In 2001 the Red Sea Outflow Experiment (REDSOX) obtained the first comprehensive survey of the outflow of Red Sea water into the Gulf of Aden. The objectives of REDSOX were (i) to describe the pathways and downstream evolution of the descending outflow plumes, (ii) to quantify the processes that control the final depth of the equilibrated Red Sea outflow water, and (iii) to identify the transport processes and mechanisms that advect Red Sea outflow Water and its properties through the Gulf of Aden and into the Indian Ocean. The field experiment and the final data processing have been successfully completed, and first results from the project have been published. This grant supports the analysis and synthesis of part of the data collected during the two REDSOX cruises such as high-resolution hydrographic and direct current surveys and direct measurements of turbulent mixing. The analysis will focus on the following specific objectives. 1. Rationalize bulk estimates of entrainment, total stress and entrainment stress of the descending plume with corresponding "direct" estimates based on overturning scales. 2. Explore the three-dimensional circulation in the two outflow channels with focus on the effects of rotation. 3. Analyze Reynolds stress and turbulence structure above the sea floor and relate the bottom stress to the interfacial stress. 4. Compare the properties and dynamics of the Red Sea plume with other outflows, such as the outflow from the Mediterranean, to attempt to generalize the results with respect to other plumes and broaden the scope and impact of the synthesis activities. The completed synthesis will provide detailed insight into the Red Sea outflow and related circulation processes in the Gulf of Aden. It will improve the understanding of descending plumes in general, especially of the critical process of entrainment and mixing. Such knowledge is crucial for improved parameterizations of these processes in ocean circulation and climate models.
