Position of electron density maxima with vertical ionization movements

A common test of the wind‐shear theory of sporadic E is to compare wind profiles with corresponding electron density profiles. The relationship between the two measurements is not always obvious. The presence of electric fields and vertical movement of the wind profile has been suggested to account for this. However, it is shown that the position of electron density maxima relative to the horizontal winds must lie in certain height ranges irrespective of electric fields or wind profile movements, provided these are steady. If the winds were suddenly to change, it would take time for the electron density profile to change. The time constants involved are estimated. Thus it should be possible to say whether the experimental results are consistent with the idea that the elecron density profile is produced by the wind profile.