Quantifying Radiation Belt Electron Precipitation and Its Effect on Atmospheric Chemistry
Abstract
In this study, we calculate the radiation belt electron loss through precipitation into the atmosphere and simulate the electron impact on atmospheric composition. While the influence of auroral electrons in the atmosphere and ionosphere have been studied extensively, the radiation belt electrons' contribution is not well known.
This work combines measurements from Van Allen Probes near the equator and FIREBIRD CubeSat at low-Earth orbit, to estimate the spatial and temporal variations of the electron precipitation flux and energy spectrum between 200 keV and 1 MeV. We calculate the flux ratio between the Van Allen Probes and FIREBIRD data during conjunctions to estimate the electron precipitation rate. We found that 90% of the time, the electron precipitation rate is less than 3%. However, during a strong electron loss event, the precipitation rate is 75% at the energy of 900 keV. To quantify the contribution of radiation belt electrons to the atmosphere, we use a global climate simulation (NCAR-WACCM) to calculate the production of HOx and NOx, and the reduction in O3. The preliminary WACCM result shows a substantial reduction of O3 (30%) at 70 km caused by a moderate radiation belt electron precipitation event. Next, we will simulate a stronger precipitation event and assess the electron energy dependence of the atmospheric impact.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSA33A..18H
- Keywords:
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- 0341 Middle atmosphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3334 Middle atmosphere dynamics;
- ATMOSPHERIC PROCESSES;
- 2716 Energetic particles: precipitating;
- MAGNETOSPHERIC PHYSICS;
- 2788 Magnetic storms and substorms;
- MAGNETOSPHERIC PHYSICS