Details

Autor(en) / Beteiligte

• Paerl, Hans W.
• Crosswell, Joseph R.
• Van Dam, Bryce
• Hall, Nathan S.
• Rossignol, Karen L.
• Osburn, Christopher L.
• Hounshell, Alexandria G.
• Sloup, Randolph S.
• Harding, Lawrence W.

Titel

Two decades of tropical cyclone impacts on North Carolina’s estuarine carbon, nutrient and phytoplankton dynamics: implications for biogeochemical cycling and water quality in a stormier world

Ist Teil von

• Biogeochemistry, 2018-12, Vol.141 (3), p.307-332

Ort / Verlag

Cham: Springer Science + Business Media

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Coastal North Carolina (USA) has experienced 35 tropical cyclones over the past 2 decades; the frequency of these events is expected to continue in the foreseeable future. Individual storms had unique and, at times, significant hydrologic, nutrient-, and carbon (C)-loading impacts on biogeochemical cycling and phytoplankton responses in a large estuarine complex, the Pamlico Sound (PS) and Neuse River Estuary (NRE). Major storms caused up to a doubling of annual nitrogen and tripling of phosphorus loading compared to non-storm years; magnitudes of loading depended on storm tracks, forward speed, and precipitation in NRE-PS watersheds. With regard to C cycling, NRE-PS was a sink for atmospheric CO₂ during dry, storm-free years and a significant source of CO₂ in years with at least one storm, although responses were storm-specific. Hurricane Irene (2011) mobilized large amounts of previously-accumulated terrigenous C in the watershed, mainly as dissolved organic carbon, and extreme winds rapidly released CO₂ to the atmosphere. Historic flooding after Hurricanes Joaquin (2015) and Matthew (2016) provided large inputs of C from the watershed, modifying the annual C balance of NRE-PS and leading to sustained CO₂ efflux for months. Storm type affected biogeochemical responses as C-enriched floodwaters enhanced air–water CO₂ exchange during ‘wet’ storms, while CO₂ fluxes during ‘windy’ storms were largely supported by previously-accumulated C. Nutrient loading and flushing jointly influenced spatio-temporal patterns of phytoplankton biomass and composition. These findings suggest the importance of incorporating freshwater discharge and C dynamics in nutrient management strategies for coastal ecosystems likely to experience a stormier future.