Processing Steps |
- Parameter or Variable: Dissolved Inorganic Carbon; Abbreviation: DIC_UMOL_KG; Unit: micromol/kg; Observation type: Discrete measurements from samples collected on CTD casts; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: Niskin bottle; Analyzing instrument: Two systems consisting of a coulometer (UIC Inc.) coupled with a Dissolved Inorganic Carbon Extractor (DICE) inlet system. DICE was developed by Esa Peltola and Denis Pierrot of NOAA/AOML and Dana Greeley of NOAA/PMEL to modernize a carbon extractor called SOMMA (Johnson et al. 1985, 1987, 1993, and 1999; Johnson 1992); Detailed sampling and analyzing information: PLEASE NOTE: DIC may also be referred to as TCO2, TCARBN, or C(sub)T in other data sets. All of these abbreviations refer to the total dissolved inorganic carbon concentration (i.e., the combined concentration of dissolved CO2, bicarbonate ion, and carbonate ion). Samples for DIC measurements were drawn according to procedures outlined in the 2007 PICES Special Publication, Guide to Best Practices for Ocean CO2 Measurements, from Niskin bottles into 310 ml borosilicate glass flasks using silicone tubing. The flasks were rinsed once and filled from the bottom with care not to entrain any bubbles, overflowing by at least one-half volume. The sample tube was pinched off and withdrawn, creating a ~7.5 ml headspace, and 0.12 ml of saturated HgCl2 solution was added as a preservative. The sample bottles were then sealed with glass stoppers lightly covered with Apiezon-L grease. DIC samples were collected from variety of depths with approximately 10% of these samples taken as duplicates. The accuracy of the DICE measurement is determined with the use of standards (Certified Reference Materials (CRMs), consisting of filtered and UV irradiated seawater) supplied by Dr. Andrew Dickson of Scripps Institution of Oceanography (SIO). The CRM accuracy is determined manometrically on land in San Diego and the DIC data reported to the Ocean Carbon and Acidification Data Portal have been corrected to this batch 154 CRM value. The CRM certified value for this batch is 2037.68 umol/kg. System 1 averaged 2033.64 and system 2 averaged 2036.88. The overall performance of the analytical equipment was quite good. Water from 1704 niskin bottles were analyzed for dissolved inorganic carbon.; Replicate information: Duplicate samples were collected from approximately 10% of the Niskins sampled, as a check of our precision. These replicate samples were interspersed throughout the station analysis for quality assurance and integrity of the coulometer cell solutions. The average absolute difference from the mean of these replicates is 0.82 umol/kg. No systematic differences between the replicates were observed.; Standardization description: Each coulometer was calibrated by injecting aliquots of pure CO2 (99.999%) by means of an 8-port valve (Wilke et al., 1993) outfitted with two calibrated sample loops of different sizes (~1ml and ~2ml). The instruments were each separately calibrated at the beginning of each cell with a minimum of two sets of these gas loop injections and then again at the end of each cell to ensure no drift during the life of the cell.; Standardization frequency: 1) Gas loops were run at the beginning and end of each cell; 2) CRM is supplied by Dr. A. Dickson of SIO, were measured near the beginning; and 3) Duplicate samples were typically run throughout the life of the cell solution.; CRM manufacturer: Dr. A. Dickson (SIO); CRM batch number: 154; Preservation method: Mercuric Chloride Solution; Preservative volume: 0.12 ml; Preservative correction: The DIC values were corrected for dilution by 0.133 ml of saturated HgCl2 used for sample preservation. The total water volume of the sample bottles was 302.55 ml. The correction factor used for dilution was 1.00044.; Uncertainty: ±0.1%; Quality flag convention: DIC_FLAG, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Dickson, A.G., C.L. Sabine, and J.R. Christian (eds.). 2007. Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, 191 pp. Johnson, K.M., A.E. King, and J. McN. Sieburth. 1985. Coulometric DIC analyses for marine studies: An introduction. Mar. Chem., 16, 61-82. Johnson, K.M., P.J. Williams, L. Brandstrom, and J. McN. Sieburth. 1987. Coulometric total carbon analysis for marine studies: Automation and calibration. Mar. Chem., 21, 117-133. Johnson, K.M. 1992. Operator's manual: Single operator multiparameter metabolic analyzer (SOMMA) for total carbon dioxide (CT) with coulometric detection. Brookhaven National Laboratory, Brookhaven, N.Y., 70 pp. Johnson, K.M., K.D. Wills, D.B. Butler, W.K. Johnson, and C.S. Wong. 1993. Coulometric total carbon dioxide analysis for marine studies: Maximizing the performance of an automated continuous gas extraction system and coulometric detector. Mar. Chem., 44, 167-189. Johnson, K.M., Kortzinger, A.; Mintrop, L.; Duinker, J.C.; and Wallace, D.W.R. 1999. Coulometric total carbon dioxide analysis for marine studies: Measurement and internal consistency of underway surface TCO2 concentrations. Marine Chemistry 67(1):123-144.; Researcher name: Dana Greeley; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Richard Feely.
