EX1124 Readme


Class of Data:  Surface ocean carbon dioxide concentrations

Dataset Identifier:  EX1124

Expocode: 33KF20110716

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:  EX1124/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          CA07952          549.89           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 atmospheric barometer was not working during the first half of the cruise.  The 
     atmospheric pressure was estimated using a constant offset (-7.87 +/- 0.47 hPa) 
     from LICOR pressure.  The offset was calculated from data (n=22,430) collected 
     over 7 cruises between 2 January and 3 April, 2011.  A new barometer was 
     installed on the ship in Bermuda.

     STD1 analyses were not used in the calibration due to lots of missing points.

     During the transit to Bermuda, the response of the LICOR analyzer was very low but 
     stable and the temperatures of the analyzer and the dry box enclosure was higher than 
     normal.  With the very low response of the analyzer, the error in the calculated fugacities
     are greater than usual and so the data are flagged.  Careful examination of the data
     should be applied before critical use.  During the transit between Bermuda and New 
     Jersey, the analyzer and enclosure temperatures were normal as was the response of 
     the analyzer.


Contact person for this dataset:  

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

Timestamp for dataset reduction:  12/2/2011

Timestamp for most recent update of dataset:  12/2/2011

Matlab version used for reduction: 1.10

Time period the dataset refers to:  7/16/2011 - 7/21/2011

Geographic area the dataset refers to:

   Day 1  - Bayonne, New Jersey (40.7 N / 74.1 W)
   Day 3  - Kings Wharf, Bermuda (32.3 N / 64.8 W)
   Day 4  - Kings Wharf, Bermuda (32.3 N / 64.8 W)
   Day 6  - Bayonne, New Jersey (40.7 N / 74.1 W)