Version number: 2.4, released 14 August 2023.

Most recent data included: 05 March 2023. Documentation: Lumpkin (2016).

On this page, you will find looper trajectory segments identified from Global Drifter Program data.

Regional Cyclonic (blue) and Anticyclonic (red) Loopers

[Fig. 4] Lumpkin (2016).

Longest Looper

The longest looper on record (ID 63994870), which looped for over 308 days!

The data are available as a Matlab file loopers.mat, which contains the following variables:

T_L: integral time scale from velocity correlation function (days).
drogue: drogue presence (1=drogued, 0=undrogued, .5=uncertain).
id: unique identification number.
lat: latitude (degrees; negative = south).
lon: longitude (degrees; negative = west).
omega: spin omega (s^-1)
period: period of rotation (days; =2 pi / omega).
perFit: period from velocity correlation function (days).
persist: persistence of looping (days).
radius: orbital radius (m).
t: time (days since 1/1/1979).
u: zonal velocity (m/s).
v: meridional velocity (m/s).

as well as a NetCDF file loopers.nc

There are also Matlab nonloopers.mat and NetCDF nonloopers.nc files that contain the data of non-looping drifters, for those variables which are defined for nonloopers.

If you wish to obtain these data in a different format, contact Rick Lumpkin.