WHAT CAN WE LEARN FROM SORCE ABOUT THE CONTRIBUTION OF DIFFERENT MAGNETIC STRUCTURES TO THE SOLAR SPECTRAL IRRADIANCE (SSI)? Anatoly Vuiets1, Thierry Dudok de Wit1 and Matthieu Kretzschmar1. 1. LPC2E and University of Orleans, France. MODELING OF SOLAR IRRADIANCE (SSI AND TSI) Lack of observational data. MODELING OF SOLAR IRRADIANCE (SSI AND TSI) Lack of observational data. strong need for modeling of the SSI MODELING OF SOLAR IRRADIANCE (SSI AND TSI) Lack of observational data. Common approach is semiempirical modeling (e.g. SATIRE, COSI). strong need for modeling of the SSI MODELING OF SOLAR IRRADIANCE (SSI AND TSI) Lack of observational data. Common approach is semiempirical modeling (e.g. SATIRE, COSI). strong need for modeling of the SSI Assumption: SSI variability is driven by evolution of surface magnetic field. MODELING OF SOLAR IRRADIANCE (SSI AND TSI) Lack of observational data. Common approach is semiempirical modeling (e.g. SATIRE, COSI). characteristic spectra + strong need for modeling of the SSI Assumption: SSI variability is driven by evolution of surface magnetic field. MODELING OF SOLAR IRRADIANCE (SSI AND TSI) Lack of observational data. Common approach is semiempirical modeling (e.g. SATIRE, COSI). characteristic spectra + magnetic structures obtained from magnetograms and continuum images strong need for modeling of the SSI Assumption: SSI variability is driven by evolution of surface magnetic field. MODELING OF SOLAR IRRADIANCE (SSI AND TSI) Lack of observational data. Assumption: SSI variability is driven by evolution of surface magnetic field. flux Common approach is semiempirical modeling (e.g. SATIRE, COSI). strong need for modeling of the SSI characteristic spectra + magnetic structures obtained from magnetograms and continuum images time ISSUES TO BE SOLVED ISSUES TO BE SOLVED - How should the magnetic structures be defined? ? ? ? ? ? ? ? ? ? ? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? ? ? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? - How important is the center-to-limb (CTL) effect? 170 nm ? ? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? - How important is the center-to-limb (CTL) effect? 170 nm ? ? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? - How important is the center-to-limb (CTL) effect? 170 nm ? ? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? ? ? 170 nm - How important is the center-to-limb (CTL) effect? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? ? ? 170 nm - How important is the center-to-limb (CTL) effect? - What is the contribution of magnetic structures to the SSI? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? ? ? 170 nm - How important is the center-to-limb (CTL) effect? - What is the contribution of magnetic structures to the SSI? - What spatial resolution is sufficient? ISSUES TO BE SOLVED ? ? - How should the magnetic structures be defined? ? ? ? ? ? ? ? ? 170 nm - How important is the center-to-limb (CTL) effect? - What is the contribution of magnetic structures to the SSI? - What spatial resolution is sufficient? To answer these questions consider an empirical (“less biased”) approach. No assumptions on atmospherical models. MORE EMPIRICAL MODEL MORE EMPIRICAL MODEL magnetogram MORE EMPIRICAL MODEL magnetogram continuum image MORE EMPIRICAL MODEL classes f magnetogram continuum image segmentation map MORE EMPIRICAL MODEL classes f magnetogram continuum image rings r segmentation map MORE EMPIRICAL MODEL classes f magnetogram continuum image rings r segmentation map Linear SATIRE-like model: - characteristic spectrum of class f in ring r - filling factor of class f in ring r (fraction of solar disk covered by magnetic structures of this class) MODEL BUILDING Difference : MODEL BUILDING Difference - spectra S are not imposed. : MODEL BUILDING Difference - spectra