All Figures

$\begin{figure} \par\includegraphics[width=7cm,clip]{4171fg1.eps} \end{figure}$ Figure 1: X-ray flux measured by GOES-8 in the wavelength range 0.05-0.4 nm. Gray areas are the flaring periods. The rise (resp. decay) phase of flares are the dark (resp. light) gray areas as defined in Sect. 3.1.
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In the text

$\begin{figure} \par\mbox{\includegraphics[width=8.5cm,clip]{4171fg2a.eps}\hspace... ...ps}\hspace{4mm} \includegraphics[width=8.5cm,clip]{4171fg2d.eps} }\end{figure}$ Figure 2: Images of AR8210: magnetic field ( top left), H $\alpha$ ( top right), FeXII at 19.5 nm ( bottom left) and soft X-ray ( bottom right) images. We label characteristic polarities on the SOHO/MDI magnetogram (see Sect. 2.1). The strength of B_z ranges from -2500 G to 1400 G. We label the flare sites (A, B, F) as described in Sect. 3.2. Line segments in lower figures roughly indicate the position of the separatrix surfaces that we deduce directly from the EUV and soft X-ray observations.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{4171fg3.eps} \end{figure}$ Figure 3: Unsigned magnetic flux for the IVM time series and the associated errors (unit of 10²² G cm²). Gray areas are the flaring periods as defined in Fig. 1.
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In the text

$\begin{figure} \par\mbox{\includegraphics[width=2.5cm,clip]{4171fg4a.eps}\hspace... ...s}\hspace*{6mm} \includegraphics[width=2.5cm,clip]{4171fg4c.eps} }\end{figure}$ Figure 4: Areas inside the black contour for which the vertical component and the transverse components are above the thresholds [B_z, B_t]: at 17:13 UT ( left) with a threshold of [25 G, 46 G], at 18:01 UT ( center) with a threshold of [30 G, 90 G], and at 21:29 UT ( right) with a threshold of [55 G, 75 G].
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In the text

$\begin{figure} \par\mbox{\includegraphics[width=4cm,clip]{4171fg5a.eps}\hspace*{4mm} \includegraphics[width=4cm,clip]{4171fg5b.eps} }\end{figure}$ Figure 5: Left: MCCD H $\alpha$ spectroheliogram at line center for AR 8210 at 20:15:35 UT. The sunspot, the filaments and the plages are easily identified. Right: the associated velocity map. Black (resp. white) velocities represent blueshifts (resp. redshifts). We label the flare sites (A, B, F) as described in Sect. 3.2.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{4171fg6.eps} \end{figure}$ Figure 6: Basic topological elements for AR 8210 at 17:13 UT. Red (resp. blue) triangles are positive (resp. negative) null points. Spine field lines are thick white lines and separatrix surfaces (or fan surfaces) are defined by two green vectors. Only the projection on the photospheric plane is shown. The characteristic null points are labelled PN1-3 and NN1.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4171fg7.eps} \end{figure}$ Figure 7: Area of interest extracted from AR 8210 (MDI image on the left) showing few characteristic field lines and the separatrix surface between two connectivity domains (straight line). Positive polarities are solid lines and negative polarities are dashed lines.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{4171fg8.eps} \end{figure}$ Figure 8: Location in AR 8210 where the effect of the sunspot rotation is stronger. The magnetic configuration is tripolar: positive polarities (P1 and P2) and one negative polarity (N1). The topology is indicated by thte separatrix surface (straight line). Few characteristic field lines are shown for the sake of clarity.
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In the text

$\begin{figure} \par\includegraphics[width=7.3cm,clip]{4171fg9a.eps}\par\vspace*{2mm} \includegraphics[width=7.3cm,clip]{4171fg9b.eps} \end{figure}$ Figure 9: Top: time evolution of magnetic energy contained in the potential field (dashed line) and in the nlff field (solid line) magnetic configurations in the coronal volume above the photosphere (unit of 10²⁸ erg s^-1). Bottom: time evolution of the rate of change of the free magnetic energy (solid line) and of the energy rate due to transverse motions (dashed line) on the photosphere (unit of 10²⁸ erg s^-1).
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{4171fg10.eps} \end{figure}$ Figure 10: Time evolution of magnetic helicities (unit of 10⁴² G² cm⁴) as $H_{\rm self}(\vec B_{\rm cl})$ (blue dot-dashed line), $H_{\rm mut}(\vec B_{\rm pot}, \vec B_{\rm cl})$ (green dashed line), $H_{\rm m}(\vec B_{\rm pot})$ or vacuum helicity (red dot-dot-dot-dashed line), $\Delta H_{\rm m}$ from the Finn-Antonsen formula (black solid line) and the sum of self and mutual helicity (stars). Gray areas are the flaring periods, dark gray areas are the impulsive phase of flares.
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{4171fg1.eps} \end{figure}$	Figure 1: X-ray flux measured by GOES-8 in the wavelength range 0.05-0.4 nm. Gray areas are the flaring periods. The rise (resp. decay) phase of flares are the dark (resp. light) gray areas as defined in Sect. 3.1.
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$\begin{figure} \par\includegraphics[width=8.2cm,clip]{4171fg3.eps} \end{figure}$	Figure 3: Unsigned magnetic flux for the IVM time series and the associated errors (unit of 10²² G cm²). Gray areas are the flaring periods as defined in Fig. 1.
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$\begin{figure} \par\mbox{\includegraphics[width=2.5cm,clip]{4171fg4a.eps}\hspace... ...s}\hspace*{6mm} \includegraphics[width=2.5cm,clip]{4171fg4c.eps} }\end{figure}$	Figure 4: Areas inside the black contour for which the vertical component and the transverse components are above the thresholds [B_z, B_t]: at 17:13 UT ( left) with a threshold of [25 G, 46 G], at 18:01 UT ( center) with a threshold of [30 G, 90 G], and at 21:29 UT ( right) with a threshold of [55 G, 75 G].
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$\begin{figure} \par\mbox{\includegraphics[width=4cm,clip]{4171fg5a.eps}\hspace*{4mm} \includegraphics[width=4cm,clip]{4171fg5b.eps} }\end{figure}$	Figure 5: Left: MCCD H $\alpha$ spectroheliogram at line center for AR 8210 at 20:15:35 UT. The sunspot, the filaments and the plages are easily identified. Right: the associated velocity map. Black (resp. white) velocities represent blueshifts (resp. redshifts). We label the flare sites (A, B, F) as described in Sect. 3.2.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{4171fg6.eps} \end{figure}$	Figure 6: Basic topological elements for AR 8210 at 17:13 UT. Red (resp. blue) triangles are positive (resp. negative) null points. Spine field lines are thick white lines and separatrix surfaces (or fan surfaces) are defined by two green vectors. Only the projection on the photospheric plane is shown. The characteristic null points are labelled PN1-3 and NN1.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4171fg7.eps} \end{figure}$	Figure 7: Area of interest extracted from AR 8210 (MDI image on the left) showing few characteristic field lines and the separatrix surface between two connectivity domains (straight line). Positive polarities are solid lines and negative polarities are dashed lines.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{4171fg8.eps} \end{figure}$	Figure 8: Location in AR 8210 where the effect of the sunspot rotation is stronger. The magnetic configuration is tripolar: positive polarities (P1 and P2) and one negative polarity (N1). The topology is indicated by thte separatrix surface (straight line). Few characteristic field lines are shown for the sake of clarity.
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