Emission of OI(630 nm) in proton aurora

A red aurora occurred over southern Canada and central Maine on April 11, 1 997, producing a brightness of O I(630 nm) of several Kilorayleighs, which lasted for several hours. Two passes of the Defense Meteorological Satellit e Program (DMSP) F12 satellite occurred during this time, and optical data were obtained from four CEDAR Optical Tomographic Imaging Facility (COTIF) sites. The DMSP F12 particle spectrometers observed proton precipitation so uth of the electron aurora with energy fluxes of several mW m(-2). Tomograp hic inversion of the COTIF optical observations gives the altitude profile of emissions along a magnetic meridian. We combine all available data using an ionospheric auroral model. Our analysis shows that the model produces t he observed auroral brightness from the proton precipitation alone.