DATA PRODUCT SPECIFICATION FOR WATER TEMPERATURE Version 1-04 Document Control Number 1341-00010 2013-04-25 Consortium for Ocean Leadership 1201 New York Ave NW, 4th Floor, Washington DC 20005 www.OceanLeadership.org in Cooperation with University of California, San Diego University of Washington Woods Hole Oceanographic Institution Oregon State University Scripps Institution of Oceanography Rutgers University Data Product Specification for Water Temperature Document Control Sheet Version Date Description Author 0-01 2011-10-18 Initial Release L. Heilman, S. Webster 0-02 2011-11-01 Reformat L. Heilman 0-03 2011-11-08 Reformat, clean up L. Heilman 0-04 2011-11-22 Continued reformatting and clean up. S. Webster 0-05 2011-11-28 Removed GPCTD because it will be S. Webster processed internally on the glider and AUV. 0-06 2011-12-12 Renamed to Data Product Specification S. Webster and updated to match Data Product Spec. Outline 0-07 2012-01-03 Updated language as per comments S. Webster from 5-Day Review. 1-00 2012-01-13 Initial Release. E. Chapman 1-01 2012-07-26 Changed to OutputFormat 0 for SBE S. Webster, 16plusV2 as per ECR 1300-00273. G. Proskurowski 1-02 2012-09-24 Formatting, copy edits E. Griffin 1-03 2013-03-18 Administrative change to correct M. Gibney reference to Processing Flow Diagram DCN. 1-04 2013-04-25 Administrative update to correct typos E. Griffin in Appendix A. Ver 1-04 1341-00010 i Data Product Specification for Water Temperature Signature Page This document has been reviewed and approved for release to Configuration Management. OOI Senior Systems Engineer: Date:2012-01-13 This document has been reviewed and meets the needs of the OOI Cyberinfrastructure for the purpose of coding and implementation. OOI CI Signing Authority: Date: 01-08-2012 Ver 1-04 1341-00010 ii Data Product Specification for Water Temperature Table of Contents 1 Abstract ................................................................................................................................... 1 2 Introduction ............................................................................................................................. 1 2.1 Author Contact Information ............................................................................................ 1 2.2 Metadata Information ..................................................................................................... 1 2.3 Instruments .................................................................................................................... 2 2.4 Literature and Reference Documents ............................................................................ 2 2.5 Terminology ................................................................................................................... 2 3 Theory ..................................................................................................................................... 3 3.1 Description ..................................................................................................................... 3 3.2 Mathematical Theory ...................................................................................................... 3 3.3 Known Theoretical Limitations ....................................................................................... 4 3.4 Revision History ............................................................................................................. 4 4 Implementation ....................................................................................................................... 4 4.1 Overview ........................................................................................................................ 4 4.2 Inputs ............................................................................................................................. 4 4.3 Processing Flow ............................................................................................................. 4 4.4 Outputs ........................................................................................................................... 5 4.5 Computational and Numerical Considerations ............................................................... 5 4.6 Code Verification and Test Data Sets ............................................................................ 5 Appendix A Example Data Processing ....................................................................................... 1 Appendix B Output Accuracy ...................................................................................................... 1 Appendix C Sensor Calibration Effects ....................................................................................... 1 Ver 1-04 1341-00010 iii Data Product Specification for Water Temperature 1 Abstract This document describes the computation used to calculate the OOI Level 1 Water Temperature data product, which is calculated using data from the Sea-Bird Electronics conductivity, temperature and depth (CTD) family of instruments. This document is intended to be used by OOI programmers to construct appropriate processes to create the L1 water temperature product. 2 Introduction 2.1 Author Contact Information Please contact Lorraine Heilman ([email protected]), Sarah Webster ([email protected]) or the Data Product Specification lead ([email protected]) for more information concerning this document. 2.2 Metadata Information 2.2.1 Data Product Name The OOI Core Data Product Name for this data product is - TEMPWAT The OOI Core Data Product Descriptive Name for this data product is - Water temperature 2.2.2 Data Product Abstract (for Metadata) The OOI Level 1 Water Temperature data product is computed by converting raw hexadecimal temperature data from the conductivity, temperature and depth (CTD) family of instruments into °C. 2.2.3 Computation Name Not required for data product algorithms. 2.2.4 Computation Abstract (for Metadata) This algorithm computes the OOI Level 1 Water Temperature data product, which is calculated by converting raw hexadecimal temperature data from the conductivity, temperature and depth (CTD) family of instruments into °C. 2.2.5 Instrument-Specific Metadata There are no instrument-specific metadata that need to be added for the algorithm. 2.2.6 Synonyms Synonyms for this data product are - Temperature - Water Temperature - In situ Water Temperature - ITS-90 Water Temperature Ver 1-04 1341-00010 Page 1 of 6 Data Product Specification for Water Temperature 2.2.7 Similar Data Products Prior to 1990, when the ITS-90 standard was adopted (Sea-Bird App Note 42, 2010), a different calibration, the IPTS-68 standard, was in use. The relationship between T_90 and T_68 is a simple, linear one (T_68 = 1.00024 * T_90). 2.3 Instruments The CTD Processing Flow document (DCN 1342-00010) describes the instrument classes and make/models that produce the data from which the L1 temperature data product is calculated. This document also describes the flow of data from the CTDs through all of the relevant QC, calibration, and data product algorithms. Note that the raw data from the GPCTD make/model—the CTDs on board the gliders and autonomous underwater vehicles (AUVs)—are processed onboard the vehicles with proprietary software from the vehicle vendors. These data are presented already in decimal format in appropriate units (°C, Siemens/meter, decibars), therefore processing raw hexadecimal data from the CTDGP is not included in the algorithm described in this document. Please see the Instrument Application in the SAF for specifics of instrument locations and platforms. 2.4 Literature and Reference Documents IOC, et al. (2010). The international thermodynamic equation of seawater-2010: Calculation and use of thermodynamic properties, UNESCO. Sea-Bird (2009), SBE 16plus V2 SEACAT User’s Manual. Manual Version #005. Sea-Bird (2011), SBE 37-IM MicroCAT User’s Manual. Manual Version #027. Sea-Bird (2010), Application Note 42. ITS-90 Temperature Scale. Revision February 2010. Sea- Bird Electronics, Inc.. Sea-Bird (2010), Application Note 31. Computing Temperature and Conductivity Slope and Offset Correction Coefficients from Laboratory Calibrations and Salinity Bottle Samples. Revision February 2010. Sea-Bird Electronics, Inc.. 2.5 Terminology 2.5.1 Definitions The following terms are defined here for use throughout this document. Definitions of general OOI terminology are contained in the Level 2 Reference Module in the OOI requirements database (DOORS). Potential temperature: “Potential temperature is the temperature that a fluid parcel would have if its pressure was changed to a fixed reference pressure in an isentropic and isohaline matter.” (IOC et al, 2010) 2.5.2 Acronyms, Abbreviations and Notations General OOI acronyms, abbreviations and notations are contained in the Level 2 Reference Module in the OOI requirements database (DOORS). The following acronyms and abbreviations are defined here for use throughout this document. Ver 1-04 1341-00010 Page 2 of 6 Data Product Specification for Water Temperature ITS-90 International Temperature Scale of 1990 2.5.3 Variables and Symbols The following variables and symbols are defined here for use throughout this document. T_L1, T_90 L1 temperature data product, using the ITS-90 temperature scale tdec, t_dec instrument temperature data in decimal thex, t_hex instrument temperature data in hexadecimal T_68 Temperature calculated using the older IPTS_68 temperature scale