Ripple formation in weakly turbulent flow A. Wierschem, C. Groh, I. Rehberg, N. Aksel and C. A. Kruelle Eur. Phys. J. E, 25 2 (2008) 213-221 Published online: 21 March 2008 DOI: 10.1140/epje/i2007-10282-4