Search Publications

On the generation of solar spicules and Alfvénic waves

De Pontieu, B.; Martínez-Sykora, J.; Hansteen, V. H. +3 more

In the lower solar atmosphere, the chromosphere is permeated by jets known as spicules, in which plasma is propelled at speeds of 50 to 150 kilometers per second into the corona. The origin of the spicules is poorly understood, although they are expected to play a role in heating the million-degree corona and are associated with Alfvénic waves tha…

Prevalence of small-scale jets from the networks of the solar transition region and chromosphere

Weber, M.; Peter, H.; Golub, L. +24 more

As the interface between the Sun’s photosphere and corona, the chromosphere and transition region play a key role in the formation and acceleration of the solar wind. Observations from the Interface Region Imaging Spectrograph reveal the prevalence of intermittent small-scale jets with speeds of 80 to 250 kilometers per second from the narrow brig…

Hot explosions in the cool atmosphere of the Sun

Peter, H.; Golub, L.; Curdt, W. +20 more

The solar atmosphere was traditionally represented with a simple one-dimensional model. Over the past few decades, this paradigm shifted for the chromosphere and corona that constitute the outer atmosphere, which is now considered a dynamic structured envelope. Recent observations by the Interface Region Imaging Spectrograph (IRIS) reveal that it …

Evidence of nonthermal particles in coronal loops heated impulsively by nanoflares

Golub, L.; Tian, H.; De Pontieu, B. +21 more

The physical processes causing energy exchange between the Sun’s hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that is highly sensitive to the coronal heating mechanism. High-resolution observations with the Interface Region…

On the prevalence of small-scale twist in the solar chromosphere and transition region

Golub, L.; Tian, H.; De Pontieu, B. +21 more

The solar chromosphere and transition region (TR) form an interface between the Sun’s surface and its hot outer atmosphere. There, most of the nonthermal energy that powers the solar atmosphere is transformed into heat, although the detailed mechanism remains elusive. High-resolution (0.33-arc second) observations with NASA’s Interface Region Imag…

The unresolved fine structure resolved: IRIS observations of the solar transition region

Golub, L.; Tian, H.; De Pontieu, B. +18 more

The heating of the outer solar atmospheric layers, i.e., the transition region and corona, to high temperatures is a long-standing problem in solar (and stellar) physics. Solutions have been hampered by an incomplete understanding of the magnetically controlled structure of these regions. The high spatial and temporal resolution observations with …

Probing the solar interface region

De Pontieu, Bart; Carlsson, Mats; Title, Alan

Looking closer at the Sun

Harra, Louise K.