HVAR 2004

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Hydrogen Lyman emission through the solar cycle
Werner Curdt Max-Planck-Institut für
Sonnensystemforschung
Co-workers H. Tian L. Teriaca
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Outline ? Motivation ? Irradiance data through
the cycle - Lyman alpha - other lines ?
Radiance data / line profiles - Lyman alpha -
Lyman beta - Lyman continuum ? The role of the
magnetic field ? Conclusion
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spectral irradiances at 1 AU
UV 1600 Å
Ly-? 1215?5 Å
EUV 300?40 Å
X-rays 1 - 8 Å
Multi-spacecraft observations (e.g., GOES, UARS,
SOHO, SORCE) compilation by C. Fröhlich
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Ly-? and Ly-? spectral irradiance variation
Ly-?
Ly-?
Lemaire et al. 2005
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solar spectral radiance variability
Solar minimum 1996
SOHO lost 1998
Schühle et al. (2000)
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June 24 and 26, 2008
June 25
July 2 (Ly-? Ly-?)
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Ly-? profile for different - radiances -
velocities
Curdt et al. 2008
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cotemporal Ly-? and Ly-? data
Ly-? radiance
Ly-? radiance / photons s-1 m-2
Ly-? / Ly-? photon ratio 188 ? 1 significantly
higher than Vernazza Reeves (1978) Lemaire
(2005)
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cotemporal Ly-? and Ly-? profiles
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cotemporal rasters in Ly-? and Ly-?
?
A flat topped
B deep revearsal
?
Tian et al. 2009a
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Center to limb variation in a polar coronal hole
Tian et al. 2009b
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Ly-? and Ly-? profiles of disk and CH emission
QS, disk
QS, limb
CH
?
?
Xia 2003 Tian et al. 2009b
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radiance distributions of Ly-?, Ly-?, Si III, and
O VI
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cotemporal radiance bins in QS Lyman continuum
Tb 7000 K
Te 9900 K
Tb 6300 K
Te 8000 K
Wilhelm Kalkofen 2003
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sunspot
quiet Sun
Curdt et al. 2001
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?
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