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Coronal Mass Ejections: Models and Their Observational Basis
Chen, P. F.
Coronal mass ejections (CMEs) are the largest-scale eruptive phenomenon in the solar system, expanding from active region-sized nonpotential magnetic structure to a much larger size. The bulk of plasma with a mass of ∼ 1011,1013 kg is hauled up all the way out to the interplanetary space with a typical velocity of several hun…
A new, lower value of total solar irradiance: Evidence and climate significance
Lean, Judith L.; Kopp, Greg
The most accurate value of total solar irradiance during the 2008 solar minimum period is 1360.8 ± 0.5 W m-2 according to measurements from the Total Irradiance Monitor (TIM) on NASA's Solar Radiation and Climate Experiment (SORCE) and a series of new radiometric laboratory tests. This value is significantly lower than the canonical val…
A Model for the Sources of the Slow Solar Wind
Antiochos, S. K.; Linker, J. A.; Mikić, Z. +2 more
Models for the origin of the slow solar wind must account for two seemingly contradictory observations: the slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind also has large angular widt…
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…
Observing Flux Rope Formation During the Impulsive Phase of a Solar Eruption
Liu, Y.; Cheng, X.; Ding, M. D. +1 more
Magnetic flux ropes are believed to be an important structural component of coronal mass ejections (CMEs). While there exists much observational evidence of flux ropes after the eruption, e.g., as seen in remote-sensing coronagraph images or in situ solar wind data, the direct observation of flux ropes during CME impulsive phase has been rare. In …
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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High-resolution solar spectral irradiance from extreme ultraviolet to far infrared
Fontenla, J. M.; Snow, M.; Woods, T. +2 more
This paper presents new extremely high-resolution solar spectral irradiance (SSI) calculations covering wavelengths from 0.12 nm to 100 micron obtained by the Solar Irradiance Physical Modeling (SRPM) system. Daily solar irradiance spectra were constructed for most of Solar Cycle 23 based on a set of physical models of the solar features and non-L…