Elemental composition and ionization state of the solar atmosphere and solar wind

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6302717

Joselyn, J A.C.

Abundance measurements have always proved useful in generating and refining astrophysical theories. Some of the classical problems of astrophysics involve determining the relative abundances of elements in the atmosphere of a star from observations of its line spectrum, and then synthesizing the physical processes which would produce such abundances. Theories of the formation of the solar system are critically tested by their ability to explain observed abundances, and, elemental abundances can serve as tracers, helping to determine the origin and transport of ions. Since the solar wind originates at the sun, it can act as a diagnostic probe of solar conditions. In particular, measurements of the composition of the solar wind should be related to the solar composition. And, assuming ionization equilibrium, measurements of the relative abundances of the ionization states in the solar wind should infer coronal temperatures and temperature gradients. However, most spherically symmetric models of the solar wind are unable to explain the relationship between the composition estimated from solar observations and as measured at 1 AU; and, recent observations of significant flow speeds in the transition region raise doubts about the validity of the assumption of ionization equilibrium.

• Research Organization: Colorado Univ., Boulder (USA)
• OSTI ID: 6302717
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALPHA PARTICLES
BARYONS
CARBON
CHARGED PARTICLES
CHEMICAL COMPOSITION
ELEMENTARY PARTICLES
ELEMENTS
EQUILIBRIUM
FERMIONS
FLUID FLOW
FLUIDS
GASES
HADRONS
HEAVY IONS
HELIUM
HYDROGEN
IONIZATION
IONS
NONMETALS
NUCLEONS
PROTONS
RADIATIONS
RARE GASES
SOLAR ACTIVITY
SOLAR ALPHA PARTICLES
SOLAR CORONA
SOLAR PARTICLES
SOLAR PROTONS
SOLAR RADIATION
SOLAR WIND
STELLAR RADIATION