TY - JOUR
T1 - Structure and Variability of the Antilles Current at 26.5°N
AU - Meinen, Christopher S.
AU - Johns, William E.
AU - Moat, Ben I.
AU - Smith, Ryan H.
AU - Johns, Elizabeth M.
AU - Rayner, Darren
AU - Frajka-Williams, Eleanor
AU - Garcia, Rigoberto F.
AU - Garzoli, Silvia L.
N1 - Funding Information:
The authors would like to express their appreciation to the ship captains and crews of the R/Vs Endeavor, Seward Johnson, Cape Hatteras, Knorr, Oceanus, and Atlantic Explorer, as well as the NOAA Ship Ronald H. Brown and the NERC Ships RRS Discovery (1962), RRS James Cook, and RRS Discovery (2013) for their outstanding support of the observational field program. The PIES array, and the collection of CTD-O2, LADCP, and SADCP data along the array, has been supported by the U.S. NOAA Climate Program Office?Ocean Observing and Monitoring Division via the Western Boundary Time Series (WBTS) project (FundRef 100007298) and by the U.S. NOAA Atlantic Oceanographic and Meteorological Laboratory. The tall moorings (current meter, MicroCAT, and moored ADCP) and the BPR are/have been jointly funded by the U.K. Natural Environment Research Council via the RAPID, RAPID-WATCH, and RAPID AMOC programmes and the U.S. National Science Foundation via the Meridional Overturning Circulation Heat-flux Array project (grants 0728108 and 1332978). C. M., R. S., R. G., E. J., and S. G. received some support from the WBTS project and/or from the NOAA Atlantic Oceanographic and Meteorological Laboratory for this work. R. G. and S. G. also were supported in part under the auspices of the Cooperative Institute for Marine and Atmospheric Studies (CIMAS), a cooperative institute of the University of Miami and NOAA, cooperative agreement NA10OAR4320143. Renellys Perez, Marion Kersal?, David Smeed, Denis Volkov, Josep Pelegr?, and an anonymous reviewer provided several suggestions that were helpful for this analysis and/or for preparing this manuscript.
Funding Information:
The authors would like to express their appreciation to the ship captains and crews of the R/Vs Endeavor, Seward Johnson, Cape Hatteras, Knorr, Oceanus, and Atlantic Explorer, as well as the NOAA Ship Ronald H. Brown and the NERC Ships RRS Discovery (1962), RRS James Cook, and RRS Discovery (2013) for their outstanding support of the observational field program. The PIES array, and the collection of CTD‐ O2, LADCP, and SADCP data along the array, has been supported by the U.S. NOAA Climate Program Office— Ocean Observing and Monitoring Division via the Western Boundary Time Series (WBTS) project (FundRef 100007298) and by the U.S. NOAA Atlantic Oceanographic and Meteorological Laboratory. The tall moorings (current meter, MicroCAT, and moored ADCP) and the BPR are/have been jointly funded by the U.K. Natural Environment Research Council via the RAPID, RAPID‐ WATCH, and RAPID AMOC programmes and the U.S. National Science Foundation via the Meridional Overturning Circulation Heat‐flux Array project (grants 0728108 and 1332978). C. M., R. S., R. G., E. J., and S. G. received some support from the WBTS project and/or from the NOAA Atlantic Oceanographic and Meteorological Laboratory for this work. R. G. and S. G. also were supported in part under the auspices of the Cooperative Institute for Marine and Atmospheric Studies (CIMAS), a cooperative institute of the University of Miami and NOAA, cooperative agreement NA10OAR4320143. Renellys Perez, Marion Kersalé, David Smeed, Denis Volkov, Josep Pelegrí, and an anonymous reviewer provided several suggestions that were helpful for this analysis and/or for preparing this manuscript.
