Electrical Properties of Vertical Dominant Charge Structures Observed in Corsican Thunderstorms With a LMA

Lightning characteristics of Corsican storms with different charge structures are investigated in this study. Observations of an LMA network are used to document the total lightning activity. Complementary lightning observations of the lightning detection network Meteorage are also used. A clustering algorithm is used to build a database of electrical cells from June to October 2018. A method is also applied to infer the vertical charge structure, as dominant dipoles, per 10-min period for each electrical cell. As an example, one cell recorded in July 2018 is discussed. The cell database is then presented as well as the main electrical properties according to the dominant charge structures. For instance, the higher in altitude the dominant dipole, the higher the flash rate. Overall, dominant negative dipole are observed for 25% of the 10-min periods and can be separated into two categories: (a) low altitude negative dipole class dominated by negative cloud-to-ground (CG) flashes with a main positive layer located between 2 and 4 km height and (b) high altitude negative dipole class, dominated by negative intracloud (IC) with a main positive layer at 5 km height. Dominant positive dipole can also be separated into two categories with (a) a dominant positive dipole located between 4.5 and 10 km high, -CG dominance, weak flash rate and (b) higher altitude dominant positive dipole, +IC dominance and a larger +CG fraction. The synergistic use of LMA and Meteorage observations independently gives a rational type and polarity classification with regard to the vertical charge structure. Lightning characteristics of Corsican storms with different charge layers distributions are investigated in this study. Observations of the 3D lightning imager SAETTA, deployed in Corsica, are used to document the total lightning activity. Complementary lightning observations recorded by the French operational lightning detection network Meteorage are also used. A algorithm is applied on the lightning data to build a database of electrical cells from June to October 2018. A method is also applied to infer the dominant dipole charge structure per 10-min period for each electrical cell. The results show that the higher in altitude the dominant dipole, the higher the flash rate. Overall, dominant negative dipole are observed for 25% of the 10-min periods and can be separated into two categories with low and high altitude of the dominant dipole that are associated with weak and strong flash rate. The synergistic use of the 3D lightning imager and the French operational lightning detection network gives a rational type and polarity classification to observed flashes with regard to the vertical charge structure. Vertical charge structures of Corsican thunderstorms and their lightning characteristics are documented based on VHF and LF observations 25% of storms 10 min-periods showed negative dipole structures with some of them the highest flash rates recorded during the 5-month period Flash polarity provided by the LF lightning locating system is consistent with the inferred charge structure