- Parameter or Variable: Total alkalinity; Abbreviation: TA_UMOL_KG; Unit: micromol/kg; Observation type: Discrete measurements from samples collected on CTD casts; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: Niskin bottle; Analyzing instrument: Custom instrument built in Dr. Andrew Dickson's lab at Scripps-UCSD in 2016.; Type of titration: Two-stage, potentiometric, open-cell titration using coulometrically analyzed hydrochloric acid.; Cell type (open or closed): Open; Curve fitting method: Non-linear least squares; Detailed sampling and analyzing information: PLEASE NOTE: TA may be referred to as TALK, ALKALI, or A(sub)T in other data sets. All of these abbreviations refer to the total alkalinity. Seawater samples for total alkalinity were drawn directly from Niskin bottles into 310 mL borosilicate glass (Corning Pyrex/Schott Duran) bottles as described in SOP1 of “The Guide to Best Practices for Ocean CO2 Measurements” (Dickson A.G., Sabine L.S. and Christian J.R, Eds., 2007 PICES Special Publication 3), using silicone tubing. The flasks were rinsed three times and filled from the bottom with care not to entrain any bubbles, overflowing by at least one full volume. The sample tube was pinched off and withdrawn, creating a ~6.2 mL headspace and preserved with 0.12 mL of a saturated mercuric chloride solution and the final alkalinity concentration corrected for this addition. The bottles were then sealed with glass stoppers lightly coated with Apiezon-L grease. The samples were subsequently analyzed according to SOP3b of “The Guide to Best Practices for Ocean CO2 Measurements” (as above), using an open cell titration system built by the Dickson Lab in 2016 at Scripps Institution of Oceanography, University of California San Diego. Sample and analysis cell temperatures were controlled and sample size was measured volumetrically and subsequently corrected to mass. The instrument was controlled and alkalinity determined by LabVIEW software written by the Dickson Lab. Instrument accuracy was monitored at regular intervals using Certified Reference Materials (CRMs), consisting of filtered and UV irradiated seawater supplied by the Dickson Lab (SIO-UCSD). Precision was monitored by analyzing replicate samples drawn from approximately 10% of the Niskins sampled. Samples were analyzed within 12 hours of being collected except for stations 134 and 135, which were run ashore.; Replicate information: We collected and analyzed duplicate samples from approximately 10% of the Niskins sampled.; Standardization description: Analytical accuracy was assessed by periodic analysis of Certified Reference Materials (CRMs) throughout the cruise. CRMs were analyzed approximately every 20 samples or less as needed. For both legs of this cruise, the CRM used was Batch 154 (certified = 2224.30). The average measured CRM on Leg 1 was 2224.93 with a standard deviation of 1.65 and a range of 7.04. For Leg 2, the average CRM was 2225.07 with a standard deviation of 1.35 and a range of 6.82. These higher than typical SD and range resulted from a less precise commercially sourced voltage amplifier used during the cruise. Samples analyzed on shore after the cruise (Stations 134 and 135), used CRM batches 154 and 145 (certified = 2226.16) with average measurements of 2223.20 (SD = 0.76, range = 2.06) and 2226.03 (SD = 1.34, range = 3.27). No corrections were made for the offset between the certified and measured CRM's. Precision was monitored by analyzing replicates drawn from approximately 10% of the Niskins sampled.; Standardization frequency: Every 20 samples or less as needed.; CRM manufacturer: Dr. Andrew Dickson (Scripps Institution of Oceanography); CRM batch number: 154 and 145; Preservation method: Mercuric Chloride Solution; Preservative volume: 0.12 ml; Preservative correction: The TA values were corrected for the resulting dilution of the added 0.12 ml of saturated HgCl2 used for sample preservation.; TA blank correction: n.a.; Uncertainty: ±0.1%; Quality flag convention: TA_FLAG, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Dickson, A.G, Sabine, C.L. and Christian, J.R. (Eds.) 2007. "Guide to Best Practices for Ocean CO2 Measurements." PICES Special Publication 3, 191 pp.; Researcher name: Julian Herndon, Morgan Langis, Martin Hernandez-Ayon, and Remy Okazaki; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Simone Alin.
