The German Bight (Bild: HZG/ESA)
Satellites provide a large-scale view of coastal regions across the globe.
The Department of Remote Sensing analyses satellite data using methods developed in-house. The colour of the ocean is used to determine seawater optical and biogeochemical properties.
Highly precise and complex measurements of these optical properties are performed in parallel, in both the laboratory and on-site. Such properties include light absorption and scattering in various types of water. This directly measured information is integrated into optical models and measurement methods to improve the satellite data analysis and processing.
In addition, to study small-scale structures in the water, there are remote sensing data gathered aircraft-assisted, e.g. with a zeppelin.
By comparing directly obtained data with satellite data, the desired quantities can then be determined from the satellite data itself. This includes scattering and absorption of sunlight in water, the transparency of the water or determining the concentration of phytoplankton, yellow substance and suspended matter in the water. Each alteration of these quantities can be seen in the changes of the ocean’s colour.
These analysis methods are especially utilised by the European Space Agency (ESA). They allow scientists to obtain important environmental information about the coastal regions. The data supplies information, for example, on the occurrence of algal blooms, which could become more or less frequent due to climate change.
Satellite data covering several decades is now available and can be evaluated in regard to natural and anthropogenic causes of climate change. Future satellite missions will continue to supplement this data.