SCIENCE GOALS AND OBJECTIVES THE OVERARCHING GOAL OF THIS PROPOSAL IS TO QUANTIFY THE EFFECTS OF QUASILINEAR AND NONLINEAR INTERACTIONS BETWEEN RADIATION BELT ELECTRONS AND WHISTLER-MODE CHORUS WAVES DURING THE EVENTS WHERE EFFICIENT LOCAL ELECTRON ACCELERATION OCCURS. THE SPECIFIC SCIENCE QUESTIONS THAT WILL BE ADDRESSED IN THIS PROPOSED PROJECT ARE: 1. WHAT ARE THE TYPICAL CHARACTERISTICS (E.G. WAVE AMPLITUDE EMISSION TYPE DISCRETENESS SWEEP RATE WAVE NORMAL ANGLE ETC.) OF CHORUS WAVES DURING ULTRARELATIVISTIC ELECTRON ACCELERATION EVENTS WHERE CLEAR GROWING RADIAL PEAKS IN ELECTRON PHASE SPACE DENSITY ARE OBSERVED? 2. UNDER WHICH CONDITIONS DO NL INTERACTIONS CAUSED BY CHORUS WAVES BECOME EFFECTIVE? 3. WHAT ARE THE RELATIVE ROLES OF QL AND NL INTERACTIONS BETWEEN RADIATION BELT ELECTRONS AND CHORUS WAVES DURING ULTRARELATIVISTIC ELECTRON ACCELERATION EVENTS? RELEVANCE TO THE DECADAL SURVEY GOALS AND THE H-SR PROGRAM OUR PROPOSED PROJECT DIRECTLY ADDRESSES THE MOST IMPORTANT QUESTIONS IN RADIATION BELT SCIENCE WHICH IS CURRENTLY ONE OF NASA S HIGHEST PRIORITIES GIVEN THE LAUNCH OF THE VAN ALLEN PROBES. THE PROPOSED RESEARCH IS HIGHLY RELEVANT TO GOALS 2 AND 4 FROM THE HELIOPHYSICS DECADAL SURVEY WHICH ARE TO DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS AND TO DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE . NASA S VAN ALLEN PROBES DATA WHICH IS THE MAJOR SOURCE FOR ANALYZING CHORUS WAVES WILL PROVIDE THE DETAILED WAVE CHARACTERISTICS THAT ARE CRUCIAL IN EVALUATING QUASILINEAR AND NONLINEAR INTERACTIONS BETWEEN RADIATION BELT ELECTRONS AND CHORUS WAVES. THE PROPOSED PROJECT PERFECTLY FITS THE SCOPE OF HELIOPHYSICS SUPPORTING RESEARCH PROGRAM. NAMELY OUR PROJECT (1) ADOPTS QUASILINEAR AND NONLINEAR THEORY AND MODELING (2) USES DATA ANALYSIS AND INTERPRETATION OF CURRENT NASA SPACECRAFT OBSERVATION (VAN ALLEN PROBES) AND (3) ADDRESSES GOALS 2 AND 4 IN THE HELIOPHYSICS DECADAL SURVEY. OUR PROPOSED TEAM INCLUDES THEORETICIANS MODELERS AND OBSERVERS WHO ARE EXPERTS IN RADIATION BELT SCIENCE AND THUS AIMS TO MAKE SIGNIFICANT PROGRESS TOWARD UNDERSTANDING THE KEY PROCESSES OF DRIVING EFFICIENT ELECTRON ACCELERATION. METHODOLOGY THE PROPOSED PROJECT WILL COMBINE THE ELECTRON AND WAVE DATA FROM THE VAN ALLEN PROBES QUASILINEAR AND NONLINEAR THEORY AND MODELING TOOLS (3D DIFFUSION CODE AND TEST PARTICLE CODE) TO ADDRESS THE ABOVE COMPELLING SCIENCE QUESTIONS. MORE SPECIFICALLY 1. FOR THE IDENTIFIED ~5 REPRESENTATIVE ELECTRON ACCELERATION EVENTS WE WILL CONSTRUCT THE EVOLUTION OF CHORUS WAVE INTENSITY ON A GLOBAL SCALE USING AN EMPIRICAL CHORUS WAVE MODEL AND THE POES TECHNIQUE AND EXAMINE THE DETAILED CHORUS WAVE PROPERTIES INCLUDING WAVE AMPLITUDE EMISSION TYPE (HISS-LIKE RISING/FALLING TONES) DISCRETENESS FREQUENCY SWEEP RATE AND WAVE NORMAL ANGLE. 2. WE WILL EXTEND THE EXISTING NONLINEAR THEORY TO CALCULATE TRANSPORT COEFFICIENTS (DRIVEN BY REALISTIC CHORUS WAVES) THAT ARE SUFFICIENTLY ACCURATE AND CONVENIENT TO USE IN LARGE-SCALE MODELING OF NONLINEAR WAVE-PARTICLE INTERACTIONS AND VALIDATE THE RESULTS WITH THE TEST PARTICLE SIMULATION. THEN WE WILL USE THE EXTENDED NONLINEAR THEORY TO EXAMINE THE CONDITIONS UNDER WHICH NONLINEAR INTERACTIONS BECOME EFFECTIVE. 3. FOR THE IDENTIFIED ACCELERATION EVENTS WE WILL PERFORM LARGE-SCALE SIMULATIONS BY INCLUDING THE EFFECTS OF VARIOUS MAGNETOSPHERIC WAVES. BY MODELING QUASILINEAR AND NONLINEAR EFFECTS SEPARATELY AND QUANTITATIVELY COMPARING WITH THE VAN ALLEN PROBES ELECTRON OBSERVATION WE WILL DETERMINE THE RELATIVE ROLES OF QUASILINEAR AND NONLINEAR INTERACTIONS BETWEEN CHORUS AND RADIATION BELT ELECTRONS.