Skill assessment of HF radar-derived products for Lagrangian simulations in the Bay of Biscay
Download
Author
Solabarrieta, Lohitzune
Forlov, Sergey
Cook, Mike
Paduan, Jeff
Rubio, Anna
González, Manuel
Mader, Julien
Charria, Guillaume
Date
2016-12Metadata
Show full item recordAbstract
Since January 2009, two long-range high-frequency (HF) radar systems have been collecting hourly
high-spatial-resolution surface current data in the southeastern corner of the Bay of Biscay. The temporal resolution of the HF radar surface currents permits simulating drifter trajectories with the same time step as that of real drifters deployed in the region in 2009. The main goal of this work is to compare real drifter trajectories with trajectories computed from HF radar currents obtained using different methods, including forecast currents. Open-boundary modal analysis (OMA) is applied to the radar radial velocities and then a linear autoregressive model on the empirical orthogonal function (EOF) decomposition of an historical data series is used to forecast OMA currents. Additionally, the accuracy of the forecast method in terms of the spatial and temporal distribution of the Lagrangian distances between observations and forecasts is investigated for a 4-yr period (2009–12). The skills of the different HF radar products are evaluated within a 48-h window. The mean distances between real trajectories and their radar-derived counterparts range
from 4 to 5 km for real-time and forecast currents after 12 hours of simulations. The forecast model improves persistence (i.e., the simulations obtained by using the last available OMA fields as a constant variable) after 6 hours of simulation and improves the estimation of trajectories up to 28% after 48 hours. The performance of the forecast is observed to be variable in space and time, related to the different ocean processes governing the local ocean circulation.
Description
The article of record as published may be found at http://dx.doi.org/10.10.1175/JTECH-D-16-0045.1
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.Collections
Related items
Showing items related by title, author, creator and subject.
-
On Liouville's normal form for Lanchester-type equations of modern warfare with variable coefficients
Taylor, James G. (Monterey, California. Naval Postgraduate School, 1978-09); NPS55-78-024This paper shows that much new information about the dynamics of combat between two homogeneous forces modelled by Lanchester-type equations of modern warfare (also frequently referred to as 'square-law' attrition equations) ... -
Minimum Fuel Circling Flight for Unmanned Aerial Vehicles in a Constant Wind
Harada, Masanori; Bollino, Kevin (The American Institute of Aeronautics and Astronautics (AIAA), 2008-08-18);This paper investigates characteristics of minimum-fuel trajectories for an Unmanned Aerial Vehicle (UAV) in high altitude, circling flight under a constant wind. Previous research has shown that periodic circling flight, ... -
An analysis of the prediction accuracy of the U.S. Navy repair turn-around time forecast model
Santos, William O. (Monterey, California. Naval Postgraduate School, 2003-06);This thesis examines the forecast accuracy of repair times for a subset of repairable U.S Navy inventory items. Forecasts are currently calculated using the Uniform Inventory Control Program (UICP) on a quarterly basis. ...