We derive sufficient conditions for advection-driven backward motion of the free boundary in a chemotaxis model with degenerate mobility. In this model, a porous-medium-type diffusive term and an advection term are in competition. The former induces forward motion, the latter may induce backward motion of the free boundary depending on the direction of advection. We deduce conditions on the gro...

approved: John P. Bolte The WET-Temp (Watershed Evaluation Tool Temperature) model is designed to take advantage of spatially explicit datasets to predict stream temperature distribution. Datasets describing vegetation cover, stream network locations, elevation and stream discharge are utilized by WET-Temp to quantify geometric relationships between the sun, stream channel and riparian areas. T...

The advection equation is the basis for mathematical models of continuum mechanics. In the approximate solution of nonstationary problems it is necessary to inherit main properties of the conservatism and monotonicity of the solution. In this paper, the advection equation is written in the symmetric form, where the advection operator is the half-sum of advection operators in conservative (diver...

A new algorithm for volume tracking which is based on the concept of flux-corrected transport (FCT) is introduced. It is applicable to incompressible 2D flow simulations on finite volume and difference meshes. The method requires no explicit interface reconstruction, is direction-split and can be extended to 3D and orthogonal curvilinear meshes in a straightforward manner. A comparison of the n...

The usefulness of high order numerical schemes for treating the advection of momentum in the primitive equations is examined. It is shown that the use of high order advection schemes for themomentum advection can improve the dynamics of potential vorticity for length scales similar to the deformation radius. This is illustrated using numerical experiments in academic and realistic configuration...

Dye advection is an intuitive and versatile technique to visualize both steady and unsteady flow. Dye can be easily combined with noise-based vector field representations and is an important element in user-centric visual exploration processes. However, texture-based dye advection usually does not consider the convergence and divergence of flow to adapt the intensity of the dye color. In this p...

In the setting of energy efficient building operation, an optimal boundary control problem governed by a linear parabolic advection-diffusion equation is considered together with bilateral control and state constraints. To keep the temperature in a prescribed range with the less possible heating cost, an economic model predictive control (MPC) strategy is applied. To speed-up the MPC method, a ...

The K-profile parameterization of upperocean mixing is tested and extended using observations and large eddy simulations of upper-ocean response to a westerly windburst. A nonlocal momentum flux term is added, and the amplitude of the nonlocal scalar flux is recalibrated. Parameterizations of Stokes drift effects are added following recent work by McWilliams and Sullivan (2001). These changes a...

Correspondence to: I. G. Stevens Abstract. A fine-resolution primitive equation numerical model is constructed for the Iberian continental shelf and slope region, with open boundaries to the north, south and west. The model is forced by climatological wind fields and relaxed at the surface to climatological temperature and salinity fields. A series of numerical experiments is conducted to inves...