Exploring Synergy Between Satellite Ocean Color and Salinity Observations Near the Amazon Outflow
[13-Nov-2013] Vandemark, D., Fournier, S., Reul, N., Salisbury, J., and Chapron, B.
Presented at the 2013 Aquarius/SAC-D Science Team Meeting
This study focuses on optimizing the combined use of ocean color satellite data and new ocean salinity measurements to better determine near surface salinity in regions with large freshwater outflow. We continue on from previous work evaluating the Amazon discharge region in the Western tropical Atlantic by developing a new monthly to seasonal assessment of ocean color data and its relation to satellite observe salinity. One goal is to more fully exploit ocean color data and its higher spatial resolution (<10 km) daily imagery to provide nearshore and frontal region salinity mapping that can complement Aquarius and SMOS measurements. This study looks at multi-year measurements from MERIS, MODIS, and SeaWiFS optical sensors along with SSS from SMOS to evaluate the accuracy and stability of weekly-to-monthly SSS derived from ocean color proxies tied to water clarity estimators (CDOM absorption and diffuse attenuation coefficients). These are not necessarily stable passive tracers due to changing land-ocean inputs and bio-optical transformations as plume waters advect and disperse. Implications for algorithm development, SSS validation across and between platforms in relatively fresh oceanic waters (SSS=32-35 psu), and synergistic use of satellite data for Amazon basin studies will be discussed.