Impact of data assimilation on ocean current forecasts in the Angola Basin
File(s)star-revision-v3 (10).pdf (9.42 MB)
Accepted version
Author(s)
Phillipson, L
Toumi, R
Type
Journal Article
Abstract
The ocean current predictability in the data limited Angola Basin was investigated using the Regional Ocean Modelling System (ROMS) with four-dimensional variational data assimilation. Six experiments were undertaken comprising a baseline case of the assimilation of salinity/temperature profiles and satellite sea surface temperature, with the subsequent addition of altimetry, OSCAR (satellite-derived sea surface currents), drifters, altimetry and drifters combined, and OSCAR and drifters combined. The addition of drifters significantly improves Lagrangian predictability in comparison to the baseline case as well as the addition of either altimetry or OSCAR. OSCAR assimilation only improves Lagrangian predictability as much as altimetry assimilation. On average the assimilation of either altimetry or OSCAR with drifter velocities does not significantly improve Lagrangian predictability compared to the drifter assimilation alone, even degrading predictability in some cases. When the forecast current speed is large, it is more likely that the combination improves trajectory forecasts. Conversely, when the currents are weaker, it is more likely that the combination degrades the trajectory forecast.
Date Issued
2017-04-22
Date Acceptance
2017-04-21
Citation
OCEAN MODELLING, 2017, 114, pp.45-58
ISSN
1463-5003
Publisher
ELSEVIER
Start Page
45
End Page
58
Journal / Book Title
OCEAN MODELLING
Volume
114
Copyright Statement
© 2017 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000403731800004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
Oceanography
Altimetry
Lagrangian data
Data assimilation
4D-Var
Angola Basin
OSCAR
NUMERICAL WEATHER-PREDICTION
MODELING SYSTEM ROMS
GULF-OF-MEXICO
VELOCITY OBSERVATIONS
LAGRANGIAN DATA
VARIATIONAL ASSIMILATION
CIRCULATION MODEL
SURFACE VELOCITY
DRIFTER DATA
CONGO RIVER
0405 Oceanography
Publication Status
Published