Dangerous space weather is driven by solar flares and Coronal Mass Ejection (CMEs). Forecasting flares and CMEs is the first step to forecasting either dangerous space weather or All Clear. MAG4 (Magnetogram Forecast), developed originally for NASA/SRAG (Space Radiation Analysis Group), is an automated program that analyzes magnetograms from the HMI (Helioseismic and Magnetic Imager) instrument on NASA SDO (Solar Dynamics Observatory), and automatically converts the rate (or probability) of major flares (M- and X-class), Coronal Mass Ejections (CMEs), and Solar Energetic Particle Events

Barghouty, Nasser

Falconer, David

Khazanov, Igor

NASA Technical Reports Server

www.nasa.gov
National Aeronautics and Space Administration
SCIENCE & TECHNOLOGY OFFICE
David Falconer
Igor Khazanov
Nasser Barghouty
How MAG4 Improves Space Weather Forecasting
https://ntrs.nasa.gov/search.jsp?R=20140002701 2019-08-29T14:37:23+00:00Z
2MAG4 Presentation to AFWA  • 2013 
Outline
1. Space Weather Background
2. MAG4 (Magnetogram Forecast)
a. What it is
b. Brief Background
c. History of R2O
3. MAG4  Automatic Process
4. Demo by Igor Khazanov
5. Improvements in the Pipeline
a. Recent Flare History
b. Vector Magnetograms
6. How Effective
a. Situational Awareness
b. 2x2 Contingence Table Metrics
7. Suggested Collaborations with AFWA
Bastille Day (2000 July 14) Flare, Coronal Mass 
Ejection and Solar Energetic Particle Event
3MAG4 Presentation to AFWA  • 2013 
Various Forms of Space Weather
SIMULTANEOUS   EFFECTS
INCREASED D-LAYER
IONIZATION
OUTBURST OF 
RADIO NOISE
GEOMAGNETIC
DISTURBANCE
RADIO
INTERFERENCE
ANOMALOUS
RADIO 
PROPAGATION
ENHANCED ENERGETIC 
PARTICLES
IONIZATION
MANNED FLIGHT
RADIATION HAZARD(I)
SPACECRAFT
RADIATION HAZARD (C3)
ANOMALOUS
RADIO 
PROPAGATION
RADAR
CLUTTER
IONOSPHERIC
STORM AND 
RADIO EFFECTS
AURORA
SATELLITE DRAG
ULTRA-VIOLET
Solar Energetic Particle 
Event (SPE or SEP Event)
Front CME                   Side CME
Flare
Dangerous space weather is driven by 
solar flares and Coronal Mass Ejection 
(CMEs).  
Forecasting flares and CMEs is the 
first step to forecasting either 
dangerous space weather or All Clear.
CME  
S
p
a
c
e
 
