By analysing three-dimensional flow patterns in models of layered anisotropic aquifers, we found that streamlines often have the shape of spirals. A bundle of such spiralling streamlines was termed a “groundwater whirl”. Experiments include aquifers in which all layers have a laterally heterogeneous anisotropy. In box-shaped aquifers with horizontal layers and a uniform horizontal gradient alon...

We present a geometric framework for aligning white matter fiber tracts. By registering tracts between brains, one expects to see overlap of anatomical structures that often provide meaningful comparisons across subjects. However, the geometry is highly heterogeneous, and finding direct tract-correspondence multiple individuals remains challenging problem. novel deformation metric allows compar...

In the following, we prove new regularity results for two-dimensional steady periodic capillary water waves with vorticity, in the absence of stagnation points. Firstly, we prove that if the vorticity function has a Hölder-continuous first derivative, then the free surface is a smooth curve and the streamlines beneath the surface will be real analytic. Furthermore, once we assume that the vor...

Potential vorticity (PV) is used as an indicator of the forcing processes and dissipation at work in the Southern Ocean. Output from the Semtner–Chervin model run with quarter-degree resolution is considered on isopycnal surfaces along Montgomery streamfunctions. Numerical results are compared with hydrographic measurements. Although simple hypotheses might suggest that subsurface PV should be ...