Poster Session 2, Tuesday, October 4, 10:40–12:40
Two shades of green in Norwegian fjords
Glacial-fed rivers, lakes and fjords take an eye-catching turquoise color during the melting season, starting in late spring and lasting for several months. The color is mainly caused by rock flour, which is fine-grained sand and silt particles, generated by grinding and erosion of bedrock by glaciers. Seasonal blooms of the algae Emiliania huxleyi produce a similar greenish color, and questions arise on the similarity of water-leaving radiances for these two cases. The optical complexity of Norwegian fjords due to varying terrestrial run-off and phytoplankton blooms makes it challenging to monitor these coastal waters using remote sensing, which is important due to the abundant fisheries and aquaculture in the region. In order to answer these questions we have conducted several field campaigns in Norwegian fjords with varying influence from glacial meltwater or Emiliania huxleyi blooms. We have measured inherent optical properties (IOPs) such as volume scattering functions, and absorption coefficients using LISST-VSF, LISST-200X and ac-s instruments, as well as analysing water samples to characterize and identify the particles in the surface layer. Measured IOPsare fed into a radiative transfer model, for a detailed comparison of spectral water-leaving reflectance for the two water types. Finally, the merit of remote sensing in these waters is assessed by comparison with satellite inferred spectra.
Borge Hamre, University of Bergen, [email protected]
Håkon Sandven, University of Bergen, [email protected]
Elinor Tessin, University of Bergen, [email protected]
Yi-Chun Chen, University of Bergen, [email protected]
Svein Rune Erga, University of Bergen, [email protected]