Funding Information:
The PIES, CTD‐O2, LADCP, and SADCP data presented herein were funded primarily by the U.S. National Oceanic and Atmospheric Administration, with additional support for ship‐time from the U.S. National Science Foundation and the U.K. Natural Environment Research Council. These data are freely available on the Western Boundary Time Series project webpage (www.aoml.noaa.gov/phod/wbts/). The BPR and tall mooring data (current meter, MicroCAT, and moored ADCP) presented herein were funded by the U.K. Natural Environment Research Council and the U.S. National Science Foundation, with additional support for ship‐time from the U.S. National Oceanic and Atmospheric Administration. The individual BPR, current meter, MicroCAT, and moored ADCP data are available on the BODC web page (www.bodc.ac.uk/rapid-moc/). The gridded tall mooring data are freely available from the RAPID‐MOC web page (www.rapid.ac. uk/rapidmoc). The Argo data used for building the GEM fields discussed herein were collected and made freely available by the Coriolis project and programs that contribute to it (www.coriolis.eu.org).
PY - 2019/6
Y1 - 2019/6
N2 - Observations from five different systems provide a robust picture of the structure and variability of the Antilles Current, an important contributor to the oceanic flux budget, at 26.5°N during 2005–2015. The analysis includes three direct measurement technologies (current meters, shipboard acoustic Doppler current profilers, and lowered acoustic Doppler current profilers) and two geostrophy-based measurement technologies (conductivity-temperature-depth profilers and pressure-equipped inverted echo sounders). The direct systems are shown to produce weaker, and less variable, Antilles Current transport estimates than the geostrophy-based systems. The record-length-mean geostrophic estimate for the Antilles Current is 4.7 Sverdrups (Sv; 1 Sv = 106 m3/s), and the daily temporal standard deviation is 7.5 Sv. The variations of the Antilles Current transport exceed those of the entire basin-wide meridional overturning circulation, illustrating the impact of this unusual current. Seasonal variability shows a maximum northward transport in August–September; however, the seasonal component of the variability is weak, and aliasing of higher frequencies is still a problem even with 10.5 years of data. The dominant time scales of variability in the spectra are at 70 and 180 days, and there is indication of westward propagation of Rossby Wave-like features into the region at a speed of 9 cm/s. There is no significant correlation between the Antilles Current transport variations and those of the Florida Current at 27°N, in phase or at lags/leads of up to 5 years, likely reflecting the varying coastal wave/wall jet time scales for information to pass from the basin interior through the Bahamas Islands.
AB - Observations from five different systems provide a robust picture of the structure and variability of the Antilles Current, an important contributor to the oceanic flux budget, at 26.5°N during 2005–2015. The analysis includes three direct measurement technologies (current meters, shipboard acoustic Doppler current profilers, and lowered acoustic Doppler current profilers) and two geostrophy-based measurement technologies (conductivity-temperature-depth profilers and pressure-equipped inverted echo sounders). The direct systems are shown to produce weaker, and less variable, Antilles Current transport estimates than the geostrophy-based systems. The record-length-mean geostrophic estimate for the Antilles Current is 4.7 Sverdrups (Sv; 1 Sv = 106 m3/s), and the daily temporal standard deviation is 7.5 Sv. The variations of the Antilles Current transport exceed those of the entire basin-wide meridional overturning circulation, illustrating the impact of this unusual current. Seasonal variability shows a maximum northward transport in August–September; however, the seasonal component of the variability is weak, and aliasing of higher frequencies is still a problem even with 10.5 years of data. The dominant time scales of variability in the spectra are at 70 and 180 days, and there is indication of westward propagation of Rossby Wave-like features into the region at a speed of 9 cm/s. There is no significant correlation between the Antilles Current transport variations and those of the Florida Current at 27°N, in phase or at lags/leads of up to 5 years, likely reflecting the varying coastal wave/wall jet time scales for information to pass from the basin interior through the Bahamas Islands.
KW - Antilles Current
KW - PIES
KW - current meter
KW - transport
KW - variability
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U2 - 10.1029/2018JC014836
DO - 10.1029/2018JC014836
M3 - Article
AN - SCOPUS:85067362208
VL - 124
SP - 3700
EP - 3723
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
SN - 2169-897X
IS - 6
ER -