W
e
a
t
h
e
r
X-EUV VISIBLE LIGHT
ELECTROMAGNETIC RADIATION
(IMMEDIATE: TIME 8 MIN)
RADIO WAVES
INDUCED 
CURRENTS
Flare
CME  
ATOMIC NUCLEI
HIGH ENERGY PARTICLES
(DELAYED  HOUR)
IONS AND ELECTRONS
ENHANCED SOLAR WIND
(DELAYED ~3 Days)
DELAYED EFFECTS
GEOMAGNETIC STORM
4MAG4 Presentation to AFWA  • 2013 
What is MAG4?
• MAG4 (Magnetogram Forecast), developed originally for NASA/SRAG 
(Space Radiation Analysis Group), is an automated program that 
analyzes magnetograms from the HMI (Helioseismic and Magnetic 
Imager) instrument on NASA SDO (Solar Dynamics Observatory), and 
automatically converts the rate (or probability) of major flares (M- and 
X-class), Coronal Mass Ejections (CMEs), and Solar Energetic Particle 
Events.
• MAG4 does not forecast a flare will occur at 12:02 tomorrow, but the 
probability of one occurring tomorrow.  
• GONG (Global Oscillations Network Group) magnetograms, can be 
used instead as a backup but at a lower forecast accuracy.
• Present cadence of new forecasts: 96 minutes.  
Vector magnetogram actual cadence: 12 minutes.  
5MAG4 Presentation to AFWA  • 2013 
MAG4 Background
• Flares and CMEs are known to be drivers of the most severe space 
weather
• Flares and CMEs typically originate in active regions (aka sunspots)
• Flares and CMEs are examples of exceptionally large explosive 
releases of magnetic energy stored in the corona 
• While the amount of free energy cannot be measured directly, free-
energy proxies can be measured 
• Event rates have been shown to be correlated with values of free-
energy proxies   
6MAG4 Presentation to AFWA  • 2013 
+-
+-M o
r
e
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
L
e
s
s
Magnetic Free Energy
Currents ~1012 Amps
Contours Vertical Magnetic Field
Arrows Transverse Magnetic Field
Twist Free Magnetic
Energy
Size
Is it Magnetic Free (title) or Free 
Magnetic as below?
7MAG4 Presentation to AFWA  • 2013 
R2O Timeline of MAG4
• 1973 The MSFC (Marshall Space Flight Center) Vector Magnetograph was made to 
support Skylab.  
• 2000-present   MSFC analyzed vector magnetograms to study CME correlation with free-
energy proxy.   
• 2007-12 Co-I in a Multidisciplinary University Research Initiative/Neutral Atmosphere 
Density Interdisciplinary Research 
• 2008 Partnered with SRAG (Space Radiation Analysis Group) and won an R20 
NASA/Technical Excellence Initiative grant: Began building a database that grew to 
~40,000 magnetograms of ~1,300 active region, covering years 1996-2004 with event 
catalog from SOHO/MDI (Solar and Heliospheric Observatory/Michelson Doppler Imager) 
observations.
• 2010-present   NASA’s HEOMD (Human Exploration and Operations Mission Directorate) 
support.  
• 2010 SDO is launched began transitioning from MDI to HMI line-of-sight magnetograms.
• 2011 MAG4 installed at SRAG a NRT (Near-Real-Time) forecasting tool,  and SRAG 
began pre-operations testing.
• 2012 Provided NOAA web access to MAG4 NRT forecasts.
• 2013 Improve MAG4 so that it can use a combination of free-energy proxy and previous 
flare activity.        
• 2013 Transition to HMI line-of-sight to vector magnetograms.
8MAG4 Presentation to AFWA  • 2013 
Flowchart MAG4 Automated Processes
Download HMI Magnetogram
Indentify Active Regions
Calculates Free-Energy Proxy
Predicted Event Rate
Make Forecasts
MAG4 is 
completely 
automated, from 
downloading 
magnetograms to 
outputting forecast 
products.
9MAG4 Presentation to AFWA  • 2013 
Process 1: Identifying Active Regions
• Magnetograms are spatial 
maps of the magnetic field 
strengths.
• They come in two basic types 
- line-of-sight (right)
- vector magnetograms
• Free-energy proxies can be 
measured for Active Regions 
(areas with sunspots) from 
either type of magnetogram.
• Line-of-sight magnetograms 
suffer reduced accuracy 
further from disk center.
06-Mar-2012 14:23NOAA  ARs
11423
11426/3
11429/5
11430/6
11431/1
NOAA 
Active 
Regions 
(ARs)
Best 
Accuracy
A full-disk line-of-sight magnetogram of 
the Sun, from SDO/HMI.Introduce Magnetogram, 
indentify ARs.
10MAG4 Presentation to AFWA  • 2013 
Process 2: Calculating the Free-Energy Proxy 
• Where the transverse 
gradient of the vertical (or 
line-of-sight) magnetic field is 
large, there is more free-
energy stored in the 
magnetic field
• For each Active Region: 
The integral of the gradient 
along the neutral line is the 
free-energy proxy
A magnetogram of an active region
Neutral Line, color coded for gradient
500 G
-500 G
11MAG4 Presentation to AFWA  • 2013 
Process 3: Converting Free-Energy 
Proxy to Predicted Event Rates
These empirical forecast curves are used to convert our free-energy proxy 
into predicted event rates.  Curves are derived from a sample of 40,000 
magnetograms, from 1300 active regions observed between 1996-2004.  
Forecast Curves Free-Energy Proxy  W(KG)
10                  100           10       100        10       100 
