Tracking phytoplankton from space in a changing Southern Ocean
Changes in the Southern Ocean (SO) have global consequences. The SO region is responsible for about half of the global annual uptake of anthropogenic carbon dioxide (CO2) from the atmosphere. As part of the atmospheric CO2 uptake is driven by phytoplankton primary production, a significant impact on...
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| Format: | Thesis |
| Language: | unknown |
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2015
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| Online Access: | https://epic.awi.de/id/eprint/38732/ https://epic.awi.de/id/eprint/38732/1/00104682-1.pdf http://elib.suub.uni-bremen.de/edocs/00104682-1.pdf https://hdl.handle.net/10013/epic.46427 https://hdl.handle.net/10013/epic.46427.d001 |
| Summary: | Changes in the Southern Ocean (SO) have global consequences. The SO region is responsible for about half of the global annual uptake of anthropogenic carbon dioxide (CO2) from the atmosphere. As part of the atmospheric CO2 uptake is driven by phytoplankton primary production, a significant impact on the feedback of phytoplankton is expected under climate change. Indeed, changes in the atmospheric and ocean temperature, wind patterns and sea ice concentration have already been documented in the SO region. However, our understanding on how phytoplankton respond to ongoing and future environmental changes strongly depends on consistent large scale and long term observations. As a remote region, substantial time and costs are required to obtain a comprehensive dataset for the SO. The use of satellite remote sensing is a cost-effective alternative and has led to important insights into the current knowledge of phytoplankton dynamics in this region. However, this technique does not come without limitations. Ocean colour remote sensing at high latitudes has to deal with different issues as for example high cloudiness and the limited number of in situ observations for development and calibration/validation of algorithms. Consequently, there is a strong need to assess the performance of ocean colour derived-products in the SO. Ocean colour remote sensing can be used to estimate net primary production (NPP), abundance of phytoplankton functional types (PFT), as well as their spatial and temporal dynamic. Although accurate information on NPP is fundamental, large differences have been observed among models hitherto applied in the SO. Apart from that, different PFTs play specific roles in the oceanic biogeochemical cycle and this information is of key importance on quantifying oceanic NPP. Diatoms, for instance, are the main primary producers in the region. Furthermore, additional insights into their variability due to environmental changes can be gained by studying the phenology of diatom blooms. The underlying aim of this ... |
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