[Ips-dsgr] ASWFC Daily Report - 17 February 25 issued 2330 UT on 17 Feb 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Tue Feb 18 10:30:50 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 FEBRUARY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 FEBRUARY AND FORECAST FOR 18 FEBRUARY - 20 FEBRUARY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Feb:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.1    1513UT  possible   lower  South American/
                                    Atlantic

Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Feb: 185/138


1B. SOLAR FORECAST
             18 Feb             19 Feb             20 Feb
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   185/138            180/133            180/133

COMMENT: Solar activity on UT day 17-Feb was at the R1 level, 
due to a single M1.1 flare at 17/1513UT. There are currently 
eleven numbered sunspot regions visible on the solar disk. AR3992 
(S05W77, beta) produced the one M-class flare of the UT day but 
appeared stable and will rotate off the solar disk over 18-Feb. 
AR3997 (N02E19, beta), AR3998 (S14E58, beta-gamma) and AR3999 
(N07E39, beta) all showed spot development over the UT day. All 
other sunspot regions are either stable or in decay. Solar activity 
is expected to be at R0-R1 levels over 18-20 Feb. S0 solar radiation 
storm conditions were observed on 17-Feb. S0 conditions are expected 
on 18-20 Feb. No Earth-directed CMEs have been observed. The 
solar wind speed on UT day 17-Feb slowly decreased, mostly ranging 
between 440 and 580 km/s and is currently near 500 km/s. The 
peak total interplanetary field strength (IMF, Bt) was 7 nT and 
the north-south IMF component (Bz) range was +6 to -6 nT. The 
solar wind speed is expected to continue decline over 18-120 
Feb due to waning coronal hole high speed wind stream effects. 
A coronal hole is visible in the northern hemisphere approaching 
a geoeffective position, but it is considered too far north to 
significantly impact the solar wind environment at Earth.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 17 Feb: G0

Estimated Indices 17 Feb : A   K           
   Australian Region      10   22223323
      Cocos Island         6   22212311
      Darwin              10   31213323
      Townsville          11   32223323
      Learmonth           11   32224322
      Alice Springs       10   22223323
      Gingin              11   32224322
      Canberra            10   22223323
      Kennaook Cape Grim  11   22224323
      Hobart              10   22223323    

Estimated Antarctic Regional K Indices 17 Feb :
      Macquarie Island    22   23345523
      Casey               28   45643223
      Mawson              25   44443335

Observed Regional daily pc3 Indices 17 Feb : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              48   (Unsettled)
      Canberra            52   (Unsettled)

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 17 Feb : A 
           Fredericksburg        10
           Planetary             12                         

Observed AFr/Ap Indices 16 Feb :  A   K
           Fredericksburg        14
           Planetary             14   2333 3324     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
18 Feb    10    G0
19 Feb     8    G0
20 Feb     5    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 17-Feb. Mostly G1 geomagnetic conditions were 
observed in the Antarctic region, with G2 conditions observed 
briefly at Casey. G0 geomagnetic conditions are expected over 
18-20 Feb.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
17 Feb      Normal         Normal-fair    Normal-poor    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
18 Feb      Normal         Normal         Normal-fair
19 Feb      Normal         Normal         Normal-fair
20 Feb      Normal         Normal         Normal

COMMENT: HF radio propagation conditions were fair to poor at 
high and mid latitudes in the southern hemisphere for the first 
half of the UT day 16-Feb. Conditions recovered to mostly normal 
for the second half of the UT day. Mostly normal HF conditions 
are expected over 18-20 Feb. Shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
17 Feb   128

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Enhanced by 35% during local day.
      Enhanced by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Jan      124
Feb      118
Mar      115

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
18 Feb   120    Near predicted monthly values
19 Feb   125    Near predicted monthly values
20 Feb   130    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 17-Feb in 
the Australian region were near predicted monthly values with 
depressions of up to 15% observed in the southern Australian 
region. Spread F was observed at Hobart and Perth during local 
night hours. MUFs are expected to be near predicted monthly values 
over 18-20 Feb. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 16 Feb
       Daily Proton Fluence >1 MeV:   5.9E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 1.20E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.1

DSCOVR Satellite Solar Wind Day Averaged Data for 16 Feb
Speed: 553 km/sec  Density:    0.9 p/cc  Temp:   146000 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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