Theory for two-dimensional electron and ion Bernstein–Greene–Kruskal modes in a magnetized plasma

A theory for two-dimensional electron and ion Bernstein–Greene–Kruskal (BGK) modes in a magnetized space plasma is presented. The BGK modes are constructed using the energy and the canonical angular momentum of the particles, which are conserved in a cylindrically symmetric potential. The typical length scale of the BGK modes is of the same order or larger than the thermal gyroradius of the particles. The results are relevant for understanding the properties of observed localized structures in the Earth's magnetosphere and auroral zone, as well as in laboratory magnetoplasmas.