Validation of FOAM near-surface ocean current forecasts using Lagrangian drifting buoys

In this study, the quality of near-surface current forecasts from the FOAM ocean forecasting system is assessed using the trajectories of Lagrangian drifting buoys. A method is presented for deriving pseudo-Eulerian estimates of ocean currents from the positions of Surface Velocity Program drifters...

Full description

Bibliographic Details
Published in:Ocean Science
Main Authors: E. W. Blockley, M. J. Martin, P. Hyder
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2012
Subjects:
geo
Online Access:https://doi.org/10.5194/os-8-551-2012
http://www.ocean-sci.net/8/551/2012/os-8-551-2012.pdf
https://doaj.org/article/48ecbc19d10b453da9de463988c44870
Description
Summary:In this study, the quality of near-surface current forecasts from the FOAM ocean forecasting system is assessed using the trajectories of Lagrangian drifting buoys. A method is presented for deriving pseudo-Eulerian estimates of ocean currents from the positions of Surface Velocity Program drifters and the resulting data are compared to velocities observed by the global tropical moored buoy array. A quantitative analysis of the global FOAM velocities is performed for the period 2007 and 2008 using currents derived from over 3000 unique drifters (providing an average of 650 velocity observations per day). A potential bias is identified in the Southern Ocean which appears to be caused by wind-slip in the drifter dataset as a result of drogue loss. The drifter-derived currents are also used to show how the data assimilation scheme and a recent system upgrade impact upon the quality of FOAM current forecasts.