[Ips-dsgr] ASWFC Daily Report - 10 April 23 issued 2342 UT on 10 Apr 2023 [SEC=OFFICIAL]

rwc rwc at ips.gov.au
Tue Apr 11 09:42:57 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/10 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 10 APRIL AND FORECAST FOR 11 APRIL - 13 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 10 Apr:  R1

Flares    Max     Fadeout    Freq.  Sectors
 M2.8     0520UT  possible   lower  E. Asia/Aust.

Observed 10.7 cm flux/Equivalent Sunspot Number for 10 Apr: 140/94


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

COMMENT: Solar activity on UT day 10-Apr was at the R1 level, 
due to an M2.8 flare from a region AR3276(S22E80, alpha) just 
behind/on the south east solar limb, currently rotating onto 
the solar disk. At this stage the region does not appear to be 
very large but more spots may rotate on to the disk. The spots 
in the largest region currently on disk, region AR3272(S21E19, 
beta), showed a mix of both growth and decay, with perhaps exhibiting 
overall decay late in the UT day 10-Apr. The other region of 
note, AR3273(N10E16, beta) has shown growth in its trailer spots. 
Neither of these regions produced significant flare activity 
in the past 24 hours, with AR3272 producing numerous C flares 
and AR3273 flare quiet. 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 11-13 Apr, with a chance 
of R2. A solar filament located at N15E15 erupted at 10/06-07UT. 
It is possible a slow westward CME followed this event, visible 
in Stereo-A from 10/0823UT, which is uncertain as no LASCO coronagraph 
data was available 10/01-16UT. At present it is considered that 
no significant Earth-directed CMEs have been observed. The solar 
wind speed on UT day 10-Apr increased, ranging from 315 to 562 
km/s, and is currently near 460 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 14 nT and the north-south IMF component 
(Bz) range was +10 to -8 nT. The increase in wind speed is due 
to a small equatorial coronal hole. The solar wind IMF Bz component 
turned mildly northward after wind stream entry.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 10 Apr: G0

Estimated Indices 10 Apr : A   K           
   Australian Region       7   22332210
      Cocos Island         7   22321310
      Darwin               7   22332201
      Townsville           -   --------
      Learmonth            6   22322210
      Alice Springs        7   22332201
      Gingin               8   22322311
      Canberra             7   22332200
      Hobart               8   22332310    

Estimated Antarctic Regional K Indices 10 Apr :
      Macquarie Island    14   12434313
      Casey                9   33322211
      Mawson              29   55642320

Observed Regional daily pc3 Indices 10 Apr : 
      Darwin               0   (Quiet)
      Townsville          NA
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra            13   (Quiet)
      Hobart              24   (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 10 Apr : A 
           Fredericksburg        12
           Planetary             14                         

Observed AFr/Ap Indices 09 Apr :  A   K
           Fredericksburg         5
           Planetary              5   2011 1112     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
11 Apr    18    G0, chance of G1
12 Apr    16    G0, slight chance of G1
13 Apr    11    G0

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 region on 10-Apr. Mostly G0 geomagnetic conditions 
were observed in the Antarctic region, with G1-G2 periods observed 
at Mawson. G0 with the chance of G1 geomagnetic conditions are 
expected on 11-12 Apr due to the combined effects of a CME component 
impact from a recent CME and coronal hole high speed wind stream 
effects from a small equatorial coronal hole. However, the solar 
wind IMF Bz component has sustained a mildly northward orientation 
after coronal hole wind stream entry, reducing induced geomagnetic 
activity. G0 geomagnetic conditions are expected on 13 Apr.

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

PCA Event : No event.

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

COMMENT: Generally normal HF propagation conditions were observed 
on 10-Apr, with degraded conditions observed at times at high 
latitudes. Mild degradations at middle to high latitudes are 
possible on 11-12 Apr due to an expected mild increase in geomagnetic 
activity, particularly during local nigh hours. Isolated shortwave 
fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
10 Apr   132

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20-35%. 
   Niue Island Region:
      Enhanced by 25% during local day.
      Enhanced by 40% during local night.
   Northern Australian Region:
      Enhanced by 15-35%.
   Southern Australian Region:
      Enhanced by 20-25%.
   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
11 Apr   130    Near to 15% above predicted monthly values
12 Apr   130    Near to 15% above predicted monthly values
13 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 10-Apr in the Australian region were enhanced 
by 15-40%. 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 11-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 09 Apr
       Daily Proton Fluence >1 MeV:   8.6E+04
       Daily Proton Fluence >10 MeV:  2.3E+04
       Daily Electron Fluence >2 MeV: 6.50E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.4

DSCOVR Satellite Solar Wind Day Averaged Data for 09 Apr
Speed: 423 km/sec  Density:    1.7 p/cc  Temp:    41000 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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