Temperature of the plasmasphere from Van Allen Probes HOPE
Temperature of the plasmasphere from Van Allen Probes HOPE
复制标题
范艾伦探测器 HOPE 的等离子体层温度
DOI：
10.1002/2016ja023047
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Niescja Turner
中科院分区：
文献类型：
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作者：
K. Genestreti;Jerry Goldstein;Grace D. Corley;William Farner;L. Kistler;Brian A. Larsen;C. Mouikis;Chae Ramnarace;Ruth M. Skoug;Niescja Turner
我们介绍了两种新的技术，用于估计非常低的能量空间等离子体的温度，主要是，在现场的数据从静电分析仪安装在一个带电的和移动的航天器。该技术被用来估计质子温度的间隔期间，大部分的离子等离子体是远低于能量的分析仪的带通。这两种技术都假设等离子体可以用一维E→×B→漂移麦克斯韦方程描述，并且可以用最简单的方式解释航天器的势场和运动，即，通过坐标的线性移动。第一种技术涉及应用一个约束的理论拟合到一个测量的分布函数。第二种技术涉及总能量数密度和部分能量数密度的比较。2013年1月15日，这两种技术都应用于货车艾伦氦、氧、质子和电子探测器在两个轨道上对等离子体的质子部分进行观测。我们发现，从这两个数量级类型的技术计算的温度与使用基于延迟电位分析仪的测量计算的等离子体层温度的典型范围非常一致-通常在0.2和2 eV（2000- 20，000 K）之间。我们还发现，温度与L壳层和热等离子体密度相关，与冷等离子体密度呈负相关。我们认为，这三种关系中的后者可能表明环电流重叠区域中等离子体的碰撞或波驱动加热。我们注意到，这些技术可以很容易地应用于类似的数据集或用于各种目的。
We introduce two novel techniques for estimating temperatures of very low energy space plasmas using, primarily, in situ data from an electrostatic analyzer mounted on a charged and moving spacecraft. The techniques are used to estimate proton temperatures during intervals where the bulk of the ion plasma is well below the energy bandpass of the analyzer. Both techniques assume that the plasma may be described by a one‐dimensional E→×B→ drifting Maxwellian and that the potential field and motion of the spacecraft may be accounted for in the simplest possible manner, i.e., by a linear shift of coordinates. The first technique involves the application of a constrained theoretical fit to a measured distribution function. The second technique involves the comparison of total and partial‐energy number densities. Both techniques are applied to Van Allen Probes Helium, Oxygen, Proton, and Electron (HOPE) observations of the proton component of the plasmasphere during two orbits on 15 January 2013. We find that the temperatures calculated from these two order‐of‐magnitude‐type techniques are in good agreement with typical ranges of the plasmaspheric temperature calculated using retarding potential analyzer‐based measurements—generally between 0.2 and 2 eV (2000–20,000 K). We also find that the temperature is correlated with L shell and hot plasma density and is negatively correlated with the cold plasma density. We posit that the latter of these three relationships may be indicative of collisional or wave‐driven heating of the plasmasphere in the ring current overlap region. We note that these techniques may be easily applied to similar data sets or used for a variety of purposes.