Naslov
Lightning activity in the deep convective clouds with the overshooting tops

Autori
Mikuš, Petra ; Strelec Mahović, Nataša

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
European Geosciences Union General Assembly 2013 Wien, Austria. / - , 2013

Skup
European Geosciences Union General Assembly 2013

Mjesto i datum
Beč, Austrija, 07.04.2013. - 14.04.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
lightning; overshooting top; convection; brightness temperature difference

Sažetak
In this study, spatial and temporal characteristics of lightning distribution and polarity as well as portion of cloud to ground (CG) and intra cloud (IC) lightning in the convective clouds with overshooting tops (OT) are analyzed. Analysis of lightning activity in the thunderstorms with OT was done for the warm part of the year, from May to September during 2009 and 2010. The study area covers region from approximately 41°N 8°E to 49.5°N 24°E. Deep convective clouds with OT were detected from the Meteosat 9 data, based on the infrared window (IRW, 10.8 μm) channel and the absorption channels of water vapor (WV, 6.2 μm) and ozone (O3, 9.7 μm) in form of brightness temperature differences (BTD). Lightning data were provided by the Lightning Location System, which is part of the International Lightning Detection Network in Europe (LINET). The LINET system detects total lightning discharge, but it also separately detects cloud to ground (CG), or intra cloud and cloud to cloud strokes (IC). For each satellite pixel meeting the OT, occurrence of lightning discharge was searched 5 min before and after the time of the scan within the range of 0.05° from the pixel position. The results show that spatial distribution of lightning activity coincides well with the spatial distribution of the detected OTs. The largest numbers of lightning strokes, as well as OTs were detected in the western Hungary, southeastern Germany, northern Adriatic and southern Adriatic coastal region at the slopes of the Dinaric Alps. In general, the largest number of OTs occur between 14 and 21 UTC, while from 06 to 10 UTC OT detections are rather rare. Lightning activity shows similar temporal distribution. Sharp increase in lightning activity and larger values of the electric current are evident at the time of the OT detections. At those times, lightnings occur well above the tropopause, being clearly related to the OT parts of the Cumulonimbus cloud.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA