In this work an empirical modeling technique is used to analyze certain Io-caused emission (ICE) structures in the Jovian decametric radio spectrographic data. Taking into account that some of these ICE structures have the appearance of great arcs with internal arclike fine structure, a geometrical model is developed in which the observed emission is seen to result from conical emission beams emanating from source regions carried on corotating field lines which are excited only as they cross an excitation zone centered on the Io flux tube. The model is also applied to the analysis of a limited set of spectrograms of the traditional Io-related sources Io A, Io B, and Io D. In some of these spectra it was possible to identify multiple-ICE structures. The model results for these spectra are consistent with a physical model in which emission is occurring from multiple spaced flux tubes positioned ahead of and moving with Io, and lend credence to the multiple Alfv¿n wave reflection hypothesis. ¿ American Geophysical Union 1989