My first research cruise went from Bremerhaven to New York. At Colorado State University guided by Mike Corrin hexagonal molecular structured silver iodide particles were doped with hygroscopic KNO3- traces to increase ice nucleation (Gravenhorst et al 1969 . Gravenhorst and Corrin 19 )
Following the first marine experience the German research group concentrated on first surveying the fait and flux of atmospheric trace substances over the ocean (e.g. Gravenhorst and Jendricke, 1975, Georgii and Gravenhorst 19 , Schaefer et al. 19 , Gravenrhorst 1978, Gravenhorst and Roos 1984, Ibrom et al. 1989).