[Ips-dsgr] ASWFC Daily Report - 09 May 25 issued 2331 UT on 09 May 2025 [SEC=OFFICIAL]

Sat May 10 09:31:02 AEST 2025

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

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 09 May: 136/90

1B. SOLAR FORECAST
             10 May             11 May             12 May
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   135/89             130/84             125/78

COMMENT: Solar activity on UT day 09-May was at the R0 level, 
with several low level C-class flares observed. There are currently 
four numbered sunspot regions visible on the solar disk. AR4079 
(N08W63, beta-delta) is the largest and most magnetically complex 
region on the disk and has shown decay in its trailer spots over 
the UT day. This region is now approaching the western limb. 
AR4081 (N07W33, beta) has decayed. All other sunspot regions 
are either stable or in decay. Solar activity is expected to 
be at R0-R1 levels over 10-12 May. No Earth-directed CMEs have 
been observed. The solar wind speed on UT day 09-May decreased, 
ranging from 395 to 500 km/s and is currently near 420 km/s. 
The peak total interplanetary magnetic field strength (IMF, Bt) 
was 10 nT and the north-south IMF component (Bz) range was -9 
to +7 nT. A period of sustained southward IMF conditions was 
observed over the interval 09/1410-2156UT. The solar wind speed 
is expected to remain elevated over 10-12 May due to coronal 
hole high speed wind stream effects.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 09 May: G0

Estimated Indices 09 May : A   K           
   Australian Region      11   22222343
      Cocos Island         7   23111232
      Darwin              10   23122333
      Townsville          11   23222243
      Learmonth           14   22222353
      Alice Springs        8   12222233
      Gingin              13   22122353
      Canberra             9   12222242
      Kennaook Cape Grim  13   23223343
      Hobart              12   22123343    

Estimated Antarctic Regional K Indices 09 May :
      Macquarie Island    15   22134442
      Casey               17   34322253
      Mawson              43   54322476

Observed Regional daily pc3 Indices 09 May : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               2   (Quiet)
      Canberra             0   (Quiet)
      Hobart               4   (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 09 May : A 
           Fredericksburg        11
           Planetary             16                         

Observed AFr/Ap Indices 08 May :  A   K
           Fredericksburg        11
           Planetary             11   2332 2214     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
10 May    16    G0-G1
11 May    12    G0, chance of G1
12 May     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 09-May. Mostly G0-G1 geomagnetic conditions 
were observed in the Antarctic region, with an isolated period 
of G3 observed at Mawson. G0-G1 geomagnetic conditions are expected 
on 10-May due to ongoing coronal hole effects. G0 geomagnetic 
conditions are expected over 11-12 May, with a chance of G1 on 
11-May.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 09-May were 
normal to fair at low and middle latitudes, and fair at high 
latitudes. HF radio propagation conditions are expected to be 
mostly normal over 10-12 May, with degradations possible at middle 
to high latitudes. Minor shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
09 May    98

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Depressed by 25% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

Monthly T index:
Month  T index
Apr      123
May      113
Jun      111

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
10 May    95    Near predicted monthly values/depressed 10 to 
                15%
11 May   100    Near predicted monthly values
12 May   100    Near predicted monthly values

COMMENT: ASWFC HF Communications Warning 45 was issued on 7 May 
and is current for 8-10 May. Maximum usable frequencies (MUFs) 
in the Australian region on UT day 09-May were near predicted 
monthly values to 25% depressed during local night. Spread F 
was observed at Hobart and Canberra during local night hours. 
MUFs are expected to be mostly near predicted monthly values 
over 10-12 May, with further depressions possible on 10-May. 
Minor shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 08 May
       Daily Proton Fluence >1 MeV:   4.5E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 5.10E+08   (high fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:23%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 08 May
Speed: 451 km/sec  Density:    2.3 p/cc  Temp:    92500 K  Bz:  -2 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