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: http://www.aoml.noaa.gov/phod/gdp/mean_velocity.php
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 http://www.aoml.noaa.gov/phod/dac/drifter_variance.nc.
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).
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.