Proton-proton collisional age to order solar wind types
Proton-proton collisional age to order solar wind types
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质子-质子碰撞年龄来排序太阳风类型
DOI：
10.1051/0004-6361/201937378
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发表时间：
2020
影响因子：
6.5
通讯作者：
Wimmer-Schweingruber
中科院分区：
文献类型：
--
作者：
Heidrich-Meisner;Berger;Wimmer-Schweingruber
太阳风的特性是由它的来源区域和传输效应决定的。与太阳风类型无关，现场测量的太阳风总是受到两者的影响。这意味着，从现场观测中可靠地确定太阳风类型，对于分析其太阳起源及其在观测太阳风的航天器旅行时间内的演变是有用的。此外，太阳风类型也影响太阳风与其他等离子体（如地球磁层）的相互作用。目的将质子-质子碰撞年龄作为1 AU处太阳风的排序参数，并探讨其与Xu & Borovsky （2015， J. Geophys）提出的太阳风分类方案的关系。答：太空物理学。， 120, 70)。我们用这个来表明明确的磁场信息是不需要的太阳风分类。此外，我们还说明，依赖太阳风参数阈值的太阳风分类方案应取决于太阳活动周期的阶段，因为各自的参数随太阳活动周期而变化。方法采用Xu & Borovsky （2015， J.地球物理学报）对太阳风进行分类。答：太空物理学。， 120,70)作为我们确定太阳风类型的参考。根据该分类的三种基本太阳风类型在质子-质子碰撞年龄方面涵盖了不同的制度，我们提出了一种简化的仅基于质子-质子碰撞年龄的太阳风分类方案。我们把这种方法称为PAC太阳风分类器。为此，我们为提出的PAC方案的两种变体推导了质子-质子碰撞年龄的时间相关阈值：(1)相似度-PAC基于与完整的Xu & Borovsky （2015， J. Geophys）的相似度。答：太空物理学。(2)分布- pac直接基于质子-质子碰撞年龄的分布。结果提出的基于质子-质子碰撞年龄的简化太阳风分类方案是完整的Xu & Borovsky （2015， J. Geophys.）的等效替代方案。答：太空物理学。[j] . Geophys. （2015， J.）对太阳风的分类方案进行了改进，并得出了与完整的Xu & Borovsky （2015， J. Geophys.）相似的分类方法。答：太空物理学。， 120,70)方案。提议的PAC太阳风分类将日冕洞风与头盔-流带等离子体以及头盔-流带等离子体（没有电流片交叉的慢太阳风）与扇形反转等离子体（有电流片交叉的慢太阳风）分开。与完整的Xu & Borovsky (2015， J. Geophys。答：太空物理学。， 120,70)方案，PAC不需要磁场信息作为输入。结论质子-质子碰撞年龄对太阳风有很好的排序。这意味着等离子体性质之间的内在关系，特别是质子温度和磁场强度在每个等离子体状态。我们认为扇区反转等离子体是特别缓慢和密集的太阳风和大多数流相互作用边界的组合。大部分太阳风参数（如磁场强度、B、氧荷态比）随太阳活动周期的变化而变化。因此，所有基于阈值的太阳风分类方案也需要适应太阳活动周期。由于PAC太阳风分类器不需要磁场信息，只需要质子等离子体测量，因此可以直接应用于太阳和日光层观测台（SOHO）的太阳风数据。
ContextThe properties of a solar wind stream are determined by its source region and by transport effects. Independently of the solar wind type, the solar wind measured in situ is always affected by both. This means that reliably determining the solar wind type from in situ observations is useful for the analysis of its solar origin and its evolution during the travel time to the spacecraft that observes the solar wind. In addition, the solar wind type also influences the interaction of the solar wind with other plasma such as Earth’s magnetosphere.AimsWe consider the proton-proton collisional age as an ordering parameter for the solar wind at 1 AU and explore its relation to the solar wind classification scheme developed by Xu & Borovsky (2015, J. Geophys. Res.: Space Phys., 120, 70). We use this to show that explicit magnetic field information is not required for this solar wind classification. Furthermore, we illustrate that solar wind classification schemes that rely on threshold values of solar wind parameters should depend on the phase in the solar activity cycle since the respective parameters change with the solar activity cycle.MethodsThe categorization of the solar wind following Xu & Borovsky (2015, J. Geophys. Res.: Space Phys., 120, 70) was taken as our reference for determining the solar wind type. Based on the observation that the three basic solar wind types from this categorization cover different regimes in terms of proton-proton collisional ageacol, p-p, we propose a simplified solar wind classification scheme that is only based on the proton-proton collisional