ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Identifier O O O O O O O O O O O O O O B-Dataset O B-Wavelength I-Wavelength O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O B-Dataset O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula B-Dataset O O O O O O O O O O O O O O O O B-Identifier O O B-Dataset O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation O B-Citation O B-Citation I-Citation I-Citation O B-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength I-Wavelength O O O O B-Wavelength I-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula I-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O
tokens: the horizontal and vertical components to contribute equally to the line-of-sight field when ∼ 1/6 radian, which is about 9° and almost one day from central meridian. This may explain why it is difficult to extract the canopy fluctuations from the background at locations more than 2–3 days west of the central meridian. 3.3. Inward Motions To study the much slower motions with speeds km s −1 , we again use running differences, but with much longer lags ∼20–30 min. The differences remove the saturated fields near the inner edge of the penumbra. The longer time lags allow the slowly moving features to change their positions by greater amounts and therefore provide stronger signals for their detection in the difference images. Figure 8 compares a jmap of the line-of-sight field for AR12218 (top) with a running difference jmap of this field (middle) and a running difference jmap of 6173 Å continuum intensity (bottom), all with slit orientations of φ = 358°. The difference jmaps were obtained using 22.6 min lags. Short strips of unsubtracted continuum jmaps are shown at the right to indicate the location of the sunspot umbra and penumbra. Also, yellow arrows are oriented at slopes corresponding to 0.5 km s −1 and placed in rows to provide a speed reference. Figure 8. φ = 358° jmaps of the line-of-sight field (top), its running difference (middle), and the continuum running difference (bottom) for AR12218. The difference jmaps show inward tracks (short arrows) along the edge of the masked umbra. Yellow lines (middle panel) separate inflows from outflows whose curved tracks resemble the legs of the quasi-parabolic track of a nearby supergranule (arrow in top panel). The middle panel shows numerous tracks extending inward and outward on both sides of the sunspot. Some of the inward tracks are marked by short arrows. These tracks have speeds comparable to the 0.5 km s −1 reference arrows, and often decelerate at rates ∼0.1 m s −2 as they move toward the gray band that masks the sunspot umbra. In the bottom panel, ingoing tracks of continuum intensity (occasionally indicated by short arrows) are visible along the edge of the masked umbra. We suppose that these continuum tracks are produced by penumbral grain, which also move inward with speeds ∼0.5 km s −1 (Muller 1973 , 1976 ; Zirin Wang 1989 , 1991 ; Lites et al. 1998 ; Sobotka et al. 1999 ; Sobotka Sütterlin 2001 ; Georgakilas et al. 2002 ). The inward tracks of the magnetic field are usually longer than the continuum tracks and show more curvature. This may be due to the greater height of formation of the Fe I 6173 Å line than of the 6173 Å continuum. In the middle panel many tracks curve outward from the mid-penumbra, decelerating as they approach the network region of positive-polarity (white) flux near R / R SG = −2. These outward tracks occasionally join inward tracks to form in/out pairs similar to the parabolic profile of diverging motion in the neighboring supergranule (indicated by the