Modeling the Auroral Precipitation Budget Using the SuperMAG SME Index and Substorm Onset Times

A precipitation model is introduced, which includes substorm cycle information and the SuperMAG SME (generalized AE) index. 22 years of particle precipitation data from the Defense Meteorological Satellite Program (DMSP) are separated by type (diffuse, monoenergetic, broadband, and ion aurora), magnetic latitude, and magnetic local time. Each bin of data is subjected to multiple linear regression analysis using the SuperMAG SME index (1-minute cadence), the time from the last substorm onset in seconds, and the time to the next substorm onset in seconds. Comparison of the multiple linear regression (MLR) auroral precipitation maps and Polar Ultraviolet Imager images show the MLR auroral precipitation maps capture the brightening and dimming of the nightside aurora but not the morphology of the auroral movement. Thus, this preliminary empirical model with the SuperMAG SME index allows the space weather community access to 25+ years of continuous high-cadence nightside auroral power. Analysis also indicates time dependence in the auroral oval for the dayside diffuse and ion aurora as well as the nightside ion aurora. Some parts of the dayside auroral oval precipitating energy flux depend on the time since the last substorm onset, declining with time. Some parts of the nightside ion auroral oval depend on the time until the next substorm onset, experiencing a decline in precipitating energy flux prior to substorm onset. Ion aurora brightenings, some of which do not correlate with substorm onset, originate in this region of time dependence. The effect of time dependence on the ion auroral brightenings and their correlation to pseudo-breakups is discussed.