THE PROJECT METHODOLOGY IS BASED ON (1) A THEORY OF WAVE-PARTICLE INTERACTIONS (BOTH RESONANT AND NON-RESONANT) BETWEEN ENERGETIC ELECTRONS AND EMIC WAVES (2) AN INCORPORATION OF A WIDE RANGE OF WAVE-PARTICLE INTERACTION PROCESSES INTO MODELS OF THE RADIATION BELT ELECTRON DYNAMICS AND (3) A QUANTITATIVE COMPARISON BETWEEN THE OBSERVED (BY LOW-EARTH-ORBITING SATELLITES) AND ESTIMATED ELECTRON PRECIPITATION BASED ON THEORY AND MODELING. THE THEORETICAL APPROACHES EXPLOIT MODERN TREATMENTS OF ADIABATIC INVARIANT BREAKING IN PLASMA SYSTEMS WITH RESONANCES. NUMERICAL SIMULATIONS INCLUDE BOTH TEST PARTICLE MODELS AND KINETIC EQUATIONS DESCRIBING THE LONG-TERM EVOLUTION OF THE ELECTRON DISTRIBUTIONS. BOTH THEORY AND SIMULATIONS WILL BE DRIVEN BY SPACECRAFT OBSERVATIONS OF WAVE CHARACTERISTICS IN THE RADIATION BELTS: VAN ALLEN PROBES THEMIS AND MMS FOR THE NEAR-EQUATORIAL OBSERVATIONS AND POES FIREBIRD AND ELFIN FOR THE OBSERVATIONS OF PRECIPITATING PARTICLES AT LOW ALTITUDES. THIS PROPOSAL CONTRIBUTES TO TWO SCIENTIFIC OBJECTIVES OF THE HELIOPHYSICS DECADAL SURVEY NAMELY GOAL 2: DETERMINING THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND GOAL 4: DISCOVERING AND CHARACTERIZING FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE BY PROVIDING A COMPREHENSIVE UNDERSTANDING OF WAVE PARTICLE INTERACTIONS BEYOND THE QUASI-LINEAR THEORY DUE TO EMIC WAVES AND ITS CONTRIBUTION TO ENERGETIC ELECTRON SCATTERING AND PRECIPITATION LOSS.