In 2016, Hurricane Matthew accounted for 25% of the annual riverine C loading to the Neuse River Estuary‐Pamlico Sound, in eastern North Carolina. Unlike inland watersheds, dissolved organic carbon (DOC) was the dominant component of C flux from this coastal watershed and stable carbon isotope and chromophoric dissolved organic matter evidence indicated the estuary and sound were dominated by wetland‐derived terrigenous organic matter sources for several months following the storm. Persistence of wetland‐derived DOC enabled its degradation to carbon dioxide (CO2), which was supported by sea‐to‐air CO2fluxes measured in the sound weeks after the storm. Under future increasingly extreme weather events such as Hurricane Matthew, and most recently Hurricane Florence (September 2018), degradation of terrestrial DOC in floodwaters could increase flux of CO2from estuaries and coastal waters to the atmosphere.
Estuaries regulate transport of dissolved organic carbon (DOC) from land to ocean. Export of terrestrial DOC from coastal watersheds is exacerbated by increasing major rainfall and storm events and human activities, leading to pulses of DOC that are shunted through rivers downstream to estuaries. Despite an upward trend of extreme events, the fate of the pulsed terrestrial DOC in estuaries remains unclear. We analyzed the effects of seven major tropical cyclones (TC) from 1999 to 2017 on the quantity and fate of DOC in the Neuse River Estuary (NC, USA). Significant TC‐induced increases in DOC were observed throughout the estuary; the increase lasting from around 50 d at head‐of‐tide to over 6 months in lower estuary. Our results suggest that pulsed terrestrial DOC associated with TCs temporarily overwhelms the estuarine filter's abiotic and biotic degradation capacity under such high flow events, enhancing the shunt of terrestrial carbon to the coastal ocean.
more » « less- NSF-PAR ID:
- 10360989
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Limnology and Oceanography Letters
- Volume:
- 6
- Issue:
- 1
- ISSN:
- 2378-2242
- Page Range / eLocation ID:
- p. 43-50
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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