Where are medium-scale solar-wind variations formed?

Composition Variations in the Solar Corona and Solar Wind

Order of magnitude variations in relative elemental abundances are observed in the solar corona and solar wind. The instruments aboard SOHO make it possible to explore these variations in detail to determine whether they arise near the solar surface or higher in the corona. A substantial enhancement of low First Ionization Potential (FIP) elements relative to high FIP elements is often seen in ...

Solar cycle variations of solar wind dynamics and structures

This paper reviews solar cycle variations in the heliosphere. We show that some solar cycle changes, such as the correlation between speed and density, result from the evolution of the solar structure from dipolar with strong latitudinal gradients at solar minimum to a disordered field with little latitudinal variation at solar maximum. Other changes, such as the variation of the solar wind dyn...

Solar Neutrinos: Where We Are

This talk compares standard model predictions for solar neutrino experiments with the results of actual observations. Here ‘standard model’ means the combined standard model of minimal electroweak theory plus a standard solar model. I emphasize the importance of recent analyses in which the neutrino fluxes are treated as free parameters, independent of any constraints from solar models, and the...

Small Scale Processes in the Solar Wind

Dissipation-Scale Turbulence in the Solar Wind

We present a cascade model for turbulence in weakly collisional plasmas that follows the nonlinear cascade of energy from the large scales of driving in the MHD regime to the small scales of the kinetic Alfvén wave regime where the turbulence is dissipated by kinetic processes. Steady-state solutions of the model for the slow solar wind yield three conclusions: (1) beyond the observed break in ...