Improved three-dimensional mapping of the electron density distribution of the solar corona

Three-dimensional maps of the distribution of coronal electron density can now be computed with two radial functions in the series expansion for the density (rather than with only one radial function as shown in our previous paper). With the improved maps we can determine the topological variation of the electron density with radial distance, and thus can (1) distinguish coronal condensations from coronal streamers, (2) trace the structure of a streamer as a function of height, and (3) determine the non-radial orientation of a streamer. We summarize the previous work in concise mathematical notation, show examples of the improved maps derived from two radial functions, and discuss in detail the expectations and limitations of the method. Of great utility are computer-simulated pictures showing the solar corona as it would appear if veiwed from above the north (or south) pole.The National Center for Atmospheric Research is sponsored by the National Science Foundation.