More Like this

1. Updated methods for global locally interpolated estimation of alkalinity, pH, and nitrate: LIR: Global alkalinity, pH, and nitrate estimates

   https://doi.org/10.1002/lom3.10232  

   Carter, B. R.; Feely, R. A.; Williams, N. L.; Dickson, A. G.; Fong, M. B.; Takeshita, Y. (February 2018, Limnology and Oceanography: Methods)
2. Monitoring, reporting, and verification for ocean alkalinity enhancement

   https://doi.org/10.5194/sp-2-oae2023-12-2023  

   Ho, David T; Bopp, Laurent; Palter, Jaime B; Long, Matthew C; Boyd, Philip W; Neukermans, Griet; Bach, Lennart T (January 2023, State of the Planet)

   Oschlies, Andreas (Ed.)

   Abstract. Monitoring, reporting, and verification (MRV) refers to the multistep process of monitoring the amount of greenhouse gas removed by a carbon dioxide removal (CDR) activity and reporting the results of the monitoring to a third party. The third party then verifies the reporting of the results. While MRV is usually conducted in pursuit of certification in a voluntary or regulated CDR market, this chapter focuses on key recommendations for MRV relevant to ocean alkalinity enhancement (OAE) research. Early stage MRV for OAE research may become the foundation on which markets are built. Therefore, such research carries a special obligation toward comprehensiveness, reproducibility, and transparency. Observational approaches during field trials should aim to quantify the delivery of alkalinity to seawater and monitor for secondary precipitation, biotic calcification, and other ecosystem changes that can feed back on sources or sinks of greenhouse gases where alkalinity is measurably elevated. Observations of resultant shifts in the partial pressure of CO2 (pCO2) and ocean pH can help determine the efficacy of OAE and are amenable to autonomous monitoring. However, because the ocean is turbulent and energetic and CO2 equilibration between the ocean and atmosphere can take several months or longer, added alkalinity will be diluted to perturbation levels undetectable above background variability on timescales relevant for MRV. Therefore, comprehensive quantification of carbon removal via OAE will be impossible through observational methods alone, and numerical simulations will be required. The development of fit-for-purpose models, carefully validated against observational data, will be a critical part of MRV for OAE. 

   more » « less
3. Autonomous in situ measurements of freshwater alkalinity

   https://doi.org/10.1002/lom3.10404  

   Shangguan, Qipei; Lai, Chun‐Ze; Beatty, Cory M.; Young, Fischer L.; Spaulding, Reggie S.; DeGrandpre, Michael D. (December 2020, Limnology and Oceanography: Methods)

   Abstract Total alkalinity (A_T) is an important parameter in the study of aquatic biogeochemical cycles, chemical speciation modeling, and many other important fundamental and anthropogenic (e.g., industrial) processes. We know little about its short‐term variability, however, because studies are based on traditional bottle sampling typically with coarse temporal resolution. In this work, an autonomous A_Tsensor, named the Submersible Autonomous Moored Instrument for Alkalinity (SAMI‐alk), was tested for freshwater applications. A comprehensive evaluation was conducted in the laboratory using freshwater standards. The results demonstrated excellent precision and accuracy (± 0.1%–0.4%) over the A_Trange from 800 to 3000 μmol L⁻¹. The system had no drift over an 8 d test and also demonstrated limited sensitivity to variations in temperature and ionic strength. Three SAMI‐alks were deployed for 23 d in the Clark Fork River, Montana, with a suite of other sensors. Compared to discrete samples, in situ accuracy for the three instruments were within 10–20 μmol L⁻¹(0.3–0.6%), indicating good performance considering the challenges of in situ measurements in a high sediment, high biofouling riverine environment with large and rapid changes in temperature. These data reveal the complex A_Tdynamics that are typically missed by coarse sampling. We observed A_Tdiel cycles as large as 60–80 μmol L⁻¹, as well as a rapid change caused by a runoff event. Significant errors in inorganic carbon system modeling result if these short‐term variations are not considered. This study demonstrates both the feasibility of the technology and importance of high‐resolution A_Tmeasurements. 

   more » « less
4. Increasing Alkalinity Export from Large Russian Arctic Rivers

   https://doi.org/10.1021/acs.est.8b01051  

   Drake, Travis W.; Tank, Suzanne E.; Zhulidov, Alexander V.; Holmes, Robert M.; Gurtovaya, Tatiana; Spencer, Robert G. (June 2018, Environmental Science & Technology)
5. Laboratory experiments testing pH, alkalinity and particle impacts on Mn removal

   https://doi.org/10.6073/pasta/84fc50f3798a1b758e04570a98caaf55  

   Ming, Cissy L; Schreiber, Madeline E (June 2023, Environmental Data Initiative)

   Laboratory experiments were conducted to investigate impacts of pH, alkalinity, and presence of particles on Mn removal in freshwater. The dataset includes monitoring data from: 1) a 14-day experiment in Mn(II) solutions in nanopure water, 2) a 24-hour experiment in Mn(II) solutions in nanopure water, and 3) a 10-day experiment in water from two drinking water reservoirs. The 14-day pH and alkalinity laboratory experiment was conducted starting October 30, 2022 and included sample collection and pH monitoring on day 0, 1, 4, 7, 10, and 14. The 24-hour pH and alkalinity laboratory experiment was conducted starting February 20, 2023 and included sample collection and pH monitoring at 0, 1, 2, 6, 12, and 24 hours. The reservoir water laboratory experiment was conducted starting March 22, 2023 and included sample collection and pH monitoring on day 0, 1, 4, 7, and 10. This experiment tested Mn removal in water collected from the lower water column of Falling Creek Reservoir (FCR) and Carvins Cove Reservoir (CCR), located in Vinton, Virginia, USA and Roanoke, Virginia, USA respectively. Both reservoirs are owned and operated by the Western Virginia Water Authority and are managed as drinking-water sources for the city of Roanoke, VA, USA. 

   more » « less