Mesoscale convective systems (MCSs) are especially visible in the summertime when there is an advection of warm maritime air from the west. Advection of air masses is enriched by water vapour, the source of which can be found over the Mediterranean Sea. In propitious atmospheric conditions, and thus significant convection, atmospheric instability or strong vertical thermal gradient leads to the development of strong thunderstorm systems. In this paper, we discuss one case of MCSs, which generated a significant amount of +CG (cloud-to-ground), −CG and intracloud (IC) discharges. We have focused on the ELF (extremely low frequency; < 1 kHz) electromagnetic field measurements, since they allow us to compute the charge moments of atmospheric discharges. Identification of the MCSs is a complex process, due to many variables which have to be taken into account. For our research, we took into consideration a few tools, such as cloud reflectivity, atmospheric soundings and data provided by PERUN (Polish system of the discharge localisation system), which operates in a very high frequency (VHF) range (113.5–114.5 MHz). Combining the above-described measurement systems and tools, we identified a MCS which occurred in Poland on 23 July 2009. Furthermore, it fulfilled our requirements since the thunderstorm crossed the path of the DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) overpass.

中文翻译：

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中尺度对流系统，作为地面系统和DEMETER（地震区域传输的电磁辐射检测）卫星记录的电磁信号源

中尺度对流系统（MCSs）在夏季特别容易看到，因为那里有来自西方的热海对流。气团的平流被水蒸气所丰富，水蒸气的来源可以在地中海上找到。在有利的大气条件下，因此在对流中，大气的不稳定性或强烈的垂直热梯度会导致强烈的雷暴系统的发展。在本文中，我们讨论了一种MCS案例，该案例产生了大量的+ CG（云对地），- CG和云内（IC）放电。我们专注于ELF（极低频；< 1 kHz）电磁场测量，因为它们使我们能够计算大气放电的电荷矩。由于必须考虑许多变量，因此MCS的识别是一个复杂的过程。在我们的研究中，我们考虑了一些工具，例如云层反射率，大气探测和PERUN（放电定位系统的波兰系统）提供的数据，这些工具在非常高的频率（VHF）范围（113.5–114.5 MHz）下运行）。结合上述测量系统和工具，我们确定了2009年7月23日在波兰发生的MCS。此外，自雷暴穿越DEMETER（地震区域传输的电磁辐射检测）以来，它满足了我们的要求。立交桥。