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One of the most enigmatic types of sprites is the dancing sprite which appears to dance above the storm as sequential luminous emissions a few 100 ms or less apart. Dancing sprites occur in relatively small proportion and many aspects of their generation remain unknown. We present a multi‐instrumental analysis of a 20‐hr duration Mesoscale Convective System (MCS) over the northwestern Mediterranean Sea on September 21, 2019, that produced 21 sprites recorded with a video camera, of which 19 (90%) were dancing sprites. The asymmetric trailing stratiform MCS developed in strong convective conditions having a CAPE of 3,500 J kg−1. It formed several convective cores (up to 2,900 km2 with cloud top temperature <−66°C) and exhibited a bow echo structure during the sprite production period. Using Lightning Mapping Array data, we show that the sprite producing positive cloud‐to‐ground (SP + CG) flashes mainly initiated at the edge of the convective line on the side of the stratiform region. The flashes propagated 100–200 km across it, producing both positive and negative CG strokes. The 19 dancing sprite events included 49 sequences, of which 46 were associated with distinct SP + CG strokes and 3 with surges during the continuing current. An especially bright and wide sprite sequence was produced by three distinct SP + CG strokes that occurred within 3 ms and spread over 54 km. This sprite sequence could be classified as a new sprite category resembling a "wall" but structured in three groups, each associated with one of the +CG strokes. Plain Language Summary: One of the most enigmatic types of sprites is the dancing sprite which appears to dance above the storm as sequential luminous emissions a few 100 ms or less apart. Dancing sprites occur in relatively small proportion and many aspects of their generation remain unknown. We present a multi‐instrumental analysis of a 20‐hr duration Mesoscale Convective System over the Mediterranean Sea on September 21, 2019, that produced 21 sprites, of which 19 were dancing. The storm developed in strong convective conditions and formed several convective cores with very high cloud‐tops and a bow‐echo structure. Most of the sprite producing flashes propagated from the convective to the stratiform region over long distances producing strokes of both polarity. The 19 events included 49 sprite sequences, of which 46 were associated with distinct strokes and 3 with surges during the continuing current. An especially bright and wide sprite was produced by three strokes that occurred within 3 ms and separated by 54 km and could be classified as a new sprite category. We accredit the high proportion of dancing sprites to a complex charge structure in the stratiform region with large potential and pockets of charge driving the leaders and allowing substantial discharge. Key Points: A high percentage (90%) of dancing sprites were produced by a large asymmetric MCS which developed in strong convective conditions over the Mediterranean SeaThe sprite parent flashes mainly initiated at the edge of the convective region and propagated 100–200 km across the stratiform regionAn especially bright and wide sprite sequence was produced by three distinct positive CG strokes that occurred within 3 ms and were separated by 54 km [ABSTRACT FROM AUTHOR]

We report the first observation of an unusual red sprite produced by negative cloud‐to‐ground (CG) lightning from the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) in Colombia on August 15, 2012. The impulse charge moment change for this event is approximately −520 C·km, barely reaching the threshold for negative sprite production. However, different from all previously reported observations, this negative sprite contains a distinct "sprite current" feature that is unambiguously identified in the very‐low‐frequency magnetic field recorded at the 3,387 km range in Duke Forest. There is no evidence that this feature was produced by a fast discharging process associated with the causative CG stroke. Instead, the sprite current signal corresponds well to high‐altitude optical emissions associated with the charge flow in the sprite body. The charge moment change caused by the charge transfer in the sprite region was estimated to be about −460 C·km. We attempt to reveal the possible causes of this atypical event from the perspective of the parent thunderstorm and the local ionosphere irregularities, whereas we believe that the most possible reason remains to lie in an extraordinarily long duration (more than 5 ms) of charge transfer to ground following the return stroke. Plain Language Summary: Although the sprite observations associated with negative cloud‐to‐ground (CG) strokes are very rare, the analyses on limited cases still yield a consensus on the typical features of negative sprites. Negative sprites have not yet been reported to contain the "sprite current" signature usually detected in bright positive sprites. With the dataset provided by the Imager of Sprites and Upper Atmospheric Lightning, we found an extremely rare case of negative sprite. The associated broadband magnetic field clearly shows the characteristic waveform indicative of sprite current, despite the impulse charge moment change (about −520 C·km) barely exceeding the critical strength for producing negative sprites. Our analyses exclude the possibility that this sprite current signature was produced by the low‐altitude lightning discharges; instead, the absence of low‐frequency emissions during the occurrence of the suspected sprite current strongly suggests that the second slow magnetic pulse was driven by the charge transfer associated with the high‐altitude optical emissions. This exceptional observation implies that there could be some situations (such as local plasma irregularities) hidden in the mesosphere. However, the most likely cause seems to be a particularly long charge transfer time (more than 5 ms) after the return stroke of the parent CG flash. Key Points: First observation of a negative halo/sprite event with the signature of sprite current in the concurrent very‐low‐frequency sferic waveformThis unusual negative sprite is produced by an impulse charge moment change (approximately −520 C·km) barely enough for producing a spriteThe occurrence of this event is likely caused by an extraordinarily long duration of charge transfer to ground following the return stroke [ABSTRACT FROM AUTHOR]

In dancing sprite events, sprite entities and groups appear in rapid succession together with a corresponding series of parent lightning strokes. Dancing sprite events, including a case with possible sprite rebrightening, were recorded on video simultaneously from two observation sites above a mesoscale convective system in Central Europe on the night of 6 August 2013. Joint analysis of triangulated locations of sprite elements, position, type, and peak current of lightning strokes from the LINET lightning detection network database and current moment waveforms deduced at the Hylaty station, Poland, showed that subsequent sprite‐parent lightning strokes occurred no further than 21 km from the closest preceding sprite entity in the cases analyzed in this study. Additionally, it was found that longer sprite delay times tend to correspond to larger sprite location offsets from the parent +CG stroke. These observations, the occurrence of +CG lightning stroke and sprite sequences, as well as sprite‐sprite delay times and displacements can be explained if +CG strokes are part of one extended lightning flash. A corresponding production mechanism based on previous findings on the formation of sprite‐producing and general +CG lightning discharges is suggested. Plain Language Summary: In dancing sprite events, sprites appear in rapid succession together with a corresponding series of parent lightning strokes. Dancing sprite events were recorded on video simultaneously from two observation sites above an extended thunderstorm system in Central Europe on the night of 6 August 2013. Comparison of triangulated sprite locations and the locations of corresponding lightning activity revealed that subsequent sprite‐parent lightning strokes occurred below or relatively near the location of the closest preceding sprite entity in the examined cases. In this paper, a mechanism is suggested for the development of lightning flashes that produce dancing sprites. The proposed mechanism accounts for prompt and delayed sprites relative to their parent lightning stroke, highlights the role of the variation of lightning current in sprite production, and can explain the observed closeness of the next +CG lightning stroke to the area of previous sprites. Key Points: The observations support that dancing sprite events tend to occur above stratiform cloud areasIf a sprite is up to 45 km away from its parent +CG stroke, the offset of the next sprite in the same sequence was found to be largerIt is suggested that +CG parent strokes in dancing sprite events are often part of one extensive lightning flash [ABSTRACT FROM AUTHOR]