Lifetime,age, and rotation of coronal magnetic fields

The rotation of the solar electron corona is determined for intervals when nearly periodic variations dominated the polarization brightness record during 1964–1976. Coronal rotation rates derived for 765 intervals vary with height, latitude, and interval length. These rotation rates show a decrease of differential rotation with height and support earlier rotation studies which included much less stationary data. Analyses of the selected intervals and autocorrelation of the complete K-coronameter data set give quantitative estimates of the rotational effects of magnetic tracer age and lifetime. The principal effects detected are a relatively fast rotation of very long-lived tracers at high latitude and a relatively fast rotation of very short-lived tracers at low latitudes. The observations indicate that high-to-low latitude magnetic connections extending through the corona speed up rotation at high latitudes and retard it at low latitudes.