AI 中文总结
研究雷暴中正电子加速问题，通过时间分辨观测阿拉加茨天文台在强雷暴期间的正电子通量等数据，引入双偶极子电动力学模型解释观测结果，确立正电子TGEs为大气高能现象新子类并提供局部正电子加速直接证据。
AI 中文摘要
雷暴地面增强（TGEs）是雷云中相对论性逃逸电子雪崩（RREAs）的已知表现。然而，正电子在TGEs中的作用及其与雷云电荷结构的关系仍知之甚少。我们报告了2026年5月16日至17日在阿拉加茨天文台强雷暴期间检测到的强烈正电子通量的时间分辨观测结果。三个事件中的两个具有近地表正电场（NSEF）、霰降水、低云底以及SEVAN和STAND3探测器测量的伽马射线和电子通量的低到中等增强。第三个事件是为比较目的而考虑的经典电子TGE。所有事件都显示出511keV湮灭线的中度到强烈增强，以及氡子体伽马射线线的增强。我们观察到电子和伽马射线TGE峰值与正电子通量最大值之间的时间间隔。为了解释这些观测结果，我们引入了双偶极子电动力学模型。大规模电子偶极子包括主要的负雷云层及其在地球表面感应的宽正镜像电荷，产生普通TGEs。同时，局部正电子偶极子由LPCR形成，其负镜像电荷直接位于LPCR足迹下方。这个较低的偶极子向下加速正电子，同时使进入同一区域的电子减速。这些结果将正电子TGEs确立为大气高能现象的一个新子类，并提供了低层大气中局部正电子加速的直接证据。
英文摘要
Thunderstorm Ground Enhancements (TGEs) are known manifestations of relativistic runaway electron avalanches (RREAs) developing inside thunderclouds. However, the role of positrons in TGEs and their relationship to thundercloud charge structure remain poorly understood. We report time resolved observations of intense positron fluxes detected at the Aragats Observatory on 16 17 May 2026 during strong thunderstorms. Two of the three events were characterized by a positive near surface electric field (NSEF), graupel precipitation, a low cloud base, and low-to-moderate enhancement of gamma ray and electron fluxes measured by SEVAN and STAND3 detectors. The third event is a classical electron TGE considered for comparative purposes. All events show moderate to strong enhancement of the 511 keV annihilation line, along with enhanced radon progeny gamma ray lines. We observe a temporal separation between the electron and gamma ray TGE peak and the positron flux maximum. To explain these observations, we introduce a dual dipole electrodynamic model. The large scale electron dipole comprises the main negative thundercloud layer and its broad positive mirror charge induced at the Earths surface, producing ordinary TGEs. Simultaneously, a localized positron dipole forms from the LPCR, with its negative mirror charge directly beneath the LPCR footprint. This lower dipole accelerates positrons downward while decelerating electrons entering the same region. These results establish positron TGEs as a new subclass of atmospheric high energy phenomena and provide direct evidence of localized positron acceleration in the lower atmosphere.
Comments11 pages, 4 figures
