[Ips-dsgr] ASWFC Daily Report - 20 March 23 issued 2330 UT on 20 Mar 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Tue Mar 21 10:30:55 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/20 MARCH 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 20 MARCH AND FORECAST FOR 21 MARCH - 23 MARCH
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 20 Mar:  R0

Flares    Max     Fadeout    Freq.  Sectors
 M1/--    0148UT  possible   lower  West Pacific

Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Mar: 156/110


1B. SOLAR FORECAST
             21 Mar             22 Mar             23 Mar
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   155/109            150/105            150/105

COMMENT: Solar activity on UT day 20-Mar was at R1 levels, with 
one R1 solar flare. AR3256 (S22E38, beta) produced a long duration 
M1 solar flare from 20/0145UT. There are currently 5 numbered 
sunspot regions on the solar disk. AR3258 (N20E22, alpha) has 
shown some minor growth and AR3256 has shown some minor instability 
in its trailer spots. New region AR3255 located near S22W50 has 
also shown minor growth, but has not yet been given a magnetic 
classification. All other sunspot regions are either stable or 
in decay. A C4 solar flare was observed at 20/1528UT near AR3258 
and a CME was observed from LASCO imagery from 20/1442UT from 
the northeast quadrant. Modelling indicates a weak glancing blow 
on 23-Mar, but confidence is low due to lack of images. At 20/1414UT 
a CME was observed from the southwest quadrant in LASCO imagery 
but is considered a farside event and not geoeffective. No other 
CMEs were observed. The 10MeV proton flux has remained enhanced 
(around 1.23 pfu) over the 24 hour period but has stayed far 
below the S1 threshold. Solar activity is expected to be at R0-R1 
levels over 21-23 Mar. On 20-Mar the solar wind speed was generally 
steady and ranged from 408 to 485 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 9 nT and the north-south IMF component 
(Bz) range was +9 to -7 nT. Bz was oriented southward from 20/1325-1445UT. 
There is a large coronal hole wind stream in the southern hemisphere 
which is expected to become geoeffective by 23-Mar. The solar 
wind speed is expected to remain steady over 21-22 Mar, but may 
become enhanced on 23-Mar due to the combination of a weak glancing 
blow from the CME observed at 20/1442UT and the large southern 
coronal hole wind stream.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 20 Mar: G0

Estimated Indices 20 Mar : A   K           
   Australian Region       9   21123412
      Cocos Island         5   11113310
      Darwin               8   21123411
      Townsville          10   21133422
      Learmonth            9   21123422
      Alice Springs        9   21123412
      Gingin              10   21133412
      Canberra             8   21033312
      Hobart              10   21133412    

Estimated Antarctic Regional K Indices 20 Mar :
      Macquarie Island    19   10055511
      Casey               18   35433312
      Mawson              14   43224420

Observed Regional daily pc3 Indices 20 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               4   (Quiet)
      Canberra             4   (Quiet)
      Hobart               5   (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 20 Mar : A 
           Fredericksburg        10
           Planetary             12                         

Observed AFr/Ap Indices 19 Mar :  A   K
           Fredericksburg         8
           Planetary              7   3113 442-     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
21 Mar     8    G0
22 Mar     8    G0
23 Mar    18    G0-G1

COMMENT: G0 geomagnetic activity was observed in the Australian 
region on UT day 20-Mar. G0-G1 geomagnetic activity was observed 
in the Antarctic region on UT day 20-Mar. G0 geomagnetic activity 
is expected over 21-22 Mar. G0-G1 geomagnetic conditions are 
expected on 23-Mar due to the combination of a weak glancing 
blow from a CME first observed on 20-Mar and a large southern 
coronal hole wind stream becoming geoeffective.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
21 Mar      Normal         Normal         Normal
22 Mar      Normal         Normal         Normal
23 Mar      Normal         Normal         Fair-normal

COMMENT: HF propagation conditions on 20-Mar were normal. Normal 
HF propagation conditions are expected over 21-22 Mar. Some mild 
degradations may be expected on 23-Mar due to anticipated geomagnetic 
activity, particularly in high latitude regions during local 
night. Isolated shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
20 Mar   144

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 30% during local night.
      Enhanced by 40% after local dawn.
   Niue Island Region:
      Enhanced by 50% during local day.
      Enhanced by 65% during local night.
      Enhanced by 40% after local dawn.
   Northern Australian Region:
      Enhanced by 25% during local day.
      Enhanced by 40% during local night.
      Enhanced by 65% after local dawn.
   Southern Australian Region:
      Enhanced by 35% during local day.
      Enhanced by 20% during local night.
      Enhanced by 30% after local dawn.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Feb      117
Mar      80
Apr      80

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
21 Mar   140    20 to 40% above predicted monthly values
22 Mar   140    20 to 40% above predicted monthly values
23 Mar   115    20% enhanced to near predicated monthly values

COMMENT: ASWFC SWF HF Communications Warning 31 was issued on 
20 March and is current for 20-22 Mar. Maximum usable frequencies 
(MUFs) on UT day 20-Mar in the Australian region were enhanced 
by 20-65%. Scintillation was observed at Darwin and Weipa between 
20/1058-1440UT. MUFs are expected to be enhanced by 20-40% over 
21-22 Mar, and tending towards monthly predicted values by 23-Mar 
due to anticipated geomagnetic activity. Isolated minor shortwave 
fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 19 Mar
       Daily Proton Fluence >1 MeV:   1.7e+06
       Daily Proton Fluence >10 MeV:  8.6e+04
       Daily Electron Fluence >2 MeV: 5.4e+06
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.5

DSCOVR Satellite Solar Wind Day Averaged Data for 19 Mar
Speed: 437 km/sec  Density:    5.2 p/cc  Temp:   117000 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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