Bibliography

Empirical radiation belt models: Comparison with in-situ data and implications for environment definition

The empirical AP8/AE8 model has been the de-facto Earth\textquoterights radiation belts engineering reference for decades. The need from the community for a better model incubated the development of AP9/AE9/SPM, which addresses several shortcomings of the old model. We provide additional validation of AP9/AE9 by comparing in-situ electron and proton data from Jason-2, POES, and the Van Allen Probes spacecraft with the 5th, 50th, and 95th percentiles from AE9/AP9 and with the model outputs from AE8/AP8. The relatively short duration of Van Allen Probes and Jason-2 missions means that their measurements are most certainly the result of specific climatological conditions. In LEO, the Jason-2 proton flux is better reproduced by AP8 compared to AP9, while the POES electron data are well enveloped by AE9 5th and 95th percentiles. The shape of the SAA from Jason-2 data is better captured by AP9 compared to AP8, while the peak SAA flux is better reproduced by AP8. The <1.5 MeV inner belt electrons from MagEIS are well enveloped by AE9 5th and 95th percentiles while AE8 over-predicts the measurements. In the outer radiation belt, MagEIS and REPT electrons closely follow the median estimate from AE9, while AP9 5th and 95th percentiles generally envelope REPT proton measurements in the inner belt and slot regions. While AE9/AP9 offer the flexibility to specify the environment with different confidence levels, the dose and trapped proton peak flux for POES and Jason-2 trajectories from the AE9/AP9 50th percentile and above are larger than the estimates from the AE8/AP8 models.

Pich, Maria; Jun, Insoo; Evans, Robin;

Published by: Space Weather      Published on: 08/2017

YEAR: 2017     DOI: 10.1002/2017SW001612

Empirical Models; Radiation belts; Radiation effects; Van Allen Probes

A novel technique to construct the global distribution of whistler mode chorus wave intensity using low-altitude POES electron data

Although magnetospheric chorus plays a significant role in the acceleration and loss of radiation belt electrons, its global evolution during any specific time period cannot be directly obtained by spacecraft measurements. Using the low-altitude NOAA Polar-orbiting Operational Environmental Satellite (POES) electron data, we develop a novel physics-based methodology to infer the chorus wave intensity and construct its global distribution with a time resolution of less than an hour. We describe in detail how to apply the technique to satellite data by performing two representative analyses, i.e., (i) for one specific time point to visualize the estimation procedure and (ii) for a particular time period to validate the method and construct an illustrative global chorus wave model. We demonstrate that the spatiotemporal evolution of chorus intensity in the equatorial magnetosphere can be reasonably estimated from electron flux measurements made by multiple low-altitude POES satellites with a broad coverage of L shell and magnetic local time. Such a data-based, dynamic model of chorus waves can provide near-real-time wave information on a global scale for any time period where POES electron data are available. A combination of the chorus wave spatiotemporal distribution acquired using this methodology and the direct spaceborne wave measurements can be used to evaluate the quantitative scattering caused by resonant wave-particle interactions and thus model radiation belt electron variability.

Ni, Binbin; Li, Wen; Thorne, Richard; Bortnik, Jacob; Green, Janet; Kletzing, Craig; Kurth, William; Hospodarsky, George; Pich, Maria;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2014

YEAR: 2014     DOI: 10.1002/jgra.v119.710.1002/2014JA019935

electron precipitation; global wave distribution; magnetospheric chorus; physics-based technique; wave resonant scattering