- Parameter or Variable: pH; Abbreviation: PH_TOT_MEA; pH scale: Total; Observation type: Discrete measurements from samples collected on CTD casts; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: Niskin bottle; Analyzing instrument: The pH of each sample was determined on the total pH scale on an Agilent 8453 spectrometer set up with a custom-made temperature-controlled cell holder.; Temperature of pH measurement: 25 (±0.05) ºC; Detailed sampling and analyzing information: Samples were collected for pH analysis immediately following O2 in the Niskin/Rosette sampling sequence. Seawater samples were collected from the Niskin bottles directly in 10-cm cylindrical optical cells (~30 mL volume) using a section of silicone tubing (about 15 cm long). One end of the silicone tubing was attached to the optical cell and the other end was attached to the nipple of the Niskin bottle. The Niskin bottle nipple was pushed in to initiate flow and the silicone tubing was squeezed to eliminate air bubbles. The optical cell was agitated to eliminate bubbles and, after 15 seconds of sample flow, the cell was capped at one end. The silicone tubing was then detached from the optical cell and, with the water still flowing, the cap was rinsed and used to seal the optical cell. Samples collected this way were not exposed to the atmosphere, and each cell was flushed with approximately three cell volumes of seawater. The samples were collected, taken into the lab, and rinsed with tap water to get rid of salt outside of the cells. The cells were dried and the optical windows were cleaned with Kimwipes. Samples were thermostatted at 25 (±0.05)°C in a custom made 36-position cell warmer. A custom macro program running on Agilent ChemStation was used to guide the measurements and data processing. The macro automated the procedures of sample input, blank and sample scans, quality control, and data archiving. The quality control steps included checking the baseline shift after dye injection and monitoring the standard deviation of multiple scans. Absorbance blanks were taken for each sample and 10 microliters of purified m-cresol purple (10 mmol/kg) were added for the analysis. pHT (total scale) for shipboard conditions (25 °C at atmospheric pressure) was calculated according to Liu et al. (2011).; Replicate information: Duplicate pH samples were collected from discrete samples taken from the Niskin bottles (N = ~80) with a precision of ±0.0012; Standardization description: calibration-free; At what temperature was pH reported: 25°C; Uncertainty: Precision was equal to ±0.0012.; Quality flag convention: PH_FLAG, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Liu, X.; Patsavas, M.C.; and Byrne, R. H. (2011). Purification and characterization of meta-cresol purple for spectrophotometric seawater pH measurements. Environmental Science and Technology, 45(11), 4862-4868. https://doi.org/10.1021/es200665d; Researcher name: Dr. Xuewu (Sherwood) Liu; Researcher institution: University of South Florida; PI: Robert Byrne.
- Parameter or Variable: CTD pressure; Abbreviation: CTDPRESSURE_DBAR; Unit: dbars; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: Sea-Bird 9plus CTD; Detailed sampling and analyzing information: The Sea-Bird 9plus CTD uses a Paroscientific Digiquartz pressure sensor. This high pressure transducer uses a quartz crystal resonator whose frequency of oscillation varies with pressure-induced stress measuring changes in pressure as small as 0.01 parts per million with an absolute range of 0 to 10,000 psia (0 to 6885 decibars). Also, a quartz crystal temperature signal is used to compensate for a wide range of temperature changes. Repeatability, hysteresis, and pressure conformance are 0.005% FS. The nominal pressure frequency (0 to full scale) is 34 to 38 kHz. The nominal temperature frequency is 172 kHz + 50 ppm/°C. Data are acquired at 24 Hz. Discrete pressure data were averaged over an 8-second interval, ±4 seconds of the sample confirm bit. Periodic pressure sensor calibrations are performed at Sea-Bird Electronics, Inc. No additional adjustments were applied.; Uncertainty: On deck pressure readings prior to each cast were within 1 dbar of calibration.; Researcher name: Ryan M. McCabe; Researcher institution: University of Washington - JISAO.
