Datasets

Datasets#

ROMS-Tools relies on several external datasets. Some are accessed automatically; others must be downloaded manually before running ROMS-Tools.

Dataset	Required for	Download needed	Access
ETOPO5	Grid (Topography)	No (auto-downloaded)	NOAA
SRTM15	Grid (Topography, high-resolution)	Yes	UCSD
EMODnet	Grid (Topography, high-resolution)	Yes	EMODnet
ETOPO2022	Grid (Topography, high-resolution)	Yes	NOAA
Natural Earth	Grid (Land-Sea Mask)	No (auto-downloaded)	Natural Earth
GSHHG	Grid (Land-Sea Mask, high-resolution)	Yes	SOEST
TPXO	Tidal Forcing	Yes	OSU
GLORYS	Initial & Boundary Conditions	Yes	Copernicus Marine
Unified BGC Dataset	BGC Initial, Boundary & Surface Forcing; Salinity Restoring	Yes	Google Drive
ERA5	Surface Forcing	Optional (streaming supported)	Climate Data Store
Dai & Trenberth	River Forcing (discharge)	No (auto-downloaded)	NCAR RDA
GloFAS	River Forcing (discharge)	Yes	Copernicus CDS
RIVR2O	River Forcing (BGC tracers)	Yes	Zenodo
River tracer defaults	River Forcing (BGC fill values)	No (auto-downloaded)	roms-tools-data repository
WOA	Surface Restoring Forcing, sea surface salinity (sss)	Yes	WOA, NOAA
MBL_co2	Time-varying CO2, Surface Forcing	No (auto-downloaded)	MBL, GML, NOAA
SODA	Surface Restoring Forcing, sea surface salinity (sDIC, sALK)	No (auto-downloaded)	OceanSODA-ETHZ, NOAA

Manual Downloads#

SRTM15#

High-resolution 1/240° global topography dataset. As an alternative, ROMS-Tools can use ETOPO5 at coarser 1/12° resolution, which is downloaded automatically.

Version:: V2.6
Required for:: Grid (Topography)
Available at:: UCSD SRTM15+ Product

EMODnet#

European high-resolution bathymetry dataset. An alternative to SRTM15, particularly well-suited for domains in European waters.

Required for:: Grid (Topography)
Available at:: EMODnet Digital Bathymetry

ETOPO2022#

High-resolution global relief model at up to 15 arc-second resolution, the successor to ETOPO5. An alternative to SRTM15 and EMODnet, providing combined topography and bathymetry worldwide. Unlike ETOPO5, ROMS-Tools does not download ETOPO2022 automatically.

Required for:: Grid (Topography)
Available at:: NOAA ETOPO 2022 Global Relief Model

GSHHG#

Global coastline shapefiles, provided at five resolutions:

f (full): original highest-detail dataset
h (high): ~80% reduction in detail and file size
i (intermediate): another ~80% reduction
l (low): another ~80% reduction
c (crude): another ~80% reduction

The full-resolution (f) dataset is recommended for accurate representation of fjords, narrow straits, and other complex coastal geometries.

Alternatively, ROMS-Tools supports Natural Earth coastlines for land-sea mask generation, which are downloaded automatically.

Version:: V2.3.7
Required for:: Grid (Land-Sea Mask)
Available at:: GSHHG Product

For download instructions see Download Instructions.

TPXO#

Global barotropic tidal model providing tidal potential, elevation, and velocities including self-attraction and loading (SAL) corrections.

Supported versions:: TPXO9v5a, TPXO10v2, TPXO10v2a (all 1/6°)
Required for:: Tidal Forcing
Available at:: OSU TPXO Tide Models

Required fields

Field	Description
`lat_z`, `lon_z`	Latitude/longitude of z nodes
`lat_u`, `lon_u`	Latitude/longitude of u nodes
`lat_v`, `lon_v`	Latitude/longitude of v nodes
`mz`, `mu`, `mv`	Water/land mask for z, u, v nodes
`hRe`, `hIm`	Tidal elevation, real and imaginary parts (m)
`URe`, `UIm`	Tidal transport WE, real and imaginary parts (m²/s)
`VRe`, `VIm`	Tidal transport SN, real and imaginary parts (m²/s)

GLORYS#

1/12° global ocean physics reanalysis providing physical ocean initial and boundary conditions.

