[Ips-dsgr] ASWFC Daily Report - 08 September 25 issued 2330 UT on 08 Sep 2025 [SEC=OFFICIAL]

Tue Sep 9 09:30:45 AEST 2025

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/08 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 08 SEPTEMBER AND FORECAST FOR 09 SEPTEMBER - 11 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 08 Sep:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 08 Sep: 124/77

1B. SOLAR FORECAST
             09 Sep             10 Sep             11 Sep
Activity     R0 chance R1       R0 chance R1       R0 chance R1 
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   135/89             130/84             125/78

COMMENT: Solar activity on UT day 08-Sep was at R0. There are 
currently five numbered sunspot regions visible on the solar 
disk with AR4213 (S13E03, beta) being the most magnetically complex 
region and has showing growth in its intermediates over the UT 
day. AR4207 (S13E16,beta) and AR4210 (N08W26,beta) have also 
shown growth in its intermediates and over the UT day. All other 
sunspot regions are either stable or in decay. No earth directed 
CME's have been observed. Solar activity is expected to be at 
the R0 Level with a chance of R1 over 09-11 Sep. S0 solar radiation 
storm conditions were observed on UT day 08 Sep. S0 solar radiation 
storm conditions are expected over 09-11 Sep. A recurrent coronal 
hole spans across south west solar hemisphere, with most of the 
area now within a geoeffective range . The solar wind speed on 
UT day 08-Sep has remained steady ranging from 469 to 556 km/s 
and is currently near 485 km/s. The peak total interplanetary 
magnetic field strength (IMF, Bt) was 7 nT and the north-south 
IMF component (Bz) range was 6- to +5nT. The solar wind speed 
is expected to remain elevated and steady due to the wind stream 
from the coronal hole located in the southern western solar hemisphere.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 08 Sep: G0 chance of 
G1

Estimated Indices 08 Sep : A   K           
   Australian Region      12   33233322
      Cocos Island         6   32112221
      Darwin              12   33233322
      Townsville          12   33233322
      Learmonth           11   33233321
      Alice Springs       12   33233322
      Gingin              11   33233321
      Canberra            10   23233222
      Kennaook Cape Grim  12   33233322
      Hobart              12   33233322    

Estimated Antarctic Regional K Indices 08 Sep :
      Macquarie Island    23   32455422
      Casey               14   44332231
      Mawson              34   55534354

Observed Regional daily pc3 Indices 08 Sep : 
      Darwin               2   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               2   (Quiet)
      Canberra             2   (Quiet)
      Hobart              33   (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 08 Sep : A 
           Fredericksburg        12
           Planetary             14                         

Observed AFr/Ap Indices 07 Sep :  A   K
           Fredericksburg         4
           Planetary              5   1111 1113     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
09 Sep    12    G0 chance of G1
10 Sep    10    G0 chance of G1
11 Sep     9    G0 chance of G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 08-Sep. In the Antarctic region G0-G1 geomagnetic 
conditions were observed. G0 with a chance of G1 are expected 
on 09-11 Sep due to ongoing coronal hole wind stream influence.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
09 Sep      Normal         Normal         Normal-fair
10 Sep      Normal         Normal         Normal-fair
11 Sep      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 08-Sep were 
fair to normal. HF radio propagation conditions are generally 
expected to be mostly fair to normal over 09-11 Sep due to the 
recurrent coronal hole in a geoeffective region. Isolated minor 
shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
08 Sep   103

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 during local day.
      Depressed by 15% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 35% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Aug      96
Sep      92
Oct      90

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
09 Sep   100    Near predicted monthly values
10 Sep   100    Near predicted monthly values
11 Sep    95    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the northern Australian 
region on UT day 08-Sep were near predicted monthly values. Spread 
F was observed at Perth during local night hours and Hobart during 
dawn hours. Spread F is forecasted at high latitudes during local 
night due to the ongoing coronal hole. MUFs are expected to be 
near predicted monthly values on 09-11 Sep. Isolated minor shortwave 
fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 07 Sep
       Daily Proton Fluence >1 MeV:   6.6E+04
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 1.80E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.2

DSCOVR Satellite Solar Wind Day Averaged Data for 07 Sep
Speed: 539 km/sec  Density:    0.2 p/cc  Temp:   130000 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