1.  学术报告：Modeling Radiation Belt Electron Dynamics with the DREAM3D Diffusion Model | | Speaker: Weichao Tu, Space Science and Applications Group, Los Alamos National Laboratory
Location: 1512
Time: Thursday, March 13, 2014
Abstract:
Earth is surrounded by two Van Allen radiation belts containing MeV electrons that are trapped by the geomagnetic field. The MeV ‘killer’ electrons in the radiation belt present a hazardous radiative environment for spacecraft operating within. Therefore, understanding the governing processes, and simulating and eventually predicting the dynamics of radiation belt electrons have been the research targets that space physicists have long pursued. The observed variation of radiation belt electrons is a delicate balance between various source, transport, and loss processes; and one of the central questions in radiation belt research is to resolve the relative contribution of source and loss mechanisms to the enhancement and decay of radiation belt electrons. To simulate these concurrent processes and resolve their relative importance, we have recently developed a 3D diffusion model which includes the diffusion of radiation belt electrons in all three dimensions: energy, pitch angle, and L-shell. This new 3D diffusion model is named DREAM3D, developed as part of the LANL (Los Alamos National Laboratory) DREAM (Dynamic Radiation Environment Assimilation Model) project. The model has been successfully applied to reproduce the long-term radiation belt electron dynamics during two multi-month intervals of the CRRES (Combined Release and Radiation Effects Satellite) mission [Tu et al., JGR 2013], as well as the fast dropout and remarkable enhancement of MeV electrons during a recent dynamic event observed by the NASA Van Allen Probes mission [Tu et al., GRL 2014]. Detailed results will be discussed in the seminar.
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