[Ips-dsgr] ASWFC Daily Report - 31 March 23 issued 2331 UT on 31 Mar 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sat Apr 1 10:31:42 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 MARCH 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 MARCH AND FORECAST FOR 01 APRIL - 03 APRIL
STATUS INDICATORS SOL:GREEN   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Mar:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Mar: 129/82


1B. SOLAR FORECAST
             01 Apr             02 Apr             03 Apr
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   130/84             125/78             125/78

COMMENT: Solar activity on UT day 31-Mar was at the R0 level 
with no significant flare activity. Several C class flares were 
observed, the largest a C9.7 at 31/2056UT on the south west limb 
at S23 with solar limb arches visible after the flare. A minor 
flare then followed from AR3262(S19W45, alpha). There are currently 
5 numbered sunspots regions on the solar disk. None of the regions 
currently on the solar disk are significant. Solar activity is 
expected to be at the R0 level over 1-3 Apr. No Earth directed 
CMEs have been observed. A north west CME was observed from 31/1408UT 
associated with a western limb prominence eruption at latitude 
range N25-30, followed by a second smaller eruption from 31/1558UT 
at latitude range N10-20. The solar wind speed on UT day 31-Mar 
decreased ranging from 453 to 692 km/s, and is currently near 
465 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 9 nT and the north-south IMF component (Bz) range was 
+4 to -7 nT. The solar wind speed is expected to continue to 
decline as high speed wind stream effects wane. Two very small 
isolated coronal holes are visible near the solar central meridian 
at N30 and S15.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 31 Mar: G0

Estimated Indices 31 Mar : A   K           
   Australian Region      10   33232222
      Cocos Island         8   32232221
      Darwin               8   33222212
      Townsville          11   33233222
      Learmonth           13   33233332
      Alice Springs        9   23233221
      Gingin              12   33232332
      Canberra             9   23232222
      Hobart              11   33242222    

Estimated Antarctic Regional K Indices 31 Mar :
      Macquarie Island    24   35454322
      Casey               16   33433333
      Mawson              88   55544488

Observed Regional daily pc3 Indices 31 Mar : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              15   (Quiet)
      Canberra            34   (Quiet to unsettled)
      Hobart              35   (Quiet to 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 31 Mar : A 
           Fredericksburg        14
           Planetary             20                         

Observed AFr/Ap Indices 30 Mar :  A   K
           Fredericksburg        11
           Planetary             13   3223 3432     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
01 Apr    14    G0
02 Apr    12    G0
03 Apr     8    G0

COMMENT: ASWFC Geomagnetic Warning 15 was issued on 28 March 
and is current for 31 Mar to 1 Apr. G0 geomagnetic conditions 
were observed in the Australian region on 31-Mar. In the Antarctic 
region an isolated G1 period was observed at Macquarie Island, 
G0 conditions were observed at Casey, and G1 conditions with 
an isolated G4 period were observed at Mawson. G0 geomagnetic 
conditions are expected on 1-3 Apr.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
31 Mar      Normal         Normal         Fair-poor      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
01 Apr      Normal         Normal         Normal-fair
02 Apr      Normal         Normal         Normal-fair
03 Apr      Normal         Normal         Normal-fair

COMMENT: Normal HF propagation conditions were generally observed 
on 31-Mar, with periods of degraded conditions at high latitudes. 
Normal HF conditions are expected 1-3 Apr.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
31 Mar   121

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

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

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
01 Apr   115    Near to 15% above predicted monthly values
02 Apr   115    Near to 15% above predicted monthly values
03 Apr   115    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 31-Mar in 
the Australian region were enhanced by 20-65%. Mild depressions 
of 15% were observed at Hobart and Canberra during the local 
day. Strong spread F was observed at Hobart during local night 
hours. Brief spread F was observed at Perth just before local 
dawn. Strongly enhanced conditions were observed at Niue. MUFs 
are expected to be near predicted monthly values to 15% enhanced.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 30 Mar
       Daily Proton Fluence >1 MeV:   2.6E+05
       Daily Proton Fluence >10 MeV:  2.3E+04
       Daily Electron Fluence >2 MeV: 3.10E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B7.5

DSCOVR Satellite Solar Wind Day Averaged Data for 30 Mar
Speed: 487 km/sec  Density:    2.8 p/cc  Temp:    67900 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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