Repeat Observations by Gliders in the Equatorial Region (ROGER)

CMIPx thumb

The Equatorial Undercurrent. Mean zonal velocity (m/s) along 93°W across all CMIP6 models. Adapted from Karnauskas et al. (2020, J. Geophys. Res.–Oceans).

ROGER was an NSF-funded project from 2012–2016 (OCE–1233282 and OCE–1232971). This page provides access to the data analyzed in the following publication:

Karnauskas, K. B., J. Jakoboski, T. M. S. Johnston, W. B. Owens, D. L. Rudnick, and R. E. Todd, 2020: The Pacific Equatorial Undercurrent in Three Generations of Global Climate Models and Glider Observations. J. Geophys. Res.–Oceans, doi: 10.1029/2020JC016609.

As described in the paper, all CMIP3, CMIP5 and CMIP6 global climate model outputs were initially acquired from the Earth System Grid Federation (ESGF). Monthly means from the 1990s were extracted from each model’s historical experiment (labeled “Climate of the Twentieth Century” [20C3M] in CMIP3, and simply “historical” in CMIP5 and CMIP6). A much-reduced and harmonized version of the entire CMIPx ocean zonal velocity (and potential temperature and salinity for CMIP6) output data set was then produced by retaining the time-means of 3D output within the domain 160°E–80°W, 3°S–3°N, 0–400 m and linearly regridding to a common grid (0.25° in longitude, 0.1° in latitude and 1 m in depth). Sections along 93°W were also saved. The resulting analysis sets are provided freely here. Each link below leads to a folder containing one .mat file for each model, which can be downloaded individually or en masse. This table is necessary to match model numbers with the official CMIPx model identifiers (e.g., C5_M11.mat = CMIP5 / GFDL CM3).


Spatially reduced and regridded time mean CMIPx fields

Zonal velocity volumes near the equator (3°S–3°N, 160°E–80°W, 0–400 m)

CMIP3  |  CMIP5  |  CMIP6

Zonal velocity sections along 93°W (3°S–3°N, 0–500 m)

CMIP3  |  CMIP5  |  CMIP6

Potential temperature sections along 93°W (3°S–3°N, 0–500 m)


Salinity sections along 93°W (3°S–3°N, 0–500 m)




Spray glider data hosted by UCSD/Scripps Institution of Oceanography:

Acoustic Doppler Current Profiler (ADCP) climatology of Johnson et al. (2002) hosted by NOAA/Pacific Marine Environmental Laboratory:


Related Publications

Rudnick, D. L., W. B. Owens, T. M. S. Johnston, K. B. Karnauskas, J. Jakoboski, and R. E. Todd, 2020: The equatorial current system west of the Galápagos Islands during the 2014-2016 El Niño as observed by underwater gliders. J. Phys. Oceanogr., doi: 10.1175/JPO-D-20-0064.1.

Jakoboski, J. K., R. E. Todd, W. B. Owens, K. B. Karnauskas, and D. L. Rudnick, 2020: Bifurcation and Upwelling of the Equatorial Undercurrent West of the Galápagos Archipelago. J. Phys. Oceanogr., 50, 887–905, doi: 10.1175/JPO-D-19-0110.1.