- Parameter or Variable: CTD temperature, ITS-90 scale; Abbreviation: CTDTEMP_ITS90_DEG_C; Unit: °C; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: Sea-Bird 3 temperature sensor; Detailed sampling and analyzing information: The Sea-Bird temperature sensing element is a glass-coated thermistor bead, pressure-protected inside an 0.8 mm diameter thin-walled stainless steel tube. Exponentially related to temperature, the thermistor resistance is the controlling element in an optimized Wien Bridge oscillator circuit. The resulting sensor frequency is inversely proportional to the square root of the thermistor resistance and ranges from approximately 2 to 6 kHz, corresponding to temperatures from -5 to 35°C. The 3plus temperature sensor has a typical accuracy/stability of 0.0002°C per month; and resolution of 0.0002°C at 24 Hz. Discrete temperature data were averaged over an 8-second interval, ±4 seconds of the sample confirm bit. Only a uniform viscous heating correction of -0.0006°C was applied.; Uncertainty: Calibrations and checks with duplicate sensors suggest uncertainty on the order of ±0.001°C. The viscous heating correction results in errors of no more than ±0.00015°C for the full range of oceanographic temperature and salinity.; Researcher name: Ryan M. McCabe; Researcher institution: University of Washington - JISAO.
- Parameter or Variable: CTD salinity; Abbreviation: CTDSAL_PSS78; Unit: 1978 Practical Salinity Scale; Observation type: profile; Sampling instrument: Sea-Bird 4 conductivity sensor; Detailed sampling and analyzing information: The Sea-Bird conductivity sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Because the outer electrodes are connected together, electric fields are confined inside the cell. The cell resistance controls the output frequency of a Wien Bridge oscillator circuit. The sensor has a frequency output of approximately 3 to 12 kHz corresponding to conductivities from 0 to 7 Siemens/meter (0 to 70 mmho/cm). The conductivity sensor has a typical accuracy/stability of 0.0003 S/m per month, and resolution of 0.00004 S/m at 24 Hz. Discrete conductivity data were averaged over an 8-second interval, ±4 seconds of the sample confirm bit. An overall linear fit of CTD and bottle data, including a station-dependent slope, single conductivity bias, and a linear pressure term (modified beta; with a coefficient multiplied by CTD pressure), produced the best results for stations 4-86 and 87-135. The fitting routine recursively throws out data greater than 2.8 standard deviations and returns a single conductivity bias, conductivity slope, and pressure term coefficient for each station. A station-dependent slope coefficient best models the gradual shift in the conductivity sensor within each station grouping with time. The order of the polynomial was chosen to keep the standard deviation of each grouping to a minimum while avoiding fitting to fluctuations due to noise in standardizations of salinity sample runs. Discrete salinity values were derived from calibrated conductivity, temperature, and pressure measurements.; Uncertainty: 80% of points were used in the fit of stations 4-86 with a residual standard deviation of 0.0017; 84% of points were used in the fit of stations 87-135 with a residual standard deviation of of 0.0051 mS/cm.; Researcher name: Ryan M. McCabe; Researcher institution: University of Washington - JISAO.
- Parameter or Variable: Bottle salinity; Abbreviation: SALINITY_PSS78; Unit: 1978 Practical Salinity Scale; Observation type: profile; Sampling instrument: ~250 ml Kimax bottle; Analyzing instrument: Guildline Autosal, model 8400B salinometer (S/N 68981); Detailed sampling and analyzing information: Niskin sample salinity measurements were made using Guildline 8400B Autosal salinometer s/n 68981 located in a temperature-controlled room in the Marine Chemistry Laboratory at the University of Washington (manager K.A. Krogslund). Two salinity samples were collected from the majority of casts. Samples were collected in ~250 ml Kimax high-alumina borosilicate bottles, sealed with custom clear plastic inserts and Nalgene caps. Salinity samples were stored during the cruise and analyzed post cruise. The Autosal bath temperature was set to 24°C. After initiating the software program, a bottle of standard seawater (batch P156) was used to determine an offset correction to be applied to the following measurements. 214 discrete salinity samples were run to validate CTD observations.; Quality flag convention: SALINITY_FLAG_W, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Ryan M. McCabe; Researcher institution: University of Washington - JISAO.
