相关论文: Zonal Jets as Transport Barriers in Planetary Atmo…
Surface buoyancy gradients over a quasigeostrophic fluid permit the existence of surface-trapped Rossby waves. The interplay of these Rossby waves with surface quasigeostrophic turbulence results in latitudinally inhomogeneous mixing that,…
We present an idealized study of the baroclinic structure of a rotating, stratified throughflow across a finite amplitude ridge in the f-plane that is forced by a steady, uniform inflow and outflow of equal magnitude. The resulting…
It remains puzzling why, despite their similar nature, Jupiter and Saturn possess a prograde equatorial jet, whereas Uranus and Neptune have a retrograde one. To understand this discrepancy, we use a two-dimensional quasi-geostrophic model…
Solar jets, characterized by small-scale plasma ejections along open magnetic field lines or the legs of large-scale coronal loops, play a crucial role in the dynamics of the solar atmosphere. Although spectral and EUV images have been…
Modelling of deep VLA images of the jets in FR I radio galaxies has allowed us to derive their three-dimensional distributions of velocity, emissivity and magnetic-field structure on kiloparsec scales. By combining our models of jet…
We show that transport in the presence of entropic barriers exhibits peculiar characteristics which makes it distinctly different from that occurring through energy barriers. The constrained dynamics yields a scaling regime for the particle…
Coronal jets are transient, collimated eruptions that occur in regions of predominantly open magnetic field in the solar corona. Our understanding of these events has greatly evolved in recent years but several open questions, such as the…
The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet's rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation…
The study of exoplanet atmospheres showed large diversity compared to the planets in our solar system. Especially Jupiter type exoplanets orbiting their host star in close orbits, the so-called hot and ultra-hot Jupiters, have been studied…
We classify within the quasi-geostrophic framework all types of traveling waves in zonal bands of the planetary atmosphere at cloud level according to their wave speeds. This classification pertains to waves of all amplitudes, going beyond…
The vortex dynamics resulting from the interaction of synthetic jets with turbulent boundary layers was investigated experimentally using stereoscopic particle image velocimetry (SPIV). Three aspect ratio 18 rectangular orifice geometries…
We explain the emergence and robustness of intense jets in highly turbulent planetary atmospheres, like on Jupiter, by a general approach of statistical mechanics of potential vorticity patches. The idea is that potential vorticity mixing…
Small-scale jet-like eruptions, such as picoflare jets and jetlets, are recognized as potential contributors to coronal heating and solar wind acceleration, yet their physical origin is still not fully established. Using…
We are developing a project aimed at studying the physical properties, origin and evolution of low-ionization structures in planetary nebulae. Within this project we have identified a number of pairs of highly collimated low-ionization…
Coronal jets and bright points occur prolifically in predominantly unipolar magnetic regions, such as coronal holes, where they appear above minority-polarity intrusions. Intermittent low-level reconnection and explosive,…
We present an alternative model for the formation of fast low-ionization emission regions (FLIERs) in planetary nebulae that is able to account for many of their attendant characteristics and circumvent the problems on the…
Evidence is beginning to be put forward that demonstrates the role of the chromosphere in supplying energy and mass to the corona. We aim to assess the role of chromospheric jets in active region dynamics. Using a combination of the…
Venus' atmosphere shows highly variable warm vortices over both of the planet's poles. The nature of the mechanism behind their formation and properties is still unknown. Potential vorticity is a conserved quantity when advective processes…
Coronal jets are collimated, dynamic events that occur over a broad range of spatial scales in the solar corona. In the open magnetic field of coronal holes, jets form quasi-radial spires that can extend far out into the heliosphere, while…
High velocity jets are among the most prominent features of a wide class of planetary nebulae, but their origins are not understood. Several different types of physical model have been suggested to power the jets, but there is no consensus…