A global surface drifter data set at hourly resolution
File(s)2016JC011716.pdf (6.82 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
The surface drifting buoys, or drifters, of the Global Drifter Program (GDP) are predominantly tracked by the Argos positioning system, providing drifter locations with O(100 m) errors at nonuniform temporal intervals, with an average interval of 1.2 h since January 2005. This data set is thus a rich and global source of information on high-frequency and small-scale oceanic processes, yet is still relatively understudied because of the challenges associated with its large size and sampling characteristics. A methodology is described to produce a new high-resolution global data set since 2005, consisting of drifter locations and velocities estimated at hourly intervals, along with their respective errors. Locations and velocities are obtained by modeling locally in time trajectories as a first-order polynomial with coefficients obtained by maximizing a likelihood function. This function is derived by modeling the Argos location errors with t location-scale probability distribution functions. The methodology is motivated by analyzing 82 drifters tracked contemporaneously by Argos and by the Global Positioning System, where the latter is assumed to provide true locations. A global spectral analysis of the velocity variance from the new data set reveals a sharply defined ridge of energy closely following the inertial frequency as a function of latitude, distinct energy peaks near diurnal and semidiurnal frequencies, as well as higher-frequency peaks located near tidal harmonics as well as near replicates of the inertial frequency. Compared to the spectra that can be obtained using the standard 6-hourly GDP product, the new data set contains up to 100% more spectral energy at some latitudes.
Date Issued
2016-05-01
Date Acceptance
2016-03-30
Citation
Journal of Geophysical Research: Oceans, 2016, 121 (5), pp.2937-2966
ISSN
2169-9275
Publisher
American Geophysical Union
Start Page
2937
End Page
2966
Journal / Book Title
Journal of Geophysical Research: Oceans
Volume
121
Issue
5
Copyright Statement
© 2016. American Geophysical Union. All Rights Reserved. This is the accepted version of the following article: Elipot, S., Lumpkin, R., Perez, R. C., Lilly, J. M., Early, J. J., and Sykulski, A. M. (2016), A global surface drifter data set at hourly resolution, J. Geophys. Res. Oceans, 121, 2937– 2966, which has been published in final form at https://doi.org/10.1002/2016JC011716
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000383466500007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Oceanography
TIDAL CURRENTS
WORLD OCEAN
Publication Status
Published
Date Publish Online
2016-04-04