1. Dr. Martin T. Auer MTU Department of Civil & Environmental Engineering ENVE5504 Surface Water Quality Modeling Lab 4. Mass Transport

2. 8 Lake Superior – 4/28/00 Completely-Mixed Lake: Lake Superior

3. Distributed System: Lake Minnetonka

4. Saginaw Bay Lake Huron 8 8 Horizontal Resolution: Saginaw Bay and Lake Huron

5. 8 8 Lake Superior – 8/25/00 Vertical Resolution – Lake Superior

6. Advection and Diffusion

7. Diffusion Diffusion is mediated by the magnitude of the diffusion coefficient and the concentration gradient. How do we express this mathematically?

8. Scales of Diffusion Molecular diffusion is the net transport of molecules from a region of higher concentration to one of lower concentration by random molecular motion. Eddy or turbulent diffusion is a diffusive process by which substances are mixed due to eddy motion. Eddys range broadly in size and energy and thus also does the turbulent diffusion coefficient.

9. Mathematics of Diffusion Fick’s 1 st Law E E Diffusion Mass Balance

10. Mathematics of Diffusion X-direction E C