[Ips-dsgr] ASWFC Daily Report - 18 March 25 issued 2330 UT on 18 Mar 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Wed Mar 19 10:30:55 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 MARCH 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 MARCH AND FORECAST FOR 19 MARCH - 21 MARCH
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 18 Mar:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Mar: 184/137


1B. SOLAR FORECAST
             19 Mar             20 Mar             21 Mar
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   185/138            185/138            190/143

COMMENT: Solar activity on UT day 18-Mar was at the R0 level, 
with several low C-class flares. There are currently twelve numbered 
active regions on the visible solar disk and one unnumbered region. 
AR4022 (N08W46, beta), AR4031 (N17W22, beta-gamma) and AR4034 
(S17E39, beta-gamma). There are no significantly flare-active 
regions on the solar disk. An unnumbered region has recently 
rotated onto the solar disk at around N15E65 with beta magnetic 
characteristics. All other regions were either stable or in decay. 
Solar activity is expected to be at R0-R1 levels over 19-21 Mar. 
S0 solar radiation storm conditions were observed on UT day 18-Mar. 
S0 solar radiation storm conditions are expected over 19-21 Mar. 
No geoeffective CMEs were observed on 18-Mar. Solar wind speed 
increased on 18-Mar, with a decline at the end of the day. The 
wind speed mostly ranged between 350 km/s and 575 km/s. The current 
wind speed is around 380 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 12 nT and the north-south IMF component 
range was +6 to -10 nT. The solar wind environment is expected 
to be near background levels on 19-Mar. An increase in speed 
is possible early on 20-Mar due to the arrival of a CME first 
observed on 16-Mar. Elevated solar wind speeds are possible on 
21-Mar.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 18 Mar: G0

Estimated Indices 18 Mar : A   K           
   Australian Region       7   22223212
      Cocos Island         6   22213210
      Darwin               5   21222202
      Townsville           7   21223212
      Learmonth            8   31223212
      Alice Springs        7   22223202
      Gingin               8   31223212
      Canberra             7   22223221
      Kennaook Cape Grim   7   22223212
      Hobart               7   22123221    

Estimated Antarctic Regional K Indices 18 Mar :
      Macquarie Island    10   22324320
      Casey               12   33332223
      Mawson              27   55433344

Observed Regional daily pc3 Indices 18 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (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 18 Mar : A 
           Fredericksburg        12
           Planetary             15                         

Observed AFr/Ap Indices 17 Mar :  A   K
           Fredericksburg        14
           Planetary             14   3332 3433     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
19 Mar    10    G0, chance of G1
20 Mar    18    G0-G1
21 Mar     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 18-Mar. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with G1 conditions observed 
at Mawson. G0 geomagnetic conditions are expected on 19-Mar with 
a chance of G1 and G0-G1 conditions are expected on 20-Mar due 
to an anticipated impact from a CME first observed on 16-Mar. 
G0 conditions are expected on 21-Mar.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
18 Mar      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
19 Mar      Normal         Normal         Normal-fair
20 Mar      Normal         Normal-fair    Fair
21 Mar      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 18-Mar were 
mostly normal. HF radio propagation conditions are expected to 
be mostly normal over 19-21 Mar, with a chance of mild degradations 
on 20-Mar at high latitudes due to anticipated geomagnetic activity. 
Equatorial scintillation is anticipated due to the proximity 
to the equinox. Minor shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
18 Mar   141

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
      Enhanced by 20% after local dawn.
   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
19 Mar   150    Near to 15% above predicted monthly values
20 Mar   140    Near to 15% above predicted monthly values
21 Mar   150    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 18-Mar were 
near predicted values to enhanced by 20%. Sporadic-E and spread 
F were observed at Hobart. MUFs are expected to be near predicted 
monthly values to 15% enhanced over 19-21 Mar, with the chance 
of some minor degradations on 20-Mar due to possible geomagnetic 
activity. Minor shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 17 Mar
       Daily Proton Fluence >1 MeV:   7.7E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 1.70E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:14%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.2

DSCOVR Satellite Solar Wind Day Averaged Data for 17 Mar
Speed: 400 km/sec  Density:    3.7 p/cc  Temp:    60400 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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