Comment on “A Study of the F2 Layer Stratification on Ionograms Using a Simple Model of TIDs” by Jiang et al.

다국어 초록 (Multilingual Abstract)

A paper by Jiang et al. (2019, https://doi.org/10.1029/2018JA026040) apparently tries to find common ground between observations of the F3 layer and TIDs by referring to the later when observed near the equatorial anomaly peak as a new type 1 and TIDs by using ray tracing models with arbitrarily adjusted TID parameters. Further confusion in conflating the two separate phenomena is created by referring to both as “stratification.” This comment points out that the F3 is a daytime temporary layer maintained by E × B uplift at the magnetic equator, normally occurs consistently within the peaks of the equatorial ionization anomaly in F2 electron density and may last for hours. Such a layer can be described as a stratification. How this effect dies out beyond the anomaly peak has yet to be experimentally ascertained. A cusp or inflection type TID is a manifestation of a gravity wave with no consistency in location and local time, of short duration measured in minutes, involving a continuous descent in height and should not be described as stratification. The theory of both is well known, and attempting to explain a possible F3 layer as a new type of layer when seen in the vicinity of an equatorial anomaly peak misunderstands the theory of the phenomenon. Attempts to characterize such a phenomenon as a TID manifestation are not defensible.


F3 layer and TID can usually be distinguished on ionograms by their time histories, consistency, location, and duration
An effort to reproduce the appearance of the F3 using a TID model is neither justified nor required