Monitoring the AMOC at 26°N
Monitoring changes in the AMOC is important for understanding decadal climate variability and change. The RAPID array across the Atlantic at 26°N has now observed the AMOC continuously for 10 years, and revealed greater variability than expected.
Low AMOC events in 2009-10 and 2010-11 coincided with cold winters in Europe and suggest a previously unsuspected role for the AMOC in climate variability. Understanding this requires a longer time series of observations, so the array will continue until 2020.
AMOC predictions: how skilled are they?
In 2015 the RAPID team challenged AMOC experts to predict what the data from the RAPID array would show. Some of their predictions, and reports from the latest RAPID cruise can be found on the
RAPID Challenge blog. After preliminary analysis of data from the array, the winners have now been found.
What does it take to collect a 10 year time series of the AMOC? To find out take a look at the 10 years of RAPID blog from the 26°N team.
Overturning in the Sub-polar North Atlantic
OSNAP is a 5-year international program to monitor the AMOC in subpolar North Atlantic. The OSNAP observing system has two legs: one from southern Labrador to the tip of Greenland across the mouth of the Labrador Sea (OSNAP West), and the second from the tip of Greenland to Scotland (OSNAP East).
OSNAP complements RAPID to give a more complete picture of Atlantic overturning.
OSNAP also uses subsurface floats to trace the pathways of overflow waters from the Nordic seas, and study currents crossing the OSNAP line.
Three new research projects
The RAPID AMOC programme is funding three new research projects to address novel uses of data from the 26°N RAPID array:
- Novel approaches to ocean state estimation using 26.5°N data
- The role of the AMOC in climate variability and predictability
- Atlantic BiogeoChemical Fluxes
Three new projects started in October 2014 and will be addressing these objectives. MORE
RAPID-AMOC meeting, London, 18-19 Sep. 2014 marked 10 years of AMOC observations and and the start of RAPID-AMOC.
2013 US AMOC - UK RAPID International Science Meeting Meeting Summary
Ten-day (colours) and three month low-pass (black) timeseries of Florida Straits transport (blue), Ekman transport (black), upper mid-ocean transport (magenta), and overturning transport (red) for the period 2nd April 2004 to September 2015. Florida Straits transport is based on electromagnetic cable measurements; Ekman transport is based on ERA winds. The upper mid-ocean transport, based on the RAPID time series, is the vertical integral of the transport per unit depth down to the deepest northward velocity (~1100 m) on each day. Overturning transport is then the sum of the Florida Straits, Ekman, and upper mid-ocean transports and represents the maximum northward transport of upper-layer waters on each day. Positive transports correspond to northward flow.
The thick black line shows the provisional RAPID data and the vertical bars are +/- 1 Sv. The thick dashed line shows the mean of all the entries. Coloured lines show the individual entries. Of these the two best estimates are highlighted with thick lines. Green being MPI and grey is the Met Office.