There are three components to this plan: (1) XRT full-disk observations, (2) XRT limb observations, and (3) SOT limb spicule observations.
(1) XRT full-disk observations. We will combine Hinode XRT coronal observations with white-light observations of the corona obtained from the ground at Svalbard, Norway (and elsewhere, weather permitting). We will use these images to compare longer-lived X-ray coronal structures (including coronal cavities and polar plumes) with those structures seen in ground-based data; this type of study between ground-based and space-based observations was recently carried out for the 2012 eclipse (Pasachoff et al. 2015, ApJ, 800, 90), and is in progress for the 2013 eclipse. The availability of images in multiple XRT filters will allow for X-ray-temperature diagnostics of such structures. (XRT has reduced spatial resolution for full-disk images, but it should still be adequate for obtaining general diagnostics of large-scale structures, such as coronal cavities.) Images taken during typical synoptic sequences should be adequate for this program, but as a minimum we require images in Al_poly and Al_mesh filters; we have found this pair to be useful for determining diagnostics of XRT polar coronal hole features (Pucci et al. 2013, ApJ, 776, 16).
(2) XRT limb observations. One objective is to observe X-ray polar plumes, and compare them with white-light plumes seen from the ground. We will also look for X-ray jets, to see whether they tend to occur at the base of plumes that are dense enough be appear in the white-light images. These observations require time series images at the solar limb. Our first-priority target is a polar coronal hole (PCH). If that is not available, then additional targets are a coronal cavity, a streamer and/or polar quiet Sun. Again as a minimum, the filters used should include Al_poly and Al_mesh.
(3) SOT observations. Ca II spicule limb observations during at least one of the periods of the limb studies, preferable during PCH observations. If no PCH is available, then the preferred target is polar quiet Sun. The objective is to study spicules at the base of coronal plumes, and/or at the base of X-ray jets (Sterling, Harra, & Moore 2010, ApJ, 722, 1644).
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