Related papers: Coronal loop widths and pressure scale heights
In this paper we discuss recent progress in using the Camassa-Holm equations to model turbulent flows. The Camassa-Holm equations, given their special geometric and physical properties, appear particularly well suited for studying turbulent…
Blood pressure regulation is commonly addressed in terms of local mechanisms such as vascular resistance, compliance and neurohumoral control. However, the human vasculature encompasses multiple quasi-closed flow loops under both…
Suspensions of swimming particles exhibit complex collective behaviors driven by hydrodynamic interactions, showing persistent large-scale flows and long-range correlations. While heavily studied, it remains unclear how such structures…
Scalar mixing fronts develop at the interface of agitated fluids of different solute concentrations. In such fronts, scalar fluctuations form at both microscopic and macroscopic scales, due to stretching-enhanced molecular diffusion and…
We present numerical models from the field-aligned Hydrodynamics and Radiation Code (HYDRAD) of a highly asymmetric closed coronal loop with near-singular expansion factor. This loop was chosen to simulate a coronal magnetic flux tube that…
Spatial information from stellar X-ray coronae can be inferred by use of scaling laws from the solar corona. This requires measurement of the physical parameters temperature and density. We concentrate on the newly available density…
It is generally believed that sunspots are the emergent part of magnetic flux tubes in the solar interior. These tubes are created at the base of the convection zone and rise to the surface due to their magnetic buoyancy. The motion of…
The slip phenomena in thin polymer films confined by either flat or periodically corrugated surfaces are investigated by molecular dynamics and continuum simulations. For atomically flat surfaces and weak wall-fluid interactions, the shear…
Quasi-constant heating at the footpoints of loops leads to evaporation and condensation cycles of the plasma: thermal non-equilibrium (TNE). This phenomenon is believed to play a role in the formation of prominences and coronal rain.…
Observations of active regions and limb prominences often show cold, dense blobs descending with an acceleration smaller than that of free fall. The dynamics of these condensations falling in the solar corona is investigated in this paper…
The effect of the electron density stratification on the intensity profiles of the H I Ly-$\alpha$ line and the O VI and Mg X doublets formed in solar coronal holes is investigated. We employ an analytical 2-D model of the large scale…
There is evidence for coronal plasma flows to break down into fragments and to be laminar. We investigate this effect by modeling flows confined along magnetic channels. We consider a full MHD model of a solar atmosphere box with a dipole…
EUV observations of warm coronal loops suggest that they are bundles of unresolved strands that are heated impulsively to high temperatures by nanoflares. The plasma would then have the observed properties (e.g., excess density compared to…
This work focus on the first results on the identification and characterization of periodic plasma density fluctuations in the outer corona, observed in STEREO-A COR1 white-light image time series. A 2D reconstruction of the spatial…
Wind tunnel experiments were conducted to study the impact of atmospheric stratification on flow and dispersion within and over a regular array of rectangular buildings. Three stable and two convective incoming boundary layers were tested…
Observations reveal an increase with height of the line width of several coronal spectral lines probably caused by outwardly propagating Alfv{\'e}n waves. However, the spectral line width sometimes shows a sudden decrease at a height…
We present observations of the extended solar cycle activity in white-light coronagraphs, and compare them with the more familiar features seen in the Fe XIV green-line corona. We show that the coronal activity zones seen in the emission…
Recent observations revealed that the solar atmosphere is highly structured in density, temperature and magnetic field. The presence of these gradients may lead to the appearance of currents in the plasma, which in the weakly collisional…
Aims. Qualitative analysis of key (but yet unappreciated) linear phenomena in stratified hydrodynamic Keplerian flows: (i) the occurrence of a vortex mode, as a consequence of strato-rotational balance, with its transient dynamics; (ii) the…
We report a theory deriving bulk flow scaling for canonical wall-bounded flows. The theory accounts for the symmetries of boundary geometry (flat plate channel versus circular pipe) by a variational calculation for a large-scale energy…