Quantifying the Role Of Non-Adiabatic Processes In The Creation Of The Outer Radiation Belts

We have reported (Fox et al., 2005) strong evidence that non-adiabatic (first invariant breaking) energization is required to explain the generation of Earth's outer electron radiation belt during intense storm events and also during more typical outer belt conditions. This evidence relies on the most conservative of assumptions that maximize the phase space densities of particle distributions adiabatically displaced in our models from the measured source population within the near-Earth magnetotail to the inner magnetospheric regions using initially only first adiabatic invariant transport, and subsequently first and second adiabatic invariant transport. Importantly, the phase space densities measured within the outer belt electron populations exceed the phase space densities of these adiabatically maximized source population distributions at energies > 1 MeV. Our goal now is to establish the quantitative levels of the contributions of the non-adiabatic energization to the creation of the outer belt electrons. Our initial approach is to bound the contributions of non-adiabatic energization processes by examining those processes that can maximally suppress the phase space densities of the distributions populations transported from the near tail regions. Those processes include pitch angle scattering losses and the mixing of full and empty flux tubes that accompanies the cross-field diffusion processes. We begin here by considering losses at the maximum pitch angle scattering rate as parameterized with characteristic transport times. The energization that electrons can acquire via non-adiabatic radial transport under these new constraints is determined using data from ISEE, CRRES and LANL geosynchronous satellites. Specifically, samples of spectra are examined at various L-values to identify the deficiencies in the modeled phase space densities. Fox, N. J., B. H. Mauk, and J. B. Blake, Establishing the role of non-adiabatic processes in the creation of the Earth's outer electron radiation belt, Geophys. Res. Lett., submitted, 2005.