Presenter: Edward Dever (Oregon State Univ.)

Description:
The Ocean Observatories Initiative (OOI) Endurance Array makes extensive measurements of collocated physical and biogeochemical parameters throughout the water column. Here we report on moored measurements from 2015 to the present off Washington and Oregon. We focus on spatial and temporal variability of pH and pCO2.  The Endurance Array team follows best practices for data quality assurance. Instruments are calibrated before every deployment. Moored time series include overlapping deployments, comparison with shipboard sensors, and bottle samples. Real time data quality control and assurance have been continually improved.  We perform weekly human in the loop (HITL) quality control and are implementing Quality Assurance of Real-Time Oceanographic Data (QARTOD) tests. HITL and QARTOD are used to flag data as suspect and failed. OOI data team members have created example Jupyter Python notebooks describing QC processes and application of QARTOD. Data processing and QC algorithms are publicly available from OOI links to GitHub.  The quality-controlled biogeochemical time series are self-consistent and in line with other regional measurements. For example, pH and pCO2 have significant onshore-offshore variation and along-shelf differences north and south of the Columbia River. This variability is related to the Columbia River plume, the strength of local upwelling, and mixing with offshore waters. On a seasonal scale, pH and pCO2 is also driven by summer upwelling and winter river inputs. The lowest pH occurs during summer upwelling. This low pH signature is strongest over the Oregon shelf and weaker offshore and north of the Columbia River off Washington. Temporal variability in pH is itself seasonal. In winter, pH and pCO2 variability on synoptic time scales is modest. In summer, upwelling and the associated biological response drive larger swings in pH and pCO2.