Objectives:
To capture very fast flows associated with chromospheric transients in an active region, such as Ellerman bombs and penumbral microjets, which is expected to be driven magnetic reconnection. This is realized by high resolution (0.2-0.3") spectroscopic observations of the chromospheric lines (by IRIS) and the photospheric lines (by Hinode SP).
Scientific Background:
We already know lots of transient events taking place in and around asunspot, such as penumbral microjets, jets above a light bridge,
Ellerman bombs, and chromospheric anemone jets (Katsukawa et al. 2007, Shimizu et al. 2009, Matsumoto et al. 2008, Shibata et al. 2007, etc.) We already have some examples of spectroscopic observations of Ellerman bombs and penumbral microjets at the Ha and CaII line by GBO (e.g. Reardon, Tritschler, Katsukawa 2013). These observations suggest magnetic reconnection take place in the upper photosphere or in the chromosphere though there are little knowledge on how fast flows is driven and how such flows influence the upper chromosphere and transition region.
Obtaining photospheric counterparts is also important to know magnetic field configuration at the roots of the chromospheric transients, such as penumbral filaments, emerging flux, and magnetic cancellation. It is also important to capture a signature of downflows from the magnetic reconnection (e.g. Katsukawa et al. 2010). |
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