Project summary

Measurements of optical properties at high spectral resolution provide an elegant and non-intrusive tool to observe the marine ecosystem both in situ and in vivo.

From a particular distribution of two different phytoplankton species (figure - top left panel) we obtain a specific absorption and scattering spectrum with depth (top right panel). Some time later, turbulence and growth has changed the system (bottom left) and we observe a different spectrum (bottom right). The main difficulty lies in relating the spectra to the water column constituents and dynamics. The issue is further complicated by the fact that there are usually more than two different types of phytoplankton present in the water column, plus several other types of abiotic particles such as sediments, detritus and minerals who all contribute to some degree to the optical spectra.

Although, the underlying theoretical framework of ocean optics is well developed, there is still an urgent need to further develop the analytical methods in order to be able to use these new technologies to their full potential. AQUALIGHT will make an important contribution to this effort. By combining radiative transfer and turbulence models, hyperspectral observations and data analysis techniques with classical observations, AQUALIGHT will try to establish quantitative linkages between the observed variability of the optical properties and changes in the physical and biological characteristics of the water column due to primary production, physiological changes, and turbulent mixing.

The result is a model which covers both the forcing side and the response, providing information on the system in unprecedented detail.