Proton transport model: A review

The linear transport model for the proton aurora developed at the Air Force Research Laboratory is reviewed. Emphasis is given on the discussion of the studies where the predictions of the model were compared with those of other theoretical methods and with the available data. The excellent agreement between the linear transport model and other theoretical methods gives credence to the accuracy of the numerical technique adopted in solving the transport equations, while good to excellent agreements between theory and observations indicate that the transport model adequately describes the important physics issues of the problem. It is concluded here that our ability to accurately model the proton aurora is limited only by the uncertainties in the input cross-section data (for some collision processes) and by our inadequate information about the incident proton spectra. Some discussions in this regard are included.