Possible effects of solar variability on the middle atmosphere

This paper discusses the possible effects on the middle atmosphere of (i) solar variability in emission in the u.v. and far u.v., (ii) solar proton events, (iii) relativistic electron precipitation events, (iv) corpuscular heating in auroras, (v) joule heating by the auroral electrojet, (vi) auroral NO production and (vii) gravity wave emission by the auroral electrojet. It is important to establish the maximum depth in the atmosphere to which these effects go, in order to be able to determine whether the reflection of planetary scale waves from the troposphere is substantially altered by them. (author)