S are not imposed. : - number of classes f is not imposed. MODEL BUILDING Difference - spectra S are not imposed. : - number of classes f is not imposed. - threshold levels between classes f are not pre-defined. MODEL BUILDING Difference - spectra S are not imposed. : - number of classes f is not imposed. - threshold levels between classes f are not pre-defined. - number of rings r is not imposed. MODEL BUILDING Difference - spectra S are not imposed. : - number of classes f is not imposed. - threshold levels between classes f are not pre-defined. - number of rings r is not imposed. - segmentation of magnetograms according to area of magnetic structures. MODEL BUILDING Difference - spectra S are not imposed. : - number of classes f is not imposed. - threshold levels between classes f are not pre-defined. - number of rings r is not imposed. - segmentation of magnetograms according to area of magnetic structures. S = I F-1 S - model atmosphere I - spectral irradiance observations F -filling factors DATA DATA - Model is calibrated with SSI observations (daily averages). Instrument Wavelength, nm Spectral band SDO/EVE 6.5-9.5 XUV SDO/EVE 10.5-35.5 EUV TIMED/SEE 36-115 EUV SORCE/SOLSTICE 121 LyA SORCE/SOLSTICE 115-200 FUV SORCE/SOLSTICE 280 MgII SORCE/SOLSTICE 200-300 MUV SORCE/TIM TSI TSI DATA - Model is calibrated with SSI observations (daily averages). Instrument Wavelength, nm Spectral band SDO/EVE 6.5-9.5 XUV SDO/EVE 10.5-35.5 EUV TIMED/SEE 36-115 EUV SORCE/SOLSTICE 121 LyA SORCE/SOLSTICE 115-200 FUV SORCE/SOLSTICE 280 MgII SORCE/SOLSTICE 200-300 MUV SORCE/TIM TSI TSI - Magnetograms and continuum images SDO/HMI and SDO/AIA respectively(4096x4096 compressed to 2048x2048 pxls) DATA - Model is calibrated with SSI observations (daily averages). Instrument Wavelength, nm Spectral band SDO/EVE 6.5-9.5 XUV SDO/EVE 10.5-35.5 EUV TIMED/SEE 36-115 EUV SORCE/SOLSTICE 121 LyA SORCE/SOLSTICE 115-200 FUV SORCE/SOLSTICE 280 MgII SORCE/SOLSTICE 200-300 MUV SORCE/TIM TSI TSI - Magnetograms and continuum images SDO/HMI and SDO/AIA respectively(4096x4096 compressed to 2048x2048 pxls) Time interval: 24/04/2010 - 01/07/2013 (about 3 years of data) SEGMENTATION OF MAGNETOGRAMS BY AREA VS INTENSITY Segmentation by magnetic field intensity is common approach. Disadvantages: SEGMENTATION OF MAGNETOGRAMS BY AREA VS INTENSITY Segmentation by magnetic field intensity is common approach. Disadvantages: Absolute calibration errors active region intensity difference intensity is big difference in area is small x SEGMENTATION OF MAGNETOGRAMS BY AREA VS INTENSITY Segmentation by magnetic field intensity is common approach. Disadvantages: Absolute calibration errors active region intensity difference intensity is big Limb processing B0 observer Blos SUN difference in area is small x limb SEGMENTATION OF MAGNETOGRAMS BY AREA VS INTENSITY Segmentation by magnetic field intensity is common approach. Disadvantages: Solution: Limb processing B0 by segmentation observer difference area. Blos intensity is Absolute calibration errors intensity active region big B = aSb SUN difference in area is small x limb MAGNETIC STRUCTURES small structures ≈ active network big structures ≈ faculae umbra penumbra quiet sun 200 400 600 800 1000 1200 1400 1600 1800 2000 200 400 600 800 1000 1200 1400 1600 1800 2000 MODEL QUALITY Model quality estimator: 0 irradiance, W/m2 10 1 � (y(f, r) − y)2 E(f, r) = N n σy2 ï2 10 ï4 10 ï6 quality estimator (error) 10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 1.2 1 0.8 Training and validations sets are different 0.6 0.4 0.2 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 wavelength, nm RECONSTRUCTION EXAMPLES TSI Model - model Observations - observations 1362 Irradiance, w/m2 1361.5 1361 1360.5 1360 1359.5 27 54 81 108 135 162 189 216 243 270 297 324 351 378 405 432 459 