What Goes Up Doesnt Necessarily Come Down! - Connecting the Dynamics of the Chromosphere and Transition Region with TRACE, Hinode and SUMER

📝 Abstract

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.

💡 Analysis

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.

📄 Content

arXiv:0901.2814v2 [astro-ph.SR] 20 Mar 2009 FULL TITLE ASP Conference Series, Vol. VOLUME, YEAR OF PUBLICATION NAMES OF EDITORS What Goes Up Doesn’t Necessarily Come Down! - Connecting the Dynamics of the Chromosphere and Transition Region with TRACE, Hinode and SUMER Scott W. McIntosh1, Bart De Pontieu2 Abstract. 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 pro- gram. 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 op- portunity to study the coupling of cooler chromospheric material to transition region emission formed as hot as 600,000K. This short article provides prelimi- nary 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 p- modes 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 Alfv´enic motion (De Pontieu et al. 2007b). How- ever, in terms of chromosphere/transition region connectivity, there are several questions that are inadequately explained at present, but may be critical in un- derstanding the interface of the cool and hot solar atmospheres:

1. What is the relationship between chromospheric spicules and the emit- ting 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 “com- ponents” 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. 1High Altitude Observatory, National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307, USA 2Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304, USA 1 2 McIntosh & De Pontieu 16:02:14 16:03:44 16:05:14 16:06:44 16:08:13 16:09:43 16:11:15 16:12:46 16:14:18 16:15:49 −1.0 −0.2 0.6 1.4 2.2 3.0 Log10 Intensity N IV 764Å 16:02:14 16:03:44 16:05:14 16:06:44 16:08:13 16:09:43 16:11:15 16:12:46 16:14:18 16:15:49 −1.0 −0.2 0.6 1.4 2.2 3.0 Log10 Intensity O VI 786Å 16:02:14 16:03:44 16:05:14 16:06:44 16:08:13 16:09:43 16:11:15 16:12:46 16:14:18 16:15:49 −1.0 −0.2 0.6 1.4 2.2 3.0 Log10 Intensity Ne VIII 770Å Figure 1. Left: Comparison of the Hinode Ca II H and TRACE 1600˚A passband images at 16:11UT in a 60′′×60′′ FOV centered on the middle por- tion of the SUMER slit (vertical dashed white line). This is the point in the image sequence where the macro-spicule is at its maximum extension. Right: Comparing consecutive SUMER spectral snapshots of N IV 764˚A (bottom), O VI 786˚A (middle) and Ne VIII 770˚A (top) emission lines over the duration of the macro-spicule eruption (ellipse) with a reversed intensity scale. The horizontal dashed line denotes the position of the SUMER continuum limb.

WHI JOP 204: Characterizing the Quiet Sun The purpose of WHI JOP2041 was to characterize the behavior of the Quiet Sun; aiming to build a better picture of the relationship between chromospheric dy- namic spicules, their extension into the transition region and (possibly) corona. In essence we hope to fully assess the role of magneto-convective driving mass and energy from the lower atmosphere into the quiet corona or solar wind. JOP 204 Observations took place between April 10th through April 16th, 2008 involving a host of observatories on the ground (NSO) and in space (SOHO, TRACE, Hinode, STEREO). We will discuss the preliminary analysis of data from Hinode/SOT, TRACE and SOHO/SUMER (Wilhelm et al. 1995) on April 12th 2008 on the South-West limb that ran from 14:00 - 17:00UT. The correspondence between above-the-limb structure in Hinode/SOT Ca II H and TRACE 1600˚A passband image sequences is striking - noting that the 1600˚A passband is dominated by 1548 and 1550˚A emission lines of C IV there. Im- mediately, we see that while the emission observed in Ca II is considerably finer

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