Containing as much carbon as the atmosphere, marine dissolved
organic matter is one of Earth’s major carbon reservoirs. With invigoration of
scientific inquiries into the global carbon cycle, our ignorance of its role in ocean
biogeochemistry became untenable. Rapid mobilization of relevant research two
decades ago required the community to overcome early false leads, but subsequent
progress in examining the global dynamics of this material has been steady.
Continuous improvements in analytical skill coupled with global ocean hydrographic
survey opportunities resulted in the generation of thousands of measurements
throughout the major ocean basins. Here, observations and model results provide new
insights into the large-scale variability of dissolved organic carbon, its contribution to
the biological pump, and its deep ocean sinks.