Speaker
Description
LOFAR is the most sensitive and precise lightning interferometer currently operational. The LOFAR lightning research group has been using this capability to unveil lightning plasma physics that is impossible to explore in any other way. In particular, the lightning group has made significant progress in imaging and understanding lightning initiation, propagation, cloud-top discharges, thunderstorm charging, and many other phenomena.
During lightning plasma channel (called leaders) propagation LOFAR observes a series of extremely fast streamer bursts that are too fast to temporally resolve with any other instrument. Each streamer burst propagates around 1x10^5 m/s over tens to hundreds of meters, and then thermalizes to produce the next section of hot leader channel. This process shares many similarities with what LOFAR observes during lightning initiation, which is likely also a burst of streamers. The similarities and differences between these two processes are guiding our understand in how streamers interact to create lightning processes.
Thunderstorms are known to produce relatively small discharges near the top of the tropopause, which are regularly seen from space-based observations as point-like flashes of light. LOFAR has also observed these cloud-top discharges in the Netherlands, able to resolve their structure, and has reviled that they are not one single type of discharge but a wide collection of different phenomena.
Finally, it has become clear in recent years that lightning flashes in the Netherlands are upside-down relative to most lightning flashes observed elsewhere. Thus, the lightning group used the radio-emission from cosmic ray air showers during thunderstorms to reconstruct the charge distribution. The result is that Dutch thunderstorms have a charge distribution that is upside-down relative to thunderstorms in other parts of the world. Precisely why this is the case is still being explored.
In this talk we will give an overview of a few of these recent advancements in lightning science being made with LOFAR with particular attention to the new plasma physics being discovered. The talk will conclude with a discussion of the new lightning science the LOFAR2.0 will enable
