Saturday, August 02, 2008

1-2 August, Italian sprites, eye-witnessed

The Corsica camera was operated last night and observed sprites over northern Italy right from the moment it was dark enough. The first sprite at 1948 UTC was quite a large one and observed also in color.
Above is a lightning map of 1950 UTC.
Several more sprites followed, a total of 9.



The storm system appeared very active after 21:15 with many lightning flashes, there could be a few more sprites hidden in the data. No images are present for the period after 00 UTC, perhaps they arrive later.
Pic du Midi also observed but only detected the 2050 UTC sprite which can be triangulated. The early sprites could not have been observed because there was still daylight in the Pyrenees, and apparently the event detection thresholds were not sufficiently sensitive, despite the other events being rather large as well (puzzling...)

The sprites have been noticed by Marko Korosec:
"I was on the beach in Lignano on the north Adriatic coast yesterday evening, when a nice MCS formed over NW Italy. And I think I saw a red sprite above that system. However I am not sure if its actually possible to observe them from sea level, though the distance was around 250km."
So, yes, it is certainly possible to see them from sea level, provided you are at a very dark location!

Thursday, July 31, 2008

Colour!


Congratulations to Enrico for his amazing catch! (see post below)
The colour image of the same sprite shows very interesting things. As luck would have it, the sprite occurred exactly at the time when two video fields switch, so the beginning is recorded in the top field and the end in the bottom field. The streamers were still going down and only luminous at their tips, something that is normally only noticed using high-speed video cameras.
Below are the blue and red pixels (the green contain almost only noise). For the eye there seem to be only small differences between the two, the red channel perhaps looks more diffuse.

July 30-31 - 6 sprites


After a good few hours with very intense lightning over Northern Italy, we got 5 sprites and this massive sprite event not too far from lake Garda (from the camera mounted in Corsica). Or we should better say this event probably covered the whole distance from Milan to lake Garda!