Institute of Meteorology and Climate Research

SPARC HEPPA Model-measurement intercomparison initiative

The high-energy particle precipitation into the atmosphere HEPPA model-measurement intercomparison comprises of two study periods so far: HEPPA-I investigates the large solar proton event in October/November 2003, HEPPA-II investigates the "EPP indirect effect" due to downwelling auroral NOx in Northern hemisphere winter 2008/2009.