Time succession of 25 Ha spicules has been studied. The spectra are obtained at a height of 6 arc sec during 21 rain (38 pictures) with the 53 cm Lyot coronagraph. Total intensities W, widths AA and radial velocities Vr are determined (about 650 Ha line profiles). For 14 spicules the sign of V, varies, for the rest the sign variation is absent or it is doubtful. Characterized period of Vr variation is 3-7 rain with a mean amplitude of • km s -1. W and AA also vary with a similar period and mean amplitudes equal to 50% and 30% respectively. AA dependence of W ( Figure 1) points to the existence of two spicules groups: group I (70%) characterized by relatively small W and AA (mean values are 0.08 A, and 1.3/~ respectively); group II comprising brighter (W~0.13/~) spicules with wider profiles (AA = 1.6 ~,). Group II may consist of the unresolved, superimposed group I spicules. We believe, that Ha spicules involve formations consisting of separate elements having the temperature of 6000 K and non-thermal velocities of -25 km s -1. ObservationsA series of spectrograms (38 pictures) obtained by G. M. Nikolsky, Yu. Platov, and A. A. Sazanov on 3 April, 1969 with a large coronagraph mounted at the High Altitude Astronomical Station near Kislovodsk has been examined. The curved slit of the spectrograph was adjusted concentric to the limb of the Sun on the East side at a height of 4200 km. The height was controlled by the method proposed by Nikolsky (1970). The dispersion was 0.962 ~ mm -1 in the second order in coud6 focus, the scale being 16 arc sec per mm. The exposure time was 0.3 s. The resolution on each photograph is not worse than 1 arc sec. The time interval -21 rain. The observations have been reported in detail earlier (Nikolsky and Platova, 1971). Measurements of SpectrogramsWe have chosen 25 spicules traced as single details on many pictures, i.e. not consisting of superimposed spicules. In order to identify the spicules precisely, large-scale prints of each frame were made.Photometric sections were made along the dispersion in the centre of each spicule (microphotometer slit cut 0.03/~ • 0.5 arc sec). Fraunhofer lines of the third order scattered light served as reference lines, from which the wave-length was Solar Physics 59 (1978) 21-28. All Rights Reserved Copyright (~) 1978 by D. Reidel Publishing Company, Dordrecht, Holland

The possibility of the existence of spicular oscillations is discussed in this paper. Ha-spicules show quasiperiodic variations of radial velocities, half-widths and line intensities with a period of 5 min. A grouping of spicules at the solar limb according to positive and negative velocities is found; this is interpreted as the collective oscillation of groups of spicules~ A theoretical analysis is given of the transformation of vertical five-minute oscillations into horizontal ones, in the presence of a magnetic field.

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Almost simultaneous height sequences of 69 spicules in the Ha line have been studied. The spectra are obtained at six heights during 6 s on the east side of the solar disk with the 53-cm Lyot coronagraph of Abastumani Astrophysical Observatory.Radial velocities V,, total intensities or equivalent widths W, full widths at half maximum of intensity (FWHM) at all heights are determined (about 300 profiles of the Ha line). It is found that:(1) Absolute values of radial velocities increase linearly with the height (see Equation (1));(2) variation of the sign of the radial velocity along single spicules was never observed. These results combined with the findings on the spicules radial velocities and shifts obtained earlier (Kulidzanishvili and Nikolsky, 1978;Nikolsky and Platova, 1970) led us to the conclusion that the 5-rain tangential oscillations of spicules involve the entire spicule at once.The intensity height scales for single spicules and for the chromosphere 'in toto' are determined; they turned out to be 2.5 x 10 a km and 1.9 • 103 km respectively (see Equations (2) and (3)).The dependence curve of the Ha line half-widths AA on the height h is drawn. The Ha line half-width for those spicule groups which are traced at all heights (10 spicules) decreases with the height (Figure 4); for the majority (-60 spicules) it remains essentially constant. Non-thermal 'turbulent' velocities Vt in Ha spicules are defined. A mean value of the 'turbulent' velocity Vt at T = 6000 ~ appeared to be 20-30 km s -1.The hydrogen concentration in the spicules at 5000 km is 6 • 1011 cm -3.