exploration physics international, inc. haf: an operational, event-driven solar wind forecast model...
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Exploration Physics International, Inc.
HAF: An Operational,
Event-driven Solar Wind Forecast Model
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Murray [email protected]
Exploration Physics International, Inc.
Goal: Improve Space Weather Forecasting
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Acc
urac
y
0
100%
0%
Forecast Lead Time
Exploration Physics International, Inc.
Geomagnetic Storm Prediction System
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CoronalModel
EventProxies
Solar WindModel
Near EarthModels
v, n, BIMF
Exploration Physics International, Inc.
VSS = V0 + V1 -
HAF Model Inputs: Ambient Solar Wind
Steady State:
• Source surface (2.5 Rs)• B, v synoptic maps
Maps from:
• SEC (Arge & Pizzo)
• Solar observatories
(NSO, MWO, WSO)
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Exploration Physics International, Inc.
HAF Model Inputs: Solar Events
Required Input Observation
Start time eg., 20010825 1642
GOES X-ray or metric type II radio event start time
Location, eg., N20 W34 H-alpha or active region report
Initial shock speed, Vs Metric type II radio report or spectra
Duration, GOES X-ray flux temporal profile
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Exploration Physics International, Inc.
“Fearless Forecast” Study
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• NOAA/SEC, EXPI, GI/UAF
• February 1997 - present
• Interplanetary shock arrival time (SAT) at Earth
• Ensemble of three models (HAF, ISPM, STOA)
• Benchmark forecast skill
Exploration Physics International, Inc.
“Fearless Forecast” Study
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Shock Arrival Time ForecastsDuring Solar Cycle 23
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1/1
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nth
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# Forecasts SEC Monthly SSN
1995 1997 1999 2001 2003
Exploration Physics International, Inc.
“April Fools Day” 2001 Events
FF# Start date/time Vs Location Comment254 20010327 1632 677 N22 E33 M2.2/1N255* 20010328 1240 1000* N18 E02 M4.3/SF256 20010329 1004 1300 N16 W12 X1.7/1N257* 20010330 1559 1850 S10 W90* Blowout?258* 20010330 1620 1600 S10 E115? Blowout?
Events
HAFv.2: Shock will overtake the two previous interplanetary ICMEs, and the combined structure's shock will arrive at 1800 UT, 30 March 2001. SSI = 1.0, and delta(dynamic pressure) = 13.2 nPa.
Forecast #256 issued 29 March 2001, 2055 UT
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Exploration Physics International, Inc.
Speed
Density
Log(P/P)
Dynamicpressure
3/28/01 4/05/01
“FF” #255-258, issuedMar. 28-30, 2001
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HAF Model Prediction
Exploration Physics International, Inc.
“April Fools Day” 2001 Event
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Exploration Physics International, Inc.
“Bastille Day” 2000 Event
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“Fearless Forecast” issued at 20:31 UT on July 14, 2000:
[Dryer et al., Solar Phys., 2001].
“Strong shock will arrive at 15 UT on July 15, 2000.”
“Fearless Forecast” Metrics
Observed
Forecast Yes No
Yes hit false alarm
No miss correct
null
Exploration Physics International, Inc. 12
Contingency Table
“Fearless Forecast” MetricsFeb. 1997 - Oct. 2000
• Success rate > 50 %
• False alarm rate ~ 50%
• Hit/Miss Ratio STOA best for strong shocks HAF best for medium, weak shocks
• Heidke skill score ~ .15 - .20
• RMS error T (SATPRED - SATOBS) ~ 11 - 12 hours
Exploration Physics International, Inc. 13
173 events, 68 observed shocks
Exploration Physics International, Inc.
Solar Cycle 23 - Lessons Learned
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• CIRs produce shocks.Dec. 25, 1998, 20 UT
Exploration Physics International, Inc.
Solar Cycle 23 - Lessons Learned
• Initial shock speed is the most important input to the SAT prediction.
• SAT forecast skill is best near Central Meridian.
• SAT forecast skill is worst for limb events because Metric Type II speeds are too low.
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Exploration Physics International, Inc.
Future of Operational, Real-Time, Sun-to-Earth Solar Wind Predictions
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Increased Customer Support:• Make Advanced Operational Decisions
Improved Forecast Skill:• Assimilate Data
• Predict Bz
Better Customer Collaboration:• Specify Needs
+
=
Exploration Physics International, Inc.
“Fearless Forecast” Web Site
http://gse.gi.alaska.edu
Email: [email protected]
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Exploration Physics International, Inc.
Metric Type II Speed
V vs. Type II SpeedFebruary, 1997 - October, 2000
-500
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0 500 1000 1500 2000 2500
Type II Speed, Vs (km/s)
Vs
-Va
ve
,
V (
km
/s)
accelerated
decelerated
62 shocks
Exploration Physics International, Inc.
• Provides realistic background and event-driven solar wind conditions at L1 and elsewhere.
• Takes in solar observations and event reports.
• Uses “modified kinematic” approach to track solar wind fluid parcels.
• Predicts interplanetary shocks in the global heliosphere.
• Drives downstream empirical and first-principle space weather models.
Hakamada-Akasofu-Fry (HAF)Solar Wind Model