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Results

Heat transport data files for the period 2004-2015 available for download.
** (updated August 2017) **
For NetCDF format, click here
For MATLAB MAT-file, right-click and select "save link as" here
Important README information
Reference for heat transport calculations: Johns et al. (2011)
Transport Profile Time-series
** (updated July 2013) **
For NetCDF format, click here.
See the readme file for a brief description.
To access the latest MOC volume transport time series published by the National Oceanography Centre, click here.
How to acknowledge data from the RAPID-MOCHA project:

Data from RAPID-MOCHA monitoring project are made freely available to
the public. The project scientists would appreciate it if you added the
following acknowledgment to any publications that use this data:

"Data from the RAPID-MOCHA program are funded by the U.S. National
Science Foundation and U.K. Natural Environment Research Council and are
freely available at www.rapid.ac.uk/rapidmoc and www.rsmas.miami.edu/users/mocha."

The meridional ocean heat transport across 26.5°N (black), and associated temperature transports (relative to 0°C) of its main components: Gulf Stream (blue), Ekman (green), and ocean interior (red), updated through March 2014. The thin lines are 10-day averages and thick lines are 90-day lowpass filtered data. Annual averages of the total heat transport for each calendar year are shown in the shaded boxes.  Both Ekman and Gulf Stream variability contribute to large short-term changes in the AMOC and heat transport, including occasional heat transport reversals, while the interannual variability of the heat transport is dominated by the geostrophic circulation and mostly by the mid-ocean heat transport. The heat transport has decreased in recent years compared to values observed prior to 2009; the 5-year mean for the pentad 2009-2013 was 1.14 PW compared to 1.34 PW for the pentad 2004-2008.

Time series of the "overturning" and "gyre" components of the meridional heat transport across 26.5°N, filtered with a 90-day lowpass filter.  Approximately 90% of the heat transport - and most of its interannual variability -  is contained in the overturning component of the heat transport, while the gyre component has maintained a stable mean value with a regular seasonal cycle.

Total heat transport (black), and overturning (red) and gyre (blue) components of the heat transport, regressed on the strength of the MOC at 26.5°N.


Temperature transports (relative to 0ºC), for each of the section contributions to the net meridional heat transport at 26.5ºN (shown in black line).  See Johns et al. (2011) for definitions of the individual components.  All components have been low-pass filtered to remove variance at periods shorter than 10 days. The total heat transport (black) and mid-ocean “eddy” heat transport (light blue) are the only ones that represent true heat fluxes, independent of temperature reference. (from Johns et al., 2011).

Time series of meridional heat transport (top) and maximum value of the meridional overturning streamfunction (bottom).  Light grey lines show the total variability; black lines show the variability attributable to the geostrophic circulation, after the direct influence of Ekman transport fluctuations are removed.  (from Johns et al., 2011).

Monthly climatology of terms comprising the total meridional heat transport, for the “mass-neutral” fluxes calculated relative to the interior ocean mean temperature (θmid-ocean = 5.33°C).  The interior contribution shown here, QINT = QMO + QWB + QEDDY, represents the sum of all the interior ocean (Bahamas to Africa) contributions. Shading around each curve represents the ± standard error of each monthly estimate.  (from Johns et al., 2011).

Monthly climatology of the overturning heat transport (QOT) and “gyre” (non-overturning) heat transport (QGYRE), derived from the 3.5 year data set.  The total heat transport is shown by the black line (repeated from Fig. 14).  Shading represents ± 1 standard error of the monthly estimates.   (from Johns et al., 2011).

Overturning streamfunction Ψ(z) = ∫ TAMOC(z) dz at 26.5N, based on 10-day low-pass filtered TAMOC(z). One profile every five days has been plotted over the 48-month-long measurement period between April 2004 and April 2008. The red dots on each profile mark the maximum northward transport ΨMAX and the corresponding depth hZC.  (from Kanzow et al., 2010).

The thin lines denote time series of ΨMAX (red), TGS (blue), TEK (black) and TUMO (magenta) for the period between April 2004 and April 2008. The data have been 10-day low-pass filtered. Also shown is the contribution of the compensation transport to ΨMAX (i.e., TC(z) integrated between the sea surface and the level of no motion). The bold lines represent the best estimates of the long-term seasonal cycles of each transport component.  (from Kanzow et al., 2010).

Seasonal cycles (black solid lines) of TGS (A), TEK (B), TUMO(C) and ΨMAX (D), as obtained from month-wise averages of the time series between April 2004 and April 2008.  The gray envelopes represent the standard error of each month (as obtained from the 4 realisations of monthly averages that are available for each month). The dashed lines in the panels A and B represent seasonal cycles of TGS and TEK based on the 26 year long time series (10/1982-01/2008) used for the computation of the spectra in Fig. 8. The dashed line in panel D represents the best guess of the long-term seasonal cycle of ΨMAX (see text). Positive values denote northward flow.  (from Kanzow et al., 2010).

ΨMAX inferred from five hydrographic snapshot estimates between 1957 and 2004 (solid diamonds), as reproduced from Bryden et al (2005).  The hydrography cruises were carried out in different seasons, namely in October 1957, August / September 1982, July / August 1991, February 1998 and April 2004.  The open squares represent the historical estimates ofΨ MAX with seasonal anomalies of TUMO subtracted.  (from Kanzow et al., 2010).

Mean northward velocity from the gridded current meter data shoreward of WB3. The red dots and lines (for ADCPs) show the measurement locations. The bold dashed line shows the topography mask used to simulate the deep shielded zone inside of mooring WB2 during the latter part of the moored transport calculation (after mid- December, 2004). Velocity contours: cm s-1 (from Johns et al., 2008).

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Time series of the transport-per-unit-depth profile (105 m2s-1) for the region extending from the coast to mooring WB3; the contour interval is decreased in the lower panel to better illustrate the deep variability. A notable reversal in the deep flow occurs during November 2004 (from Johns et al., 2008).

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Internal (red), external (blue), Ekman (green), Gulf Stream (Florida Straits, magenta) and western boundary wedge (orange) transport fluctuations. There is a two month gap in the Gulf Stream time series (04/09 - 28/10/2004). All time series have been two-day low-pass filtered and interpolated on a half-daily grid (from Kanzow et al., 2007).
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Variance conserving spectrum of transports. The red, blue, black and cyan lines denote internal (Tint), external (Text), Tint + Text + Twbw and the sum of all components (Tint + Text + Twbw + Tgs + Tek), respectively. For the computation of the cyan line, the two month gap in Tgs has been filled by a linear interpolation (04/09 - 28/10/2004). From Kanzow et al. (2007).
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Year-long time series of layer transports for the upper ocean (0 to 800 m depth, red), intermediate water (800 to 1100 m, green), upper North Atlantic Deep Water (1100 to 3000 m, light blue) and lower North Atlantic Deep Water (below 3000 m, dark blue). Negative transports correspond to southward flow (from Cunningham et al., 2007).
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Daily time series of Florida Straits transport (blue), Ekman transport (black), interior geostrophic transport (0-1100 m, magenta) and overturning transport above 1100 m (red) for the period 29 March 2004 to 31 March 2005. Overturning transport is the sum of the Florida Straits, Ekman and interior geostrophic transport (from Cunningham et al., 2007).

 

 

 

 

 

 

 


 

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Photo credits: Lisa Beal, Jon Molina, & Carlos Fonseca