Robert Castle
NOAA/Atlantic Oceanographic & Meteorological Laboratory
4301 Rickenbacker Causeway; Miami, FL 33149
305-361-4418
Robert.Castle@noaa.gov
Rik Wanninkhof
NOAA/AOML
4301 Rickenbacker Causeway; Miami Fl, 33149
305-361-4379
Rik.Wanninkhof@noaa.gov
NOAA Climate Observation Office/Climate Observations Division
2015/12/18
RB1501 - Leg 2
Research Cruise
33RO20150130
CALWATER II Leg 2
Pacific
-127.4
-117.2
32.5
37.7
20150130
20150212
San Francisco, CA
San Diego, CA
Ronald H. Brown
33RO
NOAA
xCO2_EQU_ppm
Mole fraction of CO2 in the equilibrator headspace (dry) at equilibrator temperature (ppm)
xCO2_ATM_ppm
Mole fraction of CO2 measured in dry outside air (ppm)
xCO2_ATM_interpolated_ppm
Mole fraction of CO2 in outside air associated with each water analysis. These values are interpolated between the bracketing averaged good xCO2_ATM analyses (ppm)
PRES_EQU_hPa
Barometric pressure in the equilibrator headspace (hectopascals)
PRES_ATM@SSP_hPa
Barometric pressure measured outside, corrected to sea level (hectopascals)
TEMP_EQU_C
Water temperature in equilibrator (degrees Celsius)
SST_C
Sea surface temperature (degrees Celsius)
SAL_permil
Sea surface salinity on Practical Salinity Scale (permil)
fCO2_SW@SST_uatm
Fugacity of CO2 in sea water at SST and 100% humidity (microatmospheres)
fCO2_ATM_interpolated_uatm
Fugacity of CO2 in air corresponding to the interpolated xCO2 at SST and 100% humidity (microatmospheres)
dfCO2_uatm
Sea water fCO2 minus interpolated air fCO2 (microatmospheres)
WOCE_QC_FLAG
Quality control flag for fCO2 values (2=good, 3=questionable)
QC_SUBFLAG
Quality control subflag for fCO2 values, provides explanation when QC flag=3
5 meters
Bow
Sprayhead above dynamic pool, with thermal jacket
0.95 L (0.4 L water, 0.55 L headspace)
1.5 - 2.0 L/min
70 - 150 ml/min
Yes
Gas stream passes through a thermoelectric condenser (~5 °C) and then through a Perma Pure (Nafion) dryer before reaching the analyzer (90% dry).
Primary equlibrator is vented through a secondary equilibrator
Yes, 5 readings in a group every 3.25 hours.
Bow tower ~10 m above the sea surface.
Gas stream passes through a thermoelectric condenser (~5 °C) and then through a Perma Pure (Nafion) dryer before reaching the analyzer (90% dry).
Infrared absorption of dry sample gas.
LI-COR
LI-6262
Every 150 seconds
0.01 microatmosphere
± 1 microatmospheres
0.01 ppm
± 0.2 ppm
ESRL in Boulder, CO.
Std 1: CA04957, 282.55 ppm; Std 2: CC105863, 380.22 ppm; Std 3: CB09696, 453.04 ppm; Std 4: CB09032, 539.38 ppm
The analyzer is calibrated every 3.25 hours with standards from ESRL in Boulder, CO that are directly traceable to the WMO scale. The zero gas is 99.9% nitrogen.
The instrument is located in an air-conditioned laboratory. 99.9% Nitrogen gas and the high standard (Std 4) are used to set the zero and span of the LI-COR analyzer.
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.
Bow thruster room, before sea water pump, ~5 m below water line.
Seabird
SBE-21
± 0.01 °C
0.001 °C
Factory calibration
Manufacturer's resolution is taken as precision. Maintained by ship.
In Hydro Lab, inserted into equilibrator ~ 5 cm below water line.
Hart
1521
± 0.025 °C
± 0.01 °C
Factory calibration
0.1 - 0.6 °C
Attached to CO2 analyzer exit to lab.
