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We present observations of four filaments that exhibit large-amplitude periodic mass motion. Observations are obtained using the high resolution (2 ) and high cadence (1 min) Hα telescope system at the Big Bear Solar Observatory (BBSO). The motions found in these events are along the axis of the filaments, and are associated with the activity of a nearby flare or filament. The most characteristic properties of these motions are long period (≥80 min), large distance (≥ 4 ×10 4 km) of mass transport at much higher velocity (≥ 30 km s −1 ) than ever detected from filament motions. The velocity, period, dimension and damping timescale measured for these motions are presented, and discussed to identify the most plausible restoring force and damping mechanism.

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In the framework of a refined Kolmogorov hypothesis, the scaling behavior of the B z -component of the photospheric magnetic field is analyzed and compared with flaring activity in solar active regions. We use Solar and Heliospheric Observatory Michelson Doppler Imager, Huairou (China), and Big Bear measurements of the B z -component in the photosphere for nine active regions. We show that there is no universal behavior in the scaling of the B z -structure functions for different active regions. Our previous study has shown that scaling for a given active region is caused by intermittency in the field, ðBÞ ðxÞ, describing the magnetic energy dissipation. When intermittency is weak, the B z field behaves as a passive scalar in the turbulent flow, and the energy dissipation is largely determined by the dissipation of kinetic energy in the active regions with low flare productivity. However, when the field ðBÞ ðxÞ is highly intermittent, the structure functions behave as transverse structure functions of a fully developed turbulent vector field, and the scaling of the energy dissipation is mostly determined by the dissipation of the magnetic energy (active regions with strong flaring productivity). Based on this recent result, we find that the dissipation spectrum of the B z -component is strongly related to the level of flare productivity in a solar active region. When the flare productivity is high, the corresponding spectrum is less steep. We also find that during the evolution of NOAA Active Region 9393, the B z dissipation spectrum becomes less steep as the active region's flare activity increases. Our results suggest that the reorganization of the magnetic field at small scales is also relevant to flaring: the relative fraction of small-scale fluctuations of magnetic energy dissipation increases as an active region becomes prone to producing strong flares. Since these small-scale changes seem to begin long before the start of a solar flare, we suggest that the relation between scaling exponents, calculated by using only measurements of the B z -component, and flare productivity of an active region can be used to monitor and forecast flare activity.

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We analyzed high-cadence observations of a C5.7 Ñare on 1999 August 23 at Big Bear Solar Observatory (BBSO). The observing wavelength was 1.3 in the blue wing of Ha, with a cadence of 0.033 s. In A addition, the hard X-rayÏs time proÐle obtained by the Burst And Transient Source Experiment (BATSE) and BBSO high-resolution magnetograms was compared with our Ha observations to understand in detail the particle precipitation in this event. The important results are as follows :three Ñare kernels were observed in the early phase of the Ñare. The Ñare started in a A , nonmagnetic area at the magnetic neutral line. This suggests to us that the top of a low-lying loop is the initial energy release site, while the other two kernels are the footpoints of another overlying Ñare loop, formed after the magnetic reconnection.2. We analyzed the temporal behavior of the three Ñare kernels in the impulsive phase when hard X-ray (HXR) emission was signiÐcant. We found that during a 7 s period, the Ha[1.3 brightenings at A one of the footpoints showed a very good temporal correlation with the HXR Ñux variation. Therefore, from the spatially resolved Ha o †-band observations, we identiÐed this Ñare kernel as the source of HXR emission.3. From the footpoint which exhibits the best correlation with HXR emission, the Ha[1.3 emission A shows high-frequency Ñuctuations on a timescale of a few tenths of a second. The amplitude of the Ñuc-tuations is more than 3 times the noise. Such Ñuctuations are not evident in the other Ñare kernels which also do not show good correlation with HXR emission. For this reason, we suggest that the observed high-frequency Ñuctuations may be signatures of temporal Ðne structure related to the HXR elementary bursts.