RB1203 Readme Flie

Ship:             NOAA research vessel Ronald H. Brown
Cruise Start:     Miami, FL, USA,  July 21, 2012
Cruise End:       Boston, Massachusetts, USA, August 13, 2012
Chief Scientists: Rik Wanninkhof, Leticia Barbero, Michelle Wood
System Operator:  Jonathan Shannahoff , Kevin Sullivan

Expocode: 33RO20120721

Method:
The system was built by General Oceanics (GO) and is described in 
Pierrot, et al. (2009).  The four standard gases come from CMDL in 
Boulder and are directly traceable to the WMO scale.

Sampling Cycle:
The system runs on an cycle during which 4 standard gases, 5 air 
samples from the bow tower and 50 surface water samples (from the 
equilibrator head space) are analyzed on the following schedule:

1. Four standard gases
2. Five air samples
3. Sixty-six equilibrator headspace gas samples
4. Repeat steps 1 - 3

Standards:  CA06709: 284.75 ppm, CA02813: 363.24 ppm, 
CA07921: 423.57ppm, CA07931: 545.88 ppm.

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.

Notes:

On 25 July at 15:00, there was a ship-wide power loss.  The CO2 
system was restarted approximately 90 minutes later.  The opportunity 
was taken to zero and span the CO2 channel and to zero the water 
channel of the LICOR 6262 analyzer.

The SBE-21 thermosalinograph in the ship's intrument chest behaved
well the first four days of the cruise.  Afterwards, the conductivity 
sensor became erratic.  The temperature sensor behaved well, though the 
entire TSG-21 was replaced a couple times and was undergoing testing at 
other times.  The salinity used for the CO2 data reduction was from the 
SBE-45 that was attached to the CO2 instrument.  The temperature from the 
SBE-21 was used for the data reduction.  There were two extended periods 
of testing when the SBE-21 temperature was not available, so the SBE-45 
temperature was used for data reduction (14:20 on 7 Aug to 00:30 on 8 Aug; 
and 22:25 on 5 Aug to 00:55 on 6 Aug).


For questions or comments contact: 
Bob Castle, Kevin Sullivan
4301 Rickenbacker Causeway 
Miami, FL 33149 
305-361-4418 
robert.castle@noaa.gov


Pierrot, D., C. Neil, K. Sullivan, R. Castle, R. Wanninkhof, H. Lueger, 
T. Johannson, A. Olsen, R. A. Feely, and C. E. Cosca (2009),
Recommendations for autonomous underway pCO2 measuring systems 
and data reduction routines, Deep-Sea Res II, 56, 512-522.