Modeling Diffusion as a Result of Observing Salinity, Water Temperature and Mixing of the Norwalk River into Long Island Sound

This project investigates the space and time variability of salinity and temperature in the lower Norwalk River using a one-dimensional numerical model. The project uses surface measurements taken at two locations, one at the Norwalk Maritime Museum (NMM) and the other at the mouth of the river as it drains into the Norwalk Islands region adjacent to Long Island Sound (LIS).

The model covers a relatively small distance of 1-2km. The size of the upriver neck and the first buoy is approximately five times smaller than the mouth between the second buoy site and Peach Island.

The instrumentation will be responsible for generally characterizing the thermal physics occurring at the river-ocean environment. A one-dimensional advection-diffusion model will be used to simulate results. The data points will measure the salinity, water temperature, and pressure during a series of deployments in the river during a three-season period between 2013 and 2014. Further processes will ultimately show the overall advection occurring in the river.

The upriver site is maintained by the Norwalk River Museum. A YSI XXX attached to a tether buoy is used to measure salinity and temperature at the surface.

Preliminary results suggest typical temperature range at the upriver site is greater than at the mouth of the Norwalk River, and the daily peak temperature lag depends upon several factors, such as tidal state. The phenomenon of a salt wedge will also be considered.