  To test a hypothesized faster-than-global sea-level acceleration along the
mid-Atlantic United States, I construct a Gaussian process model that
decomposes tide gauge data into short-term variability and longer-term trends,
and into globally-coherent, regionally-coherent and local components. While
tide gauge records indicate a faster-than-global increase in the rate of
mid-Atlantic U.S. sea-level rise beginning ~1975, this acceleration could
reflect either the start of a long-term trend or ocean dynamic variability. The
acceleration will need to continue for ~2 decades before the rate of increase
of the sea-level gradient between the mid-Atlantic and southeastern U.S. can be
judged as very likely unprecedented by 20th century standards. However, the
gradient is correlated with the Atlantic Multidecadal Oscillation, North
Atlantic Oscillation, and Gulf Stream North Wall indices, all of which are
currently within the range of past variability.
