Energy densities of Alfvén waves between 0.7 and 1.6 AU

Plasma and field data from Mariner 4 and 5 between 0.7 and 1.6 AU are used to study the radial dependence of the levels of microscale fluctuation associated with interplanetary Alfvén waves. The observed decrease of these levels with increasing distance from the sun is consistent with little or no local generation or damping of the ambient Alfvén waves over this range of radial distance.