Source and loss rates of radiation belt relativistic electrons
Source and loss rates of radiation belt relativistic electrons
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DOI：
10.1029/2005ja011473
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发表时间：
2006-04
期刊：
影响因子：
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通讯作者：
R. Selesnick
中科院分区：
文献类型：
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作者：
R. Selesnick
[1]辐射带电子分布作为赤道俯仰角，经度和时间的函数的数值模型相结合的数据从低空卫星估计的源和损失率的0.5至3兆电子在磁暴。稳定捕获和漂移损失锥区域中的相对强度水平提供了损失率和相关俯仰角扩散系数的量度。源速率是维持所观察到的稳定捕获组分所需的速率。源机制未明确，可能包括径向扩散和局部加速的组合。绝热效应被单独处理，并发现有一个最小的影响参数估计的存在下，俯仰角扩散。两个样本风暴期间提供的例子，不同的源和损失率估计用这种方法。它们表明，风暴主要阶段的重大损失在时间尺度上耗尽了风暴前辐射带。它是由一个来源补充，同时或在稍后的时间行动。在风暴恢复阶段，重要但可变的来源和损失过程可能会继续。风暴时间源和损失率可能会导致一个净增加或减少，在稳定被困人口相对于风暴前的水平。这些结论是支持源和损失指数，定义提供粗略估计的分数源和损失率从几个额外的磁暴，并很容易计算出的数据。
[1] A numerical model of the radiation belt electron distribution as a function of equatorial pitch angle, longitude, and time is combined with data from a low-altitude satellite to estimate the source and loss rates of ∼0.5 to 3 MeV electrons during magnetic storms. The relative intensity levels in the stable trapping and drift loss cone regions provide a measure of the loss rate and associated pitch angle diffusion coefficient. The source rate is that required to maintain the observed stably trapped component. The source mechanism is unspecified and may include a combination of radial diffusion and local acceleration. Adiabatic effects are treated separately and are found to have a minimal influence on parameter estimation in the presence of pitch angle diffusion. Two sample storm periods provide examples of the varying source and loss rates estimated with this method. They show that significant losses during the storm main phase deplete the prestorm radiation belt on a timescale ∼1 hour. It is replenished by a source that acts concurrently or at somewhat later times. Significant but variable source and loss processes may continue during the storm recovery phase. The storm time source and loss rates may result in a net increase or decrease in the stably trapped population relative to the prestorm level. These conclusions are supported by source and loss indices that are defined to provide rough estimates of the fractional source and loss rates from several additional magnetic storms and are readily calculated from the data alone.