Sea level fluctuation induced by winds on the continental shelf

Overview An REU student from Georgia Institute of Technology did a project with J. Blanton to examine the effect of wind velocity on residual water levels in the Altamaha and Sapelo estuaries. The data were obtained from the GCE-LTER monitoring network. Cross-correlation analyses were performed using the network's low-passed sub-surface pressure data together with low-passed wind velocities from the Grays Reef buoy, located offshore of the GCE- LTER site. Alongshore winds were found to correlate 10 to 30 percent higher than cross-shore winds. Residual water levels at stations closest to the ocean produced higher rates of correlation for long-shore winds when lagging water level 12 to 15 hours. Stations located upriver showed higher rates of correlation than stations closest to the ocean for long-shore winds when lagging water level 12 to 21 hours. The study indicates that wind stress causes water levels to rise as much as 60 centimeters and fall as much as 55 centimeters in a span of one to two days. When these "subtidal" fluctuations occur at spring tide, intertidal areas are subjected to larger than normal periods of inundation and drying.

Associated GCE LTER research questions Question 2: How do the spatial and temporal patterns of biogeochemical processes, primary production, community dynamics, decomposition, and disturbance vary across the estuarine landscape, and how do they relate to environmental gradients? (more information)