[Ips-dsgr] ASWFC Daily Report - 24 March 25 issued 2330 UT on 24 Mar 2025 [SEC=OFFICIAL]

Tue Mar 25 10:30:49 AEDT 2025

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 MARCH 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 MARCH AND FORECAST FOR 25 MARCH - 27 MARCH
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 Mar:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Mar: 156/110

1B. SOLAR FORECAST
             25 Mar             26 Mar             27 Mar
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     None expected      Possible           Possible
10.7cm/SSN   162/116            165/119            160/114

COMMENT: Solar activity on UT day 24-Mar was R0, with no significant 
solar flares. There are currently four numbered sunspot regions 
on the solar disk. AR4036 (N07W64, beta-gamma) has grown over 
the past day, however due to its location nearing the western 
limb analysis is restricted. All other sunspot regions are either 
stable or in decay. Solar activity is generally expected to be 
R0, with isolated R1 flares possibly from AR4036. Apart from 
AR4036 no regions currently have significant flare potential. 

S0 solar radiation storm conditions were observed on UT day 24-Mar. 
S0 solar radiation storm conditions are expected over 25-27 Mar. 

No Earth-directed CMEs were observed on UT day 24-Mar. The solar 
wind environment was mildly perturbed on UT day 24-Mar. The solar 
wind speed ranged from near 450 to 350 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 15 nT and the north-south IMF component 
range (Bz) was +10 to -9 nT. Bz was oriented southward for several 
periods of the day. The source of the disturbance is not clear, 
but is not considered CME related at this stage. The solar wind 
environment is expected to be quiet for most of UT day 25-Mar, 
but a large coronal hole dominating the southern solar hemisphere 
may connect with the Earth over 26-27 Mar to enhance the solar 
wind speed.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 24 Mar: G0

Estimated Indices 24 Mar : A   K           
   Australian Region      11   33233321
      Cocos Island         8   23232310
      Darwin              11   33233321
      Townsville          14   34333322
      Learmonth           14   33333422
      Alice Springs       12   33233322
      Gingin              13   33233421
      Canberra            11   33233321
      Kennaook Cape Grim  14   33333421
      Hobart              14   33333421    

Estimated Antarctic Regional K Indices 24 Mar :
      Macquarie Island    17   23344431
      Casey               19   35532222
      Mawson              35   66433443

Observed Regional daily pc3 Indices 24 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               6   (Quiet)
      Canberra             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 24 Mar : A 
           Fredericksburg        17
           Planetary             23                         

Observed AFr/Ap Indices 23 Mar :  A   K
           Fredericksburg         9
           Planetary             12   3242 3322     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
25 Mar    13    G0, chance G1
26 Mar    18    G0-G1
27 Mar    22    G0-G1, chance of G2

COMMENT: ASWFC Geomagnetic Warning 21 was issued on 23 March 
and is current for 25-27 Mar. G0 geomagnetic activity was observed 
in the Australian region on UT day 24-Mar. G0-G2 geomagnetic 
conditions were observed in the Antarctic region. G0 geomagnetic 
conditions are expected on UT day 25-Mar, then bouts of G1 are 
expected over 26-27 Mar due to the anticipated connection with 
the large coronal hole currently dominating the southern solar 
hemisphere.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions were generally good 
in the first half of the UT day 24-Mar, but became mildly depressed 
in the latter half, especially in the southern hemisphere. HF 
radio propagation conditions are expected to be normal on 25-Mar, 
but some degradations and depressions may begin on 26-Mar in 
high latitudes, and then further latitudes on 27-Mar due to expected 
coronal hole activity.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
24 Mar   148

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 55% during local night.
      Enhanced by 20% after local dawn.
   Niue Island Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% 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
25 Mar   155    Near predicted monthly values to 15% enhanced
26 Mar   145    Near predicted monthly values to 15% enhanced
27 Mar   135    Near predicted monthly values to 20% depressed

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region were mostly enhanced by 15% on UT day 24-Mar. Spread-F 
was observed in Hobart during local night hours and sporadic-E 
was observed in Norfolk Island. The enhancements to the MUFs 
are expected to continue on 25-Mar, and possibly dampen on 26-Mar 
but may still be intermittent. MUFs may become depressed up to 
20% on UT day 27-Mar due to expected coronal hole activity.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 23 Mar
       Daily Proton Fluence >1 MeV:   4.0E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 9.20E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.3

DSCOVR Satellite Solar Wind Day Averaged Data for 23 Mar
Speed: 428 km/sec  Density:    7.6 p/cc  Temp:    95000 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