The bow shock and the dayside magnetopause are the principle boundaries that determine the interaction of the magnetosphere with the solar wind. Specifically, the bow shock determines the properties of the shocked solar wind plasma that interacts with the magnetosphere. In addition to the shocked solar wind plasma, a number of transient events associated with the bow shock and foreshock regions can have a major impact on the magnetosphere. Among these transients, specifically so-called hot flow anomalies (HFAs) can play a significant role for magnetospheric physics including auroral and ionospheric perturbations, ultra low frequency waves, and strong deformations of the magnetospheric boundaries. This paper first reviews the properties and types of bow shock transients with a focus on HFAs, and than investigates the response of oblique fast shocks with upstream transient density depleted regions. It is demonstrated that a density depleted flux tube can cause all of the typical properties associated with HFAs. The results are discussed in the context of observations and simulation.

弓激波和日间磁绝经是决定磁层与太阳风相互作用的主要边界。具体来说，弓形激波决定了与磁层相互作用的激射太阳风等离子体的特性。除了受到冲击的太阳风等离子体外，与弓形激波和前震区域相关的许多瞬态事件也会对磁层产生重大影响。在这些瞬变中，特别是所谓的热流异常（HFA）对磁层物理学起着重要作用，包括极光和电离层扰动，超低频波以及磁层边界的强烈变形。本文首先以HFA为重点，回顾了弓形冲击瞬变的性质和类型，然后研究斜向快速震动对上游瞬态密度耗尽区域的响应。事实证明，密度不足的助焊剂管会引起与HFA相关的所有典型特性。在观察和模拟的背景下讨论了结果。