Amplitude evolution and rigidity dependence of the 26-day recurrent cosmic ray decreases : COSPIN/KET results
Amplitude evolution and rigidity dependence of the 26-day recurrent cosmic ray decreases : COSPIN/KET results
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DOI：
10.1029/1999ja900370
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发表时间：
1999-12
影响因子：
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通讯作者：
C. Paizis;B. Heber;P. Ferrando;A. Raviart;B. Falconi;S. Marzolla;M. Potgieter;V. Bothmer;H. Kunow;R. Müller-mellin;A. Posner
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文献类型：
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作者：
C. Paizis;B. Heber;P. Ferrando;A. Raviart;B. Falconi;S. Marzolla;M. Potgieter;V. Bothmer;H. Kunow;R. Müller-mellin;A. Posner
在1992年7月至1994年7月的时间间隔内，尤利西斯号从日纬10°S爬升到70°S以上。在这段时间内，太阳活动的最小条件逐渐接近，这反过来又导致了稳定和持久的旋转相互作用区（CIRs）。在此期间观测到的旋转粒子事件与约30个已记录的CIRs有关，为探测日球层的三维结构提供了一个独特的机会。在这项工作中，我们利用尤利西斯号上的宇宙射线和太阳粒子研究基尔电子望远镜（COSPIN/KET）的数据，研究了这些CIRs在不同能量下产生的26天周期性宇宙射线衰减的振幅演变，并推导了其刚度依赖性。我们发现振幅在25°-30°太阳经度附近有最大值。纬度梯度和26 d变化幅值的刚度依赖性也表现出显著的相似性。我们在我们目前对日球层现象的理解的框架内讨论这些观测结果。
In the time interval extending from July 1992 to July 1994, Ulysses climbed from 10°S heliographic latitude up to over 70°S. During this time lapse, solar minimum conditions were gradually approached, which, in turn, led to stable and long-lasting corotating interaction regions (CIRs). The corotating particle events observed during this period, associated with ∼30 registered CIRs, offer a unique opportunity to probe the three-dimensional structures of the heliosphere. In this work we use data from the Cosmic Ray and Solar Particle Investigation Kiel Electron Telescope (COSPIN/KET) instrument on board Ulysses to study the amplitude evolution of the 26-day recurrent cosmic ray decreases, generated by these CIRs, at different energies and derive its rigidity dependence. We find that the amplitude has a maximum around 25°–30° heliolatitude. We also find that the rigidity dependence of both the latitudinal gradient as well as the 26-day variation amplitude show a remarkable similarity. We discuss these observations within the framework of our current understanding of heliospheric phenomena.