Effects of Northeaster Storms on Water Level and Turbidity in a Delaware Bay Subestuary.

International audienceCoastal storms have a major influence on the ecology and geomorphology of U.S. Atlantic estuaries and tidal marshes. The purpose of this study was to determine which types of storms are most effective in flooding the marsh platform with high-turbidity water, a condition conducive for sedimentation. Eleven years (2000-10) of continuous water level and turbidity data for the St. Jones River National Estuarine Research Reserve, a subestuary of Delaware Bay, were analyzed and compared to weather events registered in the National Climate Data Center Storm Events Database. Statistically significant water-level and turbidity reference values were established and used to identify storm-produced events in the data records. Results indicate that northeasters were responsible for most (41%) of all concurrent water-level and turbidity events; other types of weather conditions, including continental lows, northern highs, and frontal storms, produced mostly isolated water level and turbidity peaks. Northeasters coincident with a high-pressure system over the north Atlantic consistently produced the highest water levels and surges, but northeaster intensity was not strongly correlated with surge height. A particular combination of remote wind forcing, intense rainfall, and river runoff distinguishes northeasters among other types of coastal storms in generating flooding events of significance to marsh sedimentation in the St. Jones estuary and, by extension, other subestuaries of Delaware Ba