On the Generation, Propagation, and Reflection of Alfven Waves from the Solar Photosphere to the Distant Heliosphere

We present a comprehensive model of the global properties of Alfven waves inthe solar atmosphere and fast solar wind. Linear non-WKB wave transportequations are solved from the photosphere to 4 AU, and for wave periods rangingfrom 3 seconds to 3 days. We derive a radially varying power spectrum ofkinetic and magnetic energy fluctuations for waves propagating in bothdirections along a superradially expanding magnetic flux tube. This workdiffers from previous models in 3 major ways. (1) In the chromosphere and lowcorona, the successive merging of flux tubes on granular and supergranularscales is described using a 2D magnetostatic model of a network element. Belowa critical merging height the waves are modeled as thin-tube kink modes, and weassume that all of the kink-mode wave energy is transformed into volume-fillingAlfven waves above the merging height. (2) The frequency spectrum of horizontalmotions is specified only at the photosphere based on prior analyses of G-bandbright point kinematics. Everywhere else the amplitudes of outward and inwardpropagating waves are computed with no free parameters. We find that the waveamplitudes in the corona agree well with off-limb nonthermal line widths. (3)Nonlinear turbulent damping is applied to the results of the linear model usinga phenomenological loss term. A single choice for the normalization of theturbulent outer-scale length produces both the right amount of damping at largedistances (to agree with in situ measurements) and the right amount of heatingin the extended corona (to agree with empirical wind acceleration models). Inthe corona, the modeled heating rate differs by more than an order of magnitudefrom a rate based on isotropic Kolmogorov turbulence.Comment: 54 pages (AASTeX), 19 figures, Ap. J. Supplement, in press (February 2005