[Ips-dsgr] ASWFC Daily Report - 17 July 23 issued 2330 UT on 17 Jul 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Tue Jul 18 09:30:08 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 JULY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 JULY AND FORECAST FOR 18 JULY - 20 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Jul: R1
Flares Max Fadeout Freq. Sectors
M2.7 2255UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Jul: 180/133
1B. SOLAR FORECAST
18 Jul 19 Jul 20 Jul
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 178/131 174/128 172/126
COMMENT: Solar activity on UT day 17-Jul was at the R1 level,
with an M2.7 flare occurring at 17/2255UT and another M-class
flare which has not yet peaked at time of writing. The M2.7 flare
was produced by AR3363 (S20W76, gamma). There are currently eight
numbered sunspot regions visible on the solar disk. AR3373 (N08E29,
beta-delta) and AR3376 (N24E43, beta-gamma), both displayed spot
development over the UT day. AR3363 is the largest sunspot region
and was responsible for the largest flare of the UT day. This
region displayed some decay over 17-Jul and will rotate off the
solar disk on 18-Jul. All other sunspot regions are either stable
or in decay. Solar activity is expected to be at the R1 level
over 18-20 Jul, with a chance of R2. The >10 MeV proton flux
was elevated on 17-Jul but below the S1 threshold and with a
declining trend. No Earth-directed CMEs were observed on 17-Jul.
Two partial halo CMEs were observed in LASCO C2 and STEREO-A
imagery from 17/0133UT and 17/0716UT. These are both considered
far side events. A slow and narrow CME is visible in LASCO C2
and STEREO-A imagery from 17/0414UT associated with an eruption
visible in GOES SUVI, SDO and H-Alpha imagery from 17/0347UT
at around S28W62 and further around the western limb. A further
narrow CME is visible in LASCO C2 and STEREO-A imagery from 17/0950UT,
associated with an eruption visible in GOES SUVI, SDO and H-Alpha
imagery from 17/0911UT at around S30E70. Neither of these CMEs
are considered geoeffective. The M2.7 flare at 17/2255UT appears
associated with an eruption visible in SDO imagery, any CME produced
by this eruption will be analysed when more coronagraph imagery
becomes available. The solar wind speed on UT day 17-Jul increased,
ranging from 389 to 620 km/s, and is currently near 535 km/s.
The peak total interplanetary field strength (IMF, Bt) was 13
nT and the north-south IMF component (Bz) range was +7 to -10
nT. A pair of sustained periods of southward IMF conditions was
observed from 17/0450UT to 17/0958UT and 17/1610UT to the end
of the UT day. The solar wind speed is expected to remain elevated
over 17-Jul with a chance of further enhancements due to an impact
from a CME first observed on 14-Jul. The solar wind speed is
expected to remain elevated over 18-19 Jul with a decline expected
from 19-Jul onwards.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 Jul: G0
Estimated Indices 17 Jul : A K
Australian Region 16 22344143
Cocos Island 11 22333033
Darwin 12 12343033
Townsville 14 12343143
Learmonth 25 22355---
Alice Springs 13 12343043
Gingin 20 22345144
Canberra 15 12344143
Hobart 18 22354143
Estimated Antarctic Regional K Indices 17 Jul :
Macquarie Island 34 21665144
Casey 23 44322263
Mawson 37 43442275
Observed Regional daily pc3 Indices 17 Jul :
Darwin 0 (Quiet)
Townsville 2 (Quiet)
Learmonth 3 (Quiet)
Alice Springs 2 (Quiet)
Gingin 6 (Quiet)
Canberra 3 (Quiet)
Hobart 6 (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 17 Jul : A
Fredericksburg 19
Planetary 24
Observed AFr/Ap Indices 16 Jul : A K
Fredericksburg 13
Planetary 10 2100 2244
2B. MAGNETIC FORECAST
Date Ap Conditions
18 Jul 24 G1, chance of G2
19 Jul 12 G0
20 Jul 8 G0
COMMENT: Mostly G0 geomagnetic conditions were observed in the
Australian region on UT day 17-Jul, with periods of G1 observed
at Learmonth, Gingin and Hobart. G2 conditions were observed
at Macquarie Island and Casey with a period of G3 observed at
Mawson. G1 geomagnetic conditions, with a chance of G2 are expected
on 18-Jul due to an anticipated impact from a CME first observed
on 14-Jul. G0 geomagnetic conditions are expected over 19-20
Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
17 Jul Poor Normal-fair Normal-fair
PCA Event : 10MeV Proton/PCA Event Began at 0625UT 16/07, Ended at 0855UT 16/07
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
18 Jul Normal Normal-fair Fair
19 Jul Normal Normal Normal-fair
20 Jul Normal Normal Normal-fair
COMMENT: HF communication conditions on UT day 17-Jul were mostly
normal. Mildly degraded conditions are possible over 18-19 Jul
due to ongoing and anticipated geomagnetic activity with normal
conditions expected on 20-Jul. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
17 Jul 118
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 30% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Enhanced by 25% during local day.
Enhanced by 60% during local night.
Enhanced by 35% after local dawn.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Depressed by 20% 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
18 Jul 110 Near predicted monthly values
19 Jul 110 Near predicted monthly values
20 Jul 120 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 17-Jul in the Australian region were generally
near predicted monthly values to 15% enhanced. Spread F was observed
during local night hours at Hobart, Townsville and Darwin. MUFs
are expected to be near predicted monthly values to 15% depressed
over 18-19 Jul, due to ongoing and anticipated geomagnetic activity.
MUFS are expected to be near predicted monthly values on 20-Jul.
Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 16 Jul
Daily Proton Fluence >1 MeV: 2.0E+06
Daily Proton Fluence >10 MeV: 2.7E+05
Daily Electron Fluence >2 MeV: 1.30E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.3
DSCOVR Satellite Solar Wind Day Averaged Data for 16 Jul
Speed: 376 km/sec Density: 0.2 p/cc Temp: 79600 K Bz: -3 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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