[Ips-dsgr] ASWFC Daily Report - 20 July 23 issued 0349 UT on 21 Jul 2023 [SEC=OFFICIAL]
rwc
rwc at ips.gov.au
Fri Jul 21 13:49:58 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/20 JULY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 20 JULY AND FORECAST FOR 21 JULY - 23 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 20 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Jul: 184/137
1B. SOLAR FORECAST
21 Jul 22 Jul 23 Jul
Activity R1, chance R2 R1, chance R2 R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 185/138 185/138 185/138
COMMENT: Solar activity on UT day 20-Jul was at the R0 level,
with a single high level C-class flare produced by AR3373 (N08W11,
beta-gamma). There are currently seven numbered sunspot regions
visible on the solar disk. AR3373 is the most magnetically complex
region on the solar disk and has exhibited spot development over
the UT day, particularly in its intermediate spots. AR3378 (S25E01,
beta) has shown slight growth in its trailer spots. All other
sunspot regions are either stable or in decay. Solar activity
is expected to be at the R1 level over 21-23 Jul, with a chance
of R2. S1 solar proton conditions declined to S0 over UT day
20-Jul. S0 conditions are expected over 21-23 Jul. A filament
eruption was observed, visible in H-alpha imagery late on UT
day 19-Jul at 19/2241UT near to N25W55. A subsequent northwest-directed
CME was observed in LASCO C2 coronagraph imagery from 19/2312UT.
Modelling indicates this CME is not geoeffective. No other Earth-directed
CMEs were observed on UT day 20-Jul. The solar wind speed on
UT day 20-Jul increased, ranging from 360 to 460 km/s, and is
currently near 405 km/s. A weak shock in the solar wind was observed
at 20/1608UT, indicative of the arrival of a CME first observed
on 17-Jul. A period of sustained southward IMF conditions was
observed from 20/1608-1802UT, however anticipated geomagnetic
activity has not eventuated. The peak total interplanetary field
strength (IMF, Bt) was 12 nT and the north-south IMF component
(Bz) range was +7 to -10 nT. The solar wind speed is expected
to increase over 21-23 Jul due to the anticipated arrival of
a CME first observed on 18-Jul.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 20 Jul: G0
Estimated Indices 20 Jul : A K
Australian Region 5 11101322
Cocos Island 4 11110320
Darwin 6 12111322
Townsville 5 11111322
Alice Springs 5 12100322
Gingin 6 11101332
Canberra 3 01001222
Hobart 2 01001221
Estimated Antarctic Regional K Indices 20 Jul :
Macquarie Island 2 00002211
Casey 13 23212532
Mawson 10 12202343
Observed Regional daily pc3 Indices 20 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth NA
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 29 (Quiet to unsettled)
Hobart 15 (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 20 Jul : A
Fredericksburg 10
Planetary 14
Observed AFr/Ap Indices 19 Jul : A K
Fredericksburg 7
Planetary 4 1110 2112
2B. MAGNETIC FORECAST
Date Ap Conditions
21 Jul 20 G1, slight chance G2
22 Jul 12 G0
23 Jul 8 G0
COMMENT: ASWFC Geomagnetic Warning 40 was issued on 19 July and
is current for 20-21 Jul. G0 geomagnetic conditions were observed
in the Australian region on UT day 20-Jul. G0-G1 geomagnetic
conditions were observed in the Antarctic region. G1 geomagnetic
conditions are expected on 21-Jul, with a slight chance of G2
due to an anticipated impact from a CME first observed on 18-Jul.
G0 geomagnetic conditions are expected over 22-23 Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
20 Jul Normal Normal Normal
PCA Event : 10MeV Proton/PCA Event Began at 0105UT 18/07, Ended at 0335UT 20/07
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
21 Jul Normal Normal-fair Fair
22 Jul Normal Normal Normal-fair
23 Jul Normal Normal Normal-fair
COMMENT: HF communication conditions on UT day 20-Jul were mostly
normal at low to mid latitudes, with poor conditions observed
at high latitudes improving to normal over the UT day. Normal
to fair HF conditions are expected at mid to high latitudes on
21-Jul. Mostly normal HF conditions are expected over 22-23 Jul.
Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
20 Jul 105
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 25% during local night.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 25% over the UT day.
Monthly T index:
Month T index
Jun 98
Jul 91
Aug 88
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
21 Jul 100 Near predicted monthly values
22 Jul 95 Near predicted monthly values
23 Jul 95 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 67 was issued on
19 July and is current for 19-21 Jul. Maximum usable frequencies
(MUFs) on UT day 20-Jul in the Australian region were generally
near predicted monthly values to 25% enhanced in northern Australia.
Spread F was observed during local night hours at Hobart. MUFs
are expected to be generally near predicted monthly values over
21-23 Jul. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 19 Jul
Daily Proton Fluence >1 MeV: 4.4E+07
Daily Proton Fluence >10 MeV: 3.0E+06
Daily Electron Fluence >2 MeV: 5.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.5
DSCOVR Satellite Solar Wind Day Averaged Data for 19 Jul
Speed: 419 km/sec Density: 3.4 p/cc Temp: 96000 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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