Bob Chen ~ Urban Oceanographer

Neponset salt marsh

Investigating Carbon Flux In
Nearshore Waters

Click this image to explore the
Neponset Estuary
Funded by a chemical oceanography grant from NSF to investigate the flux of carbon in nearshore waters, Dr. Bob Chen uses the Neponset salt marsh for his research. The marsh, located just a short drive from the UMass campus, is where his lab has established five sensor buoys that continually send data over a wireless network. Measuring dissolved organic carbon (DOC) cycling through the coastal ocean connects the Neponset salt marsh to the global carbon cycle. Preliminary estimates indicate that the amount of carbon that comes out of salt marshes is equivalent to the amount of carbon that comes out of rivers, a considerable quantity within the global carbon budget. The dissolved organic carbon pool in the ocean is about the same size as the atmospheric CO2 pool," says Bob. "Is the coastal ocean a net source or a net sink of atmospheric CO2? Even that question has not really been answered."

Bob's research focuses on the chromophoric (colored) dissolved organic matter (CDOM) in coastal waters. His data show that the salt marsh is contributing a large amount of CDOM and DOC to the material coming out of the watershed. He is using high resolution methods to observe how processes are changing the material seasonally and over fairly short distances. Observing that the end-member changes hourly as well as seasonally has prompted further study to discover the source of material coming into the estuary.