Subproject 1 (SP1): Variability of upwelling, mixing, nutrient supply and boundary circulation off Angola

SP1 focuses on observations and data analysis regarding the tropical Angolan upwelling system.

Goals:

• Understand the physical forcing of upwelling, internal wave activity, mixing and nutrient supply off Angola on subseasonal to seasonal time scales and provide the observational database for investigating intraseasonal to interannual/decadal variability of the eastern boundary circulation (collaboration with SP2, SP3, SP4).

• Study the physical processes responsible for the seasonal SST variability off Angola using moored, shipboard and glider observations taken at the continental slope at 11°S acquired during the SACUS project and to be acquired during planned research cruises.

• Hydrographic and current data that have been acquired in the EAF Nansen program will be analyzed in cooperation of INIP and GEOMAR aiming at studying the interannual to decadal variability at the eastern boundary off Angola.

• Carry out two research cruises (GEOMAR, IOW, INIP) with concurrent glider experiments to obtain high-resolution hydrographic, current and microstructure measurements in the Angolan upwelling region as well as in the Angola Benguela Frontal Zone. Data from off Angola will be used for in comparison to model results obtained in SP2, SP3, and SP4.

Figure1: a) Time series of alongshore velocity inferred from moored ADCP at 11?S. Positive (negative) values indicate northward (poleward) flow. b) Same as (a) but for cross-shore velocity. Positive (negative) indicate eastward (westward) flow.

Team:

Principal Investigators:
Prof. Dr. P. Brandt, GEOMAR Kiel, Germany
Prof. Dr. M. Visbeck, GEOMAR Kiel, Germany

PostDoc:
Dr. RA. Imbol Koungue, GEOMAR Kiel, Germany

Associated Staff:
Dr. M. Dengler, GEOMAR Kiel, Germany