[Ips-dsgr] ASWFC Daily Report - 21 February 24 issued 2341 UT on 21 Feb 2024 [SEC=OFFICIAL]

rwc rwc at ips.gov.au
Thu Feb 22 10:41:18 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 FEBRUARY 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 FEBRUARY AND FORECAST FOR 22 FEBRUARY - 24 FEBRUARY
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 21 Feb:  R3

Flares    Max     Fadeout    Freq.  Sectors
  X1.9    2307UT  probable   all    West Pacific

Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Feb: 170/124


1B. SOLAR FORECAST
             22 Feb             23 Feb             24 Feb
Activity     R1-R2              R1-R2              R1-R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   170/124            175/129            180/133

COMMENT: Solar activity on UT day 21-Feb was R3, with AR3590(N17E44, 
beta-gamma) producing an X1.8 flare. There are currently two 
numbered sunspot regions on the disk. AR3590 is a large relatively 
complex region and further flare activity is expected from this 
region. This region has shown development in its intermediate 
spots. The other solar region AR3586(N29W15, alpha) is a simple 
spot and has remained flare quiet. S0 solar radiation storm conditions 
were observed on 21-Feb. There is a slight chance for solar radiation 
storm over the next three days. Solar activity is expected to 
be R1-R2, with the chance of further isolated R3 flares over 
22-24 Feb. A solar filament located at N05W35-N30W42 erupted 
during the interval 21/1702-1818UT, visible in SDO304 and GONG 
H-alpha imagery. In LASCO C2 space based coronagraph imagery 
a westward and partially Earth directed CME is visible from 21/1848UT. 
Preliminary modelling was conducted using a small number of C2 
images and results show a relatively slow CME with a west biased 
trajectory with an estimated Earth component arrival early in 
the UT day 25-Feb. Two southeast non Earth directed CMEs, were 
observed from 21/0212UT and 21/1612UT associated with southeast 
limb activity at S40 in SDO193 imagery, which may indicate an 
active solar region is just behind the limb. LASCO imagery will 
be checked for any CME associated with the R3 flare as images 
become available. The solar wind speed ranged between 261 and 
370 km/s and is currently near 345 km/s. The solar wind speed 
showed a slight steady increase after 21/0500UT, possibly due 
to inherent background solar wind structure. The peak total interplanetary 
field strength (IMF, Bt) was 10 nT and the north-south IMF component 
(Bz) range was +8 to -6 nT. The solar wind is expected to be 
near background levels over 22-23 Feb. A weak to moderate shock 
is expected in the solar wind late on 24-Feb/early 25-Feb from 
the filament eruption. Old solar region AR3575 which previously 
produced R1-R2 flares is due to return to the southeast solar 
limb around 21-Feb at solar latitude south 37. There has been 
some plasma arch activity near this solar latitude possibly indicating 
that this region is returning.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 21 Feb: G0

Estimated Indices 21 Feb : A   K           
   Australian Region       3   10110222
      Cocos Island         3   11110221
      Darwin               3   10110113
      Townsville           5   11111223
      Learmonth            4   20111222
      Alice Springs        4   10110213
      Gingin               3   10101222
      Canberra             2   10010112
      Hobart               2   10110111    

Estimated Antarctic Regional K Indices 21 Feb :
      Macquarie Island     0   00000010
      Casey               10   13333222
      Mawson               5   30112221

Observed Regional daily pc3 Indices 21 Feb : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra            10   (Quiet)
      Hobart              10   (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 21 Feb : A 
           Fredericksburg         4
           Planetary              4                         

Observed AFr/Ap Indices 20 Feb :  A   K
           Fredericksburg         5
           Planetary              6   0022 2222     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
22 Feb     6    G0
23 Feb     6    G0
24 Feb    18    Initially G0, increasing to G1 toward the end 
                of the UT day.

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctica regions on UT day 21-Feb. G0 geomagnetic conditions 
are expected over 22-23 Feb. A CME component arrival is expected 
late 24-Feb to early 25-Feb from a recent filament eruption. 
Geomagnetic activity is expected to increase to G1 on 25-Feb, 
with the chance fo G2 periods during the first half of 25-Feb.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
21 Feb      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
22 Feb      Normal         Normal         Normal
23 Feb      Normal         Normal         Normal
24 Feb      Normal         Normal         Normal

COMMENT: HF radio communication conditions on UT day 21-Feb were 
normal. HF radio communication conditions are expected to be 
mostly normal over 22-24 Feb. Degraded HF conditions for middle 
to high latitudes are expected for 25-Feb. Fadeouts are likely 
on daylight HF circuits.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
21 Feb   127

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 45% during local night.
      Enhanced by 25% after local dawn.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Jan      144
Feb      108
Mar      108

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
22 Feb   125    Near predicted monthly values
23 Feb   125    Near predicted monthly values
24 Feb   125    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 21-Feb were 
near predicted monthly values to 15% in the Australian region. 
Ionospheric phase scintillation was observed at Darwin 21/14-15 
UT MUFs are expected to be near predicted monthly values to 15% 
enhanced over 22-24 Feb. Degraded HF conditions are expected 
on 25-Feb for the southern Australian region on 25-Feb due to 
an anticipated CME arrival.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 20 Feb
       Daily Proton Fluence >1 MeV:   1.4E+06
       Daily Proton Fluence >10 MeV:  4.1E+04
       Daily Electron Fluence >2 MeV: 1.10E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.1

DSCOVR Satellite Solar Wind Day Averaged Data for 20 Feb
Speed: 286 km/sec  Density:    2.4 p/cc  Temp:    22600 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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