William D. Smyth was trained in theoretical physics and is now a professor of oceanography at Oregon State University. He has taught graduate-level courses in fluid mechanics, geophysical waves and instabilities, descriptive oceanography, dynamic meteorology and climate. His research interests focus on instability and turbulence in geophysical flows and on the broader study of complex phenomena. He has been a visiting scientist at the Liebnitz Institute for Baltic Sea Research in Germany. He has twice received the Pattulo Award for Excellence in Teaching, and has been honoured with the Kirby Liang Fellowship from Bangor University in Wales and a Distinguished Visitor Fellowship from Xiamen University in China. Jeffrey R. Carpenter is a physical oceanographer at the Institute of Coastal Research, Helmholtz-Zentrum Geeshacht, Germany, where he is the leader of the Small Scale Physics and Turbulence Group. His work focuses on the fluid mechanics of physical process in natural water bodies, and his research interests include turbulent mixing in stable density stratification, shear flows, instability and wave interactions, double-diffusive convection, heat fluxes and eddy formation in the Arctic Ocean, turbulence measurements using ocean gliders, and the impacts of offshore wind farms on the coastal ocean.