Required for:: Initial Conditions, Boundary Forcing
Available at:: Copernicus Marine Data Store

For download instructions see Download Instructions.

Required fields

Field	Description
`time`	Time
`latitude`	Latitude (degrees north)
`longitude`	Longitude (degrees east)
`depth`	Depth (m)
`zos`	Sea surface height (m)
`thetao`	Temperature (°C)
`so`	Salinity (psu)
`uo`	Eastward velocity (m/s)
`vo`	Northward velocity (m/s)

Unified BGC Dataset#

A monthly biogeochemical climatology at 1° horizontal resolution, integrating multiple observational and model-based sources: World Ocean Atlas 2023 nutrients, oxygen, temperature and salinity; GLODAPv2 carbon chemistry; in-situ iron and nitrous oxide reconstructions; and CESM model output for the remaining nutrients and dissolved organic matter. It also carries the surface deposition fluxes (dust, iron, NOx, NHy) used for BGC surface forcing.

The file is filled across land and below the seafloor, so it has no missing values at any depth level, and ROMS-Tools applies no lateral fill to it before regridding.

Use version 2.1 or later (BGCdataset_v2_1.nc). Earlier versions are still read, with a warning: they name their dimensions lon/lat/dep, and the oldest ones lack the temp_WOA/salt_WOA fields required for density-space BGC interpolation and salinity restoring.

Required for:: BGC Initial Conditions, BGC Boundary Forcing, BGC Surface Forcing, Surface Forcing (Restoring Forces; Salinity)
Available at:: Google Drive

For download instructions see Download Instructions.

WOA Salinity Data#

A collection of salinity (and other variables) means based on profile data from the World Ocean Database (WOD). The s_an variable provided is the ‘Objectively analyzed mean fields for sea_water_salinity’.

Required for:: Surface Forcing (Restoring Forces; Salinity)
Available at:: NOAA website

For download instructions see Download Instructions.

Automatically Accessed#

ETOPO5#

Global 1/12° topography dataset. Downloaded automatically by ROMS-Tools as a coarser alternative to SRTM15.

Required for:: Grid (Topography)
Available at:: NOAA ETOPO Global Relief Model

Natural Earth#

1:10m coastline dataset, used to generate the land-sea mask. The label 1:10m refers to a map scale of 1:10,000,000, which corresponds to an effective spatial resolution of approximately 1–5 km. Accessed automatically via the regionmask package — no file download required.

Required for:: Grid (Land-Sea Mask)
Available at:: Natural Earth

ERA5#

Global 1/4° atmospheric reanalysis from ECMWF providing meteorological surface forcing. ROMS-Tools can stream ERA5 data directly from the cloud, so downloading is optional.

Required for:: Surface Forcing
Available at:: Copernicus Climate Data Store

Required fields

Field	Description
`time`	Time
`latitude`	Latitude (degrees north)
`longitude`	Longitude (degrees east)
`u10`	10 m U wind component (m/s)
`v10`	10 m V wind component (m/s)
`ssr`	Surface net short-wave radiation (W/m²)
`strd`	Surface long-wave radiation downwards (W/m²)
`t2m`	2 m temperature (K)
`d2m`	2 m dewpoint temperature (K)
`tp`	Total precipitation (m)
`sst`	Sea surface temperature (K) — used for land masking

Dai & Trenberth#

Monthly coastal river discharge for ~1,000 of the world’s largest rivers. Downloaded automatically by ROMS-Tools when source={"name": "DAI"} (the default).

