Maximum Daily Salinity on the Lower Connecticut River, 2011-2021

Timeseries plots of maximum daily salinity on the lower Connecticut River 2011-2021 for an upstream site on the river and a downstream site in the estuary. The timeseries chart uses tiles to show annual patterns in salinity compared across 10 years. At the upstream site, Essex CT (01194750), freshwater dominates the beginning of the year up until May, with some moments of low salinity levels (oligohaline). Starting in June, the upstream site increases in salinity, with moderate salinity levels (mesohaline) through November. At the downstream site, salinity levels are high (polyhaline) for the majority of the year, with short periods of freshwater during April. This reflects the timing of snowmelt and increased streamflow. Across years, the upstream site appears to be getting saltier earlier. There is no obvious trend across years at the downstream site. A map indicates that the two sites are relatively close (~6 km apart) in the Long Island Sound and surrounded by tidal marshes that require certain levels of salinity.