Temperatures of the disturbed and quiet inner solar corona

Eclipse observations of the coronal optical spectrum were carried out in order to study the temperature composition of four coronal disturbances during different epochs. The structure of the quiet inner corona was also studied in detail. It is found that three of the CDs consist of two components: a hot coronal condensation having T(e) of about 3.8 million K; and Ni XV region of T(e) = 2.3 million K. The contribution of the first region to the total CD emission was in the range 14-23 percent, while the weighted mean temperature was 2.5-2.6 million K. Despite spectral differences, the remaining two CDs has identical temperature composition. Considerable spatial variations of temperature composition were observed in the quiet inner corona: the Fe XIV (T/e/ = 1.9 million K) dominated in about 1/3 of the undisturbed corona in the minimum phase; and Ni XV regions (T/e/ = 2.3 million K) dominated in the other two thirds of the undisturbed corona. The average temperature composition was estimated in the range XV:Fe XIV:FeX = (0.42:0.38:0.20)-(0.78:0.18:0.04). Variations in the average temperature composition are traced over several epochs of solar activity.