Seminar: Dr. Arnoldo Valle-Levinson, UFL

UNC Marine Sciences’ Professor and Department Chairman Harvey Seim hosts a seminar presented by Arnoldo Valle-Levinson, Ph.D.

Seminar Title: Sea-level rise hot spots along the U.S. Atlantic coast

Presenter Affiliation: University of Florida, Civil and Coastal Engineering Department

Summary: Sea-level rise (SLR) accelerated in a “hot spot” along the north of Cape Hatteras over the past several decades, including an abrupt rise of ~13 cm in 2009-2010.  This regional acceleration in SLR has been attributed to weakening in Atlantic Meridional Overturning Circulation (AMOC), although this causal link remains debated.  I will talk about a striking shift in the pattern of SLR along the U.S. Atlantic coast during 2011-2015, whereby SLR decelerated north of Cape Hatteras and accelerated south of the Cape to >20 mm/yr, despite continued decline in AMOC strength. Tide-gauge records, 95-yr long, show that similar SLR intervals have occurred repeatedly over ~1500-km stretches of coastline.  These records reveal that hot spots of SLR have migrated northward since the 1940s and suggest that the reappearance of the hot spot in the southeastern U.S. may represent a re-initiation of a ~65-year cycle. Causes for this variability are likely associated with ENSO and NAO. The regional expression of SLR hot spots documented here is a key factor in determining coastal vulnerability in the context of continued global mean sea-level rise and should be captured in global climate models of regional sea-level change.