Setra
270
± 0.05 hPa
0.015 hPa
Factory calibration.
Pressure reading from the Setra-270 on the exit of the analyzer was added to the differential pressure reading from Setra-239 attached to the equilibrator headspace to yield the equlibrator pressure.
On bulkhead exterior on the port side of the radio room aft of the bridge at ~14 m above the sea surface.
Vaisala
PTB330
± 0.2 hPa
± 0.08 hPa
Factory calibration
Manufacturer's resolution is taken as precision. Maintained by ship.
Attached to underway system at sea water input.
Seabird
SBE-45
± 0.005 permil
0.0002 permil
Factory calibration.
Manufacturer's resolution is taken as precision.
Attached to equilibrator headspace
Setra
239
± 0.052 hPa
0.01 hPa
Factory calibration
Pressure reading from the Setra-270 on the exit of the analyzer was added to the differential pressure reading from Setra-239 attached to the equilibrator headspace to yield the equlibrator pressure.
DOE (1994). Handbook of methods for the analysis of the various
parameters of the carbon dioxide system in sea water; version
2. DOE.
Feely, R. A., R. Wanninkhof, H. B. Milburn, C. E. Cosca, M. Stapp and
P. P. Murphy (1998) A new automated underway system for making
high precision pCO2 measurements onboard research ships.
Analytica Chim. Acta 377: 185-191.
Ho, D. T., R. Wanninkhof, J. Masters, R. A. Feely and C. E. Cosca
(1997). Measurement of underway fCO2 in the Eastern
Equatorial Pacific on NOAA ships BALDRIGE and DISCOVERER,
NOAA data report ERL AOML-30, 52 pp., NTIS Springfield.
Pierrot, D., C. Neill, K. Sullivan, R. Castle, R. Wanninkhof, H.
Luger, T. Johannessen, A. Olsen, R. A. Feely, and C. E.
Cosca (2009), Recommendations for autonomous underway pCO2
measuring systems and data-reduction routines. Deep Sea
Research II, 56: 512-522.
Wanninkhof, R. and K. Thoning (1993) Measurement of fugacity of CO2 in
surface water using continuous and discrete sampling methods.
Mar. Chem. 44(2-4): 189-205.
Weiss, R. F. (1970) The solubility of nitrogen, oxygen and argon in
water and seawater. Deep-Sea Research 17: 721-735.
Weiss, R. F. (1974) Carbon dioxide in water and seawater: the
solubility of a non-ideal gas. Mar. Chem. 2: 203-215.
Weiss, R. F., R. A. Jahnke and C. D. Keeling (1982) Seasonal effects
of temperature and salinity on the partial pressure of CO2 in
seawater. Nature 300: 511-513.
(1.) It was determined that there was a 2.68 minute offset between the SST data record from the SBE-21 in the bow and the Hart 1521 temperature sensor in the equilibrator. The SST data were interpolated using this offset to determine the SST at the time of the equilibrator measurement. (2.) A total of 6273 measurements were taken with 6238 flagged as good, 14 flagged as questionable, and 15 flagged as bad. All measurements flagged as 4 (bad) have been removed from the final data file. (3.) On 2/5 at 1929, an emergency shutdown of the system
occurred due to water getting into the atm condenser. The survey tech cleared out the water and restarted the system on 2/6 at 2130. A second emergency shutdown occurred on 2/8 at 1431 and was cleared
on 2/8 at 1738. No data was acquired during the shutdown periods.
Wanninkhof, R., R. D. Castle, and J. Shannahoff. 2013. Underway pCO2 measurements aboard the R/V Ronald H. Brown during the 2014 cruises. http://cdiac.ornl.gov/ftp/oceans/VOS_Ronald_Brown/RB2013/. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee. doi: 10.3334/CDIAC/OTG.VOS_RB_2012
http://www.aoml.noaa.gov/ocd/gcc/rvbrown_introduction.php
All AOML fCO2 underway data from the R/V Ronald H. Brown are posted on this site.
underway