The dispersion relation, which describes the nonlinear coupling of a large-amplitude electromagnetic pump wave with low-frequency collisional modes in the high-latitude ionosphere, is derived. In particular, we point out that the nonlinearities in the electron-neutral collision term are important for the long-wavelength part of the spectrum. This fact has been overlooked by previous authors.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.