We propose a series of Hinode and BBSO coordinated observations to investigate physical processes in the solar chromosphere. The importance of this poorly understood layer of the solar atmosphere is increasing in the solar research.
For the study of chromospheric features, Chae and his collaborators have developed the Fast Imaging Solar Spectrograph (FISS) on the New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO). From the early observations of a quiet region using this instrument, they obtained solid evidence that strong shocks of three-minute period are not only dominating the dynamics of the upper chromosphere of the intranetwork quiet region, but also are responsible for the heating of the chromosphere and corona there. This gave them a strong motivation to investigate shock phenomenon and other processes in the soalr chromosphere in detail. On the other hand, Tsuneta and his collaborators not only have produced a number of significant scientific results using the Hinode, but also are now preparing for a challenging sounding rocket experiment: the Chromospheric Lyman-alpha SpectroPolarimeter (CLASP) that aims to measure magnetic field of chromospheric features using the Hanle effect in Lyman alpha. If successfully carried out, this instrument will open a new era of directly measuring magnetic field in the chromospheric level.
We focus on shocks and magnetic reconnection events occurring in the chromosphere in various contexts. It is very likely that shocks are very common in the chromosphere and have different natures (acoustic, slow or fast), mostly depending on the magnetic environment. Chromospheric reconnection events may often occur in various scales, with some being associated with cancelling magnetic features. The ultimate goal of our study is to reveal their physical natures and estimate how each of these processes is important in the heating of the chromospheres and corona. In addition, of our specific interest is whether reconnection events drive waves that develop into shocks.
Our approach is to combine 1) magnetic and velocity data of the photosphere taken by Hinode/SOT, and 2) spectral data and imaging data of the chromospheres taken by FISS/NST and Hinode/SOT 3) spectral data of the corona taken by Hinode/EIS.
We propose to operate two-hour observing run for each target each day. The targets include 1) a near-disk-center quiet region, 2) a near-limb quiet region 3) a plage region 4) a sunspot 5) a pore. The specific choice of the target is to be made by the observer at time as close to the observing day as possible.
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