ECMWF low resolution experiments: 

~1 deg, equatorial meridional refinement to 1/3 of degree, 42 levels
in the vertical. Forcing daily fluxes ERA40 (1958-1988)+ERA Interim onwards
Flux forcing.  


AMOC_ORAS4_YYYY.nc : from ORAS4 reanalyses. 
See Balmaseda et al 2013, QJ.

AMOC_CNTL0_YYYY.nc : as ORAS4, but no data assimilation. 

AMOC_CNTL1_YYYY.nc : as ORAS4, but not data assimilation, and
diffirent spin up.

Notes on spinup strategies:

1) For reanalyses, one would like the initial conditions to be close
to observations. So usaully spinup with relaxation to climatology is
used.  ORAS4 and CNTL0 have this spin up. 
The CNTL0 integration will show the drift due to model/forcing
error. Comparison with ORAS4 shows the impact of assimilation.

2) For model only runs, one would like a spin up to produce states
consitent with the model dynamics, even if it is far from the observed
state. CNTL1 has this spin up, to avoid drift during the integration.