Supporting data for figures in Freshwater composition and connectivity of the Connecticut River plume during ambient flood tides by Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. MacDonald, Kimberly D. Huguenard. The scientific journal article is published in Frontiers in Marine Science (2021). The main objectives of this study on the Connecticut River plume formed during ambient flood tidal conditions are: 1) determining the contributions of river source waters from different parts of the tidal cycle and 2) quantifying the degree and spatial distribution of connectivity of these source waters with the bounding plume fronts. A high-resolution numerical modeling approach is taken. Data are from the Regional Ocean Modeling System (RO...