[Ips-dsgr] ASWFC Daily Report - 09 September 25 issued 2330 UT on 09 Sep 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Wed Sep 10 09:30:49 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/09 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 09 SEPTEMBER AND FORECAST FOR 10 SEPTEMBER - 12 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 09 Sep:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 09 Sep: 121/73


1B. SOLAR FORECAST
             10 Sep             11 Sep             12 Sep
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   125/78             125/78             120/72

COMMENT: Solar activity on UT day 09-Sep was at R0 with only 
C class flares observed. There are currently seven numbered and 
two unnumbered sunspot regions visible on the solar disk with 
AR4213 (S13E03, beta) being the most magnetically complex region 
which has shown slight decay in its intermediates over the UT 
day. AR4214 (N05W36, beta) is a new spot which has shown growth 
through the UT day. Unnumbered spots (N22W12, beta) and (N15W03, 
alpha) are new spots showing 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 with a chance of R1 over 10-12 
Sep. A CME was observed from around the western limb from 09/1224UT 
bit is considered farside and therefore not geoeffective. North 
directed filament eruptions have continued from near AR4207 (N31W53, 
beta) which has been associated with narrow CME's which are not 
considered geoeffective. No other CME's were observed. S0 solar 
radiation storm conditions were observed on UT day 09 Sep. S0 
solar radiation storm conditions are expected over 10-12 Sep. 
A recurrent coronal hole in the south western hemisphere was 
in a geoeffective position throughout the UT day. The solar wind 
speed on UT day 09-Sep has remained steady ranging from 410 to 
580 km/s and is currently near 510 km/s. The peak total interplanetary 
magnetic field strength (IMF, Bt) was 8 nT and the north-south 
IMF component (Bz) range was -7 to +5nT. The solar wind speed 
is expected to start to slowly decline due to the wind stream 
from the coronal hole located in the southern western solar hemisphere 
starting to move out of a geoeffective position through the UT 
day.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 09 Sep: G1

Estimated Indices 09 Sep : A   K           
   Australian Region       9   22222224
      Cocos Island         7   22221123
      Darwin              11   32322224
      Townsville          11   22332224
      Learmonth            8   22322123
      Alice Springs        9   22221224
      Gingin               8   22221233
      Canberra            10   22232224
      Kennaook Cape Grim  10   22232224
      Hobart              11   22232234    

Estimated Antarctic Regional K Indices 09 Sep :
      Macquarie Island    10   22243222
      Casey               16   34432323
      Mawson              31   35433256

Observed Regional daily pc3 Indices 09 Sep : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              15   (Quiet)
      Canberra            26   (Quiet to unsettled)
      Hobart              24   (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 09 Sep : A 
           Fredericksburg         9
           Planetary              9                         

Observed AFr/Ap Indices 08 Sep :  A   K
           Fredericksburg         10
           Planetary              12  3433 2232     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
10 Sep    12    G0-G1
11 Sep    10    G0, chance of G1
12 Sep     8    G0, chance of G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 09-Sep. In the Antarctic region G0 geomagnetic 
conditions with isolated G1 conditions were observed. G0 with 
a chance of G1 are expected on 10-12 Sep due to ongoing coronal 
hole wind stream influence. Another recurrent coronal hole will 
start crossing the central meridian over the UT day and will 
be in a geoeffective position in 4-5 days.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 09-Sep were 
fair to normal. HF radio propagation conditions are generally 
expected to be mostly fair to normal over 10-12 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
09 Sep    84

Observed Australian Regional MUFs
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Southern Australian Region:
      Depressed 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
10 Sep    90    Near predicted monthly values/depressed 10 to 
                15%
11 Sep    95    Near predicted monthly values/depressed 10 to 
                15%
12 Sep    95    Near predicted monthly values/depressed 10 to 
                15%

COMMENT: Maximum usable frequencies (MUFs) in the northern Australian 
region on UT day 09-Sep were near predicted monthly values to 
depressed by 15% during local night. Spread F was observed at 
Canberra and Hobart during local night and 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 to depressed by 15% on 10-12 Sep. Isolated minor 
shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 08 Sep
       Daily Proton Fluence >1 MeV:   1.1E+05
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 2.00E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B5.9

DSCOVR Satellite Solar Wind Day Averaged Data for 08 Sep
Speed: 516 km/sec  Density:    1.2 p/cc  Temp:    79900 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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