Perspectives on in situ Sensors for Ocean Acidification Research

Abstract

As ocean acidification (OA) sensor technology develops and improves, in situ deployment of such sensors is becoming more widespread. However, the scientific value of these data depends on the development and application of best practices for calibration, validation, and quality assurance as well as on further development and optimization of the measurement technologies themselves. Here, we summarize the results of a 2-day workshop on OA sensor best practices held in February 2018, in Victoria, British Columbia, Canada, drawing on the collective experience and perspectives of the participants. The workshop on in situ Sensors for OA Research was organized around three basic questions: 1) What are the factors limiting the precision, accuracy and reliability of sensor data? 2) What can we do to facilitate the quality assurance/quality control (QA/QC) process and optimize the utility of these data? and 3) What sort of data or metadata are needed for these data to be most useful to future users? A synthesis of the discussion of these questions among workshop participants and conclusions drawn is presented in this paper.

Cardinal Buoys: An Opportunity for the Study of Air-Sea CO2 Fluxes in Coastal Ecosystems

“…The recent OceanObs 2019 conference highlighted the need for innovative and sustained coastal observatories (Farcy et al, 2019) notably for the study of FCO 2 . In the last decade, the emergence of new high-performance pH and pCO 2 sensors has been extremely valuable for the investigation of OA and FCO 2 (Sastri et al, 2019). Here, the implementation of a cardinal buoy of opportunity equipped with such novel sensors into an existing network of time-series and Ferrybox monitoring programs provided a robust multiple year assessment of FCO 2 and also pH variability in a temperate coastal ecosystem.…”

“…In the past decade, autonomous moorings and observing platforms considerably improved estimates of air-sea CO 2 fluxes at various time and spatial scales to better constrain carbon budgets in coastal ecosystems (Sutton et al, 2014;Xue et al, 2016;Reimer et al, 2017). Recent technical advances in terms of measurement of partial pressure of surface CO 2 (pCO 2 ) and pH (Sastri et al, 2019) mean that it is now possible to develop accurate long-term records of these parameters in nearshore ecosystems. Combining HF measurements of pH or pCO 2 with discrete carbonate system parameters (DIC/TA) can be a valuable tool for carbon cycle research based on autonomous moorings (Cullison Gray et al, 2011).…”

Monitoring Ocean Acidification within State Borders: Lessons from Washington State (USA)

“…Regulatory agencies undertaking OA monitoring may wish to calculate and report Ω Ar and Ω Ca to understand when conditions cross known biological thresholds, and this is best accomplished through measuring at least two marine CO 2 system parameters. If only one parameter can be measured, empirical relationships can be used to estimate a second parameter (Pimenta and Grear 2018;Sastri et al 2019). For instance, salinity might be used as a proxy for TA in regions where this relationship is well described (as in Fassbender et al 2017).…”

Temporal variability and driving factors of the carbonate system in the Aransas Ship Channel, TX, USA: a time series study

“…Despite the need for high-frequency measurements, sensor deployments have been limited in estuarine environments (especially compared to their extensive use in the open ocean) because of the challenges associated with highly variable salinities, biofouling, and sensor drift (Sastri et al, 2019). Carbonate chemistry monitoring in the Gulf of Mexico (GOM), has been relatively minimal compared to the United States east and west coasts.…”