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METRIC

Meridional ovErTurning ciRculation diagnostIC (METRIC) is a Python package for calculating Atlantic Meridional Overturning Circulation (AMOC) diagnostics at observational arrays in ocean general circulation models.

Background

METRIC originated as a fork of the RapidMoc package, which enabled users to perform observational-equivalent calculations along the RAPID (26.5°N) array in ocean models.

The latest version of METRIC extends this to allow users to estimate overturning, heat and freshwater transports at:

• RAPID (26.5°N) array
• MOVE (16°N) array
• SAMBA (34.5°S) array

METRIC also includes the option to use alternative observational approaches when estimating meridional volume, heat and freshwater transports.

A new experimental feature is the metric validate automated validation feature, which generates a PDF report comparing a given ocean model to available RAPID 26.5°N observations.

Getting Started:

Installation

Users should install METRIC into a new virtual environment via GitHub using pip:

pip install git+https://github.com/AMOCcommunity/metric.git

Using METRIC

Once METRIC has been installed, users can use the metric command-line interface to calculate AMOC diagnostics at the RAPID 26.5°N, MOVE 16°N, and SAMBA 34.5°S observing arrays and write outputs to a single netCDF file:

   metric run [-c] [-t] [-s] [-v] [-ssh] [-taux]

After producing AMOC diagnostics at RAPID 26.5°N, users can then generate figures and a PDF report validating their ocean general circulation model against available observations using:

   metric validate [-c]

Required Arguments:

-c = Path to configuration file.\

Optional Arguments:

-t = Path to netcdf file containing temperature data.
-s = Path to netcdf file containing salinity data.
-v = Path to netcdf file containing meridional velocity data.
-ssh = Path to netcdf file containing sea surface height data.
-taux = Path to netcdf file containing zonal wind stress data. --outdir = Path to output directory (overwrites configuration file).
--name = Name of the output file (overwrites configuration file).
--shift = Shift output dates for plotting.

Examples:

Example configuration files for POP and NEMO ocean model outputs are provided for users in the configs directory.

Users will also find two example workflows, including SLURM job submission scripts, to run METRIC with large multi-file datasets in configs/NEMO/NOC/.

Coming Soon:

• **Validation workflows for MOVE 16°N & SAMBA 34.5°S.
• AMOC Diagnostics for NOAC 47N.
• AMOC Diagnostics for OSNAP.

Citations

METRIC

Please cite the associated digital object identifier and Danabasoglu et al. (2021) if you use METRIC in your research.

Code:

Castruccio F. S., 2021: NCAR/metric: metric v0.1. doi/10.5281/zenodo.4708277

Publication:

Danabasoglu, G., Castruccio, F. S., Small, R. J., Tomas, R., Frajka-Williams, E., and Lankhorst, M., (2021). Revisiting AMOC Transport Estimates from Observations and Models. Geophysical Research Letters, in review.

Rapidmoc

The original RapidMoc package should be cited using the associated digital object identifiers and Roberts et al. (2013)

Code:

Roberts, C.D., 2017: cdr30/RapidMoc: RapidMoc v1.0.1. doi:10.5281/zenodo.1036387

Publlication:

Roberts, C. D., et al. (2013), Atmosphere drives recent interannual variability of the Atlantic meridional overturning circulation at 26.5°N, Geophys. Res. Lett., 40, 5164–5170 doi:10.1002/grl.50930.