Primary Productivity and Circulation Patterns Downstream of South Georgia: A Southern Ocean Example of the ‘‘Island Mass Effect”

• Main Authors: Borrione, Ines, Aumont, Olivier, Schlitzer, Reiner
• Other Authors: Lohmann, Gerrit, Grosfeld, Klaus, Wolf-Gladrow, Dieter, Unnithan, V., Notholt, J., Wegner, Anna
• Format: Book Part
• Language: unknown
• Published: Springer 2013
• Subjects: Southern Ocean
• Online Access: https://epic.awi.de/id/eprint/33719/; https://epic.awi.de/id/eprint/33719/1/Springer-chapter_IBorrione_inbook.pdf; https://hdl.handle.net/10013/epic.42088; https://hdl.handle.net/10013/epic.42088.d001

Growth of phytoplankton in the Southern Ocean (SO) is largely limited by insufficient concentrations of the micronutrient iron, so that despite the large macronutrient reservoir, the SO is considered a High Nutrient Low Chlorophyll region. Therefore, phytoplankton growth is enhanced where exogenous iron is introduced to the system, for example downstream from islands. These confined regions sustain very rich ecosystems and are hot spots for atmospheric carbon dioxide drawdown. In this study, a combination of satellite derived measurements and model simulations are used to investigate the biological and physical environmental disturbances of the island of South Georgia (37°W, 54°S), which is located in the southwestern part of the Atlantic sector of the SO. We show not only that the island shelf is an important source of dissolved iron to the system, but also that the characteristic surface circulation patterns found downstream of the island play an important role in maintaining the shape and distribution of the developing phytoplankton bloom.