Song
Shuzhen
Song
Shuzhen
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DatasetDiscrete bottle sample measurements for carbonate chemistry, organic alkalinity and organic carbon from samples collected in Waquoit Bay and Vineyard Sound, MA in 2016(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-02-26) Wang, Zhaohui Aleck ; Song, Shuzhen ; Gonneea, Meagan ; Kroeger, KevinDiscrete bottle sample measurements for carbonate chemistry, organic alkalinity and organic carbon from samples collected in Waquoit Bay and Vineyard Sound, MA in 2016. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/794163
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ArticleParticle triggered reactions as an important mechanism of alkalinity and inorganic carbon removal in river plumes(American Geophysical Union, 2021-05-20) Wurgaft, Eyal ; Wang, Zhaohui Aleck ; Churchill, James H. ; Dellapenna, Timothy M. ; Song, Shuzhen ; Du, Jiabi ; Ringham, Mallory C. ; Rivlin, Tanya ; Lazar, BoazThe effects of heterogeneous reactions between river-borne particles and the carbonate system were studied in the plumes of the Mississippi and Brazos rivers. Measurements within these plumes revealed significant removal of dissolved inorganic carbon (DIC) and total alkalinity (TA). After accounting for all known DIC and TA sinks and sources, heterogeneous reactions (i.e., heterogeneous CaCO3 precipitation and cation exchange between adsorbed and dissolved ions) were found to be responsible for a significant fraction of DIC and TA removal, exceeding 10% and 90%, respectively, in the Mississippi and Brazos plume waters. This finding was corroborated by laboratory experiments, in which the seeding of seawater with the riverine particles induced the removal of the DIC and TA. The combined results demonstrate that heterogeneous reactions may represent an important controlling mechanism of the seawater carbonate system in particle-rich coastal areas and may significantly impact the coastal carbon cycle.
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ArticleOrganic alkalinity as an important constituent of total alkalinity and the buffering system in river‐to‐coast transition zones(American Geophysical Union, 2023-07-28) Song, Shuzhen ; Bellerby, Richard Garth James ; Wang, Zhaohui Aleck ; Wurgaft, Eyal ; Li, DaojiOrganic acid-base species in the dissolved organic carbon pool have been shown to make an important contribution (i.e., organic alkalinity; OrgAlk) to the total alkalinity (TA) in many coastal systems. This study documents an intensive investigation of OrgAlk characteristics in the river-to-coast transition zones of six southeast Chinese rivers. OrgAlk, mainly originating from river input, accounted for an important proportion of TA (0.3%–12%) in six estuaries. Carboxylic acid groups were commonly present in all estuaries. Notable differences in the TA values (1–18 μmol kg−1) determined by several established TA measurement approaches were identified in estuaries where organic acids with pKa <5.2 were abundant. The most widely used open-cell titration method, in comparison with closed-cell titration and single-step titration, is the best approach to incorporate OrgAlk in titrated TA when the pKa values of organic acids were >5 in the study estuaries. Across our study sites, OrgAlk might modify H+ concentrations by 3%–69% (i.e., pH by 0.01–0.78) and aragonite saturation states by 1%–72%, indicating that OrgAlk can play a significant role in the coastal carbonate buffering system. It is essential to improve current TA measurement approaches to more accurately represent OrgAlk in the coastal system and assess impacts of OrgAlk on coastal carbonate chemistry.
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ArticleHigh-frequency variability of carbon dioxide fluxes in tidal water over a temperate salt marsh(Association for the Sciences of Limnology and Oceanography (ASLO), 2023-07-27) Song, Shuzhen ; Wang, Zhaohui Aleck ; Kroeger, Kevin D. ; Eagle, Meagan ; Chu, Sophie N. ; Ge, JianzhongExisting analyses of salt marsh carbon budgets rarely quantify carbon loss as CO2 through the air–water interface in inundated marshes. This study estimates the variability of partial pressure of CO2 (pCO2) and air–water CO2 fluxes over summer and fall of 2014 and 2015 using high-frequency measurements of tidal water pCO2 in a salt marsh of the U.S. northeast region. Monthly mean CO2 effluxes varied in the range of 5.4–25.6 mmol m−2 marsh d−1 (monthly median: 4.8–24.7 mmol m−2 marsh d−1) during July to November from the tidal creek and tidally-inundated vegetated platform. The source of CO2 effluxes was partitioned between the marsh and estuary using a mixing model. The monthly mean marsh-contributed CO2 effluxes accounted for a dominant portion (69%) of total CO2 effluxes in the inundated marsh, which was 3–23% (mean 13%) of the corresponding lateral flux rate of dissolved inorganic carbon (DIC) from marsh to estuary. Photosynthesis in tidal water substantially reduced the CO2 evasion, accounting for 1–86% (mean 31%) of potential CO2 evasion and 2–26% (mean 11%) of corresponding lateral transport DIC fluxes, indicating the important role of photosynthesis in controlling the air–water CO2 evasion in the inundated salt marsh. This study demonstrates that CO2 evasion from inundated salt marshes is a significant loss term for carbon that is fixed within marshes.