Posts Tagged ‘BCO-DMO’
Now Available from BCO-DMO: Time Series Water Sample Data from Four OOI Arrays
OOI launched a collaboration in 2023 with the Biological & Chemical Oceanography Data Management Office (BCO-DMO) to make OOI water sampling data available via the BCO-DMO website and ERDDAP server. BCO-DMO curates publicly available research-ready oceanographic data in accordance with FAIR data principles. Advantages of distributing OOI data through BCO-DMO include concatenation of the cruise-by-cruise data into a single dataset with a Digital Object Identifier (DOI) and provisioning through ERDDAP, which provides both human and machine-to-machine interfaces. The BCO-DMO Dataset pages include descriptions of sampling and processing methods, and README files for each cruise.
Currently BCO-DMO has data from the OOI Station Papa Array (Gulf of Alaska, annual cruises over 11 years), Irminger Sea Array (North Atlantic, 10 years), Southern Ocean Array (SW of Chile, 6 years) and Argentine Basin Array (South Atlantic, 4 years). You can access the datasets via this direct link or from the BCO-DMO home page: Click on Projects, then search for “OOI Discrete CTD and Water Sampling Cruise Data”.
Figures 1 and 2 provide an example of the concatenated datasets using 10 years of data from the Irminger Sea Array. A Python script (implemented in a Jupyter Notebook available in https://github.com/WHOIGit/ooi-on-bco-dmo) was used to access the data from the BCO-DMO ERDDAP server, extract variables of interest, apply available quality control (QC) flags, and visualize the data. Figure 1 shows profiles of selected variables for successive cruises to give a sense of the depth-time data coverage. Note that the sample depths are relatively sparse since the OOI sampling goal is to validate instruments on the moorings rather than collect comprehensive profile data. Figure 2 represents profile variability over time by an overplot color-coded by year.
Even though constrained to “Acceptable” QC flags, some of the values plotted appear to be outliers, indicating the need for the user to consider further data quality assessment. Note that Discrete README files within the BCO-DMO dataset and CTD Cast Logs on OOI’s Raw Data Archive provide useful information. For example, the low values of oxygen in 2021are noted as inconsistent with oxygen from the CTD cast, whereas the high values of salinity in 2015 appear to be real, associated with a salinity maximum observed by the CTD. Since creating the Jupyter Notebook, data for two of the Irminger Sea cruises in OOI’s Raw Data Archive have been updated (including Nitrate for the 2021 cruise); these updates will be in the next version of the Irminger Sea dataset on BCO-DMO.
For additional Python scripts to explore OOI Discrete CTD and Water Sampling Cruise Data as distributed by BCO-DMO, for example to plot a discrete parameter against its corresponding CTD sensed parameter, see notebooks available in https://github.com/WHOIGit/ooi-on-bco-dmo/tree/main/notebooks.
[caption id="attachment_36331" align="alignnone" width="472"]
Figure 1. Profiles of a) oxygen, b) salinity, and c) nitrate at the OOI the Irminger Sea Array from discrete bottle samples.[/caption]
[caption id="attachment_36332" align="alignnone" width="532"] Figure 2. Temporal variability of a) oxygen, b) salinity, and c) nitrate over 10 years depicted as overlaid profiles.[/caption]
Read More Water Sample Data Available thru BCO-DMO Repository
Hydrographic sampling performed by the Ocean Observatories Initiative (OOI) as part of each Array turn represents a significant collection of valuable physical, chemical, and biological information. In addition to the CTD (conductivity, temperature, depth) casts themselves, collected hydrographic data from bottle samples include discrete oxygen, salinity, nutrients (nitrate, nitrite, silicate, phosphate, ammonium), chlorophyll, and carbon system measurements. These data are subsequently merged into a concatenated “discrete summary” file with quality assessment flags and an associated readme file detailing important notes about the data. Although the primary purpose of these data are for the evaluation and validation of deployed OOI instrumentation, the annual (Global) or biannual (Coastal) collection of data at the same locations provides a unique time series of water properties following established community standards and methods.
Currently, OOI discrete water sampling data are made available via the OOI Alfresco Web Document Server and via the OOI Data Explorer. Water sampling data served through these platforms are organized so each dataset represents a single cruise at a specific Array.
Recent efforts within the ocean observing community have focused on improving FAIR (Findable, Accessible, Interoperable, Reusable) Data practices from programs and projects, such as the Marine Ecological Time Series (METS-RCN)-hosted international workshop on FAIR Data Practices for Ship-based Ocean Time Series. As part of the OOI’s effort to improve FAIR data practices, OOI is working with the Biological & Chemical Oceanography Data (BCO-DMO) Management Office to make the water sampling data collected during OOI operation and management cruises available via the BCO-DMO website and database. BCO-DMO curates publicly available research-ready oceanographic data in accordance with FAIR data principles.
[media-caption path="https://oceanobservatories.org/wp-content/uploads/2023/08/CTD_at_sunset-640x427-1.jpg" link="#"]A CTD Rosette frame being lowered into the Atlantic Ocean from the R/V Neil Armstrong at sunset. Credit: Rebecca Travis © WHOI.[/media-caption]Re-distributing OOI data through BCO-DMO will enhance the FAIR qualities of OOI Discrete CTD and water sample data by: (1) providing a robust version control strategy that assigns DOIs (Digital Object Identifiers) as these datasets are updated; (2) making the data available to a larger audience, for use in novel science research beyond the intended scope of instrument validation; (3) concatenating the cruise-by-cruise data into a single dataset that is more readily available for analysis; and (4) providing machine-to-machine interoperability by making data available through an ERDDAP server.
Starting from the BCO-DMO home page, OOI water sampling data will be available as part of the “OOI Program Page” as the project “OOI Discrete CTD and Water Sampling Cruise Data.” Within the BCO-DMO data management system, water sampling data for each array will be organized into a single, concatenated data table. For example, the OOI Argentine Basin CTD and Water Sampling Data, which spans all four Argentine Basin mooring turn cruises (AT26-30, AT39-03, NBP1510, NBP1609) from 2015-2018, are currently available here.
This distribution of OOI data is but one example of OOI’s continuing quest to make its data available in multiple ways so that the data are broadly used to advance understanding of ocean processes.
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