What Goes Up Doesn’t Necessarily Come Down! - Connecting the Dynamics of the Chromosphere and Transition Region with TRACE, Hinode and SUMER

We explore joint observations of the South-East limb made by Hinode, TRACE and SOHO/SUMER on April 12, 2008 as part of the Whole Heliosphere Interval (WHI) Quiet Sun Characterization targeted observing program. During the sequence a large, 10Mm long, macro-spicule was sent upward and crossed the line-of-sight of the SUMER slit, an event that affords us an opportunity to study the coupling of cooler chromospheric material to transition region emission formed as hot as 600,000K. This short article provides preliminary results of the data analysis. The Solar Optical Telescope (SOT; Tsuneta et al. 2008) of Hinode (Kosugi et al. 2007) has revolutionized our view of the dynamic chromosphere revealing the existence of at least two types of spicule (De Pontieu et al. 2007c). “Type-I” spicules are long-lived (3-5 minutes) and exhibit longitudinal motions of the order of 20km/s that are driven by shocks resulting from the leakage of pmodes in regions around strong magnetic flux concentrations (Hansteen et al. 2006; De Pontieu et al. 2007a). “Type-II” spicules, on the other hand, are a relative unknown that show much shorter lifetimes (50-100s), higher velocities (∼100 km/s), are considerably taller (5-8 Mm) and rarely exhibit any recession (downfall) of material that is ejected upward. It has been demonstrated that both types of spicules undergo Alfvénic motion (De Pontieu et al. 2007b). However, in terms of chromosphere/transition region connectivity, there are several questions that are inadequately explained at present, but may be critical in understanding the interface of the cool and hot solar atmospheres: 1. What is the relationship between chromospheric spicules and the emitting transition region structures observed above the limb? 2. How are these spicules heated and to what temperature? 3. Is the transition region really composed of two physically different “components” and do these spicule types play a role? 4. What mechanism drives Type-II spicules? 5. Do the unresolved transverse and longitudinal motions of the spicules produce the observed non-thermal line widths? These are points we wish to address with the WHI joint observations and the detailed work is in its early stages. The present paper discusses some of the interesting preliminary analysis pertaining to points 1 and 2. High Altitude Observatory, National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307, USA Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304, USA