We compute, for several solar models, the rates P at which the solar radial p modes are expected to be excited. The solar models are computed with two different local treatments of convection : the classical mixinglength theory (MLT hereafter) and Canuto et al. (1996, CGM hereafter)’s formulation. For one set of solar models (EMLT and ECGM models), the atmosphere is gray and assumes Eddington’s...

The Sun is a source of high energy neutrinos (E ∼ 10 GeV) produced by cosmic ray interactions in the solar atmosphere. We study the impact of three-flavor oscillations (in vacuum and in matter) on solar atmosphere neutrinos, and calculate their observable fluxes at Earth, as well as their event rates in a kilometer-scale detector in water or ice. We find that peculiar three-flavor oscillation e...

The physical mechanisms behind accelerating solar and stellar winds are a long-standing astrophysical mystery, although recent breakthroughs have come from models invoking the turbulent dissipation of Alfvén waves. The existence of Alfvén waves far from the Sun has been known since the 1970s, and recently the presence of ubiquitous Alfvénic waves throughout the solar atmosphere has been confirm...

We detail observations of gamma rays produced by interactions of cosmic rays and solar-energetic particles on the Earth’s atmosphere. The Solar Maximum Mission (SMM) spectrometer accumulated the quiescent atmospheric spectrum over its full 9-year lifetime and our analysis revealed 20 resolved line features. We compare this spectrum with one collected on October 20, 1989, when SMM observed gamma...

Alfvén waves have been proposed as an important mechanism for the heating of the Sun's outer atmosphere and the acceleration of solar wind, but they are generally believed to have no significant impact on the Earth's upper atmosphere under quiet geomagnetic conditions due to their highly fluctuating nature of interplanetary magnetic field (i.e., intermittent southward magnetic field component)....

We present the main characteristics of cosmic ray population in the atmosphere and its variability (11-and 22-year solar cycle variations, solar protons originating from powerful solar flares, energetic electron precipitation during geomagnetic disturbances and Forbush decreases of cosmic rays). The experimental data were obtained from the long-term cosmic ray monitoring in the atmosphere from ...

This paper presents an overview of the main advances in the Key Questions identified by the Task Group ‘What is the Solar Influence on Climate’ by the SCOSTEP CAWSES-II science program. We go through different aspects of solar forcing from solar irradiance, including total solar irradiance (TSI) and solar spectral irradiance (SSI), to energetic particle forcing, including energetic particle pre...

If the upper atmosphere and ionosphere of Triton are controlled by precipitation of electrons from Neptune's magnetosphere as previously proposed, Triton could have the only ionosphere in the solar system not controlled by solar radiation. However, a new model of Triton's atmosphere, in which only solar radiation is present, predicts a large column of carbon atoms. With an assumed, but reason...

The Sun provides the main energy input to the terrestrial atmosphere, and yet the impact of solar variability on long-term changes remains a controversial issue. Direct radiative forcing is the most studied mechanism. Other much weaker mechanisms, however, can have a significant leverage, but the underlying physics is often poorly known. We review the main mechanisms by which solar variability ...

The upper atmosphere is a strongly driven system in which the global state is rapidly altered by the solar drivers. Oneof themaindrivers of theupper atmosphere is the solar irradiance in the extremeultraviolet andx-raybands.The solar irradiance in these bands is proxied by ground-basedmeasurements ofF10.7, which is the solar irradiance at the wavelength of 10.7 cm. The problem of estimating F10...