12MAG4 Presentation to AFWA  • 2013 
Process 4: Forecast
2012/03/06 14:23
#   AR#     WL!DSG!N Lng Lat 24 Hour Event Rate                        Dist
(kG)   (deg)            M&X    CME    FCME     X    SPE     (deg)
3 11428          9            -21  -17                 0.020  0.020  0.009  0.002  0.003     27 
5 11429         65           -41   17                 0.700  0.400  0.200  0.100  0.080     44!
6 11430         11           -25   20                 0.020  0.030  0.010  0.004  0.005     32!
1 11431          1            36  -27                  0.000  0.001  0.001  0.000  0.000     45!
Disk Forecast Rates                  0.800  0.400  0.200  0.100  0.090
Multiplicative Uncertainties               2.7x   2.1x   2.2x   3.0x   2.4x
Disk All-Clear Forecast Probabilities          50.00% 70.00% 80.00% 90.00% 92.00%
Uncertainties                        40.00% 20.00% 10.00% 10.00%  7.00%
06-Mar-2012 14:23NOAA  ARs
11423
11426/3
11429/5
11430/6
11431/1
Multiplicative uncertainty example
Rate             1 sigma Probability
Events/day   66% Confidence
0.02              0.01-0.05 0.7-5%
0.7  0.3-1.9 20-80%
For a Multiplicative Uncertainty of 2.7x
MAG4 Forecast
lots of layers on this page – not sure 
what you wanted showing
13MAG4 Presentation to AFWA  • 2013 
Comparison of Safe and Not Safe Days
June 26, 2013
C1, C1.5 flares
March 7, 2012
X5.4, X1.3, C1.6
CME 2684, 1825 km/sec,
Solar Energetic Proton Event reaches 
6530 particle flux unit >10MeV
14MAG4 Presentation to AFWA  • 2013 
How Free Energy Proxy Evolves
•
The Free-Energy Proxy evolves on time periods of days, 
and the forecast is on those time scales.  
X-Class Flares *
M-Class Flares  +
Evolution of Free-Energy Proxy Forecasted X&M Flare Rate
15MAG4 Presentation to AFWA  • 2013 
Operation of MAG4   
•
16MAG4 Presentation to AFWA  • 2013 
Improving the Forecasts:
1. Recent Flare History (In Progress) 
Free Energy Only
Recently Flaring            
Recently Non-flaring    
Active regions that have  recently produced an X- or M-Class flare are 
more likely to produce flares in the near future
17MAG4 Presentation to AFWA  • 2013 
Improving the Forecasts:
2. Vector Magnetograms (In Progress)
• MAG4 presently uses SDO/HMI 
line-of-sight magnetograms  
• Near-real-time Ambiguity-
Resolved SDO/HMI vector-
magnetograms have recently 
become available 
• We are transitioning to using 
these new data from SDO
• Implementation just started
18MAG4 Presentation to AFWA  • 2013 
MAG4 Improvements: Vector Magnetograms
Actual Examples
False Neutral 
Lines occur on 
limbward sides of 
sunspots.
Problem fixed by 
converting from 
BLOS and 
BTransverse to BZ
and BHorizontal
Limbward
• Both vectors shown in 
red have positive Bz
(magnetic field out of 
the sun), but have 
opposite sign BLOS and 
thus a false 
(unphysical) neutral line 
in the line-of-sight 
(LOS) field.
Earth
19MAG4 Presentation to AFWA  • 2013 
How Well Does MAG4 Forecast:
• During periods when flare-productive active regions cross the disk, the 
predicted rate and actual rate both increase, providing situational awareness
• The results are best when flares and predicted rates are limited to inner 45 
degree circle (Right)
M or X-Class Flares
Predicted Event Rate Predicted Event Rate Inner 45o
1. Situational Awareness
20MAG4 Presentation to AFWA  • 2013 
How Well Does MAG4 Forecast:
Forecast Method YY YN NY NN PC POD FAR HSS TSS
McIntosh/NOAA 259 638 631 18476 93.7 0.29 0.71 0.26 0.26
Free-Energy Proxy
Present MAG4
273 284 618 18830 95.5 0.31 0.50 0.35 0.47
Free-energy proxy and 
previous flare activity
Upgraded MAG4
340 317 551 18797 95.7 0.38 0.48 0.42 0.49
Best 890 0 0 19114 100 1 0 1 1
Truth Table Actual Yes Actual No
Predict Yes YY YN
Predict No NY NN
PC Percent Correct
POD Probability of Detection
FAR False Alarm Rate
HSS Heidke Skill Score
TSS True Skill Score
2. Skill Metrics
21MAG4 Presentation to AFWA  • 2013 
Suggested Collaboration Tasks with AFWA
• Customizing MAG4 to AFWA needs
• Further development of MAG4
- R2O: use time series, Heliosphere propagation of CME, 
Helioseimology, Improve forecasts as with flare history
- Operational Tool: Robustness, usability, interface
• Independent Verification Tests
22MAG4 Presentation to AFWA  • 2013 
Backup Slides
23MAG4 Presentation to AFWA  • 2013 
How Well Does MAG4 Forecast:
Actual Yes Actual No
Predict Yes YY YN
Predict No NY NN
Metric Equations
2. Skill Metrics Equations
Percent Correct      PC=(YY+NN)/(YY+YN+NY+YY)
Probability of Detection POD=YY/(YY+NY)
False Alarm Rate FAR=YN/(YY+YN)
Heidke Skill Score HSS=2*(YY*NN-YN*NY)/[(YY+NY)* 
(NY+NN)+(YY+YN)*(YN+NN)]
True Skill Score TSS=(YY*NN-NY*YN)/((YY+NY)*(YN+NN))
24MAG4 Presentation to AFWA  • 2013 
How well it works (All-Clear)
Flares occur when high free-energy proxy active regions crossing disk.
Times of X or 
M Flares


How MAG4 Improves Space Weather Forecasting

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