Topic outline

  • Overview

    This course provides an introduction to the steps required to obtain and utilize ocean data including product generation using Ocean Data View (ODV), desktop software for analysis and visualization of oceanographic, atmospheric and other geo-referenced profile or time-series data.

    Course Outline

    1. Introduction to Ocean Data Management
    2. Introduction to Ocean Data View
    3. Creating a Data Collection from World Ocean Database
    4. Basic Data Analysis with ODV
    5. Exporting Data and Products from ODV
    6. Adding CTD Data to ODV
    7. Adding Spreadsheet Data to ODV
    8. Quality Control with ODV
    9. Adding Operational Data to ODV
    • Introduction to Ocean Data Management

      Marine Data Format Types (from Ocean Teacher Digital Library). A description of some of the major data formats used to manage ocean data. Browse through the subsections describing the different data formats. Of particular interest for this course are:

      • Archive Formats. These formats include the World Ocean Database format which will be used in this course.
      • Spreadsheet Formats. Spreadsheets are one of the more popular formats to describe marine data. The Ocean Data View spreadsheet format will be used in the ODV exercises.

      Integration SchematicIntegration Schematic for Data, Formats and Software

      Physical Oceanographic Measurements (from Ocean Teacher Digital Library). A brief description of physical oceanographic parameters and instruments to provide a conceptual framework and terminology for marine data managers.

      Marine Parameter Value Ranges (from Ocean Teacher Digital Library). A simplified global range table for some common parameters.

      Standard Depths for Marine Measurement (from Ocean Teacher Digital Library). Oceanographic measurements have traditionally been taken at standard ("nominal") depths,

      Major Global Data Collection Projects. There are a few important programmes that collect and manager global oceanographic data and make these data availabel in standard formats. They include:

      • World Ocean Database (WOD). WOD is a project established by the Intergovernmental Oceanographic Commission (IOC) of UNESCO which represents the world’s largest collection of ocean profile-plankton data available internationally without restriction
      • Global Temperature and Salinity Profile Program (GTSPP). GTSPP is a cooperative international program to develop and maintain a global ocean Temperature-Salinity resource with data that are both up-to-date and of the highest quality. It is a joint World Meteorological Organization (WMO) and Intergovernmental Oceanographic Commission (IOC) program.
      • Argo. Argo is a global array of 3,000 free-drifting profiling floats that measures the temperature and salinity of the upper 2000 m of the ocean.

      Folder Structure for Data

      An important component of good data management is the ability to store all data files in an efficient manner. A database management system (DBMS) can be used to to store and manipulate data however most datasets will be recieved in a variety of formats that may not be easily imported to a DBMS. To manage the many files used by a data manager, as well as the products that are created, some sort of "standard" folder structure is required.  This is an example of a "basic" folder structure, consisting of the top levels only (2 or 3 levels within the main folder).  You can of course add more subfolders as appropiate.  Long, descriptive files names are also important to uniquely identify datasets. 

      As this course will be using only ODV, a simplified folder structure can used for the exercises:

      NAMIBIA - Project files for this area

      - DATA

      - - OCEAN

      - - - WOD

      - - - CTD

      - METADATA (Detailed information about any of these datasets)

      - PRODUCTS (Created by ODV)

      - - ODV (Collections and their products made with Ocean Data View)

      - - - COLLECTIONS (Individual collections of data by data type, area or other original selection criteria)

      - - - IMAGES  (Saved images of graphics)

      - - - INTERPOLATIONS  (XYZ data triplets exported from ODV's "surface mode" analyses)

      - - - SUBSETS (Spreadsheets of data taken from larger collections)

      - - - TIMESERIES

      • Introduction to Ocean Data View

        Ocean Data View (ODV) is a software package for the interactive exploration, analysis and visualization of oceanographic and other geo-referenced profile, time-series, trajectory or sequence data. ODV runs on Windows (7, Vista, XP, 9x, Me, NT, 2000), Mac OS X, Linux, and UNIX (Solaris, Irix, AIX) systems. ODV data and configuration files are platform-independent and can be exchanged between different systems.

        The ODV software can be downloaded from http://odv.awi.de/en/software/download. Registration is required.

      • Creating a Data Collection from World Ocean Database

        The goal of this section is to create a data collection from the World Ocean Database, which can serve as the foundation for the addition of other data.

