Related papers: On the variation of solar coronal rotation using S…
Context. The corona of the Sun is the part of the solar atmosphere with temperatures of over one million Kelvin, which needs to be heated internally in order to exist. This heating mechanism remains a mystery; we see large magnetically…
The recent analysis of observations taken with the EIS instrument on Hinode suggests that well constrained measurements of the temperature distribution in solar active regions can finally be made. Such measurements are critical for…
We measure differential rotation and meridional flow in the Sun's surface shear layer by tracking the motions of the magnetic network seen in magnetograms from SOHO/MDI and SDO/HMI over solar cycles 23, 24, and the start of 25 (1996-2022).…
We review solar studies using AIA, HMI, and EVE data from the SDO spacecraft that revolutionized our physical understanding of the Sun. The relevant SDO studies cover the entire 15-year lifetime of SDO, from 2010 May 1 to 2025 May 1. The…
Solar jets are an important field of study, as they may contribute to the mass and energy transfer from the lower to the upper atmosphere. We use the Interface Region Imaging Spectrograph (IRIS) and Solar Dynamic Observatory (SDO)…
A detailed study is presented of the decaying solar active region NOAA 10103 observed with the Coronal Diagnostic Spectrometer (CDS), the Michelson Doppler Imager (MDI) and the Extreme-ultraviolet Imaging Telescope (EIT) onboard the Solar…
The heating of coronal loops is investigated to understand the observational consequences in terms of the thermodynamics and radiative losses from the Sun as well as the magnetized coronae of stars with an outer convective envelope. The…
The dynamics of regions of the solar corona are investigated using Atmospheric Imaging Assembly (AIA) 171\AA\ and 193\AA\ data. The coronal emission from the quiet Sun, coronal loop footprints, coronal moss, and from above a sunspot is…
In a previous paper, I described a new way of determining the high-latitude solar rotation rate statistically from space-time maps of polar faculae observed in the 6767 \r{A} continuum by the Michelson Doppler Interferometer (MDI) on the…
A coronal loop of 290~Mm length, observed at 171~\AA\ with SDO/AIA on February 6th 2024 near AR 13571, is found to oscillate with two significantly different oscillation periods, $48.8 \pm 6.1$~min and $4.8\pm 0.3$~min. The oscillations…
Employing Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) multi-wavelength images, we report the coronal condensation during the magnetic reconnection (MR) between a system of open and closed coronal loops. Higher-lying…
Above the top of the solar corona, the young slow solar wind transitions from low-beta, magnetically structured flow dominated by radial structures, to high-beta, less structured flow dominated by hydrodynamics. This transition, long…
We present observations of high temperature emission in the core of a solar active region using instruments on Hinode and SDO. These multi-instrument observations allow us to determine the distribution of plasma temperatures and follow the…
Chromospheric differential rotation is a key component in comprehending the atmospheric coupling between the chromosphere and the photosphere at different phases of the solar cycle. In this study, we therefore utilize the newly calibrated…
A well known behavior of EUV light curves of discrete coronal loops is that the peak intensities of cooler channels or spectral lines are reached at progressively later times than hotter channels. This time lag is understood to be the…
The theoretical expectation that coronal loops should expand with height contrasts with observations that typically show constant cross-sections. We investigate the idea that this discrepancy results from loops being composed of fine…
Available helioseismic data now span almost the entire solar activity cycle 23 making it possible to study solar-cycle related changes of the solar rotation rate in detail. In this paper we study how the solar rotation rate, in particular,…
The variation with time from 1956-2002 of the globally averaged rate of ionization produced by cosmic rays in the atmosphere is deduced and shown to have a cyclic component of period roughly twice the 11 year solar cycle period. Long term…
Longitudinal intensity oscillations along coronal loops that are interpreted as signatures of magneto-acoustic waves are observed frequently in different coronal structures. The aim of this paper is to estimate the physical parameters of…
The Atmospheric Imaging Assembly (AIA) telescope on board the Solar Dynamics Observatory (SDO) provides coronal EUV imaging over a broader temperature sensitivity range than the previous generations of instruments (EUVI, EIT, and TRACE).…