EX0824 Readme


Class of Data:  Surface ocean carbon dioxide concentrations

Dataset Identifer:  EX0824

Expocode: 33KF20080817

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:  EX0824/Explorer

Data quality issues:

     At the start of this cruise, the major reconfiguration of the oceanographic 
     instruments on the flowing seawater system was incomplete.  Several days 
     into this cruise the reconfiguration was completed, and data acquisition 
     was initiated around latitude 24.5 deg North.  The operation of the pCO2 
     instrumentation was optimized over the first days of use.

     A unexpected decrease in the atmospheric CO2 occurred around YearDay 235.3 
     and 32 deg North.  There was a coincident drop in sea surface temperature 
     and seawater CO2, though no analytical causes for these changes were found.

     Standard Gases and Reference Gas:  The three standard gases come from CMDL
     in Boulder and are directly traceable to the WMO scale.  The reference gas
     is a non-calibrated gas from a commercial company.  Any value outside the
     range of the standards (300 ppm, 360 ppm, and 420 ppm) should be considered
     approximate (5 ppm).  While individual data points above 420 or below 300 may
     not be 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              CA02020          458.04           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.Sullivans@noaa.gov

Timestamp for dataset reduction:  1/14/2009

Timestamp for most recent update of dataset:  1/14/2009

Time period the dataset refers to:  8/17/2008 - 8/23/2008

Geographic area the dataset refers to:

     Day 1  - Bayonne, New Jersey (40.7 N/74.1 W)
     Day 5  - Philisburg, St. Maarten (18.0 N/63.0 W)
     Day 6  - Charlotte Amalie, St. Thomas (18.3 N/64.9 W)
     Day 7  - San Juan, Puerto Rico (18.5 N/66.1 W)
     Day 10 - Bayonne, New Jersey (40.7 N/74.1 W)