• Amazon Plume;
  • light absorption;
  • salinity

[1] In the age of satellite sensors, ocean surface salinity detections have remained an elusive, yet important, property. Rivers discharge massive quantities of fresh water to the oceans every year, changing surface salinities and altering ocean circulation patterns. Researchers noticed that changes in surface salinity due to river discharge were often paced by the concentration of colored detrital matter (CDM), a more easily observable ocean property. They developed a technique to estimate surface salinity from CDM—a blanket term for dissolved organics, sediment, and other nonphotosynthetic particulate matter prevalent in river discharge. But the 2002 deployment of NASA's Aqua satellite, whose Advanced Microwave Scanning Radiometer-Earth Observing System is able to directly estimate surface salinity, allowed Salisbury et al. to reassess the assumed linear relationship between CDM and salinity.