Search Publications
Evolution of the solar irradiance during the Holocene
Solanki, S. K.; Usoskin, I.; Krivova, N. A. +1 more
Context. Long-term records of solar radiative output are vital for understanding solar variability and past climate change. Measurements of solar irradiance are available for only the last three decades, which calls for reconstructions of this quantity over longer time scales using suitable models.
Aims: We present a physically consistent rec…
The underlying physical meaning of the νmax - νc relation
Baudin, F.; Samadi, R.; Mosser, B. +4 more
Asteroseismology of stars that exhibit solar-like oscillations are enjoying a growing interest with the wealth of observational results obtained with the CoRoT and Kepler missions. In this framework, scaling laws between asteroseismic quantities and stellar parameters are becoming essential tools to study a rich variety of stars. However, the phys…
A new approach to the long-term reconstruction of the solar irradiance leads to large historical solar forcing
Schmutz, W.; Rozanov, E.; Shapiro, A. I. +4 more
Context. The variable Sun is the most likely candidate for the natural forcing of past climate changes on time scales of 50 to 1000 years. Evidence for this understanding is that the terrestrial climate correlates positively with the solar activity. During the past 10 000 years, the Sun has experienced the substantial variations in activity and th…
Photospheric flux cancellation and associated flux rope formation and eruption
Green, L. M.; Kliem, B.; Wallace, A. J.
Aims: We study an evolving bipolar active region that exhibits flux cancellation at the internal polarity inversion line, the formation of a soft X-ray sigmoid along the inversion line and a coronal mass ejection. The aim is to investigate the quantity of flux cancellation that is involved in flux rope formation in the time period leading up …
The Sun as a star: observations of white-light flares
Kretzschmar, M.
Context. Solar flares radiate energy at all wavelengths, but the spectral distribution of this energy is still poorly known. White-light continuum emission is sometimes observed, and these flares are then called "white-light flares" (WLFs).
Aims: We investigate if all flares are WLFs and how the radiated energy is distributed spectrally.
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Intermittent heating in the solar corona employing a 3D MHD model
Peter, H.; Bingert, S.
Aims: We investigate the spatial and temporal evolution of the heating of the corona of a cool star such as our Sun in a three-dimensional magneto-hydrodynamic (3D MHD) model.
Methods: We solve the 3D MHD problem numerically in a box representing part of the (solar) corona. The energy balance includes Spitzer heat conduction along the ma…
A single picture for solar coronal outflows and radio noise storms
Aulanier, G.; Klein, K. -L.; Del Zanna, G. +1 more
We propose a unified interpretation for persistent coronal outflows and metric radio noise storms, two phenomena typically observed in association with quiescent solar active regions. Our interpretation is based on multi-wavelength observations of two such regions as they crossed the meridian in May and July 2007. For both regions, we observe a pe…
Kinematical evidence for physically different classes of large-scale coronal EUV waves
Mann, G.; Warmuth, A.
Context. Large-scale wavelike disturbances have been observed in the solar corona in the EUV range since more than a decade. The physical nature of these so-called "EIT waves" is still being debated controversially. The two main contenders are on the one hand MHD waves and/or shocks, and on the other hand magnetic reconfiguration in the framework …
Damped large amplitude transverse oscillations in an EUV solar prominence, triggered by large-scale transient coronal waves
Foullon, C.; Nakariakov, V. M.; Verwichte, E. +1 more
Aims: We investigate two successive trains of large amplitude transverse oscillations in an arched EUV prominence, observed with SoHO/EIT on the north-east solar limb on 30 July 2005. The oscillatory trains are triggered by two large scale coronal waves, associated with an X-class and a C-class flare occurring in the same remote active region…
Solar irradiance variability: a six-year comparison between SORCE observations and the SATIRE model
Krivova, N. A.; Solanki, S.; Harder, J. W. +2 more
Aims: We investigate how well modeled solar irradiances agree with measurements from the SORCE satellite, both for total solar irradiance and broken down into spectral regions on timescales of several years.
Methods: We use the SATIRE model and compare modeled total solar irradiance (TSI) with TSI measurements over the period 25 February…