Numerical Computations of Advective and Diffusive Transports of Chloride in Lake Erie, 1970

This paper is concerned with a numerical simulation of lakewide advective and diffusive transports of conservative pollutants or nutrients, such as chloride, in Lake Erie. The study is a continuation of a hydrodynamic modeling experiment to compute water circulations throughout the 1970 shipping season, also in this issue, and makes use of ship observations of chloride distributions at approximately 4-wk intervals during 1970, together with estimates of river loadings for the same periods.The model equations are based on the time-dependent, mass-conserving advection–diffusion equation. A vertically mixed, one-layer, two-dimensional model is employed for spring and fall, whereas a two-layer model is used to simulate the stratified lake in summer. The equations are solved by finite-difference formulations on a horizontal grid with a mesh size of 6.67 km. Using time steps of 6 h, predictions are made of the change of chloride concentrations between pairs of cruises and the results are compared with observati...