Small-scale dynamics in the quiet Sun play an important role in coronal heating and mass transport for the solar wind. In particular, jets, mostly in the form of spicules, may be responsible for carrying energy and momentum sustaining heating and flows. The recent discovery of type II spicules is of particular importance due to their high speed, rapid heating, and large vertical extent. About a decade ago, a new kind of jets was identified on the solar surface using fast spectrograph scans obtained at Big Bear Solar Observatory (BBSO). They were named as the "H-alpha Upflow Events" (Chae et al. 1998; Lee et al. 2000). Using more recent observations, a few researchers found similar features and named them "Rapid Blueshifted Excursions" (RBEs; Langangen et al. 2008). It is highly probable that Upflow Events (or RBSs) are the disk counterparts of type II spicules on the limb. However, discrepancies between them, especially in the detected speed, exist and need further exploration.
We propose to carry out a coordinated observing run using Hinode and the Vacuum Tower Telescope (VTT) at the Observatorio del Teide, Tenerife, Spain to quantitatively study small-scale jets on the solar disk in both the quiet Sun and active regions. We will observe with the VTT high-resolution spectrograph simultaneously the chromospheric H-alpha and photospheric Fe I 709.0 nm lines to study the properties (velocity, density, temperature and statistical distribution) of these small-scale ejections and associated heating. Using high-resolution vector magnetograms from Hinode/SP, the photospheric magnetic structure and evolution associated with these features will be investigated. In particular, the magnetic reconnection at small scales will be characterized. The corresponding counterparts of those jets in the transition region and corona will be investigated using EIS and XRT observations. We will study their vertical extent, mass flow propagation, and heating processes. We will chose a small FOV within quiet Sun regions inside and outside coronal holes as well as in active regions that may produce microflares.
References: Chae, J., Wang, H., Lee, C.Y., Goode, P. R. & Schuehle, U., 1998, ApJ, 504, 123 Lee, C.Y., Chae, J. & Wang, H., 2000, ApJ, 545, 1124 Langangen, O. et al. 2008, ApJ, 679, L167
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