Search Publications
Observation and modelling of solar jets
Shen, Yuandeng
The solar atmosphere is full of complicated transients manifesting the reconfiguration of the solar magnetic field and plasma. Solar jets represent collimated, beam-like plasma ejections; they are ubiquitous in the solar atmosphere and important for our understanding of solar activities at different scales, the magnetic reconnection process, parti…
Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)
Andretta, Vincenzo; Ayres, Thomas R.; Liu, Wei +87 more
The National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST) will revolutionize our ability to measure, understand, and model the basic physical processes that control the structure and dynamics of the Sun and its atmosphere. The first-light DKIST images, released publicly on 29 January 2020, only hint at the extraordinary capabiliti…
Reconnection nanojets in the solar corona
Antolin, Patrick; Pagano, Paolo; Testa, Paola +2 more
The solar corona is shaped and mysteriously heated to millions of degrees by the Sun's magnetic field. It has long been hypothesized that the heating results from a myriad of tiny magnetic energy outbursts called nanoflares, driven by the fundamental process of magnetic reconnection. Misaligned magnetic field lines can break and reconnect, produci…
Magnetohydrodynamic Waves in Open Coronal Structures
Tian, H.; Wang, T. J.; Banerjee, D. +8 more
Modern observatories have revealed the ubiquitous presence of magnetohydrodynamic waves in the solar corona. The propagating waves (in contrast to the standing waves) are usually originated in the lower solar atmosphere which makes them particularly relevant to coronal heating. Furthermore, open coronal structures are believed to be the source reg…
A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS)
Reeves, Katharine K.; Polito, Vanessa; Liu, Wei +11 more
The Interface Region Imaging Spectrograph (IRIS) has been obtaining near- and far-ultraviolet images and spectra of the solar atmosphere since July 2013. IRIS is the highest resolution observatory to provide seamless coverage of spectra and images from the photosphere into the low corona. The unique combination of near- and far-ultraviolet spectra…
Mapping solar magnetic fields from the photosphere to the base of the corona
Hara, Hirohisa; De Pontieu, Bart; Carlsson, Mats +25 more
Routine ultraviolet imaging of the Sun's upper atmosphere shows the spectacular manifestation of solar activity; yet we remain blind to its main driver, the magnetic field. Here we report unprecedented spectropolarimetric observations of an active region plage and its surrounding enhanced network, showing circular polarization in ultraviolet (Mg I…
Upflows in the Upper Solar Atmosphere
Tian, Hui; Brooks, David H.; Baker, Deborah +2 more
Spectroscopic observations at extreme- and far-ultraviolet wavelengths have revealed systematic upflows in the solar transition region and corona. These upflows are best seen in the network structures of the quiet Sun and coronal holes, boundaries of active regions, and dimming regions associated with coronal mass ejections. They have been intensi…
Chromospheric Heating by Magnetohydrodynamic Waves and Instabilities
Srivastava, A. K.; Murawski, K.; Cally, P. S. +7 more
The importance of the chromosphere in the mass and energy transport within the solar atmosphere is now widely recognized. This review discusses the physics of magnetohydrodynamic waves and instabilities in large-scale chromospheric structures as well as in magnetic flux tubes. We highlight a number of key observational aspects that have helped our…
Extreme-ultraviolet bursts and nanoflares in the quiet-Sun transition region and corona
Peter, H.; Chitta, L. P.; Young, P. R.
The quiet solar corona consists of myriads of loop-like features, with magnetic fields originating from network and internetwork regions on the solar surface. The continuous interaction between these different magnetic patches leads to transient brightenings or bursts that might contribute to the heating of the solar atmosphere. The literature on …
The origin of reconnection-mediated transient brightenings in the solar transition region
Winebarger, Amy R.; Bahauddin, Shah Mohammad; Bradshaw, Stephen J.
The ultraviolet emission from the solar transition region is dominated by dynamic, low-lying magnetic loops. The enhanced spatial and temporal resolution of the solar observation satellite Interface Region Imaging Spectrograph (IRIS) has made it possible to study these structures in fine detail. IRIS has observed `transient brightenings' in these …