Western Boundary Time Series
Florida Current Transport Time Series - Data Products
The Florida Current transport time series presented in these products are shown in Sverdrups (Sv). One Sverdrup is a flow rate defined to equal one million cubic meters per second (1 Sv=106 m3s-1). The long term mean transport of the Florida Current has been found to be 32 Sv (Larsen, 1992; Baringer and Larsen, 2001; Meinen et al., 2010; Volkov et al., 2024). Four Florida Current transport time series products are available below:
1) Florida Current transports from vessel surveys along 27°N in the Florida Straits
1982 to present
This time series product includes in situ Florida Current transport measurements from cable calibration cruises and hydrographic surveys conducted across the Florida Straits at 27°N over the project's history (dating back to 1982). These section transports are integrated from ocean velocity data measured at nine sites spanning the Straits at 27°N (note: on some cruises in the 1990s, only eight sites were used). Data are collected via Pegaus profiler, GPS dropsonde or lowered acoustic Doppler current profiler (LADCP), measuring the full water column. The data have been corrected for the barotropic tide using the tidal constituents derived by Mayer et al. (1984). In the figure above, values from this file collected between 2000 and 2024 are represented as red (dropsonde) and blue (LADCP) dots.
2) Daily Florida Current transports estimated from the Florida Straits cable voltages
1982 to present
This time series product includes daily estimates of Florida Current transports derived from voltage measurements recorded from a submarine telecommunications cable spanning the Florida Straits near 27°N, between West Palm Beach Florida, and Eight Mile Rock, Grand Bahama Island. The recorded cable voltages can be correlated to the transport of the Florida Current flowing across the cable. More information on this technique can be found on the project's cable physics page. Since 2000, NOAA/AOML has managed the processing and public distribution of these cable transports. We have recently determined that voltages collected since 2000 required a processing update to include a correction for the secular change in the earth's magnetic field over time (Volkov et al., 2024). The data linked below have had this correction applied (and are represented as the black line in the figure above).Beginning in 2008, a pair of shallow-water pressure gauges, deployed on either side of the Straits of Florida at 27°N, have provided hourly measurements of bottom pressure for the project. Satellite altimetry data available for the region can be used to improve the quality of these pressure records by correcting them for spurious drifts. When both pressure gauge records are present, their difference can be used to determine the cross-strait pressure / sea level gradient and the Florida Current transport at 27°N (item 3 below on this page) as detailed in Meinen et al. (2020) and Volkov et al (2025). During periods when the cable is out of service and when transport data are available from this new transport time series, we are now incorporating the pressure gauge derived transports into the existing cable transport record. In a delayed mode, the yearly files below, from 2008 through the present, now include an additional quality flag indicating when the daily transport shown has been determined using the pressure gauge data. See the file headers for additional information.
Finally, prior to 2000, data processing for this effort was managed by Dr. Jimmy Larsen, who led the Florida Current project out of NOAA/PMEL. These historical cable transport estimates (from 1982 through 1998) are also linked below (Larsen, 1992). In all cases, the daily mean transport values are averaged around noon GMT, and missing data are denoted by a "NaN" value.
3) Florida Current transports from pressure gauges
2008 to present
This time series product includes Florida Current transport estimates derived from a pair of pressure gauge moorings located on either side of the Florida Straits 27°N section. As previously mentioned, moored pressure gauge instruments (including both SBE 26plus and RBR quartz3 Q|plus gauges) have been deployed at ~12 meters depth on the east and west banks of the 27°N section since 2008. The bottom pressure differences between the two sites yield a cross-strait pressure / sea level gradient that, due to geostrophy, can be used to infer daily estimates of the Florda Current transport. Additionally, similar gradients, determined from altimetry for the region during satellite overpasses (every 10 days) can be used to improve the quality of the pressure gauge derived time series. See Meinen et al. (2020) and Volkov et al. (2025) for more details. As with other data products presented here, values are averaged around noon GMT, and missing data are denoted by a "NaN" value.
4) Florida Current transports from altimetry
1993 to present
This time series product includes Florida Current transport estimates from satellite altimetry. These transport estimates are obtained from the linear regression of the cable transport estimates on the crossflow sea level differences along the descending track 178 of Topex/Poseidon, Jason series, and Sentinel-6MF satellites, and are available every 10 days (Volkov et al., 2020). More information on this technique can be found on the project's altimetry page.
Additional hydrographic survey and moored time series products
may be found on the WBTS Data Products page.
Citing Western Boundary Time Series (WBTS) project data:
The data products linked above are made freely available to the public. Please acknowledge any use of these
data with the following (or similar) reference:
"These Florida Current transport velocity times series are made freely available by NOAA's Western Boundary Time Series project at (https://www.aoml.noaa.gov/western-boundary-time-series/), and are funded by NOAA's Global Ocean Monitoring and Observing (GOMO) program."