486 513 540 567 594 621 648 675 702 729 756 783 810 837 864 891 918 945 972 Time, days RECONSTRUCTION EXAMPLES TSI Model - model Observations - observations 1362 Irradiance, w/m2 1361.5 Good 1361 1360.5 1360 1359.5 27 54 81 108 135 162 189 216 243 270 297 324 351 378 405 432 459 486 513 540 567 594 621 648 675 702 729 756 783 810 837 864 891 918 945 972 Time, days RECONSTRUCTION EXAMPLES Ly Alpha, 121 nm (SORCE) ï3 9 x 10 Model Data - model - observations irradiance, W/m2 8.5 8 7.5 7 6.5 6 Aprï2010 Julï2010 Octï2010 Janï2011 Aprï2011 Julï2011 time Octï2011 Janï2012 Aprï2012 Julï2012 Octï2012 RECONSTRUCTION EXAMPLES Ly Alpha, 121 nm (SORCE) ï3 9 x 10 Model Data - model - observations irradiance, W/m2 8.5 Good 8 7.5 7 6.5 6 Aprï2010 Julï2010 Octï2010 Janï2011 Aprï2011 Julï2011 time Octï2011 Janï2012 Aprï2012 Julï2012 Octï2012 RECONSTRUCTION EXAMPLES 56 nm (TIMED) ï5 2.8 x 10 Model Data - model - observations 2.7 irradiance, W/m2 2.6 2.5 2.4 2.3 2.2 2.1 2 Aprï2010 Julï2010 Octï2010 Janï2011 Aprï2011 Julï2011 Octï2011 time, days Janï2012 Aprï2012 Julï2012 Octï2012 RECONSTRUCTION EXAMPLES 56 nm (TIMED) ï5 2.8 x 10 Model Data - model - observations 2.7 irradiance, W/m2 2.6 2.5 Data has problem with degradation correction 2.4 2.3 2.2 2.1 2 Aprï2010 Julï2010 Octï2010 Janï2011 Aprï2011 Julï2011 Octï2011 time, days Janï2012 Aprï2012 Julï2012 Octï2012 RECONSTRUCTION EXAMPLES 270 nm (SORCE) 0.279 Model Data - model - observations 0.278 irradiance, W/m2 0.277 0.276 0.275 0.274 0.273 0.272 0.271 Aprï2010 Julï2010 Octï2010 Janï2011 Aprï2011 Julï2011 time Octï2011 Janï2012 Aprï2012 Julï2012 Octï2012 RECONSTRUCTION EXAMPLES 270 nm (SORCE) 0.279 Model Data 0.278 irradiance, W/m2 0.277 - model - observations Data suffer from instrumental artifacts 0.276 0.275 0.274 0.273 0.272 0.271 Aprï2010 Julï2010 Octï2010 Janï2011 Aprï2011 Julï2011 time Octï2011 Janï2012 Aprï2012 Julï2012 Octï2012 THE CENTER-TO-LIMB VARIATION ction Theoretical center-to-limb curves THE CENTER-TO-LIMB VARIATION ction Theoretical center-to-limb curves optically thin optically thin emissions emissions THE CENTER-TO-LIMB VARIATION ction Theoretical center-to-limb curves optically thin emissions THE CENTER-TO-LIMB VARIATION ction Theoretical center-to-limb curves optically thin emissions optically thick emissions optically thick emissions THE CENTER-TO-LIMB VARIATION ction Theoretical center-to-limb curves optically thin emissions optically thick emissions THE CENTER-TO-LIMB VARIATION XUV/EUV 0.55 1 ring, 1 class 0.5 error 0.45 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm THE CENTER-TO-LIMB VARIATION Rings in model = CTL effect XUV/EUV 0.55 1 ring, 1 class 0.5 error 0.45 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm THE CENTER-TO-LIMB VARIATION Classes in model = atmosphere models Rings in model = CTL effect XUV/EUV 0.55 1 ring, 1 class 0.5 error 0.45 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm THE CENTER-TO-LIMB VARIATION Classes in model = atmosphere models Rings in model = CTL effect XUV/EUV 0.55 1 ring, 1 class 2 ring, 1 class 0.5 error 0.45 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm THE CENTER-TO-LIMB VARIATION Classes in model = atmosphere models Rings in model = CTL effect XUV/EUV 0.55 1 ring, 1 class 2 ring, 1 class 0.5 error 0.45 Empirical refinement: major part of XUV/EUV emission is optically thin (as expected). 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm THE CENTER-TO-LIMB VARIATION Classes in model = atmosphere models Rings in model = CTL effect XUV/EUV 0.55 1 ring, 1 class 2 ring, 1 class 1 ring, 2 class 0.5 error 0.45 Empirical refinement: major part of XUV/EUV emission is optically thin (as expected). 