[Ips-dsgr] ASWFC Daily Report - 17 March 24 issued 2330 UT on 17 Mar 2024 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Mon Mar 18 10:30:08 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 MARCH 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 MARCH AND FORECAST FOR 18 MARCH - 20 MARCH
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Mar:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Mar: 151/106


1B. SOLAR FORECAST
             18 Mar             19 Mar             20 Mar
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   155/109            160/114            162/116

COMMENT: 

Solar activity on UT day 17-Mar was at the R0 level, with several 
C-class flares observed. 

There are currently six numbered active sunspot regions visible on 
the solar disk and one unnumbered region. The largest region is, the 
newly numbered, AR3614 (N16E72, alpha) which has recently rotated 
onto the solar disk and appears stable. AR3607 (S17W18, beta-gamma) 
is the most magnetically complex region on the solar disk and showed 
development over the UT day. AR3608 (N09W09, beta) and AR3613 
(S23W27, beta) both also showed spot development, but are magnetically 
simple. All other numbered sunspot regions are stable. The sunspot 
region which produced a pair of M-class flares on 16-Mar is now 
visible on the solar disk as an unnumbered region at S12W80. 
Foreshortening due to proximity to the eastern limb makes the 
magnetic classification difficult to determine but it appears to 
have complex magnetic characteristics with a possible beta-gamma 
configuration. Solar activity is expected to be at R0-R1 levels 
over 18-20 Mar. 

The >10 MeV proton flux is currently elevated, but below the S1 level 
and declining. S0 conditions are expected over 18-20 Mar. 

A faint partial halo CME, directed broadly to the southwest, is visible 
from 17/0336UT in SOHO and STEREO-A imagery. A brighter component is also 
visible, directed to the south. This event is associated with a long 
filament lift off centered around S34W20 and visible from 17/0138UT in 
H-Alpha, SDO and GOES SUVI imagery. The majority of this filament is 
directed to the south, explaining the brighter southward directed component. 
Modelling indicates that there is a chance of a glancing impact with 
Earth on 20-Mar at 1300UT +/- 12 hours. This impact is not expected to 
be significant. No other CMEs were observed on 17-Mar. 

The solar wind speed on UT day 17-Mar was in decline, ranging from 282 
to 443 km/s and is currently near 285 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 4 nT and the north south IMF component (Bz) 
range was +4 to -2 nT. A slight increase in solar wind speed is possible 
early on UT day 18-Mar due to a possible glancing impact from a CME first 
observed on 15-Mar. 

The solar wind speed is expected to return to background levels and remain 
there on 19-Mar. A further slight increase is possible on 20-Mar due to 
a possible glancing impact from a CME first observed on 17-Mar.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 17 Mar: G0

Estimated Indices 17 Mar : A   K           
   Australian Region       1   11100001
      Darwin               1   11100001
      Townsville           0   10100000
      Learmonth            1   11100001
      Alice Springs        1   11100001
      Gingin               1   11100001
      Canberra             0   01100000
      Kennaook Cape Grim   0   01100000    

Estimated Antarctic Regional K Indices 17 Mar :
      Macquarie Island     0   00000000
      Casey                4   13310010
      Mawson               1   02200000

Observed Regional daily pc3 Indices 17 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth           NA
      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 17 Mar : A 
           Fredericksburg         4
           Planetary              5                         

Observed AFr/Ap Indices 16 Mar :  A   K
           Fredericksburg         3
           Planetary              3   0001 1121     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
18 Mar    10    G0, chance of G1
19 Mar     5    G0
20 Mar    10    G0, chance of G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 17-Mar. G0 geomagnetic conditions, 
with a chance of G1 are expected on 18-Mar due to a possible 
glancing impact from a CME first observed on 15-Mar. G0 conditions 
are expected over 19-20 Mar, with a further chance of G1 on 20-Mar 
due to a possible glancing impact from a CME first observed on 
17-Mar.

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

PCA Event : 10MeV Proton/PCA Event Began at 0015UT 16/03, Ended at 1450UT 16/03

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

COMMENT: HF radio communication conditions on UT day 17-Mar were 
mostly normal. HF radio communication conditions are expected 
to be mostly normal over 18-20 Mar. Minor shortwave fadeouts 
are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
17 Mar   122

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 40% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Enhanced by 15% over the UT day.

Monthly T index:
Month  T index
Feb      138
Mar      111
Apr      112

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

COMMENT: ASWFC SWF HF Communications Warning 27 was issued on 
17 March and is current for 17-19 Mar. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 17-Mar were mostly 
near predicted monthly values, with enhancements of up to 15% 
in the southern Australian region during local night. Spread 
F was observed at Hobart during local night hours. Ionospheric 
scintillation was observed at Niue at 17/0928UT and 17/0948UT. 
MUFs are expected to be near predicted monthly values over 18-20 
Mar. Minor shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 16 Mar
       Daily Proton Fluence >1 MeV:   4.9E+06
       Daily Proton Fluence >10 MeV:  8.8E+05
       Daily Electron Fluence >2 MeV: 5.20E+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 16 Mar
Speed: 379 km/sec  Density:    1.3 p/cc  Temp:    63500 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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