Authors: Alessandro Bruno (CUA & NASA/GSFC), Ian G. Richardson (UMD & NASA/GSFC)

SEPSTER2D is a new empirical model to predict SEP event-integrated and peak intensity spectra, along with the times of peak intensity, between 10 and 130 MeV at 1 AU. The model is based on multi-point spacecraft proton measurements from STEREO, GOES, and PAMELA. The analyzed data sample includes 32 SEP events occurring between 2010 and 2014, with a statistically significant signal at energies in excess of a few tens of MeV, unambiguously recorded at three spacecraft locations. The spatial distributions of SEP intensities are reconstructed by assuming an energy-dependent 2D Gaussian functional form, and accounting for the correlation between the intensity and the speed of the parent CME, and the magnetic-field-line connection angle. The CME measurements used are from the DONKI catalog. The model performance, including its extrapolations to lower/higher energies, was tested by comparing with the spectra of 20 SEP events not used to derive the model parameters. Despite the simplicity of the model, the observed and predicted event-integrated and peak intensities at Earth and at the STEREO spacecraft for these events show remarkable agreement, both in the spectral shapes and their absolute values.