For the first time, the relationship between total (cloud-to-ground and intracloud) lightning activity and the Mediterranean Oscillation (MO) is addressed in this work. Data from optical transient detector (OTD) and lightning imaging sensor (LIS) were used to calculate the total flash density, and the MO was described using the Mediterranean Oscillation index (MOi). The study intended to analyse the monthly values of the variables, for the 19-year period from October 1995 to February 2015 and for the region between 31.25 N and 46.25 N, and between 3.75 W and 38.75 E (the Mediterranean Sea and bordering land areas). Moreover, the study was carried out for the whole year and a comparative analysis was also conducted with the results obtained for the cold periods (October to March) and warm periods (April to September), both for the positive and negative phases of the MOi. The results revealed that the lightning activity in the annual and cold periods was clearly similar, and the maximum values tended to concentrate over southern Italy and the central part of the Mediterranean Sea, while in the warm period lightning was scattered over the whole study area. When analysing the data from the cold period for the positive phase, significant negative correlations were observed in the west and central area. On the contrary, for the warm period, the significant negative correlation values tend to be concentrated in the eastern limit of the studied territory. During the negative phase of the MOi, most of the studied area showed significant positive correlation values during the cold period, whereas only a small area with negative correlation tended to concentrate on the eastern boundary during the warm period. The results are explained in terms of the circulation dynamics and temperature changes recorded for the MO.

中文翻译：

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地中海振荡对总闪电活动的影响

这项工作首次解决了总（云对地和云内）闪电活动与地中海涛动（MO）之间的关系。来自光学瞬态探测器 (OTD) 和闪电成像传感器 (LIS) 的数据用于计算总闪光密度，并使用地中海涛动指数 (MOi) 描述 MO。该研究旨在分析从 1995 年 10 月到 2015 年 2 月的 19 年期间以及北纬 31.25 到 46.25 之间以及西纬 3.75 到 38.75 之间的区域（地中海和毗邻陆地区域）的月度值）。此外，对全年进行了研究，并对寒冷期（10月至3月）和温暖期（4月至9月）的结果进行了比较分析，MOi 的正相和负相。结果表明，全年和寒冷期的闪电活动明显相似，最大值倾向于集中在意大利南部和地中海中部，而温暖期闪电则分散在整个研究区。在分析正相寒冷期的数据时，西部和中部地区观察到显着的负相关。相反，对于暖期，显着的负相关值往往集中在研究区域的东部边界。在 MOi 的负阶段，大部分研究区域在寒冷期表现出显着的正相关值，而暖期只有一小部分负相关区域倾向于集中在东部边界。结果根据 MO 记录的循环动力学和温度变化进行了解释。