Research papersShelf edge reflection of atmospherically generated long ocean waves along the central U.S. East Coast

- Strong sea level oscillations have been observed along the central U.S. east coast.
- These waves are from atmospheric origin and amplified on the shelf.
- A time shift has been observed between the forcing and the sea peaks.
- The forced waves are reflected on the shelf edge and could explain the time shift.

This paper describes an investigation of unusual large-amplitude high­frequency sea level events (∼40-60 cm) observed during the period 2006-2012 along the central U.S. East Coast. These events occurred 2-3 h after offshore propagating atmospheric pressure disturbances crossed the coastline. The large amplitudes of the oscillations may be explained by Proudman resonance, as the average speed of the atmospheric pressure disturbances, estimated to be between 16 and 25 m/s, was similar to the shallow-water wave speed over the shelf, ∼15-20 m/s. The observed lag of 2-3 h of the events can be explained by shoreward-propagating free waves generated as the atmospheric-forced waves crossed the shelf edge. The estimated pathways of the forced and reflected free ocean waves seem to have been coherent and in good agreement with the lag observed at tide gauge stations.