Convective mixing in porous media is triggered by a Rayleigh-Bénard-type hydrodynamic instability as a result of an unstable density stratification of fluids. While convective mixing has been studied extensively, the fundamental behavior of the dissolution flux and its dependence on the system parameters are not yet well understood. Here, we show that the dissolution flux and the rate of fluid ...

Using the MST radar data of vertical wind, the characteristics of the tropical tropopause, following four different definitions, depending on 1) temperature lapse rate, 2) cold point, 3) convective outflow and 4) potential temperature lapse rate minimum, are studied. From the vertical wind data of the radar, the altitude profiles of temperature and horizontal divergence are derived, from which ...

Intense precipitation events are often convective in nature. A deeper understanding of the properties and the dynamics of convective rain cells is, therefore, necessary both from a physical and operational point of view. The aim of this work is to study the spatial-temporal properties of convective rain cells by using a fully parameterized nonhydrostatic code (Lokal Model) in simplified model c...

A statistical convective adjustment scheme is proposed that attempts to account for the effects of mesoscale and submesoscale variability of temperature and salinity typically observed in the oceanic convective regions. Temperature and salinity in each model grid box are defined in terms of their mean, variance, and mutual correlations. Subgrid-scale instabilities lead to partial mixing between...

We study initial boundary value problems for the convective Cahn-Hilliard equation ∂tu+ ∂ 4 xu+ u∂xu+ ∂ 2 x(|u| u) = 0. It is well-known that without the convective term, the solutions of this equation may blow up in finite time for any p > 0. In contrast to that, we show that the presence of the convective term u∂xu in the Cahn-Hilliard equation prevents blow up at least for 0 < p < 4 9 . We a...

This study documents the preferred location and diurnal cycle of extreme convective storms that occur in the tropical band containing the east Pacific Ocean, Central and South America, the Atlantic Ocean, and northern Africa. Data from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar show three types of convective-stratiform structures that constitute extreme convective events...

Interactions between soil moisture and the atmosphere are driven by the partitioning of sensible and latent heating, through which soil moisture has been connected to atmospheric modifications that could potentially lead to the initiation of convective precipitation. The majority of previous studies linking the land surface to subsequent precipitation have used atmospheric reanalysis or model d...

We describe the results of three-dimensional (3D) numerical simulations designed to study turbulent convection in the stellar interiors, and compare them to stellar mixing-length theory (MLT). Simulations in 2D are significantly different from 3D, both in terms of flow morphology and velocity amplitude. Convective mixing regions are better predicted using a dynamic boundary condition based on t...

This study identifies the precursor signals of convective initiation within sequences of 1-km-resolution visible (VIS) and 4–8-km infrared (IR) imagery from the Geostationary Operational Environmental Satellite (GOES) instrument. Convective initiation (CI) is defined for this study as the first detection of Weather Surveillance Radar-1988 Doppler (WSR-88D) reflectivities 35 dBZ produced by conv...

A temporally resolved flow visualization system that produces 17 flow images over a time span of 128 microseconds is used to visualize the mixing layers of a Mach 1.28 (M c =0.59) and a Mach 2.06 (M c =0.87) ideally expanded high Reynolds number axisymmetric jets. These image sequences revealed details about the effects of compressibility on the dynamics of turbulence structures. In general, th...