Mathematical Biology Seminar Courtenay Strong University of Utah, Department of Atmospheric Sciences Wednesday Nov. 9th, 2011 3:05pm in LCB 225 "The width of things non-convex: an application of Laplace's equation" Abstract: Many objects in nature are non-convex, meaning that lines connecting two points in the object are not always contained in the object. For such non-convex objects, an objective width can be defined based on a two-dimensional or three-dimensional solution to Laplace's equation inside the object. The solution to Laplace's equation represents a potential, and width can be measured along curves orthogonal to the isolines or isosurfaces of that potential (i.e., along "field lines"). The method has been used in medical imaging to measure the width of human organs. Here, the method is applied to satellite-based sea ice data to uncover trends and variability in the width of the Arctic marginal ice zone - a biologically active region where intense atmosphere-ice-ocean interactions broadly impact climate.