proton conditions 
were observed on UT day 31-Jul. S0 solar proton conditions are 
expected over 01-03 Aug. No significant Earth-directed CMEs have 
been observed. The solar wind speed over 31-Jul mildly decreased, 
ranging from 380 to 475 km/s and is currently near 450 km/s. 
The peak total interplanetary magnetic field strength (IMF, Bt) 
was 9 nT and the north-south IMF component (Bz) range was -6 
to +8 nT. The solar wind speed is expected to remain near background 
levels over 01-03 Aug.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 31 Jul: G0

Estimated Indices 31 Jul : A   K           
   Australian Region       5   21122211
      Cocos Island         4   21211120
      Darwin               6   21222222
      Townsville           7   22223211
      Learmonth            6   21222221
      Alice Springs        5   22112211
      Gingin               6   21113221
      Canberra             5   11123211
      Kennaook Cape Grim   6   21123211
      Hobart               6   21123211    

Estimated Antarctic Regional K Indices 31 Jul :
      Macquarie Island     5   10024210
      Casey               13   34422222
      Mawson              21   54332244

Observed Regional daily pc3 Indices 31 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 31 Jul : A 
           Fredericksburg         9
           Planetary             10                         

Observed AFr/Ap Indices 30 Jul :  A   K
           Fredericksburg         9
           Planetary              8   3212 2321     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
01 Aug     6    G0
02 Aug     5    G0
03 Aug     5    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region and a period of G1 at Mawson on UT day 31-Jul. G0 geomagnetic 
conditions are expected over 01-03 Aug.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
01 Aug      Normal         Normal         Normal-fair
02 Aug      Normal         Normal         Normal
03 Aug      Normal         Normal         Normal

COMMENT: HF radio propagation conditions on UT day 31-Jul were 
mostly normal, with periods of fair conditions at high latitudes. 
HF radio propagation conditions are expected to be mostly normal 
over 01-03 Aug.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
31 Jul   102

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 25% during local day.
      Enhanced by 20% during local night.
   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):
      Depressed by 15% over the UT day.

Monthly T index:
Month  T index
Jun      79
Jul      104
Aug      102

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
01 Aug   100    Near predicted monthly values
02 Aug   100    Near predicted monthly values
03 Aug   100    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 31-Jul were 
near predicted monthly values in the Australian region. Spread 
F was observed during local night hours at Townsville, Brisbane, 
Canberra, Hobart and Learmonth. Ionospheric scintillation was 
observed at Niue at 31/0808UT. MUFs are expected to be near predicted 
monthly values over 01-03 Aug.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 30 Jul
       Daily Proton Fluence >1 MeV:   3.4E+05
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 2.60E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.8

DSCOVR Satellite Solar Wind Day Averaged Data for 30 Jul
Speed: 419 km/sec  Density:    1.0 p/cc  Temp:   123000 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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