Application of Marine Remote Sensing technologies for the study of coastal and marine waters of the South-Eastern Baltic Sea

Gediminas Vaitkus

Vilnius University (LT)

The planned scientific activity aims at improving the monitoring and environmental assessment of algal blooms in the south-eastern Baltic Sea based on remote sensing data and creating a pilot operational monitoring system. Local algorithms for extracting chlorophyll a information from remotely sensed images will be improved and the influence of hydrodynamic processes on phytoplankton blooms will be evaluated by a combination of remote sensing and numerical modeling of hydrodynamic processes.

Phytoplankton chlorophyll a is frequently used as a proxy for phytoplankton biomass in environmental assessment of eutrophication in the Baltic Sea. During summer, blooms of cyanobacteria, among them toxic species, are a regular feature of the seasonal phytoplankton dynamics. Hydrodynamic processes - water column mixing and surface transport - significantly influence the surface distribution of algae. Information on the concurrent hydrodynamic processes is therefore essential for eutrophication assessment based on indicators of bloom strength. To fully benefit from the cost-efficiency of the use of remote sensing and to obtain timely information on the movement of potentially toxic blooms, the processing chain of image acquisition, data interpretation and Internet publishing of results will be automated, creating a pilot operational monitoring system.

The overall scope of activities focus on a) improvement of local algorithms for extracting chlorophyll a concentrations from remotely sensed images in the south-eastern Baltic Sea, using multivariate statistical methods to link the information of various sensor bands to a ground truthing database from marine monitoring observations; b) classification of hydrodynamical processes based on remote sensing (MODIS IR and VIS images) and numerical modeling, describing and quantifying water flows during hydrodynamical situations typical for the study area during the growth season; c) assessment of bloom dynamics in the context of hydrodynamical processes, identifying processes triggering blooms in the study area and producing a semi-empirical matrix to take the variability in surface water transport into account when assessing eutrophication in the study area; and d) the development of an on-line web based pilot information service, which would carry the necessary structural and technological compatibility, as well as data interoperability with the existing operational marine information services within GMES.