Ground-based observations of the relations between lightning charge-moment-change and the physical and optical properties of column sprites

Abstract

Ground-based observations of the relations between lightning charge-momentchange and the physical and optical properties of column sprites. Optical observations of 66 sprites, using a calibrated commercial CCD camera, were

Sprite climatology in the Eastern Mediterranean Region

“…Adachi et al (2004) analyzed 13 sprite events in winter thunderstorms over the Sea of Japan and reported a positive correlation between the CMC values and the numbers of sprite entities (R 2 = 0.45) and a higher correlation with the parent strokes' peak currents (R 2 = 0.9). More recently, Yaniv et al (2014) analyzed 26 events in winter thunderstorms in the Eastern Mediterranean and found a very weak correlation (R 2 = 0.15) with the CMC of the parent stroke. Fig.…”

“…We did not perform a full dimensional analysis of the columns in this database (e.g. of their lengths and volumes occupied), however Yaniv et al (2014) analyzed a partial sample and reported a linear correlation between the sprite column's lengths and the CMC of the parent flash: stronger flashes produce longer columns, due to the larger quasi-electrostatic field that enables the propagation of sprite streamers to lower altitudes. With the benefits of high-speed imagery at 10,000 frames per second, Stenbaek-Nielsen and McHarg (2008) showed that in US summer thunderstorms, column (or C-) sprites are typically downward-only moving straight luminous features, while carrot sprites exhibit both downward and upward streamer movement, the latter forming the diffuse appearance on top, resembling the leaves of garden carrots.…”

Time and space correlation between sprites and their parent lightning flashes for a thunderstorm observed during the HyMeX campaign

“…The range of the present CMC values is similar to those reported by Hu et al [] for summer storms in U.S. plains or to that in van der Velde et al [] for storms in the South of Europe. However, it is larger than that in Matsudo et al [] for winter storms in Japan and that in Yaniv et al [] for winter storms observed during campaigns conducted from Israel. The HyLMA data allow analyzing several characteristics of most of these flashes, especially their duration, as reported in Table .…”

Positive streamers in air of varying density: experiments on the scaling of the excitation density

“…The background gray level (GL 0 ) is determined using two ROI parallel and outside of the streamer section with the same dimensions (solid boxes in Figure 2 (a)). A similar method to determine the background signal was used by Yaniv et al [45]. Several hundred streamer sections were analyzed in this manner at each pressure.…”