A temporal three‐dimensional simulation of samarium release in the ionosphere

For understanding plasma processes of the ionosphere and magnetosphere, the alkali and alkaline‐earth metals are usually released in space for artificially increasing the electron density. However, it is a limitation that these releases must be in sunlight where the photoionization can take place. In recent years, the lanthanide metals, such as samarium, have been released to produce electrons in reaction with atomic oxygen in the upper space. The reaction could proceed without sunlight so that the restriction on experimental periods is broken. Unfortunately, any sophisticated models even preliminary ones are unavailable yet in the literature. A temporal three‐dimensional model is presented for the samarium release in detail with respect to various altitudes and mass. Especially, the plasma diffusion equation is remarkably extended from 2‐D to 3‐D by importing the influence of geomagnetic declination, which could be also useful for other chemical releases. The field‐aligned terms are brought so as to the presented model can describe the diffusion along the geomagnetic field subtly. On the basis of the presented model, behaviors of radio waves propagating through the release area are simulated by using ray tracing. This model could be as the theoretical support for samarium releases, and it also helpful for the research on the generation and evolution of the ionosphere irregularities. Key Points Any sophisticated models even preliminary ones are unavailable yet Especially, the plasma diffusion equation is remarkably extended from 2‐D to 3‐D The presented model can describe the diffusion along the geomagnetic field subtly