age. We call the resulting method the PAC solar wind classifier. For this purpose, we derive time-dependent threshold values in the proton-proton collisional age for two variants of the proposed PAC scheme: (1) similarity-PAC is based on the similarity to the full Xu & Borovsky (2015, J. Geophys. Res.: Space Phys., 120, 70) scheme, and (2) distribution-PAC is based directly on the distribution of the proton-proton collisional age.ResultsThe proposed simplified solar wind categorization scheme based on the proton-proton collisional age represents an equivalent alternative to the full Xu & Borovsky (2015, J. Geophys. Res.: Space Phys., 120, 70) solar wind classification scheme and leads to a classification that is very similar to the full Xu & Borovsky (2015, J. Geophys. Res.: Space Phys., 120, 70) scheme. The proposed PAC solar wind categorization separates coronal hole wind from helmet-streamer plasma as well as helmet-streamer plasma (slow solar wind without a current sheet crossing) from sector-reversal plasma (slow solar wind with a current sheet crossing). Unlike the full Xu & Borovsky (2015, J. Geophys. Res.: Space Phys., 120, 70) scheme, PAC does not require information on the magnetic field as input.ConclusionsThe solar wind is well ordered by the proton-proton collisional age. This implies underlying intrinsic relationships between the plasma properties, in particular, proton temperature and magnetic field strength in each plasma regime. We argue that sector-reversal plasma is a combination of particularly slow and dense solar wind and most stream interaction boundaries. Most solar wind parameters (e.g., the magnetic field strength,B, and the oxygen charge state ratio ) change with the solar activity cycle. Thus, all solar wind categorization schemes based on threshold values need to be adapted to the solar activity cycle as well. Because it does not require magnetic field information but only proton plasma measurements, the proposed PAC solar wind classifier can be applied directly to solar wind data from the Solar and Heliospheric Observatoty (SOHO), which is not equipped …
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通过 k-Means 聚类算法对太阳风进行分类
DOI：
10.1016/b978-0-12-811788-0.00016-0
发表时间：
2018
期刊：
影响因子：
--
作者：
Heidrich-Meisner;Wimmer-Schweingruber
通讯作者：
Wimmer-Schweingruber
影响因子：
8.6
作者：
L. Berger;R. Wimmer–Schweingruber;G. Gloeckler
通讯作者：
L. Berger;R. Wimmer–Schweingruber;G. Gloeckler
影响因子：
64.8
作者：
Kasper, J. C.;Bale, S. D.;Schwadron, N. A.
通讯作者：
Schwadron, N. A.
影响因子：
2.8
作者：
Richardson, I. G.;Cane, H. V.
通讯作者：
Cane, H. V.
作者更正：针对革兰氏阴性菌的嵌合拟肽抗生素
影响因子：
64.8
作者：
Anatol Luther;Matthias Urfer;M. Zahn;Maik Müller;Shuang;M. Mondal;A. Vitale;Jean;T. Sharpe;Fabio Lo Monte;Harsha Kocherla;E. Cline;G. Pessi;P. Rath;S. Modaresi;Petra Chiquet;Sarah Stiegeler;Carolin T. Verbree;T. Remus;Michel Schmitt;Caroline Kolopp;Marie;Nicolas Desjonquères;Emile Brabet;S. Hell;Karen LePoupon;A. Vermeulen;Régis Jaisson;Virginie Rithié;G. Upert;Alex Lederer;P. Zbinden;A. Wach;K. Moehle;Katja Zerbe;H. Locher;F. Bernardini;G. Dale;L. Eberl;B. Wollscheid;S. Hiller;John A. Robinson;D. Obrecht
通讯作者：
D. Obrecht