        The World Ocean Database represents the world’s largest collection of ocean profile data available without restriction. Data comes from a number of sources including (a) the IODE network of National Oceanographic Data Centres, (b) International Ocean Observing Projects such as the completed World Ocean Circulation Experiment (WOCE) and Joint Global Ocean Flux Study (JGOFS), as well as currently active programs such as CLIVAR and Argo, (c) International Ocean Data Management Projects such as the IOC/IODE Global Oceanographic Data Archaeology and Rescue Project (GODAR), and (d) Real-time Ocean Observing Systems such as the IOC/IODE Global Temperature-Salinity Profile Project (GTSPP). Read more about WOD in the OceanTeacher Digital Library.

      • Basic Data Analysis with ODV

        ODV provides the tools for the graphical analysis of the data. Some of the common analysis plots used by marine scientists are:

        • STATION PLOTS: Graphs of selected parameters plotted versus depth, for 1 or more stations
        • SCATTER PLOTS: Graphs of two (sometimes three) parameters plotted against each other, usually for multiple stations and multiple depths One famous scatter plot is the T-S Diagram, plotting temperature (Y-axis) against salinity (X-axis)
        • SECTION PLOTS: Graphs of a selected parameter versus depth along a path ("spine") through the AOI
        • SURFACE PLOTS: Graphs of one variable coincident with a surface within the ocean volume defined by a constant value of a second variable (for example a graph showing salinity on the surface where the temperature is equal to 11 degrees); the term "surface" here should not be confused with the ocean surface.
        • ANIMATIONS: ODV has the ability to produce animated series of sequential plots in the form of an animated GIF file. Animation is a useful tool to visualize the data.
      • Exporting Data and Products from ODV

        The basic products provided by data centers are images (including maps of data distribution), datasets and analysis.

        Quality graphic images, suitable for pulications, can be created in several common formats (GIF, JPG, PNG)

        ODV allows easy export of subsets of the raw data, according to applied spatial and temporal filters, in spreadsheet format. This method is used to transfer data between researchers or programs.

        ODV also allows the export of data interpolated to any surface created in surface mode. This is particularly useful for producing a set of values for any parameter at a specific depth.

      • Adding CTD data to ODV

        CTD instruments measure conductivity, temperature and pressure (depth) to a high accuracy and CTD data make an important contribution to the hydrography measurements in the ocean. CTDs typically consist of an array of sensors that measure the frequency or voltage response that represents changes in an ocean parameter.

        CTD data collected by Sea-Bird instruments can be converted into and ASCII format called CNV which can be viewed with a text editor. A recent addition to ODV now allows CTD data from Seabird instruments to be easily imported.

        ICES Guidelines for CTD Data describes the collection and handling of CTD data collected on oceanographic research vessels.

        CTD collection
      • Quality Control with ODV

        Introduction to Quality Control (from OceanTeacher Digital Library).

        Quality control of data is an essential component of oceanographic data management.  Data quality control information tells users of the data how it was gathered, how it was checked, processed, what algorithms have been used, what errors were found, and how the errors have been corrected or flagged. Without it data from different sources cannot be combined or re-used to gain the advantages of integration, synthesis, and the development of long time series. Read through the OceranTeacher Digital Library sections on:

        • General Marine Data Quality Control. References to various QC manuals and procedures
        • Marine Data Quality Flags. A summary of quality control flags used iused by different programmes and data management offices.
      • Adding Operational Data to ODV

        Data useful for operational oceanography are obtained by diverse means including in-situ (ships, drifters, floats, moorings, , etc) and satellites. They come in different forms, from a single variable measured at a single point to multivariate, four dimensional collections of data. Coriolis is a Data Assembly Centers that integrates data coming from a wide variety of platforms and providers, quality controls the data, then distrubutes the data in a standard format

        Argo Programme

        Argo is an international ocean-observing programme that has deployed more than 3,500 drifting floats that gather temperature and salinity profiles in the upper 2,000 metres of the world’s oceans. In conjunction with satellite observations, the profiles gathered by these floats have allowed scientists to make significant advances in their quest to better understand the role of the oceans in world climate.

        Video on the importance of the Argo array produced for Scripps Institution of Oceanography
        Argo distribution - November 2014

        netCDF Data

        netCDF (Network Common Data Form) is a set of software libraries and self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data (see Unidata). The netCDF format is bcome a defacto standard for describing oceanographic data and is used by Argo, World Ocean Atlas and Group for High Resolution Sea Surface Temperature (GHRSST).