RB-10-01 
PIRATA Northeast Extension (PNE) Readme Flie

Ship:			NOAA research vessel Ronald H. Brown
Cruise Start:		Takoradi, Ghana, April 26, 2010
Cruise End:		Charleston, S.C., May 22, 2010
Chief Scientists:	Claudia Schmid
System Operator:	Jonathan Shannahoff
Expocode:               33RO20100426

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. Zero and span of Licor
2. Four standard gases
3. Five air samples
4. Fifty equilibrator headspace gas samples
5. Repeat steps 2 - 4 nine more times
6. Restart from step 1

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:

1. During the processing of the data, it was determined that there is a 2.5 minute offset between the SST data record (i.e. SBE21 in the instrument chest) and the equilibrator temperature data record. The water takes about 2.5 minutes to travel from the inlet at the hull to the analytical equilibrator.

2. There were several air analyses that were flagged as questionable because they were not
representative of the marine boundry layer concentrations.  Some of these analyses were
likely due to contamination from the ship's exhaust; however, some were likely influenced
by land-based sources.

3. During the period of JD 127.3806 (5/7 9:08am) and JD 137.4879 (5/18 11:44 am), there was gas circulation problem in the system including the equilibrator. The system was restated on JD 137.53 (5/18 12:02pm) and went back to normal condition. The water CO2 measurement data collected for that period were deleted. Only air measurements were reported.

4. January 2017 made minor format changes to the header, added expocode and changed missing value to -999. Data was not altered.  


For questions or comments contact: 
Bob Castle 
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.