Amodel for falling- tone chorus

作者：Soto Chavez A R^*; Wang G; Bhattacharjee A; Fu G Y; Smith H M

来源：Geophysical Research Letters, 2014, 41(6): 1838-1845.

DOI：10.1002/2014GL059320

• chorus
• Van Allen radiation belts
• wave-particle resonances
• whistlers
• frequency sweep

Motivated by the fact that geomagnetic field inhomogeneity is weak close to the chorus generation region and the observational evidence that falling-tone chorus tend to have large oblique angles of propagation, we propose that falling-tone chorus start as a marginally unstable mode. The marginally unstable mode requires the presence of a relatively large damping, which has its origins in the Landau damping of oblique waves in this collisionless environment. A marginally unstable mode produces phase-space structures that release energy and produce wave chirping. We show that the present model produces results in reasonable agreement with observations.
Key Points We reproduce falling-tone chorus without spatial inhomogeneities

• 出版日期2014-3-28