River Mouth Mixing Visualization

During periods of heavy rain, rivers appear “dirty” because they carry large quantities of soil sediments. This change in the river water color provides a great opportunity to visualize the turbulent mixing that goes on at the river mouth, where the river meets the ocean. This type of mixing is commonly seen at a much smaller scale when one stirs milk into a black cup of coffee. Naturally occurring large scale turbulent mixing is not commonly seen in our everyday life. Here is a picture that I took over the pacific coast of Central America during the rainy season where one can visualize the mixing from a few different rivers as they meet the ocean.