Surface Current Variance from Drifter Data


Contains information about current variance (eddy kinetic energy) derived from residuals with respect to the time-mean, seasonal, spatial gradient, and SOI-related currents. The file contains the following variables:

  • Lon (1x720): longitude (degrees), negative=West.

  • Lat (1x317): latitude (degrees), 73S to 85N.

  • Up2bar (317x720): Zonal Velocity Variance, mean(u’ ^2) (m^2/s^2).

  • Vp2bar (317x720): Meridional Velocity Variance, mean(v’ ^2) (m^2/s^2).

  • rA (317x720): Variance ellipse semimajor axis (m^2/s^2).

  • rB (317x720): Variance ellipse semiminor axis (m^2/s^2).

  • angle (317x720): Orientation angle of variance ellipse (degrees, 0=east/west).

  • N (317x720): Number of drifter-days per square degree.

Note that Up2bar+Vp2bar=rA+rB, which is twice the eddy kinetic energy.

For more information, see:

The global near-surface current climatology described here is publicly available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC), and through NOAA/AOML at

This climatology was developed by Rick Lumpkin (NOAA/AOML) and Lucas Laurindo (Univ. Miami), in collaboration with Arthur Mariano (Univ. Miami), Mayra Pazos (NOAA/AOML), and Erik Valdes (CIMAS/AOML). Previous versions were developed with Gregory Johnson (NOAA/PMEL), Silvia Garzoli (NOAA/AOML), Jessica Redman (CIMAS), and Zulema Garraffo(Univ. Miami).



Release Policy

Please cite as reference: Laurindo, L., A. Mariano, and R. Lumpkin, 2017: An improved near-surface velocity climatology for the global ocean from drifter observations Deep-Sea Res. I, 124, pp.73-92, doi:10.1016/j.dsr.2017.04.009.


Laurindo et al. (2017)

bibtex file

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