Deciphering the dynamics of inorganic carbon export from intertidal salt marshes using high-frequency measurements
Chu, Sophie N.
Wang, Zhaohui Aleck
Gonneea, Meagan E.
Kroeger, Kevin D.
Ganju, Neil K.
MetadataShow full item record
The lateral export of carbon from coastal marshes via tidal exchange is a key component of the marsh carbon budget and coastal carbon cycles. However, the magnitude of this export has been difficult to accurately quantify due to complex tidal dynamics and seasonal cycling of carbon. In this study, we use in situ, high-frequency measurements of dissolved inorganic carbon (DIC) and water fluxes to estimate lateral DIC fluxes from a U.S. northeastern salt marsh. DIC was measured by a CHANnelized Optical Sensor (CHANOS) that provided an in situ concentration measurement at 15-min intervals, during periods in summer (July – August) and late fall (December). Seasonal changes in the marsh had strong effects on DIC concentrations, while tidally-driven water fluxes were the fundamental vehicle of marsh carbon export. Episodic events, such as groundwater discharge and mean sea water level changes, can impact DIC flux through altered DIC concentrations and water flow. Variability between individual tides within each season was comparable to mean variability between the two seasons. Estimated mean DIC fluxes based on a multiple linear regression (MLR) model of DIC concentrations and high-frequency water fluxes agreed reasonably well with those derived from CHANOS DIC measurements for both study periods, indicating that high-frequency, modeled DIC concentrations, coupled with continuous water flux measurements and a hydrodynamic model, provide a robust estimate of DIC flux. Additionally, an analysis of sampling strategies revealed that DIC fluxes calculated using conventional sampling frequencies (hourly to two-hourly) of a single tidal cycle are unlikely to capture a representative mean DIC flux compared to longer-term measurements across multiple tidal cycles with sampling frequency on the order of tens of minutes. This results from a disproportionately large amount of the net DIC flux occurring over a small number of tidal cycles, while most tides have a near-zero DIC export. Thus, high-frequency measurements (on the order of tens of minutes or better) over the time period of interest are necessary to accurately quantify tidal exports of carbon species from salt marshes.
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Chemistry 206 (2018): 7-18, doi:10.1016/j.marchem.2018.08.005.
Suggested CitationMarine Chemistry 206 (2018): 7-18
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivatives 4.0 International
Showing items related by title, author, creator and subject.
Wang, Zhaohui Aleck; Kroeger, Kevin D.; Ganju, Neil K.; Gonneea, Meagan E.; Chu, Sophie N. (John Wiley & Sons, 2016-07-18)Dynamic tidal export of dissolved inorganic carbon (DIC) to the coastal ocean from highly productive intertidal marshes and its effects on seawater carbonate chemistry are thoroughly evaluated. The study uses a comprehensive ...
Sensor measurements for dissolved inorganic carbon from the Sage Lot Pond salt marsh tidal creek in Waquoit Bay, MA from July to December 2015 Wang, Zhaohui Aleck; Gonneea, Meagan; Kroeger, Kevin (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2019-05-29)Sensor measurements for dissolved inorganic carbon from the Sage Lot Pond salt marsh tidal creek in Waquoit Bay, MA from July to December 2015. DIC was measured with an autonomous sensor called CHANnelized Optical Sensor ...
Lake Michigan water chemistry data, including dissolved and particulate phosphorus, chlorophyll a, carbon dioxide, total dissolved inorganic carbon, and dissolved organic carbon. Bootsma, Harvey; Liao, Qian (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: firstname.lastname@example.org, 2019-03-15)Lake Michigan water chemistry data, including dissolved and particulate phosphorus, chlorophyll a, carbon dioxide, total dissolved inorganic carbon, and dissolved organic carbon. For a complete list of measurements, refer ...