BB-TRANS: Three-dimensional circulation and transport within the south-eastern Bay of Biscay from a multi-platform approximation

User group PI: Ainhoa B. Caballero Reyes, Azti Foundation, Spain

Hosting infrastructure: HZG COSYNA Glider, Germany

Main Objectives

The complex circulation of the coastal and shelf break of the South-Eastern Bay of Biscay (SE-BoB) and the relevant human activities linked to the marine resources concentrated in this area, make that the accurate monitoring of 4D (horizontal, vertical and temporal planes) transport patterns of this area represents a challenge towards an integrated management of its ocean resources. This challenge also motivated the progressive development of the Coastal Ocean Observing System (COOS) of the SE-BoB, which nowadays is composed of a network of coastal oceanographic-meteorological stations, a slope buoy and a HFR system. However, research effort is still needed to make a step forward towards the estimation of more accurate oceanic transports. Besides, satellite data afford complementary information the COOS. Satellite altimetry have been proved to be an efficient database for studying mesoscale circulation in the study area; nevertheless, its quality declines near the coast (due to e.g. insufficient sampling, corruption of radiometer-altimeter waveforms), a great part of the area covered by the COOS of the SE-BoB. Recent studies are focused on the evaluation of the capabilities of altimetry using HFR, and with the combined use of HFR and glider measurements, concluding that both approximations offer useful data that can help to improve the processing of altimetry data for coastal studies. Finally, providing information of the circulation and transport of the water column, from the expansion of the surface information of HFR to deeper levels can extend the applications of these data for biological and environmental purposes. Several approaches, based on the combination of HFR data with information on the water column (from in-situ moored instruments, remote sensing or numerical models) using statistic and/or dynamic, have proven promising for understanding the three-dimensional coastal circulation. The combination of glider and HF radar data will offer a unique opportunity to describe local ocean processes at high spatial and temporal resolution and to investigate their role in the coastal transport.

Summarizing, the purpose of this project is to recover measurements of the water column, within the area covered by the coastal HFR system of the SE-BoB, in order to evaluate on the one hand, the accuracy of coastal altimetry along-track data within the HFR footprint area, and on the other hand, the performance of different methodologies for deriving transport in the water column, by means of HFR and glider data blending.


Project Report: BB-TRANS_report_final.pdf