Barghouty, Nasser

Falconer, David

Khazanov, Igor

Moore, Ron

NASA Technical Reports Server

www.nasa.gov
National Aeronautics and Space Administration
SCIENCE & TECHNOLOGY OFFICE
David Falconer, Nasser Barghouty, Igor Khazanov, and Ron Moore
Jan 24, 2016
http://www.uah.edu/cspar/research/mag4-page
An All-Clear Space Weather Forecasting System Based on Magnetogram 
in Near Real Time
https://ntrs.nasa.gov/search.jsp?R=20160001328 2019-08-31T04:15:00+00:00Z
2Science for Space Weather
Outline
1. MAG4 background
2. Measurement
3. Effectiveness
4. Transitioning to Vector
5. Future improvements
Bastille Day (2000 July 14) Flare, Coronal Mass 
Ejection and Solar Energetic Particle Event
3Science for Space Weather
MAG4 Automated Processes
Download HMI Magnetogram
Line-of-Sight (LOS) or Vector
Identify Active Regions LOS
Use SHARPS for vector
Calculates Free-Energy Proxy
Predicts Event Rate
Makes Forecasts
MAG4 is 
completely 
automated, from 
downloading 
magnetograms to 
outputting and 
storing forecast 
products.
4Science for Space Weather
MAG4 Science 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 the magnitude of 
the  free-energy proxies   
5Science for Space Weather
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 predicts the event rate (or probability) of major flares (M-
and X-class), Coronal Mass Ejections (CMEs), and Solar Energetic 
Particle Events
• MAG4 does not forecast that a flare will occur at a particular time in the 
next 24 or 48 hours; rather the probability of one occurring!  
• 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 (60 minutes for 
CCMC)                     Vector magnetogram actual cadence: 12 minutes
6Science for Space Weather
R2O Timeline of MAG4
• 1973 The MSFC (Marshall Space Flight Center) vector magnetograph was built to support 
Skylab   
• 2000-present   MSFC used vector magnetograms to study CME correlation with free-
energy proxy    
• 2007-12 A DOD/Multidisciplinary University Research Initiative/Neutral Atmosphere 
Density Interdisciplinary Research helped support funding of the basic research 
• 2008 Partnered with JSC/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
• 2015 Transition to HMI line-of-sight to vector magnetograms
7Science for Space Weather
Calculating the Free-Energy Proxy 
• When 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
0.1G/km
0 G/km
8Science for Space Weather
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)
1                   10                  100           10       100        10       100 
9Science for Space Weather
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 LOS 
Accuracy
A full-disk line-of-sight magnetogram of 
the Sun, from SDO/HMI.
Magnetograms & identify ARs 
10Science for Space Weather
Forecast
2012/03/06 14:23
#   AR#     WLSG 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
11Science for Space Weather
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
12Science for Space Weather
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
2. Skill Metrics    Significance of Upgrade
Improvement in Metric PC(%) POD FAR HSS TSS
McIntosh/NOAA
Present MAG4
1.8±0.5
(4σ)
0.03±0.05
(0.3σ)
0.21±0.07
(3σ)
0.10±0.04
(2σ)
0.21±0.07
(3σ)
Present MAG4
Upgraded MAG4
0.2±0.2
(0.7σ)
0.08±0.03
(2σ)
0.02±0.05
(0.5σ)
0.06±0.03
(2σ)
0.03±0.05
(0.5σ)
13Science for Space Weather
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 45
o
1. Situational Awareness
14Science for Space Weather
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
15Science for Space Weather
Results of transitioning to Vector
• For LOS most accurate to 30 
heliocentric degrees. (RED)
• For Vector similar accuracies 
should exist to 60 heliocentric 
degrees.  
06-Mar-2012 14:23NOAA  ARs
11423
11426/3
11429/5
11430/6
11431/1
NOAA 
Active 
Regions 
(ARs)
Best LOS 
Accuracy
A full-disk line-of-sight magnetogram of 
the Sun, from SDO/HMI.
Magnetograms & identify ARs 
Best Vector Accuracy?
16Science for Space Weather
Near Future Improvements
• MAG4 presently
– Predicts what MDI 
will measure if AR 
was at disk center.
– Then uses the 
forecast curves from 
MDI to forecast 
events.
• MAG4 needs to 
upgrade to take full 
advantage of vector 
magnetograms.
• http://www.uah.edu/csp
ar/research/mag4-page
17Science for Space Weather
BACKUP
18Science for Space Weather
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))
19Science for Space Weather
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 273 284 618 18830 95.5 0.31 0.50 0.35 0.47
Free-energy proxy and 
previous flare activity
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  (0 to 100%)
POD Probability of Detection (0 to 1)
FAR False Alarm Rate   ( 1 to 0)
HSS Heidke Skill Score (-1 to 1)
TSS True Skill Score   (-1 to 1)
2. Skill Metrics
20Science for Space Weather
Improvements with Vector MAG4
• Correct for systemic errors in measurements due to radial dependence 
of transverse field noise and foreshortening.
• Access skill scores relative to present LOS
• Investigate if a vector measure is better than LOS measure
• Investigate if change of measure is important
• Investigate if combination produces better measure
• Correct SPE forecasts based on Longitude of source region
• Partner with heliosphere modeling to better forecast where the particles 
would go.
• Twin CME`
21Science for Space Weather
Basic Research to do for later R20
• Determine if growth/decay phase 
of an active region has additional 
prediction ability 
• Determine if looking at twin-CME 
or single-CME can produce 
improved SEP forecasts
22Science for Space Weather
Research to Operations and Operations for FY14
• Continue to supply support, and upgrades to NASA/SRAG 
• Finish and evaluate using vector magnetograms 
• Fully implement in consultation with SRAG using combined free-energy 
proxy and previous flare activity
• Improve All Clear Forecast for SEP 
• Partner with Air Force, and through them NOAA 
23Science for Space Weather
Improving the Forecasts:
1. Recent Flare History
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
1           10         100
Free-Energy Proxy  W(kG)
1           10         100
Free-Energy Proxy  W(kG)
24Science for Space Weather
+-
+
-
M
o
re
  
  
  
  
  
  
  
 L
e
s
s
Free-Magnetic Energy
Currents ~1012 Amps
Contours Vertical Magnetic Field
Arrows Transverse Magnetic Field
Twist Free Magnetic Energy
Or Nonpotentiality
Size
25Science for Space Weather
How Free Energy Proxy Evolves and Clustering of Flares
•
The free-energy proxy evolves on time periods of days =>
the forecast is on those time scales  
X-Class Flares *
M-Class Flares  +
Evolution of Free-Energy Proxy Forecasted X&M Flare Rate
100
80
60
40
20
0
F
re
e
-E
n
e
rg
y
 P
ro
x
y
  
W
(k
G
)
26Science for Space Weather
How well it works (All-Clear)
Flares occur when high free-energy proxy active regions crossing disk.
Times of X or 
M Flares


An All-Clear Space Weather Forecasting System Based on Magnetogram in Near Real Time

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