Cosmic rays, high-energy subatomic particles of extraterrestrial origin, are systematically measured by space-borne and ground-based instruments. A specific interest is paid to high-energy ions accelerated during solar eruptions, so-called solar energetic particles. In order to build a comprehensive picture of their nature, it is important to fill the gap and inter-calibrate ground-based and space-borne instruments. Here, we focus on ground-based detectors, specifically neutron monitors, which form a global network and provide continuous recording of cosmic ray intensity and its variability, used also to register relativistic solar energetic particles. The count rate of each neutron monitor is determined by the geomagnetic and atmospheric cut-offs, both being functions of the location. Here, on the basis of Monte Carlo simulations with the PLANETOCOSMICS code and by the employment of a new verified neutron monitor yield function, we assessed the atmospheric cut-off as a function of the altitude, as well as for specific stations located in the polar region. The assessed in this study altitude profile of the atmospheric cut-off for primary cosmic rays builds the basis for the joint analysis of strong solar proton events with different instruments and allows one to clarify recent definitions and related discussions about the new sub-class of events, so-called sub-ground-level enhancements (sub-GLEs).

宇宙射线是来自外星的高能亚原子粒子，由星载和地面仪器系统地测量。人们特别关注太阳爆发期间加速的高能离子，即所谓的太阳能高能粒子。为了全面了解它们的性质，重要的是填补空白并相互校准陆基和星载仪器。在这里，我们专注于地面探测器，特别是中子监测器，它们形成一个全球网络并提供宇宙射线强度及其可变性的连续记录，也用于记录相对论的太阳高能粒子。每个中子监测器的计数率由地磁和大气截止值决定，两者都是位置的函数。这里，在使用 PLANETOCOSMICS 代码的蒙特卡罗模拟的基础上，并通过使用新的经过验证的中子监测产率函数，我们评估了作为高度函数的大气截止，以及位于极地地区的特定站。本研究评估的初级宇宙射线大气截止高度剖面为使用不同仪器联合分析强太阳质子事件奠定了基础，并使人们能够澄清关于新事件子类的最新定义和相关讨论，所谓的次地面增强（sub-GLEs）。