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Optimisation of a Steady State Radial Diffusion Model to Derive Diffusion Coefficients for the Proton Radiation Belt

Alexander Lozinski - British Antarctic Survey; Richard Horne - British Antarctic Survey, United Kingdom; Sarah Glauert - British Antarctic Survey, United Kingdom; Giulio Del Zanna - DAMTP, University of Cambridge, United Kingdom; Jay Albert - Air Force Research Lab/RVBXA, United States

Earth's Magnetosphere and Radiation Belts


Proton flux measurements from the Proton Telescope instrument aboard CRRES are used to drive a radial diffusion model of the inner proton belt at 1.1≤ L≤1.7. Our model utilises a physics-based evaluation of the cosmic ray albedo neutron decay (CRAND) source, and coulomb collisional loss driven by plasmaspheric electron density from the Global Core Plasma Model. We drive our model using time-averaged data at L=1.7 to calculate steady state profiles of phase space density, and optimise radial diffusion coefficients to fit data. This is first performed for a quiet period when the belt is near steady state. Additionally, we investigate fitting steady state solutions to time averages taken during active periods that exhibit limited deviation from steady state, demonstrated by CRRES measurements following the 24th March 1991 storm. We discuss how to make the optimisation process more reliable by excluding periods of variability in plasmaspheric density from any time average. Lastly, we compare our resultant diffusion coefficients to those derived in previous work, including those derived for electrons from ground and in situ observations. We find that higher diffusion coefficients are derived compared with previous work, but that our estimates may be increased by uncertainty in inner zone plasmaspheric density.

Approaching deadlines:

Registration opens:

16 July 2020

Abstract submission opens:

16 July 2020

European Space Weather Medals:

6 September 2020

Registration deadline:

25 September 2020

Registration deadline: [extended]

10 October 2020

Abstract submission deadline:

4 September 2020