Tropical deep convection exhibits complex organization over a wide range of scales. This study investigates the relationships between the spatial organization of deep convection and the large-scale atmospheric state. By using several satellite datasets and reanalyses, and by defining a simple diagnostic of convective aggregation, relationships between the degree of convective aggregation and th...

According to conventional view, sunspots form when coherent magnetic flux tubes intersect the surface. Such tubes would rise from the bottom of the convection zone as a result of an instability. In this study an alternative view is advanced where the field is produced throughout the entire convection zone and sunspots may form from local flux concentrations near the surface. In order to underst...

We report on measurements of a two-dimensional (2D) dye concentration field in turbulent Rayleigh–Bénard (RB) convection using the planar laser-induced fluorescence technique. The measurements were made in a vertical plane near the sidewall of a rectangular convection cell filled with water and with the Rayleigh number Ra varying from 109 to 1010, all at a fixed Prandtl number Pr = 5.3 and Schm...

Gravity or buoyancy plays an important role in atmospheric and geophysical flows. The flow is destabilized when heavier or colder fluid is on top of a lighter or hotter fluid, often seen in thermal convection (Fig 1(a)). Convection plays an important role in interiors of many planets and stars, and it is one of the mechanisms for the generation of a magnetic field. Conversely, the flow is stabi...

In the last decades it has been recognized that the very high Rayleigh number convective boundary layer (CBL) has more complex nature than might be reckoned. Besides the fully organized component naturally considered as the mean flow and the chaotic small-scale turbulent fluctuations, one more type of motion has been discovered, namely, long-lived large-scale structures, which are neither turbu...

This paper reports an application of gas-kinetic BGK scheme to the computation of turbulent compressible convection in the stellar interior. After incorporating the Subgrid Scale (SGS) turbulence model into the BGK scheme, we tested the effects of numerical parameters on the quantitative relationships among the thermodynamic variables, their fluctuations and correlations in a very deep, initial...