[Ips-dsgr] ASWFC Daily Report - 16 March 26 issued 2330 UT on 16 Mar 2026 [SEC=OFFICIAL]

Tue Mar 17 10:30:49 AEDT 2026

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/16 MARCH 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 16 MARCH AND FORECAST FOR 17 MARCH - 19 MARCH
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 16 Mar:  R0-R1

Flares    Max     Fadeout    Freq.  Sectors
  M2.7    1215UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 16 Mar: 111/62

1B. SOLAR FORECAST
             17 Mar             18 Mar             19 Mar
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   110/60             112/63             112/63

COMMENT: Solar activity on UT day was R1, with an isolated M2.8 
flare from active region (AR) 4392 (beta, S15E19). There are 
currently four numbered sunspots on the solar disk. Most regions 
have shown a small growth phase followed by a small decay phase, 
with no region showing any overall major net growth. Solar activity 
is expected to be R0-R1 over 17-19 Mar. 

A CME directed to the southeast that was associated with a small 
filament eruption from 0924UT is considered not geoeffective. 
A CME with ejecta heading both southeast and north can be seen from 
1248UT and is associated with the M2.8 solar flare. This CME is expected 
to arrive at Earth late on UT day 19-Mar. 

S0 solar radiation storm conditions were observed on UT day 16-Mar. 
S0 solar radiation storm conditions are expected over 17-19 Mar. 

On UT day 16-Mar the solar wind environment was declining from a recent coronal 
hole disturbance. The solar wind speed ranged from 620 km/s trending 
to 450 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 6 nT and the north-south IMF component (Bz) ranged from 
+5 to -4 nT. The solar wind is expected to continue to slowly 
trend to background levels over 17-18 Mar. A disturbance to the 
solar wind is then expected late on 19-Mar.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 16 Mar: G0

Estimated Indices 16 Mar : A   K           
   Australian Region       6   22222211
      Cocos Island         3   21112200
      Darwin               7   22------
      Townsville           5   22112212
      Learmonth            6   22222211
      Alice Springs        4   12212201
      Gingin               6   22222211
      Canberra             4   12122201
      Kennaook Cape Grim   6   12223211
      Hobart               6   12223211    

Estimated Antarctic Regional K Indices 16 Mar :
      Macquarie Island    12   22235310
      Casey               16   35432212
      Mawson              23   54533421

Observed Regional daily pc3 Indices 16 Mar : 
      Darwin             120   (Major storm)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              42   (Unsettled)
      Canberra            36   (Quiet to unsettled)
      Hobart               8   (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 16 Mar : A 
           Fredericksburg        12
           Planetary             14                         

Observed AFr/Ap Indices 15 Mar :  A   K
           Fredericksburg        14
           Planetary             17   4224 3334     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
17 Mar     8    G0
18 Mar     6    G0
19 Mar    16    G1-G2

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 16-Mar. G0-G1 geomagnetic conditions were observed 
in the Antarctic region. G0 geomagnetic conditions are expected 
over 17-18 Mar. G1-G2 geomagnetic conditions may begin late on 
19-Mar.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 16-Mar were 
mildly degraded at all latitudes for most of the day. HF radio 
propagation conditions are expected to improve over 17-18 Mar, 
but likely to become degraded at the end of 19-Mar.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
16 Mar    87

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 30% during local day.
      Depressed by 15% during local night.
   Northern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Feb      98
Mar      87
Apr      85

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
17 Mar    95    Near predicted monthly values
18 Mar   100    Near predicted monthly values
19 Mar   100    Near predicted monthly values to 15% depressed

COMMENT: Maximum usable frequencies (MUFs) on UT day 16-Mar were 
depressed by 15% to enhanced by 25%. Sporadic-E was observed 
in Hobart during local night hours. MUFs are expected to be mostly 
near predicted values over 17-18 Mar. Some depressions up to 
15% may begin at the end of 19-Mar.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 15 Mar
       Daily Proton Fluence >1 MeV:   8.5E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 3.80E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B4.1

DSCOVR Satellite Solar Wind Day Averaged Data for 15 Mar
Speed: 645 km/sec  Density:    0.2 p/cc  Temp:   163000 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