Greenland Sea primary production with respect to changes in sea ice cover.

• Main Author: Cherkasheva, Alexandra
• Format: Thesis
• Language: unknown
• Published: University Bremen 2014
• Subjects: Arctic; Arctic Ocean; Greenland; Climate change; Greenland Sea; Phytoplankton; Sea ice
• Online Access: https://epic.awi.de/id/eprint/35951/; https://epic.awi.de/id/eprint/35951/1/00103817-1.pdf; http://elib.suub.uni-bremen.de/edocs/00103817-1.pdf; https://hdl.handle.net/10013/epic.43851; https://hdl.handle.net/10013/epic.43851.d001

Currently the world marine primary production estimates range by a factor of two between different models. When the Arctic ocean alone is considered the factor rises to as much as fifty, because sea ice complicates remote sensing, and bio-optical properties of water as well as vertical distribution of phytoplankton differ from those of global waters. Arctic phytoplankton today deserve special attention as they are already living in waters with most prominent climate change effect, which are shifting towards fresher surface layer, thinner sea ice, more open water area and are very likely to experience ice-free summers in the near future. These shifts in turn alter solar irradiation, nutrient transport and plankton seasonality, and whether such an impact will result in an increase or a decrease of phytoplankton remains questionable. Since polar regions are difficult to access with the research vessels, field data are scarce here and remote sensing data provide an alternative. However it is not recommended to use remote sensing data alone, as the satellite ocean color algorithms are known to perform poorly at polar latitudes even if developed explicitly for the Arctic waters. Gaps in satellite data, which occur at these latitudes because of the presence of sea ice, clouds and low sun elevation angles, are also a source of error. The current study combined remote sensing, simulated and field data for the years 1998-2012 to investigate the seasonal cycle, variability and productivity of phytoplankton in the Greenland Sea, which is one of the most productive and field data-abundant regions of the Arctic. Specific objectives of our case Greenland Sea study were: 1) to study the interaction between phytoplankton and the physical factors, such as sea ice concentration and thickness, water temperature and salinity; 2) to investigate temporal trends, seasonal cycle and spatial variability of phytoplankton; 3) to obtain more accurate estimates of primary production. First the focus was set to northern part of Greenland Sea ...