Oceanographic laser remote sensing: measurement of hydrographic fronts in the German Bight and in the Northern Adriatic Sea

Abstract With fluorescence lidar operated from aircraft a nearly synoptic investigation of hydrographic conditions in the surface layer of the sea is achieved. Raman and fluorescence spectroscopy allow a registration of spectral attenuation coefficients as well as concentrations of chlorophyll-^ and gelbstoff (DOM, Dissolved Organic Matter). In particular gelbstoff can be used as a natural tracer for the identification of water types and frontal systems in coastal areas. Results obtained in the Adriatic Sea and in the southern North Sea are presented in this article. Both areas are characterized by strong river run-off. However, their hydrographic character as well as the optical conditions differ markedly, and this allows the demonstration of the application of lidar remote sensing in different coastal seas.