Anomalous Sea Level Rise in the Southeastern United States From 2011 To 2015

This study documents a recent sea-level rise acceleration in the southeastern United States and proposes possible causes for the change. Tide gauge data from the eastern seaboard of the United States show sea-level rise rates in the South Atlantic Bight that are ~6 to 9 times the eustatic rates in the period 2010-2015. This acceleration in sea-level rise followed a peak in the Mid-Atlantic Bight during 2009-2010, which has since plateaued. The recent acceleration of sea-level rise in the South Atlantic Bight is between 18 and 20 mm/yr, which makes it the greatest 5-year trend in that region since reliable records for these calculations began in 1920. The spatial structure associated with this sea-level rise change in the eastern United States (increase restricted to the South Atlantic Bight) resembles a structure in the mid-1940s. However, the causative factors for the accelerations in the 1940s and the 2010s appear to be unrelated. Potential drivers of the most recent sea-level change in the South Atlantic Bight seem to be a combination of declining Atlantic Meridional Overturning Circulation, Gulf Stream transport, Florida Current transport, and wind velocities, and increasing regional water temperatures. It is still unclear whether the anomalous upsurge in the South Atlantic Bight will continue or whether it is part of the intra-decadal and multi-decadal variability observed over the eastern coast of the United States during the last century.