EX1133 Readme


Class of Data:  Surface ocean carbon dioxide concentrations

Dataset Identifier:  EX1133

Expocode: 33KF20110915

Statement of how to cite dataset:

     For information on dataset citation and more, please see Master Readme File.
     Explorer website: http://www.aoml.noaa.gov/ocd/gcc/explorer_introduction.php

Measurement platform identifier:  EX1133/Explorer

Data quality issues:

     Standard Gases and Reference Gas:  The three standard gases come from CMDL
     in Boulder and are directly traceable to the WMO scale.  The zero gas
     is a non-calibrated gas from a commercial company.  Any value outside the
     range of the standards should be considered approximate (5 ppm).
     While individual data points above 550 or below 300 may less accurate,
     the general trends should be indicative of the seawater chemistry.  
     The standards used on the cruise are:

      STANDARD        TANK #       CONCENTRATION       VENDOR
        STD1                            0.00         Commercial
        STD2         CA05988          593.64           CMDL
        STD3         CA02040          319.82           CMDL  
        STD4         CA02030          377.14           CMDL        

     Units:  All xCO2 values are reported in parts per million (ppm) and fCO2
     values are reported in microatmospheres (uatm) assuming 100% humidity at the
     equilibrator temperature.

     The gas flow meter had failed the morning before this cruise.  Since the 
     software controlling the CO2 instrument incorporates an active feedback loop 
     for maintaining the gas flow during EQU analyses, the calibration coefficients 
     for the gas flow meter were assigned dummy values.  These dummy coefficients 
     allowed the software to continue running without adjusting the EQU gas pump 
     speed and flow outside of the optimal range.  The data did not include 
     measurements of gas flow rate for any analyses.

     During three intervals, the pattern and values of CO2 and water in the 
     equilibrator gas indicated that the gas flows were close to zero.  For these 
     intervals (10:30 on 16 Sept to 09:30 on 17 Sept; 03:00 to 09:30 on 18 Sept; 
     19:00 on 19 Sept to 03:45 on 20 Sept) no equilibrator analyses were kept.


Contact person for this dataset:  

     Kevin Sullivan
     (305)361-4382
     Kevin.Sullivan@noaa.gov

Timestamp for dataset reduction:  11/28/11

Timestamp for most recent update of dataset:  11/28/11

Matlab version used for reduction: 1.10

Time period the dataset refers to:  9/15/2011 - 9/24/2011

Geographic area the dataset refers to:

   Day 1  - Bayonne, New Jersey (40.7 N / 74.1 W)
   Day 3  - Portland, Maine (43.7 N / 70.2 W)
   Day 4  - Bar Harbor, Maine (44.4 N / 68.2 W)
   Day 5  - St.Johns, New Brunswick (45.3 N / 66.1 W)
   Day 6  - Halifax, Nova Scotia (44.6 N / 63.6 W)
   Day 8  - Boston, Massachusetts (42.3 N / 71 W)
   Day 10 - Bayonne, New Jersey (40.7 N / 74.1 W)