RB1202 ECS Mapping Readme Flie Ship: NOAA research vessel Ronald H. Brown Cruise Start: Charleston, South Carolina, July 2, 2012 Cruise End: Miami, FL, July 15, 2012 Chief Scientists: Shep Smith System Operator: Jonathan Shannahoff QC: Bob Castle April 13, 2013 Expocode: 33RO20120702 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: 423.57 ppm 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. The pCO2 system was removed from the ship in May, 2010 and reinstalled in September. After that, recorded licor pressure values were 5-7 hPa higher than sea level pressures. However, historical data showed that Licor pressure values were slightly lower than sea level pressures. There were no possible mechanisms that could increase the Licor pressure as much as 7 hPa. It was concluded that the recorded Licor pressure values were incorrect. So, the Licor pressure values were estimated from the sea level pressures using a constant offset of -0.80 hPa. The offest was calcualted from data collected for the 5 previous cruises (RB0901, RB0902, RB0903, RB0904 in 2009 and RB2010_PNE in 2010, n=48,953). The corrected pressure values were further modified by adding the reading of the differential pressure transducer in the equilibrator. 2. 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. 3. Anomalous readings from the differential pressure sensor in the equilibrator resulted in 60 Equ values being flagged as questionable. 4. A total of 5938 Equ measurements were taken with 5876 flagged as good, 60 flagged as questionable, and 2 flagged as bad. A total of 450 air measurements were taken with 436 flagged as good, 13 flagged as questionable, and 1 flagged as bad. 5. 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.