Oceanic Chlorophyll-\u3cem\u3ea\u3c/em\u3e Content

Ever since the first Earth-observing satellite was launched, it became the dream of oceanographers to measure ocean chlorophyll a from space. Through more than a decade of dedicated theoretical, laboratory, and field research, the Coastal Zone Color Scanner was launched onboard NASA’s Nimbus-7 satellite in 1978. Originally intended as a proof-of-concept mission, the CZCS endured well beyond its two-year design life (1978–1986), and provided oceanographers with clear evidence that ocean chlorophyll a could be observed from space. Continued community effort led to the successor missions of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, 1997–2010), Moderate Resolution Imaging Spectroradiometer (MODIS, 1999—present for Terra and 2002—present for Aqua), Medium Resolution Imaging Spectrometer (MERIS, 2002–2012), and other modern satellite instruments. This chapter provides a brief review of how oceanic chlorophyll a is “measured”, validated, and used in various research studies and applications including the ocean’s response to climate variability and the assessment of coastal ocean changes to help resource management. Particular emphasis is given to atmospheric correction, bio-optical inversion, and algorithm validation. Finally, future satellite ocean color missions and research directions to support these missions are briefly discussed