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

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Wed Mar 26 10:30:59 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 MARCH 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 MARCH AND FORECAST FOR 26 MARCH - 28 MARCH
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Mar:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Mar: 156/110


1B. SOLAR FORECAST
             26 Mar             27 Mar             28 Mar
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     None expected      Possible           Possible
10.7cm/SSN   155/109            155/109            160/114

COMMENT: Solar activity on UT day 25-Mar was R0, with the largest 
flare being C9 from the vicinity of AR4028 (S16W82) near the 
western limb. There are currently four numbered sunspot regions 
on the disk. AR4035 (N15W32, beta) is the largest, but nearing 
the limb and hence visibility is restricted. AR4043 (N14E57, 
beta) has shown some growth in the past day. Solar activity is 
expected to mostly be R0, with a small chance for R1 
over 26-28 Mar. 

No Earth-directed CMEs were observed in available 
imagery, however there were long gaps in today's imagery. 

S0 solar radiation storm conditions were observed on UT day 25-Mar. 
S0 solar radiation storm conditions are expected over 26-28 Mar. 

The solar wind environment on UT day 25-Mar was mostly steady, 
but a slight increase to the solar wind speed at the end of the 
UT day may indicate connection to the coronal hole dominating 
the southern solar hemisphere. The solar wind speed ranged from 
343 to 400 km/s, currently on an incline. The peak total interplanetary 
field strength (IMF, Bt) was 13 nT and the north-south IMF component 
range (Bz) was +6 to -11 nT, with Bz oriented south from 1500 
UT onwards. The solar wind speed is expected to become further 
enhanced over 26-28 Mar, with stronger enhancements likely later 
in the period due to the large coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 25 Mar: G1

Estimated Indices 25 Mar : A   K           
   Australian Region      14   22232352
      Cocos Island         8   22221142
      Darwin               9   22222242
      Townsville          12   32232342
      Learmonth           15   32232352
      Alice Springs       12   22222252
      Gingin              14   32221353
      Canberra            12   22232343
      Kennaook Cape Grim  15   22232353
      Hobart              15   22232353    

Estimated Antarctic Regional K Indices 25 Mar :
      Macquarie Island    24   22352553
      Casey               16   34432242
      Mawson              21   34332345

Observed Regional daily pc3 Indices 25 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            2   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               8   (Quiet)
      Canberra             2   (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 25 Mar : A 
           Fredericksburg        21
           Planetary             30                         

Observed AFr/Ap Indices 24 Mar :  A   K
           Fredericksburg        18
           Planetary             19   4424 4433     


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

COMMENT: ASWFC Geomagnetic Warning 21 was issued on 23 March 
and is current for 25-27 Mar. G1 geomagnetic conditions were 
observed in the Australian region on UT day 25-Mar due to an 
extended period of southward oriented Bz. G0-G1 geomagnetic conditions 
were observed in the Antarctic region. G0-G1 geomagnetic conditions 
are expected over 26-28 Mar, with a chance for G2 on 27-Mar due 
to a large coronal hole currently dominating the southern solar 
hemisphere.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 25-Mar were 
mostly normal. Sporadic-E was common near low latitudes and some 
mild depressions began towards the end of the UT day. HF radio 
propagation conditions are expected to be normal to fair over 
26-28 Mar due to a large coronal hole. Equatorial scintillation 
is possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
25 Mar   130

Observed Australian Regional MUFs
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
      Enhanced by 50% after local dawn.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 35% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 30% 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
26 Mar   115    Near predicted monthly values to 10-15% depressed
27 Mar   110    Near predicted monthly values to 10-15% depressed
28 Mar   105    Near predicted monthly values to 10-20% depressed

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 25-Mar were near predicted values. Persistent 
sporadic-E was observed in all low latitudes stations during 
local night hours. Spread-F was observed in Hobart. MUFs are 
expected to be mostly near predicted monthly values on UT day 
26-Mar, with mild depressions setting in possibly late in the 
day. Depressions are expected to deepen over 27-28 Mar. Spread-F 
is possible at high latitudes during local night hours.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 24 Mar
       Daily Proton Fluence >1 MeV:   3.7E+05
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 3.80E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 24 Mar
Speed: 406 km/sec  Density:   13.3 p/cc  Temp:    91900 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



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