Real time assimilation of HF radar currents into a coastal ocean model

• Published in: Journal of marine systems Vol. 28; no. 3; pp. 161 - 182
• Main Authors: BREIVIK, Oyvind, SAEETRA, Oyvind
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 01.04.2001; Elsevier
• Subjects: (4°E, 60°N) – (5°E, 61°N); Bergen; Bounding coordinates; Current sensors; Data assimilation; Dynamics of the ocean (upper and deep oceans); Earth, ocean, space; Europe; Exact sciences and technology; External geophysics; Fedje; Marine; Norway; Ocean currents; Ocean modelling; Physics of the oceans; Regional terms; Subject keywords; Norway; Europe; North Sea; ANE, Norway; Regional terms; Bounding coordinates; Subject keywords; Short term; Surface current; Forecast model; Coastal zone; Ocean model; Ship observation; Interpolation; Current measurement; Covariance; Coastal current; Sea current; Radar observation; Optimal approximation; Data assimilation
• ISSN: 0924-7963; 1879-1573
• DOI: 10.1016/S0924-7963(01)00002-1

A real time assimilation and forecasting system for coastal currents is presented. The purpose of the system is to deliver current analyses and forecasts on based on assimilation of high-frequency radar surface current measurements. The local Vessel Traffic Service monitoring the ship traffic to two oil terminals on the coast of Norway received the analyses and forecasts in real time. A new assimilation method based on optimal interpolation is presented where spatial covariances derived from an ocean model are used instead of simplified mathematical formulations. An array of high frequency radar antennae provides the current measurements. A suite of nested ocean models comprises the model system. The observing system is found to yield good analyses and short range forecasts that are significantly improved compared to a model twin without assimilation. The system is fast, analysis and 6-h forecasts are ready at the Vessel Traffic Service 45 min after acquisition of radar measurements.