资源环境科技发展态势分析平台

This paper reports observation of five sprites captured over a mesoscale convective system in a 15-min window. One of them (11:49hr sprite) was preceded by a negative cloud-to-ground with peak current of -40.9kA that was detected both by the local lightning detection network (sprite time delay <70-90ms) and the extremely low frequency (ELF) magnetic field data. Another sprite (11:46hr sprite) was preceded by a negative stroke (sprite time delay <10ms) with peak current of -106.6kA but the ELF signal of the stroke could not be recognized. In addition, no positive strokes were recorded 1.5min before the 11:46hr sprite. The rest of the sprites were confirmed as positive both by the local lightning detection network and the ELF magnetic field data. The negative sprite occurred during strong convection, indicated by the increase of the area of the thundercloud with radar echo top of 8-11, 9-11, and 6-12km. The strong convection and large wind shear in the thunderstorm middle and upper region provide favorable conditions to produce the parent cloud-to-ground lightning discharges of the negative sprites.

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