[Ips-dsgr] ASWFC Daily Report - 11 April 23 issued 2331 UT on 11 Apr 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Wed Apr 12 09:31:10 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 APRIL AND FORECAST FOR 12 APRIL - 14 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 11 Apr:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.3    1016UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Apr: 143/97


1B. SOLAR FORECAST
             12 Apr             13 Apr             14 Apr
Activity     R1,chance R2       R1,chance R2       R1,chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   145/99             150/105            155/109

COMMENT: Solar activity on UT day 11-Apr was at the R1 level, 
due to an M1.3 flare from region AR3272(S21E06, beta-gamma). 
This region continued to show a mix of both growth and decay, 
though overall appears to be in slow decay. Solar region AR3273(N10E02, 
beta) initially showed growth in its intermediate spots then 
decay later in the UT day. The spot configuration of the solar 
region that recently rotated over the south east solar limb AR3276(S22E64, 
beta), was stable. Solar region AR3272 and AR3276 produced numerous 
C class flares and AR3273 a single low level C flare. A slowly 
declining C5.9 flare was in progress from AR3272 at the time 
of writing. There are currently five numbered solar regions on 
the disk. Other regions are unremarkable. Solar activity is expected 
to be at the R1 level over 12-14 Apr, with a chance of an isolated 
R2 event. No significant Earth-directed CMEs have been observed. 
The solar wind speed on UT day 11-Apr decreased, ranging from 
477 to 378 km/s, and is currently near 378 km/s. The peak total 
interplanetary field strength (IMF, Bt) was 9 nT and the north-south 
IMF component (Bz) range was +7 to -5 nT. Two small coronal holes 
are now visible in the northern and southern solar hemispheres, 
near the solar central meridian, at solar latitudes N30 and S35 
respectively. These holes may increase solar wind slightly in 
coming days but the combination of their small size and moderately 
high solar latitude is likely to reduce any effects. A previously 
flaring solar region AR3256 (solar latitude S22), which produced 
isolated R2 and R3 flares in its previous disk transit, is due 
back to the south east limb on 13-Apr. However, confidence is 
low for this regions return as the region was showing some decay 
in its trailer spots as it rotated over the western solar limb 
on 31-Mar, together with the generally exhibited shorter solar 
region lifetimes for solar cycle 25.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 11 Apr: G0

Estimated Indices 11 Apr : A   K           
   Australian Region       5   12311111
      Cocos Island         3   12211110
      Darwin               4   12301111
      Townsville           4   12211111
      Learmonth            5   12311111
      Alice Springs        2   11201011
      Gingin               3   02310110
      Canberra             2   11211010
      Hobart               3   02310011    

Estimated Antarctic Regional K Indices 11 Apr :
      Macquarie Island     8   33410012
      Casey                8   24321111
      Mawson              11   13422232

Observed Regional daily pc3 Indices 11 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              17   (Quiet)
      Canberra            11   (Quiet)
      Hobart              34   (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 11 Apr : A 
           Fredericksburg         6
           Planetary              6                         

Observed AFr/Ap Indices 10 Apr :  A   K
           Fredericksburg        11
           Planetary             12   3333 3322     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
12 Apr    16    G0, slight chance of G1
13 Apr    16    G0, slight chance of G1
14 Apr    14    G0, slight chance of G1

COMMENT: ASWFC Geomagnetic Warning 17 was issued on 8 April and 
is current for 11-12 Apr. G0 geomagnetic conditions were observed 
in the Australian and Antarctic region on 11-Apr. Predominately 
G0 with the chance of isolated G1 geomagnetic periods are expected 
during 12-14 Apr due to possible weak CME component impacts from 
a recently erupting solar filaments.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
11 Apr      Normal         Normal         Fair-normal    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
12 Apr      Normal         Normal         Normal-fair
13 Apr      Normal         Normal-fair    Fair
14 Apr      Normal         Normal         Normal-fair

COMMENT: Generally normal HF propagation conditions were observed 
on 11-Apr. Mild degradations at middle to high latitudes are 
possible on 12-14 Apr due to an anticipated mild increase in 
geomagnetic activity, particularly during local night hours. 
Isolated shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
11 Apr   119

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 40-80% during local day.
   Niue Island Region:
      Enhanced by 15% 
   Northern Australian Region:
      Enhanced by 15-60% 
   Southern Australian Region:
      Enhanced by 15-25% 
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Mar      132
Apr      84
May      84

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
12 Apr   130    Near to 15% above predicted monthly values
13 Apr   130    Near to 15% above predicted monthly values
14 Apr   130    Near to 15% above predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 35 was issued on 
10 April and is current for 10-12 Apr. Maximum usable frequencies 
(MUFs) on UT day 11-Apr in the Australian region were enhanced 
by 15-80%. Stong enhancements were observed at Cocos Island. 
Spread F observed during local night hours at Hobart. MUFs are 
expected to be near predicted monthly values to 15% enhanced 
over 11-13 Apr. Mild degradations are possible during local night 
hours on 12-14 Apr, due to expected mild increase in geomagnetic 
activity. Isolated shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 10 Apr
       Daily Proton Fluence >1 MeV:   4.3E+05
       Daily Proton Fluence >10 MeV:  2.2E+04
       Daily Electron Fluence >2 MeV: 1.80E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B7.7

DSCOVR Satellite Solar Wind Day Averaged Data for 10 Apr
Speed: 483 km/sec  Density:   11.4 p/cc  Temp:   207000 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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