Thunderstorm charge structures favouring cloud-to-ground lightning
Thunderstorm electrical structures favouring cloud-to-ground lightning were investigated through a Lightning Mapping Array (LMA), an accurate three-dimensional lightning location system that allows inferring the heights of the regions of charge. The present study focused on classical, convective-sca...
| Autores: | , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/354656 |
| Acesso em linha: | https://hdl.handle.net/2117/354656 https://dx.doi.org/10.1016/j.atmosres.2021.105577 |
| Access Level: | acceso abierto |
| Palavra-chave: | Atmospheric electricity Lightning mapping array Cloud-to-ground flash rate Electrification Thunderstorm electrical structure Electricitat atmosfèrica Àrees temàtiques de la UPC::Enginyeria elèctrica |
| Resumo: | Thunderstorm electrical structures favouring cloud-to-ground lightning were investigated through a Lightning Mapping Array (LMA), an accurate three-dimensional lightning location system that allows inferring the heights of the regions of charge. The present study focused on classical, convective-scale thunderstorms, aiming to shed new light on how the charge structure affects lightning production, especially the cloud-to-ground fraction, including flash rate and polarity. Results showed that lightning flashes mainly initiate at two levels, around -41 °C (9,150 m MSL) and around -7 °C height (4,730 m MSL). These initiation levels, located between the dominant positive and negative charge regions, allowed to define three main charge structures: an upper dipole (positive above negative), a classical tripole and a lower dipole (negative above positive). Several differences were found between the three categories in terms of the cloud-to-ground lightning production: (i) the classical tripole structure is the one presenting a higher cloud-to-ground flash rate (5.2 flashes·min-1); (ii) in terms of intensity, the presence of an upper positive charge region is more relevant than a lower positive below the main mid negative; (iii) conversely, the lower positive favours higher cloud-to-ground peak currents; (iv) A higher upper positive charge region favours a higher cloud-to-ground rate. |
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