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Abstract Caribbean through‐flow accounts for two‐thirds of the Florida Current and consequently is an important conduit of heat and salt fluxes in the upper limb of the Atlantic Meridional Overturning Circulation (AMOC). Considering there is evidence that up to one‐half of the Florida Current originates as South Atlantic Water (SAW), determining the distribution of SAW throughout the Caribbean Island passages is important as this constitutes the major pathway for cross‐equatorial AMOC return flow. The Anegada Passage (AP) is a major pathway for subtropical gyre inflow and suggested to be a potential SAW inflow pathway worth revisiting. Here, we present glider‐based observations of temperature, salinity and subsurface velocity that represent the first observations of any type in the AP in nearly 20 years. An isopycnal water mass analysis is conducted to quantify the transport of water masses with South Atlantic or North Atlantic origin. Two potentially new aspects of AP transport are revealed. The total AP transport (−4.8 Sv) is shown to be larger than previously estimated, potentially by up to a factor of two. The transport of SAW through the AP (−1.66 Sv) is also shown to be larger than previously estimated, which represents 35% of the total transport reported here and 28% of the SAW entering the Caribbean north of the Windward Island Passages. These results indicate the AP may be an important pathway for cross‐equatorial AMOC return flow. These results also provide evidence that gliders with acoustic doppler profilers are a viable method for measuring island passage transport.
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What can Hydrography Tell Us About the Strength of the Nordic Seas MOC Over the Last 70 to 100 Years?
Abstract The flow of warm water into the Nordic Seas plays an important role for the mild climate of central and northern Europe. Here we estimate the stability of this flow thanks to the extensive hydrographic record that dates back to the early 1900s. Using all casts in two areas with little mean flow just south and north of the Greenland‐Scotland Ridge that bracket the two main inflow branches, we find a well‐defined approximately ±0.5 Sv volume transport (and a corresponding ±30 TW heat flux) variation in synchrony with the Atlantic multidecadal variability that peaked most recently around 2010 and is now trending down. No evidence is found for a long‐term trend in transport over the last 70 to 100 years.
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- Award ID(s):
- 1658226
- PAR ID:
- 10366864
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 47
- Issue:
- 12
- ISSN:
- 0094-8276
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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