Virginia Institute of Marine Science
This study uses a neural network model trained with in situ data, combined with satellite data and hydrodynamic model products, to compute the daily estuarine export of dissolved organic carbon (DOC) at the mouths of Chesapeake Bay (CB) and Delaware Bay (DB) from 2007 to 2011. Both bays show large ﬂux variability with highest ﬂuxes in spring and lowest in fall as well as interannual ﬂux variability (0.18 and 0.27 Tg C/year in 2008 and 2010 for CB; 0.04 and 0.09 Tg C/year in 2008 and 2011 for DB). Based on previous estimates of total organic carbon (TOCexp) exported by all Mid‐Atlantic Bight estuaries (1.2 Tg C/year), the DOC export (CB + DB) of 0.3 Tg C/year estimated here corresponds to 25% of the TOCexp. Spatial and temporal covariations of velocity and DOC concentration provide contributions to the ﬂux, with larger spatial inﬂuence. Differences in the discharge of fresh water into the bays (74 billion m3/year for CB and 21 billion m3/year for DB) and their geomorphologies are major drivers of the differences in DOC ﬂuxes for these two systems. Terrestrial DOC inputs are similar to the export of DOC at the bay mouths at annual and longer time scales but diverge signiﬁcantly at shorter time scales (days to months). Future efforts will expand to the Mid‐Atlantic Bight and Gulf of Maine, and its major rivers and estuaries, in combination with coupled terrestrial‐estuarine‐ocean biogeochemical models that include effects of climate change, such as warming and CO2 increase.
Signorini, SR; Mannino, A; Friedrichs, Marjorie A.M.; St-Laurent, Pierre; al, et; Da, F; and al, et, Estuarine Dissolved Organic Carbon Flux From Space: With Application to Chesapeake and Delaware Bays (2019). JGR Oceans.