1. Professor, School of Engineering, Univ. of Aberdeen, Fraser Noble Building, Kings College, Aberdeen, AB24 3UE, U.K. (corresponding author). E-mail: v.nikora@abdn.ac.uk
2. Science Leader, National Institute of Water and Atmospheric Research, P.O. Box 8602, Christchurch, New Zealand.
3. Teaching Fellow, School of Engineering, Univ. of Aberdeen, Fraser Noble Building, Kings College, Aberdeen, AB24 3UE, U.K.
4. Postdoctoral Fellow, Hydrodynamics Group, National Institute of Water and Atmospheric Research, P.O. Box 8602, Christchurch, New Zealand.
5. Research Assistant, Hydrodynamics Group, National Institute of Water and Atmospheric Research, P.O. Box 8602, Christchurch, New Zealand.