Colloquium: Dr. Bingqing Liu | Florida State University

ABSTRACT:  Phytoplankton are the foundation of aquatic food webs and play a critical role in global carbon sequestration, regulating atmospheric CO₂ levels and climate. Highly responsive to environmental changes, they act as early responders, impacting marine food webs and biogeochemical cycles. As a diverse community, phytoplankton vary in cell shape, ecological function,

and physiological responses to climate factors. Understanding their

composition is central to understanding complex Earth science questions,

which demand attention at both regional, and global scales.

How can satellites, orbiting hundreds of kilometers above Earth, monitor and

distinguish these microscopic organisms in oceans? The answer lies in their

complex interactions with light field in water. In this talk, I will discuss the

optical characterization of phytoplankton groups and how these properties

(e.g., absorption, backscattering and reflectance) underpin ocean color

remote sensing. Specifically, I will highlight how ocean color observations—including NASA’s new hyperspectral mission, PACE and EMIT—can be used to investigate seasonal variations and episodic phytoplankton responses (e.g., harmful algal blooms) to extreme events, such as hurricanes, in the context of climate change and anthropogenic disturbances, with high spatiotemporal resolution at regional scales.