[Ips-dsgr] ASWFC Daily Report - 23 March 25 issued 2330 UT on 23 Mar 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Mon Mar 24 10:30:51 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 MARCH 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 MARCH AND FORECAST FOR 24 MARCH - 26 MARCH
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Mar:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Mar: 168/122


1B. SOLAR FORECAST
             24 Mar             25 Mar             26 Mar
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   170/124            170/124            165/119

COMMENT: Solar activity on UT day 23-Mar was R0. Solar region 
AR4036 (N07W47, beta) is now decaying. This spot group was the 
most notable region on the visible solar disk. Other on disk 
regions are currently quite small. There are currently nine numbered 
sunspot regions on the solar disk. All other sunspots are either 
stable or in decay. Solar activity is expected to be R0 over 
24-26 Mar. S0 solar radiation storm conditions were observed 
on 23-Mar. S0 solar radiation storm conditions are expected over 
24-26 Mar. No Earth directed CMEs have been observed. The anticipated 
shock arrival on 23-Mar has failed to eventuate and is now not 
expected. The solar wind speed on 23-Mar slowly declined due 
to the abating influence of a coronal hole wind stream, ranging 
between 488 km/sec to 369 km/sec and is currently at 369 km/sec. 
The peak total interplanetary field strength (IMF, Bt) was 8 
nT and the north-south IMF component range (Bz) was 2 to -5 nT. 
The IMF Bz component was mildly southward during the interval 
23/0515-0845UT. A large coronal hole is visible in the southeast 
solar quadrant which is now crossing the solar central meridian. 
Most of the area of this coronal hole is at a southward latitudinal 
location on the Sun which suggests that the bulk of the wind 
stream from this hole may pass under the Earth, with wind stream 
entry expected from 27-Mar. This coronal hole has less equatorial 
area for this solar rotation. In general, solar wind 27 day recurrence 
patterns suggest that elevated solar wind conditions may be experienced 
from mid 25-Mar to 26-Mar with a further increase over 27-28 
Mar.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 23 Mar: G0

Estimated Indices 23 Mar : A   K           
   Australian Region       5   22211121
      Cocos Island         5   22211121
      Darwin               5   22211112
      Townsville           7   22321122
      Learmonth            5   22211122
      Alice Springs        5   22211122
      Gingin               6   22211131
      Canberra             6   22321121
      Kennaook Cape Grim   6   12322121
      Hobart               7   22322121    

Estimated Antarctic Regional K Indices 23 Mar :
      Macquarie Island    14   32533221
      Casey                9   33321122
      Mawson              20   54332243

Observed Regional daily pc3 Indices 23 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              44   (Unsettled)
      Canberra            13   (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 23 Mar : A 
           Fredericksburg        21
           Planetary             35                         

Observed AFr/Ap Indices 22 Mar :  A   K
           Fredericksburg        20
           Planetary             28   5532 4444     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
24 Mar    10    G0
25 Mar    16    G0, chance G1
26 Mar    18    G0-G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 23-Mar. The anticipated CME arrival has failed 
to eventuate. In the Antarctic region G1 periods were observed 
at Macquarie Island and Mawson, with G0 conditions at Casey. 
Geomagnetic 27 day recurrence patterns indicate that G1 periods 
are likely during the interval 25-28 Mar.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
23 Mar      Normal         Fair-normal    Fair           

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 23-Mar were 
fair to normal. Degraded HF conditions did not eventuate and 
are now not expected. HF radio propagation conditions are expected 
to be fair to normal over 24-26 Mar.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
23 Mar   133

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Enhanced 30% early in UT day then near predicted monthly values.
   Southern Australian Region:
      Enhanced 30% early in UT day then near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 35% over the UT day.

Monthly T index:
Month  T index
Feb      127
Mar      117
Apr      114

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
24 Mar   125    Near predicted monthly values
25 Mar   125    Near predicted monthly values
26 Mar   125    Near predicted monthly values

COMMENT: ASWFC Preliminary HF Communications Warning 30 was issued 
on 23 March and is current for 23-24 Mar. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 23-Mar were near predicted 
values to 30% enhanced 23/0000-0300UT. Spread-F was observed 
in Hobart during local night hours. An anticipated CME arrival 
has failed to eventuate. MUFs are expected to be near predicted 
values 24-26 Mar.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 22 Mar
       Daily Proton Fluence >1 MeV:   1.8E+06
       Daily Proton Fluence >10 MeV:  2.0E+04
       Daily Electron Fluence >2 MeV: 2.10E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.6

DSCOVR Satellite Solar Wind Day Averaged Data for 22 Mar
Speed: 470 km/sec  Density:    8.3 p/cc  Temp:   212000 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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