EUV Irradiance Reconstruction in view of PROBA2
Margit Haberreiter, PMOD/WRC, Davos, Switzerland
Cis Verbeeck, Veronique Delouille, Rami Qahwaji
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter 1
O
Absorption of EUV in the Earth‘s atmosphere
Altitude-wavelength dependence of energy deposition from solar irradiance
units of Log10(Wm-
4)
From Solomon and Qian 2005
Solar minimum conditions
EUV varies by a factor of 2 and more!!
Global Mean Neutral Density vs F10.7
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter
Long-term variation due to solar forcing (here F10.7)
Short-term variations visible in geomagnetic variations (Ap index)
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Neutral Density versus EUV irradiance
5ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter
Modeling the Solar EUV Spectrum
•Wavelengths – UV: 120 – 400 nm– EUV: 10 – 120 nm
•Contribution from the – Chromophere– Transition region – Corona
I(λ,μ,φ,t)
nlevel, nel,nion,…
(x,y,z,t)
I(λ,μ,φ,t)
Iterative
process
EUV reconstruction - Semi-empirical modeling
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter 7
Comparison to SDO/EVE observations
Haberreiter, 2011, Solar Physics, 274, 473ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter
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Synthetic EUV Spectra
50 1001 10
7
1 106
1 105
1 104
1 103
0.01
0.1
1
SPRM 1SPRM 2SPRM 3SPRM 4SPRM 5
Wavelength (nm)
Irra
dian
ce (
erg
cm-2
s-1
nm
-1)
Quiet CoronaQuiet Coronal NetworkActive Coronal NetworkHot loops Super hot loops
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter 9
EIT Image DecompositionJune 1, 2003
Coronal Hole Mask Active Region Mask
SPoCA Image Decomposition: Cis Verbeeck, ROBESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter 10
Area coverage over solar cycle 23
Data from Barra et al, 2009 Barra et al., 2009, A&AESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter 11
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter
Reconstruction of the EUV for solar cycle 23
Haberreiter, 2012, IAU Symposium 286
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SWAP integrated intensities
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter
Mean of off-limb contribution: 35%
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Reconstruction of the EUV for solar cycle 23
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter 14
FP7 Space Project SOLID
• SOLID: First European Comprehensive SOLar Irradiance Data exploitation
• Coordinator PMOD/WRC (W. Schmutz, Project Manager: M. Haberreiter)
• Start: December 2012
• 10 Partners from 7 European Countries (CH, F, B, UK, D, EL, I)
• Compilation and Analysis of the existing irradiance observations from the XUV/EUV, UV, visible to the IR along with the state-of-the-art irradiance modelling results
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter
Poster 3.1
Haberreiter et. al
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Conclusion
ESWW9, Brussels, Nov 4-7 2012 Margit Haberreiter
• Understanding the physical mechanisms that drive solar spectral irradiance variations is important for Space Weather studies
• Successful reconstruction based on EIT image analysis
• Improvement of implementation of extended corona
• Extend the reconstruction to PROBA2 time series based on SWAP decomposition
• More to come soon within the FP7 SOLID project
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