Observation of a short-lived pattern in the solar chromosphere

In this work we investigate the dynamic behavior of inter-network regions of the solar chromosphere. We observed the chromosphere of the quiet Sun using a narrow-band Lyot filter centered at the Ca II K 2v emission peak with a bandpass of 0.3A. We achieved a spatial resolution of on average 0.7" at a cadence of 10s. In the inter-network we find a mesh-like pattern that features bright grains at the vertices. The pattern has a typical spatial scale of 1.95" and a mean evolution time scale of 53s with a standard deviation of 10s. A comparison of our results with a recent three-dimensional radiation hydrodynamical model implies that the observed pattern is of chromospheric origin. The measured time scales are not compatible with those of reversed granulation in the photosphere although the appearance is similar. A direct comparison between network and inter-network structure shows that their typical time scales differ by at least a factor of two. The existence of a rapidly evolving small-scale pattern in the inter-network regions supports the picture of the lower chromosphere as a highly dynamical and intermittent phenomenon.Comment: Letter A&A 4 pages 5 figure

Preface

Arnd Wedemeyer and Christoph F. E. Holzhey, ‘Preface’, in Re-: An Errant Glossary, ed. by Christoph F. E. Holzhey and Arnd Wedemeyer, Cultural Inquiry, 15 (Berlin: ICI Berlin Press, 2019), p. vii-xv <https://doi.org/10.25620/ci-15_01

Errans:Going Astray, Being Adrift, Coming to Nothing

Today’s critical discourses and theorizing vanguards agree on the importance of getting lost, of failure, of erring — as do life coaches and business gurus. The taste for a departure from progress and other teleologies, the fascination with disorder, unfocused modes of attention, or improvisational performances cut across wide swaths of scholarly and activist discourses, practices in the arts, but also in business, warfare, and politics. Yet often the laudible failures are only those that are redeemed by subsequent successes. What could it mean to think errancy beyond such restrictions? And what would a radical critique of productivity, success, and fixed determination look like that doesn’t collapse into the infamous ‘I would prefer not to’? This volume looks for an answer in the complicated word field branching and stretching from the Latin errāre. Its contributions explore the implications of embracing error, randomness, failure, non-teleological temporalities across different disciplines, discourses, and practices, with critical attention to the ambivalences such an impossible embrace generates.‘Submit Your References’: Introduction | ARND WEDEMEYER | 1–18The Punakawans Make an Untimely Appearance: In Praise of Caves, Shadows, and Fire (or A Response to Plato’s Doctrine of Truth) | PRECIOSA DE JOYA | 19–47The Animal That Laughs at Itself: False False Alarms about the End of ‘Man’ | JAMES BURTON | 49–74Not Yet: Duration as Detour in Emmanuelle Demoris’s Mafrouza Cycle | ROSA BAROTSI | 75–92Incomplete and Self-Dismantling Structures: The Built Space, the Text, the Body | ANTONIO CASTORE | 93–112Camera Fog; or, The Pendulum of Austerity in Contemporary Portugal | MARIA JOSÉ DE ABREU | 113–40Rinko Kawauchi: Imperfect Photographs | CLARA MASNATTA | 141–58Inbuilt Errans: What Is and Is Not ‘Radical Indifference’ | ZAIRONG XIANG | 159–75Errant Counterpublics: ‘Solidarność’ and the Politics of the Weak | EWA MAJEWSKA | 177–99‘The Exile from the Law’: Keeping and Transgressing the Limits in Jewish Law | FEDERICO DAL BO | 201–31Errans: Going Astray, Being Adrift, Coming to Nothing, ed. by Christoph F. E. Holzhey and Arnd Wedemeyer, Cultural Inquiry, 24 (Berlin: ICI Berlin Press, 2022) <https://doi.org/10.37050/ci-24

Weathering:Ecologies of Exposure

Weathering is atmospheric, geological, temporal, transformative. It implies exposure to the elements and processes of wearing down, disintegration, or accrued patina. Weathering can also denote the ways in which subjects and objects resist and pass through storms and adversity. This volume contemplates weathering across many fields and disciplines; its contributions examine various surfaces, environments, scales, temporalities, and vulnerabilities. What does it mean to weather or withstand? Who or what is able to pass through safely? What is lost or gained in the process

Re-:An Errant Glossary

What’s in a prefix? How to read a prefix as short as ‘re-’? Does ‘re-’ really signify? Can it point into a specific direction? Can it reverse? Can it become the shibboleth of a ‘postcritical’ reboot? At first glance transparent and directional, ‘re-’ complicates the linear and teleological models commonly accepted as structuring the relations between past, present, and future, opening onto errant temporalities

Morphology and Dynamics of the Low Solar Chromosphere

The Interferometric Bidimensional Spectrometer (IBIS) installed at the Dunn Solar Telescope of the NSO/SP is used to investigate the morphology and dynamics of the lower chromosphere and the virtually non-magnetic fluctosphere below. The study addresses in particular the structure of magnetic elements that extend into these layers. We choose different quiet Sun regions in and outside coronal holes. In inter-network regions with no significant magnetic flux contributions above the detection limit of IBIS, we find intensity structures with the characteristics of a shock wave pattern. The magnetic flux elements in the network are long lived and seem to resemble the spatially extended counterparts to the underlying photospheric magnetic elements. We suggest a modification to common methods to derive the line-of-sight magnetic field strength and explain some of the difficulties in deriving the magnetic field vector from observations of the fluctosphere.Comment: accepted by ApJ, 16 pages, 8 figure