DOI: 10.1029/2017JG004023
Scopus记录号: 2-s2.0-85049866855
论文题名: Seasonal Drivers of Carbon Dioxide Dynamics in a Hydrologically Modified Subtropical Tidal River and Estuary (Caboolture River, Australia)
作者: Jeffrey L.C. ; Santos I.R. ; Tait D.R. ; Makings U. ; Maher D.T.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 6 起始页码: 1827
结束页码: 1849
语种: 英语
英文关键词: greenhouse gas
; groundwater discharge
; hydrology
; modified wetland
Scopus关键词: annual variation
; carbon cycle
; carbon dioxide
; chlorophyll a
; discharge
; dissolved organic matter
; estuarine dynamics
; greenhouse gas
; groundwater
; hydrological modeling
; physicochemical property
; river system
; seasonal variation
; subtropical region
; water column
; wetland
; Australia
; algae
英文摘要: Estuaries are dynamic hot spots for carbon cycling and atmospheric evasion. Here we assess the dynamics and drivers of CO2 in a hydrologically modified subtropical Australian estuary. Over 1 year, 10 high-resolution spatial surveys of pCO2, radon, chromophoric dissolved organic matter, chlorophyll a, and physicochemical parameters were conducted from the estuary mouth to a weir located 25 km upstream. The riverine respiratory quotient revealed that processes besides water column respiration were driving high CO2 within the tidal river (salinity < 2) but not in the estuary (salinity > 2). Conservative mixing plots for pCO2 and 222Rn implied that groundwater may be a contributing source of CO2 during most surveys, but not during dry conditions. A multiple linear regression model explained 88% of the annual pCO2 variability, indicating that mixing, metabolism, temperature, and groundwater inputs were key drivers of CO2. Inputs from an upstream wastewater outfall potentially fuel observed seasonal algal blooms, resulting in the lowest daytime CO2 emissions periods. Postbloom surveys had the highest daytime CO2 emissions. The average tidal river CO2 atmospheric flux rate was 379 ± 53 mmol m−2 day−1. The average estuarine CO2 flux was 78 ± 17 mmol m−2 day−1, equating to 28 ± 6 mol m−2 yr−1. Although the tidal river surface area was ~10 times smaller than the estuary, about one third (35%) of the CO2 emissions were derived from the tidal river. Our results suggest that CO2 emissions along the tidal river-estuary continuum are dynamic over small temporal and spatial scales and that a combination of hydrological and biological processes is a controlling factor of this variability. ©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/113796
Appears in Collections: 气候减缓与适应
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作者单位: National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW, Australia; SCU Geoscience, Southern Cross University, Lismore, NSW, Australia
Recommended Citation:
Jeffrey L.C.,Santos I.R.,Tait D.R.,et al. Seasonal Drivers of Carbon Dioxide Dynamics in a Hydrologically Modified Subtropical Tidal River and Estuary (Caboolture River, Australia)[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(6)