Electric field changes generated by preliminary breakdown pulse for positive lightning ground flashes in Sweden
(English)Manuscript (preprint) (Other academic) [Artistic work]
This is the new study of the electric field changes generated by the preliminary breakdown for positive cloud-to-ground flashes which concerning on the association of slow field changes in preliminary breakdown process. In this study, a 107 positive cloud-to-ground lightning flashes recorded from the total of 14 thunderstorms generated by the whole flash were examined. The electric fields were measured with nanosecond resolution by using the slow electric field, fast electric field and narrowband radiation field at 3 and 30 MHz signals simultaneously. Our result shows that there is a pre-starting time, i.e. the duration between the first preliminary breakdown pulse and slow field changes starting point, which is found to be after the first preliminary breakdown pulse. The pre-starting time has the arithmetic mean – 3.0 ms and geometric mean – 1.8 ms, ranging from 0.3 to 21.7 ms. This study is consistent with the latest finding for the slow field changes in negative ground flashes where the slow field changes never start before the preliminary breakdown process.
Positive cloud-to-ground lightning flashes, Initiation position, slow field changes, close ground flashes, preliminary breakdown process
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject Engineering Science with specialization in Atmospheric Discharges
IdentifiersURN: urn:nbn:se:uu:diva-222826OAI: oai:DiVA.org:uu-222826DiVA: diva2:712381
FunderSwedish Research Council, 621-2006-4299Swedish Foundation for Strategic Research , IG2004–2031