ST Solar-Terrestrial Sciences
The 2012 Division Outstanding Young Scientists Award is awarded to Alejandro Luque for his outstanding contribution to the understanding of the electrodynamics of plasma streamers found in Transient Luminous Events (TLEs) occurring in the mesosphere of the Earth.
Alejandro Luque is a plasma physicist working at the Instituto de Astrofísica de Andalucía (IAA – CSIC) in Granada, Spain. His scientific work is focused on the physics underlying the inception, formation, propagation and interaction of plasma streamers occurring in Transient Luminous Events (TLEs) like sprites (the most frequent TLE) in the mesosphere of the Earth. He has developed sophisticated electrodynamic models investigating for the first time the effect of the density gradient along the sprite propagation length. In this manner he was able to explain many previously unexplained features of sprites such as the attraction of a channel towards a previous one, the emergence of upward-propagating, negatively charged channels and the emissions from the sprite body that other authors attributed to chemical processes whereas he pointed that they are the result of direct impact excitation of nitrogen molecules. In 2009 Luque published a paper in Nature Geoscience where a realistic model was proposed for the first time to unveil the physics of the inception of sprites in the mesosphere. Previous modeling work had to use unrealistic metal electrodes to study the inception and propagation of sprite streamers. However, he showed that sprites may emerge from the destabilization of a wide ionization wave that propagates downward from the ionosphere after a strong thunder strike. His calculations agree quite well with previous observations. Later observations proved the existence of the ionization wave that he postulated. Finally, in 2008 Luque published the first study about the interaction of two sprite streamers where he showed that there is a competition between a repulsive electrostatic force and an attractive interaction due to the ionization of the space between the two streamers.