[Ips-dsgr] ASWFC Daily Report - 22 April 23 issued 2330 UT on 22 Apr 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sun Apr 23 09:30:10 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 22 APRIL AND FORECAST FOR 23 APRIL - 25 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** RED **     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 22 Apr:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 22 Apr: 141/95


1B. SOLAR FORECAST
             23 Apr             24 Apr             25 Apr
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   140/94             135/89             135/89

COMMENT: Solar activity on UT day 22-Apr was at the R0 level, 
with several low level C-class flares. There are currently six 
numbered sunspot regions visible on the solar disk and one unnumbered 
region. AR3282 (N11W47, beta) remains the largest region on the 
disk and has shown some minor development in its intermediate 
spots. AR3279 (S19W65, alpha) has exhibited spot growth over 
the UT day. An unnumbered region recently appeared at N15E40 
(alpha) and is stable and unremarkable. The background level 
of X-ray flux has declined to B-class levels. Solar activity 
is expected to be at the R0 level over 23-25 Apr, with a chance 
of R1. Several CMEs were observed, but none are considered geoeffective. 
An eastward CME was observed, visible in LASCO C2 coronagraph 
imagery from 22/0424UT. This CME is considered to originate from 
a farside source and is therefore not geoeffective. The solar 
wind speed on UT day 22-Apr increased in the first half of the 
UT day before decreasing late in the day, ranging from 370 to 
450 km/s, and is currently near 380 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 6 nT and the north-south IMF component 
(Bz) range was +5 to -5 nT. A large coronal hole in the southern 
solar hemisphere may increase solar wind speeds over 23-24 Apr, 
but its influence is likely limited due to its southern extent.

-----------------------------------------------------------
2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 22 Apr: G0

Estimated Indices 22 Apr : A   K           
   Australian Region       3   22100112
      Cocos Island         3   22000012
      Darwin               3   22100012
      Townsville           4   22100122
      Learmonth            5   23100122
      Alice Springs        2   12100011
      Gingin               4   22000222
      Canberra             3   12100112
      Hobart               2   12100111    

Estimated Antarctic Regional K Indices 22 Apr :
      Macquarie Island     1   12000001
      Casey                9   34311112
      Mawson              20   43210146

Observed Regional daily pc3 Indices 22 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               0   (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 22 Apr : A 
           Fredericksburg         7
           Planetary              8                         

Observed AFr/Ap Indices 21 Apr :  A   K
           Fredericksburg         8
           Planetary              9   2112 2323     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
23 Apr    60    G2-G3
24 Apr    30    G1, chance G2
25 Apr    12    G0

COMMENT: ASWFC Geomagnetic Warning 19 was issued on 21 April 
and is current for 23-24 Apr. G0 geomagnetic conditions were 
observed in the Australian region on UT day 22-Apr. Mostly G0 
geomagnetic conditions were observed in the Antarctic region, 
with an isolated period of G2 observed at Mawson. G2-G3 geomagnetic 
conditions are expected on 23-Apr due to the expected arrival 
of a CME first observed on 21-Apr. G1 geomagnetic conditions 
are expected on 24-Apr, with a chance of G2 as CME impacts abate. 
G0 geomagnetic conditions are expected on 25-Apr.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
23 Apr      Poor           Poor           Poor
24 Apr      Fair           Fair           Fair-poor
25 Apr      Normal         Normal         Normal-fair

COMMENT: Mostly normal HF propagation conditions were observed 
on 22-Apr, with some degradations observed during local night 
hours. Fair to poor HF conditions are expected over 23-24 Apr 
due to a CME impact from a CME first observed on 21-Apr. Mostly 
normal HF propagation conditions are expected on 25-Apr.

-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
22 Apr   116

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 25% during local day.
      Enhanced by 95% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
      Enhanced by 20% after local dawn.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Enhanced by 15% 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
23 Apr   105    Near predicted monthly values
24 Apr    60    Depressed 15%/near predicted monthly values
25 Apr    95    Near predicted monthly values

COMMENT: ASWFC Preliminary HF Communications Warning 38 was issued 
on 22 April and is current for 23-24 Apr. Maximum usable frequencies 
(MUFs) on UT day 22-Apr in the Australian region were enhanced 
by 15-20%. Sporadic-E was observed at Brisbane, Learmonth and 
Perth. Spread F was observed at Hobart and Perth during local 
night hours. MUFs are expected to be near predicted monthly values 
on 23 and 25-Apr. MUFs are expected to be depressed by 15% on 
24-Apr due to a CME impact on 23-Apr.

-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 21 Apr
       Daily Proton Fluence >1 MeV:   4.3E+04
       Daily Proton Fluence >10 MeV:  2.3E+04
       Daily Electron Fluence >2 MeV: 1.40E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.5

DSCOVR Satellite Solar Wind Day Averaged Data for 21 Apr
Speed: 379 km/sec  Density:    4.1 p/cc  Temp:    48400 K  Bz:  -2 nT

(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au



More information about the ips-dsgr mailing list