[Ips-dsgr] ASWFC Daily Report - 18 July 23 issued 2330 UT on 18 Jul 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Wed Jul 19 09:30:10 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 JULY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 JULY AND FORECAST FOR 19 JULY - 21 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 18 Jul: R2
Flares Max Fadeout Freq. Sectors
M2.7 17/2255UT possible lower East Pacific/
North American
M5.0 17/2334UT possible lower West Pacific
M5.7 0007UT possible lower West Pacific
M1.5 0657UT possible lower Mid East/Indian
M1.3 1948UT possible lower East Pacific/
North American
M2.1 2027UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Jul: 219/169
1B. SOLAR FORECAST
19 Jul 20 Jul 21 Jul
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 210/161 210/161 210/161
COMMENT: Solar activity on UT day 18-Jul was at the R1 level,
with a long duration M5.7 flare at 18/0006UT, an M1.5 flare at
18/0656UT, an M1.3 flare at 18/1947UT, an M1.5 flare at 18/2005UT
and an M2.2 flare at 18/2027UT. There are currently eight numbered
sunspot regions visible on the solar disk and three unnumbered
regions. AR3363 (S20W82, beta) produced the M5.7 flare, which
was the largest flare of the day. This region is in the process
of rotating off the solar disk. AR3376 (N24E29, beta-gamma-delta)
was responsible for the three M-class flares from 18/1947UT onwards
and showed development over the UT day. AR3373 (N08E17, beta-gamma-delta)
showed trailer spot development. All other numbered regions are
either stable or in decay. An unnumbered region developed on
the solar disk at S32E30 with beta magnetic characteristics.
To=wo sunspot regions with alpha magnetic characteristics rotated
on to the solar disk on 18-Jul, one at S29E65 and one at N13E85.
Solar activity is expected to be at the R1 level over 19-21 Jul,
with a chance of R2. The >10 MeV proton flux reached the S2 level
from 18/0145UT until 18/1425UT, with a maximum flux at 18/0615UT,
due to the long duration M5.7 flare at 18/0006UT. The >10 MeV
proton flux is currently at the S1 level, with a chance of S2
on 19-Jul. A partial halo CME associated with the M5.7 flare
at 18/0006UT was observed in LASCO C2 and STEREO-A imagery from
17/2336UT. An eruption is visible in SDO and GOES SUVI imagery
from 17/2235UT. Modelling indicates this CME has a geoeffective
component with an impact expected on 20-Jul at 0600UT +/- 12
hours. A north east directed CME is visible in LASCO C2 and STEREO-A
imagery from 18/2024UT. An eruption is visible in GOES SUVI,
SDO and H-Alpha imagery from 18/1935UT associated with the three
M-class flares produced from 18/1947UT by AR3376. Modelling indicates
this CME has a geoeffective component with an impact expected
on 21-Jul at 0800UT +/- 12 hours. No other geoeffective CMEs
were observed. The solar wind speed on UT day 18-Jul declined,
ranging from 567 to 450 km/s, and is currently near 470 km/s.
The peak total interplanetary field strength (IMF, Bt) was 7
nT and the north-south IMF component (Bz) range was +6 to -6
nT. The solar wind speed is expected to continue to decline over
19-Jul. An increase is expected on 20-Jul due to an anticipated
impact from a CME first observed on 17-Jul. A further increase
is expected on 21-Jul due to an anticipated impact from a CME
first observed on 18-Jul.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 18 Jul: G0
Estimated Indices 18 Jul : A K
Australian Region 8 32223121
Cocos Island 6 32113120
Darwin 9 33223121
Townsville 9 33223122
Learmonth - --------
Alice Springs 7 32223120
Gingin 8 33223020
Canberra 7 32232021
Hobart 7 32132021
Estimated Antarctic Regional K Indices 18 Jul :
Macquarie Island 9 32431021
Casey 11 44222122
Mawson 36 75435221
Observed Regional daily pc3 Indices 18 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth NA
Alice Springs 0 (Quiet)
Gingin 8 (Quiet)
Canberra 20 (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 18 Jul : A
Fredericksburg 16
Planetary 21
Observed AFr/Ap Indices 17 Jul : A K
Fredericksburg 19
Planetary 23 3244 4254
2B. MAGNETIC FORECAST
Date Ap Conditions
19 Jul 10 G0
20 Jul 60 G2-G3
21 Jul 50 G1-G2, chance of G3
COMMENT: ASWFC Geomagnetic Warning 39 was issued on 18 July and
is current for 19-21 Jul. G0 geomagnetic conditions were observed
in the Australian region on UT day 18-Jul. Mostly G0 conditions
were observed in the Antarctic region, with G3 conditions observed
at Mawson. G0 geomagnetic conditions are expected on 19-Jul.
G2-G3 conditions are expected on 20-Jul due to an anticipated
impact from a CME first observed on 17-Jul. G1-G2 conditions,
with a chance of G3 are expected on 21-Jul due to an anticipated
impact from a CME first observed on 18-Jul, combined with possible
ongoing effects from the previous CME impact on 20-Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
18 Jul Normal Normal-fair Poor(PCA)
PCA Event : 10MeV Proton/PCA Event Began at 0145UT 18/07, Ended at 1425UT 18/07
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
19 Jul Normal Normal Poor(PCA)
20 Jul Poor Poor Poor
21 Jul Poor Poor Poor
COMMENT: HF communication conditions on UT day 18-Jul were mostly
normal at low to mid latitudes, with poor conditions observed
at high latitudes due to polar cap absorption events caused by
S2 conditions. Normal conditions are expected at low to mid latitudes
on 19-Jul, with poor conditions expected at high latitudes due
to ongoing S1 conditions. HF communication conditions are expected
to be degraded over 20-21 Jul due to anticipated geomagnetic
activity caused by impacts from CMEs first observed on 17-Jul
and 18-Jul.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
18 Jul 113
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20% during local day.
Depressed by 20% during local night.
Niue Island Region:
Enhanced by 15% during local day.
Enhanced by 30% during local night.
Northern Australian Region:
Enhanced by 20% during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
Proton event in progress, increased absorption observed.
Monthly T index:
Month T index
Jun 98
Jul 91
Aug 88
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
19 Jul 110 Near to 15% above predicted monthly values
20 Jul 100 Near predicted monthly values
21 Jul 100 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 66 was issued on
17 July and is current for 17-19 Jul. Maximum usable frequencies
(MUFs) on UT day 18-Jul in the Australian region were generally
near predicted monthly values with enhancements of up to 20%
observed in the northern Australian region. Spread F was observed
during local night hours in the southern Australian region. MUFs
are expected to be near predicted monthly values to 15% enhanced
in the northern Australian region on 19-Jul. Depressions are
expected, particularly in the southern Australian region over
20-21 Jul due to anticipated geomagnetic activity caused by impacts
from CMEs first observed on 17-Jul and 18-Jul.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 17 Jul
Daily Proton Fluence >1 MeV: 1.2E+06
Daily Proton Fluence >10 MeV: 5.1E+04
Daily Electron Fluence >2 MeV: 1.20E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.5
DSCOVR Satellite Solar Wind Day Averaged Data for 17 Jul
Speed: 522 km/sec Density: 1.3 p/cc Temp: 178000 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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