EX1111 Readme


Class of Data:  Surface ocean carbon dioxide concentrations

Dataset Identifier:  EX1111

Expocode: 33KF20110414

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:  EX1111/Explorer

Data quality issues:

     No atmospheric pressure was recorded. So, atmospheric pressure values 
     were estimated using a constant offset (-7.87 +/- 0.47 hPa) from Licor Pressure. 
     The offset was calculated from data (n=22,430) collected for JD 2.9-93.4.

     The GPS signal to the CO2 instrument was lost between 21:00 on 14 April and 16:43 on 18 April.  
     The positions for the 1226 analyses during that time period were taken from files of navigational
     data saved separately. 
     The data was merged based on date and time. 
     For 20 analyses immediately following this time gap, the merged positions were less than 20 meters
     different than the GPS positions recorded in real time.

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

     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.


Contact person for this dataset:  

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

Timestamp for dataset reduction:  11/21/11

Timestamp for most recent update of dataset:  11/21/11

Matlab version used for reduction: 1.09

Time period the dataset refers to:  4/14/2011 - 4/23/2011

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  - Nassau, Bahamas (25.1 N / 77.3 W)
   Day 7  - Co Co Cay, Bahamas (25.8 N / 77.9 W)
   Day 10 - Bayonne, New Jersey (40.7 N / 74.1 W)