Version:: May 2019 update
Required for:: River Forcing (discharge; default source)
Available at:: NCAR RDA

Required fields

Field	Description
`station`	Station index
`time`	Time (encoded as YYYYMM numeric values)
`lat_mou`	River mouth latitude
`lon_mou`	River mouth longitude
`FLOW`	Monthly mean volume at station (m³/s)
`ratio_m2s`	Ratio of volume between river mouth and station
`riv_name`	River name
`vol_stn` (optional)	Annual volume at station; used to sort rivers by size

GloFAS#

Global daily river discharge from the Global Flood Awareness System (GloFAS) v4.0. Must be downloaded and preprocessed by the user before use. ROMS-Tools expects a NetCDF file in which river mouths have been placed on coastal cells using the GloFAS Large-scale Drainage Direction (LDD) algorithm. For a ready-to-run preprocessing workflow, see the Preprocessing GloFAS discharge for ROMS-Tools notebook.

Version:: v4.0
Required for:: River Forcing (discharge; source={"name": "GLOFAS", "path": ...})
Available at:: Copernicus CDS

Required fields

Field	Description
`station`	Station index
`time`	Time (CF-compliant `datetime64`)
`lat_mou`	River mouth latitude
`lon_mou`	River mouth longitude
`FLOW`	River discharge (m³/s)
`ratio_m2s`	Ratio of volume between river mouth and station
`riv_name`	River name
`vol_stn` (optional)	Station volume metric; used to sort rivers by size

RIVR2O#

Global annual river biogeochemical export fields on a regular lat/lon grid (~0.5°). One NetCDF file per year; used as the dynamic BGC source when include_bgc=True and bgc_source={"name": "RIVR2O", "path": ...}. MARBL tracers not provided by RIVR2O are filled from river_tracer_defaults.nc.

Coverage:: 1903–2024
Required for:: River Forcing (BGC tracers; optional)
Available at:: Zenodo

Required fields (per yearly file)

Field	Description
`lat`, `lon`	Regular lat/lon grid coordinates
`DIC`, `DOC_l`, `DOC_sl`, `POC`	Carbon export (10⁶ g C yr⁻¹)
`DIN`, `DIP`	Nitrogen and phosphorus export (renamed to `NO3` and `PO4` internally)

River tracer defaults#

Recommended default MARBL river tracer concentrations. Downloaded automatically by ROMS-Tools. Used as the default BGC source (bgc_source={"name": "CONSTANTS"}) and as the fill source for tracers missing from RIVR2O.

Required for:: River Forcing (BGC; optional)
Source:: roms-tools-data repository (river_tracer_defaults.nc)

MBL_co2#

Marine boundary layer values for CO2 (µmol mol⁻¹). Data are from a collection of NOAA’s atmospheric sampling sites, and available about weekly. Data are available for 1979 to 2025. Downloaded automatically by ROMS-Tools.

Required for:: Surface Forcing (time-varying CO₂)
Available at:: NOAA’s GML, MBL

OceanSODA#

A global gridded marine carbonate system dataset calculated from machine learning estimates of Total Alkalinity and the fugacity of carbon dioxide. Data taken from NOAA’s OceanSODA-ETHZ version 2025. Monthly data for years 1982-2024 at 1 degree resolution for the surface water. Downloaded automatically by ROMS-Tools.

Version:: 2025
Required for:: Surface Forcing (Restoring Forces; DIC & ALK)
Available at:: NOAA’s OceanSODA

Datasets

Contents

Datasets#

Manual Downloads#

SRTM15#

EMODnet#

ETOPO2022#

GSHHG#

TPXO#

GLORYS#

Unified BGC Dataset#

WOA Salinity Data#

Automatically Accessed#

ETOPO5#

Natural Earth#

ERA5#

Dai & Trenberth#

GloFAS#

RIVR2O#

River tracer defaults#

MBL_co2#

OceanSODA#

Download Instructions#

Field	Description
`lat`	Latitude (degrees north)
`lon`	Longitude (degrees east)
`z`	Topography (m)