- Parameter or Variable: CTD Oxygen; Abbreviation: CTDOXY_UMOL_KG; Unit: micromoles/kg; Observation type: profile; Sampling instrument: Sea-Bird 43 oxygen sensor; Detailed sampling and analyzing information: The Sea-Bird oxygen sensor uses an electrochemical cell that is constantly polarized. The sensor is temperature compensated using special temperature sensing and an internal microcomputer. The interface electronics reports voltages for oxygen current only. A linear equation of the form I=mV+b, where m=1.0e-6 and b=0.0, yields sensor current as a function of sensor output voltage. The sensor has a thermal time constant of approximately 2.5 seconds; and an oxygen response time constant that is temperature dependent, increasing with cooler temperatures, ranging from 2 to 12 seconds. Hysteresis between the down and up oxygen profiles at deep stations warranted using the downcast oxygen data for calibration, matched by potential density anomalies referenced to the closest 1000-m interval. An overall least squares fit was determined for each of the two oxygen sensors used during this cruise.; Uncertainty: 83% of the points were used in the fit with a residual standard deviation of 1.7623 micro-mol/kg for stations 4-135.; Researcher name: Ryan M. McCabe; Researcher institution: University of Washington - JISAO.
- Parameter or Variable: bottle dissolved oxygen; Abbreviation: OXYGEN_UMOL_KG; Unit: micromol/kg; Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Brinkman Dosimat automated titrator; Detailed sampling and analyzing information: The analysis method is based upon the Carpenter (1965) whole flask titration of iodine, which is produced by an equivalent amount of dissolved oxygen. An automated titrator (Brinkman Dosimat) uses an amperometric end-point detection as described by Culberson and Huang (1987) and modified for IBM-PC computers by Knapp et al. (1990). The nominal 125-ml iodine flasks are used for sampling are pre-calibrated so their volumes are precisely known. Samples were titrated within a few hours of being collected. 1055 discrete oxygen samples were analyzed to validate sensor O2 observations on the CTD package.; Uncertainty: 1.4 micromol per kilogram; Quality flag convention: OXYGEN_FLAG_W, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Dale Hubbard and Carrie Weekes; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: Carbonate ion (CO3-2) concentration; Abbreviation: CARBONATE_UMOL_KG; Unit: micromoles/kg; Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: The total carbonate ion concentration of each sample was determined on an Agilent 8453 spectrometer set up with a custom-made temperature-controlled cell holder.; Detailed sampling and analyzing information: Samples were collected for carbonate (CO3) analysis immediately following pH in the Niskin/Rosette sampling sequence, following the same sampling and thermostatting procedure as the pH samples. A custom macro program running on Agilent ChemStation was used to guide the measurements and data processing. The macro automated the procedures of sample input, blank and sample scans, quality control, and data archiving. The quality control steps included checking the baseline shift after dye injection and monitoring the standard deviation of multiple scans. Absorbance blanks were taken for each sample and 20 microliters of Pb(ClO4)2 (22 mmol/kg) were added for the analysis. Total carbonate ion concentration ([CO32-]T) at shipboard conditions (25°C and atmospheric pressure) was calculated according to the equations of Sharp et al. (2017) and the modified -log[CO32-]T model of Byrne and Yao (2008) (Eq. 8 of Sharp et al., 2017).; Replicate information: Duplicate [CO32-]T samples were collected from discrete samples taken from the Niskin bottles (N = ~80) with a precision equal to 1.9 micromol/kg.; Uncertainty: 1.9 micromol/kg; Quality flag convention: CARBONATE_FLAG_W, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Sharp, J.D.; Byrne, R.H.; Liu, X; Feely, R.A.; Cuyler, E.E.; Wanninkhof, R.; Alin, S.R. (2017). Spectrophotometric Determination of Carbonate Ion Concentrations: Elimination of Instrument-Dependent Offsets and Calculation of In Situ Saturation States. Environmental Science and Technology 51, 9127-9136.; Researcher name: Dr. Xuewu (Sherwood) Liu; Researcher institution: University of South Florida, PI: Robert Byrne.
