COMPARISON OF MIXING PROPERTIES IN CONVECTION WITH THE PARTICLE-LINE METHOD

Spatial resolution in mixing processes is an acute problem. We propose a line method, akin to the contour dynamics technique, which is an ex tension of the particle method but with the particles redistributed on the line with time. We have used up to 10(5) particles per line and t en lines to investigate the dynamical and structural properties of mix ing for both Newtonian and non-Newtonian temperature-dependent viscosi ty convection in 2D geometry. The spatial structures and the time hist ory of the lines formed in Newtonian convection are different from tho se produced in non-Newtonian convection, which has the tendency for pr oducing long-living horizontal structures. Efficient mixing in the upp er mantle would be inhibited by non-Newtonian rheology.