Radial diffusion is one of the dominant physical mechanisms driving acceleration and loss of radiation belt electrons. A number of parameterizations for radial diffusion coefficients have been developed, each differing in the data set used. Here, we investigate the performance of different parameterizations by Brautigam and Albert (2000), https://doi.org/10.1029/1999ja900344, Brautigam et al. (2005), https://doi.org/10.1029/2004ja010612, Ozeke et al. (2014), https://doi.org/10.1002/2013ja019204, Ali et al. (2015), https://doi.org/10.1002/2014ja020419; Ali et al. (2016), https://doi.org/10.1002/2016ja023002; Ali (2016), and Liu et al. (2016), https://doi.org/10.1002/2015gl067398 on long-term radiation belt modeling using the Versatile Electron Radiation Belt (VERB) code, and compare the results to Van Allen Probes observations. First, 1-D radial diffusion simulations are performed, isolating the contribution of solely radial diffusion. We then take into account effects of local acceleration and loss showing additional 3-D simulations, including diffusion across pitch-angle, energy, and mixed diffusion. For the L* range studied, the difference between simulations with Brautigam and Albert (2000), https://doi.org/10.1029/1999ja900344, Ozeke et al. (2014), https://doi.org/10.1002/2013ja019204, and Liu et al. (2016), https://doi.org/10.1002/2015gl067398 parameterizations is shown to be small, with Brautigam and Albert (2000), https://doi.org/10.1029/1999ja900344 offering the smallest averaged (across multiple energies) absolute normalized difference with observations. Using the Ali et al. (2016), https://doi.org/10.1002/2016ja023002 parameterization tended to result in a lower flux than both the observations and the VERB simulations using the other coefficients. We find that the 3-D simulations are less sensitive to the radial diffusion coefficient chosen than the 1-D simulations, suggesting that for 3-D radiation belt models, a similar result is likely to be achieved, regardless of whether Brautigam and Albert (2000), https://doi.org/10.1029/1999ja900344, Ozeke et al. (2014), https://doi.org/10.1002/2013ja019204, and Liu et al. (2016), https://doi.org/10.1002/2015gl067398 parameterizations are used.

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1-D 和 3-D 长期辐射带模拟中径向扩散系数的比较

径向扩散是驱动辐射带电子加速和损失的主要物理机制之一。已经开发了许多径向扩散系数的参数化，每个参数在使用的数据集上都不同。在这里，我们研究了 Brautigam 和 Albert (2000)、https://doi.org/10.1029/1999ja900344、Brautigam 等人的不同参数化的性能。(2005)，https://doi.org/10.1029/2004ja010612，Ozeke 等人。(2014)，https://doi.org/10.1002/2013ja019204，Ali 等。(2015)，https://doi.org/10.1002/2014ja020419；阿里等人。(2016)，https://doi.org/10.1002/2016ja023002；Ali (2016) 和 Liu 等人。(2016)，https://doi.org/10.1002/2015gl067398 关于使用多功能电子辐射带 (VERB) 代码的长期辐射带建模，并将结果与​​ Van Allen Probes 观察结果进行比较。第一的，执行一维径向扩散模拟，隔离单独径向扩散的贡献。然后，我们考虑了局部加速和损失的影响，显示了额外的 3-D 模拟，包括跨俯仰角的扩散、能量和混合扩散。对于所研究的 L* 范围，Brautigam 和 Albert (2000)、https://doi.org/10.1029/1999ja900344、Ozeke 等人的模拟之间的差异。(2014)、https://doi.org/10.1002/2013ja019204 和 Liu 等人。(2016)，https://doi.org/10.1002/2015gl067398 参数化显示很小，Brautigam 和 Albert (2000)，https://doi.org/10.1029/1999ja900344 提供最小的平均值（跨多个能量）与观测值的绝对归一化差异。使用阿里等人。（2016 年），https://doi.org/10。1002/2016ja023002 参数化倾向于导致比使用其他系数的观察和 VERB 模拟更低的通量。我们发现 3-D 模拟对选择的径向扩散系数比 1-D 模拟更不敏感，这表明对于 3-D 辐射带模型，无论 Brautigam 和 Albert ( 2000)，https://doi.org/10.1029/1999ja900344，Ozeke 等人。(2014)、https://doi.org/10.1002/2013ja019204 和 Liu 等人。(2016), https://doi.org/10.1002/2015gl067398 参数化被使用。无论 Brautigam 和 Albert (2000), https://doi.org/10.1029/1999ja900344, Ozeke et al. (2014)、https://doi.org/10.1002/2013ja019204 和 Liu 等人。(2016), https://doi.org/10.1002/2015gl067398 参数化被使用。无论 Brautigam 和 Albert (2000), https://doi.org/10.1029/1999ja900344, Ozeke et al. (2014)、https://doi.org/10.1002/2013ja019204 和 Liu 等人。(2016), https://doi.org/10.1002/2015gl067398 参数化被使用。