- Parameter or Variable: Orthosilicic acid; Abbreviation: SILICATE_UMOL_KG; Unit: micromoles/kg (converted from umol per Liter by Dana Greeley using a sigma theta calculated from a lab temperature of 22 C); Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 components were used for silicic acid, nitrate, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were stored in a freezer on board. Once the ship returned to port the samples were sent to the lab and analyzed. The Silicic Acid method is based on that of Armstrong et al. (1967) as adapted by Atlas et al. (1971). Addition of an acidic molybdate reagent forms silicomolybdic acid, which is then reduced by stannous chloride.; Uncertainty: 1.0 micromol per kilogram; Quality flag convention: NUTRIENTS_FLAG_W, One flag used for all nutrient samples, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Gordon et. al. (1993). A Suggested Protocol for Continuous Flow Automated Analysis of Seawater Nutrients (Phosphate, Nitrate, Nitrite and Silicic Acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. Methods Manual WHPO. 91-1.; Researcher name: Joe Jennings; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: Ammonium; Abbreviation: AMMONIUM_UMOL_KG; Unit: micromoles/kg (converted from umol per Liter by Dana Greeley using a sigma theta calculated from a lab temperature of 22 C); Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 components were used for silicic acid, nitrate, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were stored in a freezer on board. Once the ship returned to port the samples were sent to the lab and analyzed. An indophenol blue ammonium method is modified from ALPKEM RFA methodology which references Methods for Chemical Analysis of Water and Wastes, March 1984, EPA-600/4-79-020, "Nitrogen Ammonia", Method 350.1 (Colorimetric, Automated Phenate); Uncertainty: 0.06 micromoles per kilogram; Quality flag convention: NUTRIENTS_FLAG_W, One flag used for all nutrient samples, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Gordon et. al. (1993). A Suggested Protocol for Continuous Flow Automated Analysis of Seawater Nutrients (Phosphate, Nitrate, Nitrite and Silicic Acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. Methods Manual WHPO. 91-1.; Researcher name: Joe Jennings; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: Nitrate; Abbreviation: NITRATE_UMOL_KG; Unit: micromoles/kg (converted from umol per Liter by Dana Greeley using a sigma theta calculated from a lab temperature of 22 C); Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 components were used for silicic acid, nitrate, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were stored in a freezer on board. Once the ship returned to port the samples were sent to the lab and analyzed. The nitrate + nitrite analysis uses the basic method of Armstrong et al. (1967), with modifications to improve the precision and ease of operation. Sulfanilamide and N-(1-Napthyl)ethylenediamine dihydrochloride react with nitrite to form a colored diazo compound. For the nitrate + nitrite analysis, nitrate is first reduced to nitrite using an OTCR and imidazole buffer as described by Patton (1983). Nitrite analysis is performed on a separate channel, omitting the cadmium reductor and the buffer.; Uncertainty: 0.2 micromol per kilogram; Quality flag convention: NUTRIENTS_FLAG_W, One flag used for all nutrient samples, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Gordon et. al. (1993). A Suggested Protocol for Continuous Flow Automated Analysis of Seawater Nutrients (Phosphate, Nitrate, Nitrite and Silicic Acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. Methods Manual WHPO. 91-1.; Researcher name: Joe Jennings; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: Nitrite; Abbreviation: NITRITE_UMOL_KG; Unit: micromoles/kg (converted from umol per Liter by Dana Greeley using a sigma theta calculated from a lab temperature of 22 C); Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 components were used for silicic acid, nitrate, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were stored in a freezer on board. Once the ship returned to port the samples were sent to the lab and analyzed. The nitrate + nitrite analysis uses the basic method of Armstrong et al. (1967), with modifications to improve the precision and ease of operation. Sulfanilamide and N-(1-Napthyl)ethylenediamine dihydrochloride react with nitrite to form a colored diazo compound. For the nitrate + nitrite analysis, nitrate is first reduced to nitrite using an OTCR and imidazole buffer as described by Patton (1983). Nitrite analysis is performed on a separate channel, omitting the cadmium reductor and the buffer.; Uncertainty: 0.03 micromol per kilogram; Quality flag convention: NUTRIENTS_FLAG_W, One flag used for all nutrient samples, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Gordon et. al. (1993). A Suggested Protocol for Continuous Flow Automated Analysis of Seawater Nutrients (Phosphate, Nitrate, Nitrite and Silicic Acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. Methods Manual WHPO. 91-1.; Researcher name: Joe Jennings; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: Phosphate; Abbreviation: PHOSPHATE_UMOL_KG; Unit: micromoles/kg (converted from umol per Liter by Dana Greeley using a sigma theta calculated from a lab temperature of 22 C); Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 components were used for silicic acid, nitrate, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were stored in a freezer on board. Once the ship returned to port the samples were sent to the lab and analyzed. The phosphate method is a modification of the molybdenum blue procedure of Bernhardt and Wilhelms (1967), in which phosphate is determined as reduced phosphomolybdic acid employing hydrazine as the reductant.; Uncertainty: 0.02 micromol per kilogram; Quality flag convention: NUTRIENTS_FLAG_W, One flag used for all nutrient samples, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Gordon et. al. (1993). A Suggested Protocol for Continuous Flow Automated Analysis of Seawater Nutrients (Phosphate, Nitrate, Nitrite and Silicic Acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. Methods Manual WHPO. 91-1.; Researcher name: Joe Jennings; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: Total extracted chlorophyll a; Abbreviation: CHL_A_UG_L_GFF; Unit: micrograms per liter; Observation type: Discrete measurements from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Turner Designs Trilogy; Detailed sampling and analyzing information: Samples were collected in amber 250 mL HDPE bottles and filtered onto Whatman GF/F filters (25-mm diameter) within 30 minutes of collection. Each filter was then placed inside a borosilicate glass tube and stored frozen (-20 deg C) until analysis. Chlorophyll was extracted in the dark at -20 deg C using 90 % (v/v) over a period not exceeding 24 h, and subsequently analyzed by in vitro fluorometry using the non-acidification method of Welschmeyer (1994). Concentrations of chlorophyll estimated from samples collected with these glass fiber filters (nominal pore size of 0.7 um) represent the chlorophyll from the total phytoplankton community.; Replicate information: None collected; Quality flag convention: CHL_A_FLAG_W, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn; Method reference: Welschmeyer, N.A. 1994. Fluorometric analysis of chlorophyll a in the presence of chlorophyll b and pheopigments. Limnology and Oceanography 39: 1985-1992.; Researcher name: Christopher Ikeda; Researcher institution: San Francisco State University, Romberg Tiburon Center for Environmental Studies; PI: William Cochlan.
- Parameter or Variable: Size-fractionated chlorophyll a from cells larger than 10 um; Abbreviation: CHL_A_UG_L_PC; Unit: micrograms per liter; Observation type: Discrete measurments from samples collected on CTD casts; Sampling instrument: Niskin bottle; Analyzing instrument: Turner Designs Trilogy; Detailed sampling and analyzing information: Samples were collected in amber 250 mL HDPE bottles and filtered onto a 10-um polycarbonate filters (25-mm diameter) within 30 minutes of collection. Each filter was then placed inside a borosilicate glass tube and stored frozen (-20 deg C) until analysis. Chlorophyll was extracted in the dark at -20 deg C using 90 % (v/v) over a period not exceeding 24 h, and subsequently analyzed by in vitro fluorometry using the non-acidification method of Welschmeyer (1994). Concentrations of chlorophyll estimated from samples collected with these 10-um polycarbonate filters represent the chlorophyll from phytoplankton 10 um or larger in size.; Replicate information: None collected; Quality flag convention: CHL_A_FLAG_W, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn; Method reference: Welschmeyer, N.A. 1994. Fluorometric analysis of chlorophyll a in the presence of chlorophyll b and pheopigments. Limnology and Oceanography 39: 1985-1992.; Researcher name: Christopher Ikeda; Researcher institution: San Francisco State University, Romberg Tiburon Center for Environmental Studies; PI: William Cochlan .
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