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm THE CENTER-TO-LIMB VARIATION Classes in model = atmosphere models Rings in model = CTL effect XUV/EUV 0.55 1 ring, 1 class 2 ring, 1 class 1 ring, 2 class 3 ring, 2 class 0.5 error 0.45 Empirical refinement: major part of XUV/EUV emission is optically thin (as expected). 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm THE CENTER-TO-LIMB VARIATION Classes in model = atmosphere models Rings in model = CTL effect XUV/EUV 0.55 1 ring, 1 class 2 ring, 1 class 1 ring, 2 class 3 ring, 2 class 0.5 error 0.45 Empirical refinement: major part of XUV/EUV emission is optically thin (as expected). 0.4 0.35 0.3 0.25 0.2 5 10 15 20 25 30 35 wavelength, nm Empirical refinement: 2 classes are needed to reconstruct XUV/ EUV. THE CENTER-TO-LIMB VARIATION FUV/MUV 1 1 ring 1 class 0.9 0.8 bad data quality error 0.7 0.6 0.5 0.4 0.3 0.2 120 140 160 180 200 220 240 260 280 wavelength, nm THE CENTER-TO-LIMB VARIATION FUV/MUV 1 1 ring 1 class 2 ring 1 class 0.9 0.8 bad data quality error 0.7 0.6 0.5 0.4 0.3 0.2 120 140 160 180 200 220 240 260 280 wavelength, nm THE CENTER-TO-LIMB VARIATION FUV/MUV 1 1 ring 1 class 2 ring 1 class 1 ring 2 class 0.9 0.8 bad data quality error 0.7 0.6 0.5 0.4 0.3 0.2 120 140 160 180 200 220 240 260 280 wavelength, nm THE CENTER-TO-LIMB VARIATION FUV/MUV 1 1 ring 1 class 2 ring 1 class 1 ring 2 class 3 ring 2 class 0.9 0.8 bad data quality error 0.7 0.6 0.5 0.4 0.3 0.2 120 140 160 180 200 220 240 260 280 wavelength, nm THE CENTER-TO-LIMB VARIATION FUV/MUV 1 1 ring 1 class 2 ring 1 class 1 ring 2 class 3 ring 2 class 0.9 error 0.7 classes are more important than rings bad data quality 0.8 0.6 0.5 0.4 0.3 0.2 120 140 160 180 200 220 240 260 280 wavelength, nm THE CENTER-TO-LIMB VARIATION FUV/MUV 1 0.9 error 0.7 classes are more important than rings bad data quality 0.8 0.6 0.5 0.4 0.3 0.2 1 ring 1 class 2 ring 1 class 1 ring 2 class 3 ring 2 class classes and rings are of equal importance 120 140 160 180 200 220 240 260 280 wavelength, nm THE CENTER-TO-LIMB VARIATION FUV/MUV 1 rings are important 0.9 error 0.7 classes are more important than rings bad data quality 0.8 0.6 0.5 0.4 0.3 0.2 120 140 160 180 1 ring 1 class 2 ring 1 class 1 ring 2 class 3 ring 2 class classes and rings are of equal importance 200 220 240 260 280 wavelength, nm THE CENTER-TO-LIMB VARIATION FUV/MUV 1 rings are important 0.9 error 0.7 classes are more important than rings bad data quality 0.8 0.6 0.5 0.4 0.3 0.2 120 140 160 180 1 ring 1 class 2 ring 1 class 1 ring 2 class 3 ring 2 class classes and rings are of equal importance 200 220 240 260 280 wavelength, nm 3 rings and 2 classes are needed to reconstruct FUV/MUV range. THE CENTER-TO-LIMB VARIATION FUV/MUV 1 rings are important 0.9 error 0.7 classes are more important than rings bad data quality 0.8 0.6 0.5 0.4 0.3 0.2 120 140 160 180 1 ring 1 class 2 ring 1 class 1 ring 2 class 3 ring 2 class classes and rings are of equal importance 200 220 240 260 3 rings and 2 classes are needed to reconstruct FUV/MUV range. 280 wavelength, nm Most part of FUV/MUV emission is optically thick. Especially in range: 170-265 nm. CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 Big magnetic structures contribute more to shortwavelength emissions wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 Big magnetic structures contribute more to shortwavelength emissions Small magnetic structures contribute more to long-wavelength emissions wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative relative contribution contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative relative contribution contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative relative contribution contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative relative contribution contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 1 Active network small structures Faculae big structures 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative relative