Likely weakening of the Florida Current during the past century revealed
by sea-level observations
- Christopher Piecuch
Abstract
The Florida Current marks the beginning of the Gulf Stream at Florida
Straits, and plays an important role in climate. Nearly continuous
measurements of Florida Current transport are available at 27N since
1982. These data are too short for assessing possible multidecadal or
centennial trends. Here I reconstruct Florida Current transport during
1909-2018 using probabilistic methods and principles of ocean physics
applied to the available transport data and longer coastal sea-level
records. Florida Current transport likely declined steadily during the
past century. Transport since 1982 has likely been weaker on average
than during 1909-1981. The weakest decadal-mean transport in the last
110 y likely took place in the past two decades. Results corroborate
hypotheses that the deep branch of the overturning circulation declined
over the recent past, and support relationships observed in climate
models between the overturning and surface western boundary current
transports at multidecadal and longer timescales.