Will modeling demographic differences in xylem vulnerability and stomatal closure in tropical trees improve drought response predictions of tropical forests?

Chlorophyll fluorescence has been a major tool for basic research in photosynthesis for nearly a century. Recently, it was discovered that solar induced fluorescence (SIF) can be accurately retrieved from space using high spectral resolution radiances from the Japanese GOSAT and European GOME-2 instruments. Over the last five years, global SIF measurements have provided key new insights into the global distribution and functioning of plant photosynthesis, providing a new way to quantify global gross primary production (GPP), detect regional-scale changes in plant productivity in relation to light use efficiency and water stress, disentangle biological contributions to atmospheric CO2 mole fractions, and refine process understanding in terrestrial biosphere models. OCO-2, launched in July 2014, promises to drive further scientific advances through unprecedented sampling density and smaller ground pixel sizes. We highlight some of the key recent research applications of satellite SIF, discuss future research directions, and present first results from OCO-2.