contribution contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 Active network small structures Faculae big structures 1 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 Big magnetic structures contribute more to hot lines (T > 5K oC) wavelength, nm CONTRIBUTION OF DIFFERENT CLASSES TO SSI VARIABILITY 0 relative relative contribution contribution irradiance, W/m2 10 ï2 10 ï4 10 ï6 10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 1.5 Active network small structures Faculae big structures 1 0.5 0 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200210220230240250260270280290300310320 Big magnetic structures contribute more to hot lines (T > 5K oC) Small magnetic structures contribute more to cold lines (T < 5K oC) wavelength, nm FILLING FACTORS MS class 1 -penumbra MS class 2 4.5 Umbra Penumbra 4 - umbra arbitrary units 3.5 3 - large structures ≈ faculae 2.5 2 1.5 1 1 28 55 82 109 136 163 190 217 244 271 298 325 352 379 406 433 460 487 514 541 568 595 622 649 676 703 730 757 784 811 838 865 892 919 946 973 Time, days - small structures ≈ active network LOWER THRESHOLD FOR AREA What spatial resolution for solar images is needed? Gradually increase the lower limit for area of active regions that are taken into the model and see how the reconstruction quality changes. LOWER THRESHOLD FOR AREA XUV/EUV What spatial resolution for solar images is needed? 1 2 3 4 5 6 7 8 0.8 Error, % Gradually increase the lower limit for area of active regions that are taken into the model and see how the reconstruction quality changes. 1 0.6 0.4 0.2 0 size[pixels] = 2 pow (bin number - 1) 20 40 Wavelength, nm 60 LOWER THRESHOLD FOR AREA XUV/EUV What spatial resolution for solar images is needed? 1 0.8 Error, % Gradually increase the lower limit for area of active regions that are taken into the model and see how the reconstruction quality changes. 0.6 0.4 0.2 0 size[pixels] = 2 pow (bin number - 1) FUV/MUV bin number = 1 2 3 4 5 6 7 8 Error, % 1 0.8 0.6 0.4 0.2 150 200 250 Wavelength, nm 300 1 2 3 4 5 6 7 8 350 20 40 Wavelength, nm 60 LOWER THRESHOLD FOR AREA XUV/EUV What spatial resolution for solar images is needed? 1 1 2 3 4 5 6 7 8 0.8 Error, % Gradually increase the lower limit for area of active regions that are taken into the model and see how the reconstruction quality changes. 0.6 0.4 0.2 0 20 40 Wavelength, nm size[pixels] = 2 pow (bin number - 1) FUV/MUV 60 TSI 0.6 bin number = 1 2 3 4 5 6 7 8 Error, % 1 0.8 0.6 0.4 0.2 150 200 250 Wavelength, nm 300 350 Error, % 0.5 0.4 0.3 0.2 0.1 1 2 3 4 5 6 Size lower limit (bin number) 7 8 LOWER THRESHOLD FOR AREA XUV/EUV What spatial resolution for solar images is needed? 1 1 2 3 4 5 6 7 8 0.8 Error, % Gradually increase the lower limit for area of active regions that are taken into the model and see how the reconstruction quality changes. 0.6 0.4 0.2 0 20 40 Wavelength, nm size[pixels] = 2 pow (bin number - 1) FUV/MUV 60 TSI 0.6 bin number = 1 2 3 4 5 6 7 8 Error, % 1 0.8 0.6 0.4 0.2 150 200 250 Wavelength, nm 300 350 Error, % 0.5 0.4 0.3 0.2 0.1 1 2 3 4 5 6 Size lower limit (bin number) 7 8 Magnetic structures with are less than 23 pixels (8’’x 8’’) do not bring new information to the model. CONCLUSIONS - We find 4 principal classes of magnetic structures (big magnetic structures ≈ faculae, small magnetic structures ≈ active network, umbra and penumbra) that allow to reconstruct the SSI variability in the optimal way. - Big magnetic structures have size grater that 128’’ x 128’’. - Small magnetic structures have size from 8’’ x 8’’ to 128’’ x 128 ’’. - Small magnetic structures contribute more to cold emissions from chromosphere and photosphere. - Big magnetic structures contribute more to hot lines . - Center -to-limb variation effect plays significant role for MUV/FUV emissions in range from 170 to 265 nm. Thank you!