HB1206 ReadMe

Class of Data:  Surface ocean carbon dioxide concentrations

Dataset Identifier:  HB1206_L1-4

Expocode: 33HH20120907

Statement of how to cite dataset:

     Bigelow website: http://www.aoml.noaa.gov/ocd/gcc/rvbigelow_introduction.php
     For more information on dataset citation please see Master Readme File.

Measurement platform identifier:  NOAA Ship Henry B. Bigelow, R225

Time period the dataset refers to:  7 Sept, 2012 - 11 Nov, 2012

Geographic area the dataset refers to:

      Latitude,  34.3 to 44.4 degree north
      Longitude,  65.7 to 76.4 degree west

Standard and Reference Gases:  
     The four CO2 standard cylinders come from Scott-Marrin, Inc., and are 
     calibrated with primary standards that are directly traceable to the 
     WMO scale.  The zero gas is ultra-high purity air.  Any value outside
     the range of the standards should be considered approximate (+/-5 ppm).
     While individual data points above 520 or below 200 may less accurate,
     the general trends would be indicative of the seawater chemistry.  
     The standards used on the cruise are:

      STANDARD        TANK #        [CO2]ppm       VENDOR
         STD1         JA02645        204.74      Scott-Marrin
         STD2         JA02273        317.49      Scott-Marrin
         STD3         JA02285        372.23      Scott-Marrin
         STD4         JA02647        518.24      Scott-Marrin
         STD5         JA03093          0.00      Scott-Marrin

Data quality issues:

     The analytical system operated well throughout this cruise.

     During leg three, the reading from the ship's barometer was not available
     for approximately one hour starting at 15:15 on 19 October.  The outside 
     barometric pressure for this interval was estimated by subtracting 
     1.14 mbar from LICOR pressure.  This offset, 1.14 (+/- 0.18) mbar, 
     was calculated from the 100 data records before and after the gap.

     During leg four, the sea water flow reaching the TSG and CO2 instruments
     in the dry lab was very low for approximately thirty hours starting at
     13:30 on 3 November.  Only outside air analyses are reported for this
     interval.  For the majority of the four legs of this cruise, the water 
     flow through the pCO2 instrument was generous (1.6 - 2.1 L/min).

     For two days during leg four starting at 12:00 on 7 November, the ship 
     sought protection from a severe storm.  In the relative calm of 
     Cape Cod Bay, the flowing sea water system was secured and the CO2 
     data acquisition was interrupted.  The cruise was completed with no
     additional disruptions.

Timestamp for dataset reduction:  27 Nov, 2012

Timestamp for most recent update of dataset:  27 Nov, 2012

Matlab version used for reduction: 1.10

Contact person for this dataset:  

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