RB1204 WACS Readme Flie

Ship:			NOAA research vessel Ronald H. Brown
Cruise Start:		Boston, MA, Aug. 19, 2012
Cruise End:		St. Georges, Bermuda, Aug. 27, 2012
Chief Scientists:	Patricia Quinn
System Operator:	Jonathan Shannahoff
QC:			Bob Castle Dec. 18, 2012
Expocode:               33RO20120819

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

Sampling Cycle:
The system runs on a 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. Removed first 3 hours of data due to bad Licor pressure readings.

2. Removed last 6 readings due to missing SST data from the ship.

3. The ship experienced a power failure on Aug. 27 at 0300 GMT.  All data on Aug.
27 from 0302 to 0358 have been removed.

4. During the processing of the data, it was determined that there was 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.  SST values have been
adjusted to include this delay.

5. A total of 3749 Equ measurements were taken with 3748 flagged as good and 1 
flagged as bad.  A total of 290 air measurements were taken
with 288 flagged as good, and 2 flagged as bad.

6. During the first 4 days of the cruise air values ranged from ~379 - 385 ppm
instead of the expected value of approximately 390.  We have observed low air
values in this region before and there is no indication of instrument malfunction
so they appear to be real and have been left in the data set.

7. 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.