Dataset for 16 parameters of ten thunderstorm ground enhancements (TGEs) allowing recovery of electron energy spectra and estimation the structure of the electric field above earth’s surface

The atmospheric electric field not only initiates lightning flashes but also originates huge fluxes of electrons and gamma rays incident on the earth’s surface. To reach a complete understanding of both phenomena and to find new and easily measured indicators of the global change in the climate system, the monitoring of the atmospheric electric fields is vitally demanded. Commercially available electric field meters are monitoring the near-surface (NS) atmospheric electric field worldwide in different weather conditions. Special sensors are designed for airborne measurements of the electric field profile with meteorological balloon systems. However, balloon measurements are rare and very slow (20-40 minutes to traverse a storm), performing measurements along the uncontrolled and random flight path, balloons are often taken away by the wind or occasionally destroyed by a lightning flash. However, till now balloon soundings provide the only available data to sample the depth of a storm. Based on these measurements overall understanding was reached that a strong electric field above 1.0 kV/cm started on heights above 1-2 km from the earth's surface. Large electric fields were measured well above 2 km over the ground. Although we cannot expect the same behavior at different destinate
ions, the overall understanding in the atmospheric physics community is that strength of the electric field at altitudes below 1-2 km above ground is well below the critical energy necessary for a runaway process (accelerating and multiplying electrons from the ambient population of cosmic rays). The electron energy spectra measured at Aragats at an altitude of 3200, in this concern, are attributed to the Compton scattered electrons originated by a “gamma ray beam”, from the relativistic electron-gamma ray cascades unleashed high in the atmosphere.
In the posted dataset we demonstrate that, at Aragats, a strong accelerating electric field can be continued almost to the earth’s surface. We present 10 TGE events observed in 2018-2021 allowing recovering electron energy spectra and estimating the heights of the termination of the strong electric field above the ground. The estimates vary from 10 to 150 m above ground, thus the electric field can reach ≈ 2.0 kV/cm at altitudes 3250 – 3350 m.

大气电场（atmospheric electric field）不仅会触发闪电，还会产生大量入射至地球表面的电子与伽马射线（gamma rays）通量。为全面理解这两种现象，并找到气候系统（climate system）全球变化的新型、易测量指标，对大气电场的监测至关重要。目前，商用电场仪（electric field meters）已在全球不同天气条件下监测近地表（near-surface，NS）大气电场。另有专用传感器搭载于气象气球系统（meteorological balloon systems），用于电场廓线的机载探测。然而，气球探测不仅数量稀少，且耗时极长（穿越一次雷暴（storm）需20至40分钟），且沿不受控的随机飞行路径开展测量，气球常被风吹走，或偶尔遭闪电击毁。但截至目前，气球探空仍是获取雷暴垂直深度数据的唯一可行手段。基于此类测量，学界已形成共识：距地表1至2千米以上的高空可出现强度超过1.0 kV/cm的强电场，在地面上方2千米以上的区域也观测到了极强电场。尽管不同区域的电场表现未必一致，但大气物理学界普遍认为，距地表1至2千米以下的高空电场强度，远低于逃逸过程（runaway process，即从宇宙射线（cosmic rays）本底群体中加速并增殖电子的过程）所需的临界能量。在此背景下，在海拔3200米的阿拉加茨山测得的电子能谱，被归因于由“伽马射线束”产生的康普顿散射电子（Compton scattered electrons），而该伽马射线束源自高空触发的相对论电子-伽马射线级联（relativistic electron-gamma ray cascades）过程。本次发布的数据集证明，在阿拉加茨山，强加速电场可近乎延伸至地球表面。我们展示了2018至2021年间观测到的10次TGE（Terrestrial Gamma-ray Event）事件，通过这些事件可重构电子能谱，并估算地面上方强电场终止的高度。估算结果介于地面以上10至150米之间，因此在海拔3250至3350米的高度，电场强度可达约2.0 kV/cm。