Comparison of storm surges in eastern and western Louisiana lake estuaries

Coastal Louisiana experiences hurricane storm surges, mostly in summer, on an irregular inter-annual basis and winter storm surges on a quasi-regular seasonal basis every late fall to the following spring. Some of the important fish habitats in southern Louisiana are shallow lake estuaries with seasonally variable river discharges. They are surrounded by wetlands and with very limited connections with the coastal ocean through narrow channels (~ 100 m wide). The storm surge related flushing of these systems are of importance to the sediment transport, wetland and ecosystem health, and the surrounding community. In the present work, we present a comparison between two such semi-enclosed lake-estuarine systems, one in the west and one in the east of the southern Louisiana coast – the Calcasieu Lake Estuary and Lake Pontchartrain Estuary. Data for several storm surges have been collected by our team. These data are analyzed for both systems, focusing on the basin scale oscillation and flushing of the systems in response to the atmospheric forcing. We have applied a Weather Research Forecast (WRF) model to provide insight to how the atmospheric forcing evolves. Using the WRF model output as forcing, we applied a hydrodynamic model for the response of these lake estuaries. With the extensive data and model experiments, we are able to compare the storm surges and flushing of the two lake estuarine systems in the western and eastern Louisiana.