Content:
This repository contains documentation (doc/) and model configuration files (code/, namelist/) for official releases of the ECCO version 4 ocean and sea-ice state estimates. Model configuration files allow users to reproduce the state estimate or conduct new simulation experiments.
ECCO Version 4 is the first multidecadal global ECCO product (Forget et al., 2015). Unlike previous ECCO versions, Version 4 uses a nonlinear free surface formulation and real freshwater flux boundary condition, permitting a more accurate simulation of sea level change. In addition to estimating forcing and initial conditions as done in earlier analyses, Version 4 estimates also adjusts the model’s mixing parameters that enables an improved fit to observations (Forget et al., 2015a).
The first official release of the ECCO Version 4 ocean and sea-ice state estimation system. See Forget et al., 2015. For the configurations for ECCOv4 Release 1 and Release 2, please see the ECCOv4 github page: https://github.com/gaelforget/ECCOv4
ECCO version 4 release 2 is a minor update of the original ECCO version 4 solution (Forget et al., 2015) that benefits from a few additional corrections and improvements listed in Forget et al. (2016) including geothermal heating and an adjusted global mean precipitation to better match observed global mean sea level time-series observations.
For the configurations for ECCOv4 Release 1 and Release 2, please see the ECCOv4 github page: https://github.com/gaelforget/ECCOv4
ECCO version 4 release 3 extends the estimation time period through 2015, includes new observational data: Aquarius, GRACE, Arctic T, S profiles, sea-ice concentration, global mean sea level & ocean mass. Model controls now include initial u, v, ssh. In addition, atmospheric model controls are separated into time-invariant & time-dependent variables. See v4r3_summary.pdf for more details.
ECCO version 4 release 4 extends the estimation time period through 2017, includes new/updated observational data: GRACE ocean bottom pressure, altimetry sea surface height, in situ temperature/salinity profiles, Aquarius sea surface salinity, sea surface temperature, sea-ice concentration, mean dynamic topography, global mean sea level & ocean mass.
The atmosphere pressure forcing is added to the estimate post optimization. The product has daily outputs of the estimate, including budget terms, to allow for daily budget calculations.
The devel directory contains pieces of code that are useful, but not checked into the main MITgcm repository.
If user support is needed, please contact ecco-support@mit.edu or mitgcm-support@mit.edu.
References:
Forget, G., J.-M. Campin, P. Heimbach, C. N. Hill, R. M. Ponte, and C. Wunsch, 2015: ECCO version 4: an integrated framework for non-linear inverse modeling and global ocean state estimation. Geoscientific Model Development, 8, 3071-3104, http://dx.doi.org/10.5194/gmd-8-3071-2015, http://www.geosci-model-dev.net/8/3071/2015/
Forget, G., J.-M. Campin, P. Heimbach, C. N. Hill, R. M. Ponte, and C. Wunsch, 2016: ECCO Version 4: Second Release, http://hdl.handle.net/1721.1/102062, direct download