Post on 15-Jun-2015
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A new solar prominence catalogue with SOPRA
Nicolas Labrosse1, Silvia Dalla2,
Jinchang Ren3, and Steve Marshall3
1- University of Glasgow, Scotland
2- University of Central Lancashire, England
3- University of Strathclyde, Scotland
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13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• Fact: some attempts to make large statistical studies of
global prominence properties
– Manual detection
E.g. Gilbert et al (2000): identify distinguishing characteristics of APs and
EPs and study the relationship between prominence activity and CMEs
– Automatic detection
Foullon & Verwichte (2005); Wang et al. (2010)
• Can be improved by producing large catalogues for
statistical studies
• Link with filament / flare / CME catalogues
• Automatic feature recognition from SDO/AIA data
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Aims
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• What does SOPRA mean?
• sopra prep
• a (gen) over
• b (più in su di) above
Solar Off-limb Prominence Reconstruction Algorithm
• Approach
– Process only He II 304 images
Prominences are best viewed in this channel
Limits dependence on other channels' availability
Faster to process than when using additional channels
• Now developed for SOHO/EIT data
• Being tested on SDO/AIA
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SOPRA
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• Pre-processing of image
• Take radial intensity profiles, calculate moments and label them
• Train Support Vector Machine
• Algorithm recognises off-limb structures based on the moments of the radial intensity profiles
• At the position on the limb where a prominence is detected, morphological image reconstruction is applied
• Prominence characteristics are extracted
– Results feed the catalogue
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Method
Training of classifier
Classification
Reconstruction
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• Pre-processing of image
• Take radial intensity profiles, calculate moments and label them
• Train Support Vector Machine
• Algorithm recognises off-limb structures based on the moments of the radial intensity profiles
• At the position on the limb where a prominence is detected, morphological image reconstruction is applied
• Prominence characteristics are extracted
– Results feed the catalogue
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Method
Classification
Reconstruction
prominence
active region quiet corona
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• Pre-processing of image
• Take radial intensity profiles, calculate moments and label them
• Train Support Vector Machine
• Algorithm recognises off-limb structures based on the moments of the radial intensity profiles
• At the position on the limb where a prominence is detected, morphological image reconstruction is applied
• Prominence characteristics are extracted
– Results feed the catalogue
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Method
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• Pre-processing of image
• Take radial intensity profiles, calculate moments and label them
• Train Support Vector Machine
• Algorithm recognises off-limb structures based on the moments of the radial intensity profiles
• At the position on the limb where a prominence is detected, morphological image reconstruction is applied
• Prominence characteristics are extracted
– Results feed the catalogue
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Method
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• We processed 29367 FITS files covering ~ all EIT full-disk
images at 304 Å between 01/1996 and 06/2011
– Took > 2 weeks on 4x Quad Core AMD with 64 GB of RAM
• 315307 unique prominences detected
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Applying SOPRA on the EIT database
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011 8
Results: histograms
Prominence area
Latitude
Time
Altitude
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011 9
Results: correlations
Area vs time
Altitude vs time
Latitude vs time
Altitude vs latitude
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011
• SOPRA: Solar Off-limb Prominence Reconstruction Algorithm
– Labrosse et al., Solar Physics, 262, 449 (2010)
• The algorithm as a whole is working well
– Production of catalogue from EIT observations since 1996
– Generates HEK-compliant output
– Large samples for statistical studies (> 300000 detections so far)
– Track prominence eruptions
– Link with filament / flare / CME catalogues
– Monitor impact of prominence eruptions on space weather
Thank you for listening to this last talk!
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Conclusions
13th European Solar Physics Meeting, Rhodes, Greece, 12-16 September 2011 – Nicolas Labrosse – 16/9/2011 11
AIA