DOI: 10.1002/2017JG004243
Scopus记录号: 2-s2.0-85041173761
论文题名: Watershed-Scale Drivers of Air-Water CO2 Exchanges in Two Lagoonal North Carolina (USA) Estuaries
作者: Van Dam B.R. ; Crosswell J.R. ; Anderson I.C. ; Paerl H.W.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 1 起始页码: 271
结束页码: 287
语种: 英语
英文关键词: CO2 flux
; estuary
; pCO2
; residence time
; storms
Scopus关键词: air-water interaction
; alkalinity
; carbon dioxide
; carbon flux
; climatology
; estuarine dynamics
; estuary
; flux measurement
; freshwater input
; gas exchange
; nutrient dynamics
; partial pressure
; residence time
; river
; storm
; watershed
; Neuse Estuary
; New River Estuary
; North Carolina
; United States
英文摘要: Riverine loading of nutrients and organic matter act in concert to modulate CO2 fluxes in estuaries, yet quantitative relationships between these factors remain poorly defined. This study explored watershed-scale mechanisms responsible for the relatively low CO2 fluxes observed in two microtidal, lagoonal estuaries. Air-water CO2 fluxes were quantified with 74 high-resolution spatial surveys in the neighboring New River Estuary (NewRE) and Neuse River Estuary (NeuseRE), North Carolina, which experience a common climatology but differ in marine versus riverine influence. Annually, both estuaries were relatively small sources of CO2 to the atmosphere, 12.5 and 16.3 mmol C m−2 d−1 in the NeuseRE and NewRE, respectively. Large-scale pCO2 variations were driven by changes in freshwater age, which modulates nutrient and organic carbon supply and phytoplankton flushing. Greatest pCO2 undersaturation was observed at intermediate freshwater ages, between 2 and 3 weeks. Biological controls on CO2 fluxes were obscured by variable inputs of river-borne CO2, which drove CO2 degassing in the river-dominated NeuseRE. Internally produced CO2 exceeded river-borne CO2 in the marine-dominated NewRE, suggesting that net ecosystem heterotrophy, rather than riverine inputs, drove CO2 fluxes in this system. Variations in riverine alkalinity and inorganic carbon loading caused zones of minimum buffering capacity to occur at different locations in each estuary, enhancing the sensitivity of estuarine inorganic C chemistry to acidification. Although annual CO2 fluxes were similar between systems, watershed-specific hydrologic factors led to disparate controls on internal carbonate chemistry, which can influence ecosystem biogeochemical cycling, trophic state, and response to future perturbations. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114839
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, United States; CSIRO Oceans and Atmosphere, Brisbane, QLD, Australia; Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA, United States
Recommended Citation:
Van Dam B.R.,Crosswell J.R.,Anderson I.C.,et al. Watershed-Scale Drivers of Air-Water CO2 Exchanges in Two Lagoonal North Carolina (USA) Estuaries[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(1)