[Ips-dsgr] ASWFC Daily Report - 23 May 23 issued 2331 UT on 23 May 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Wed May 24 09:31:36 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 MAY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 MAY AND FORECAST FOR 24 MAY - 26 MAY
STATUS INDICATORS SOL:** RED **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 May:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M3.0    1213UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 23 May: 155/109


1B. SOLAR FORECAST
             24 May             25 May             26 May
Activity     R1-R2              R1-R2              R1-R2              
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   155/109            155/109            160/114

COMMENT: Solar activity on UT day 23-May reached the R1 level 
due to a single M3.0 flare at 23/1213UT produced by AR3311 (N18E07, 
beta-gamma-delta). There are currently five numbered sunspot 
regions on the solar disk. AR3310 (S20W01, beta), AR3311, AR3312 
(S24E16, beta) and AR3313 (N22E23, alpha) all displayed development 
in their trailer spots over the UT day, whilst newly arrived 
AR3315 (S17E46, beta) showed slight decay. AR3311 is the largest 
and most complex active region on the solar disk and produced 
the only M-class flare of the day. Flaring activity has been 
quieter over the last two days, but sunspot complexity remains. 
Solar activity is expected to be at R1-R2 levels over 24-26 May. 
Several CMEs were observed on 23-May, but none are considered 
to be geoeffective. A west directed CME is visible from 23/0824UT 
which may be associated with a filament lift off visible in SDO, 
GOES SUVI and H-Alpha imagery from 23/0117UT at around S20W50. 
Modelling indicates this CME has no geoeffective component. A 
halo CME is visible from 23/1101UT in LASCO and STEREO-A imagery. 
No on disk activity is associated with this CME and modelling 
suggests it is a far side event. The solar wind speed on UT day 
23-May was elevated and variable throughout the day. The solar 
wind speed ranged between 459 to 640 km/s and is currently near 
570 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 9 nT and the north-south IMF component range was +7 to 
-6 nT. The solar wind speed is expected to remain elevated over 
24-26 May due to ongoing coronal hole high speed wind stream 
effects.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 23 May: G0

Estimated Indices 23 May : A   K           
   Australian Region       7   22220033
      Cocos Island         6   21310023
      Darwin               6   22220023
      Townsville           7   22220033
      Learmonth            9   22321133
      Alice Springs        7   22220033
      Gingin              11   32210144
      Canberra             6   22220023
      Hobart               7   22320123    

Estimated Antarctic Regional K Indices 23 May :
      Macquarie Island    13   33431033
      Casey               20   33331236
      Mawson              68   35631278

Observed Regional daily pc3 Indices 23 May : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              48   (Unsettled)
      Canberra            35   (Quiet to unsettled)
      Hobart              42   (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 23 May : A 
           Fredericksburg        11
           Planetary             15                         

Observed AFr/Ap Indices 22 May :  A   K
           Fredericksburg        17
           Planetary             23   4433 3344     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
24 May    15    G0, chance G1
25 May    12    G0
26 May    12    G0

COMMENT: ASWFC Geomagnetic Warning 30 was issued on 22 May and 
is current for 23-24 May. G0 geomagnetic conditions were observed 
in the Australian region on UT day 23-May. Mostly G0 conditions 
were observed at Macquarie Island and Casey, with an isolated 
period of G2 observed at Casey. Periods of G1-G4 were observed 
at Mawson. G0 geomagnetic conditions are expected over 24-26 
May, with a chance of G1 on 24-May due to ongoing coronal hole 
high speed wind stream effects.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
24 May      Normal         Normal         Normal-fair
25 May      Normal         Normal         Normal-fair
26 May      Normal         Normal         Normal-fair

COMMENT: On UT day 23-May, HF communication conditions were mildly 
degraded at high and low latitudes and were mostly normal at 
mid latitudes. Propagation conditions over 24-26 May are expected 
to be mostly normal with a chance of mildly degraded conditions, 
especially in high latitude regions, due to coronal hole high 
speed wind stream effects. Shortwave fadeouts are probable.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
23 May    92

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

Monthly T index:
Month  T index
Apr      120
May      87
Jun      88

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
24 May   100    Near predicted monthly values
25 May   100    Near predicted monthly values
26 May   100    Near predicted monthly values

COMMENT: ASWFC HF Communications Warning 48 was issued on 21 
May and is current for 22-24 May. ASWFC SWF HF Communications 
Warning 49 was issued on 22 May and is current for 23-25 May. 
Maximum usable frequencies (MUFs) on UT day 23-May were near 
predicted monthly values in the northern Australian region and 
up to 15% depressed in the southern Australian region during 
local night. Spread-F and sporadic E were observed at Canberra, 
Hobart, Brisbane and Norfolk Island during local night hours. 
MUFs are expected to be near predicted monthly values over 24-26 
May, with a chance of mild depressions due to coronal hole high 
speed wind stream effects. Shortwave fadeouts are probable.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 22 May
       Daily Proton Fluence >1 MeV:   5.2E+04
       Daily Proton Fluence >10 MeV:  2.2E+04
       Daily Electron Fluence >2 MeV: 2.20E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.5

DSCOVR Satellite Solar Wind Day Averaged Data for 22 May
Speed: 565 km/sec  Density:    3.4 p/cc  Temp:   272000 K  Bz:  -1 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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