Remote Sensing of phytoplankton blooms and dust emission events in the Patagonian shelf

RIVAROSSA, MARTÍN; WILLIAMS, GABRIELA NOEMÍ; DOGLIOTTI, ANA INÉS; GAGLIARDINI, DOMINGO ANTONIO

Puerto Madryn

Workshop; SAC-D/Aquarius Workshop; 2008

CONAE

Exceptional phytoplankton blooms, like dinoflagellates red tides or milky white coccolithophorid blooms, do often occur in form of distinct patches in water bodies with uncommon and isolates hydrographic and biochemical conditions. The spatial and temporal changes of bloom patches are sometimes very complex and occur on small scales with sharp fronts, therefore they are hard to map from ships. In many cases exceptional blooms have been detected incidentally only at their mature state so that its development could no be reconstructed afterwards. Satellite data could be used for continuous monitoring such exceptional blooms and they could guide research vessel to its locations. Furthermore, satellite images offer the opportunity to backtrack the origin of the bloom in time and space. At the present time, there are different satellite missions that are capable of detecting these blooms. Exceptional phytoplankton blooms are very common in the Patagonian shelf from September to March. Dust emissions from the desert introduce changes in the atmospheric optical properties. Therefore, in cloud free regions they are also clearly observed from space when dust is transported over the ocean. In particular, over the Patagonian shelf, dust emissions have been observed in satellite imagery during austral summer months, from September to March. A cooperation project between the Instituto de Astronomía y Física del Espacio (IAFE) and the Centro Nacional Patagónico (CENPAT) exits to monitor, using satellite imagery, exceptional phytoplankton blooms and dust emission events and to determine if both phenomena are somehow related. In this way, the analysis of historical data from SeaWiFS (since 1998), MODIS (Since 2001), SAC-C (since 2001) and LANDSAT-TM/ETM+ has been recently initiated. The objective of this work is to present examples of some blooms and dust events observed over the Patagonian shelf by the mentioned satellite missions. Also, spatial and temporal changes, and spectral characteristic of specific patches of probable blooms are shown.