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- 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: 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 The sample tube was pinched off and withdrawn, creating a ~7.5 ml headspace and 0.12 ml of saturated HgCl2 solution was added as a preservative.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. A. 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 data base have been corrected to this batch 119 CRM value. The CRM certified value for this batch is 2014.78 umol/kg. Summary The overall performance of the analytical equipment was good during the cruise. We were able to sample every niskin Niskin made available to us; and including the duplicates and samples drawn from the underway seawater line, 1,081 samples 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 0.7 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's 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); Preservation method: Mercuric Chloride Solution; Preservative volume: 0.12 ml; Preservative correction: The DIC values were corrected for dilution by 0.12 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 1.0004.; Uncertainty: minus plus 0.1%; Quality flag convention: DIC_QC, 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 at PMEL and modeled after an earlier generation of those made in Andrew Dickson's lab.; 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: Seawater total alkalinity (TA) was measured by acidimetric titration. The specific method used was based upon the open-cell method described by Dickson et al (2003). This method involves first acidifying the sample to reduce the sample pH to less than 3.6 followed by bubbling CO2-free air through the sample to facilitate removal of the CO2 evolved by the acid addition. After removal of the carbonate species from solution, the titration proceeds until a pH of less than 3.0 is attained, and the equivalence point evaluated from titration points in the pH region 3.0-3.5 using a non-linear least squares procedure that corrects for the reactions with sulfate and fluoride ions (Dickson et al. 2003). Titration progress is monitored by measuring the electromotive force (E) of a combination glass-reference electrode. Samples were drawn from the Niskin-type bottles into cleaned 250-ml borosilicate glass bottles using Tygon tubing with silicone ends. Bottles were rinsed twice and filled from the bottom, overflowing half a volume and taking care not to entrain any bubbles. The sample tube was closed off and withdrawn from the sample bottle, creating a 5 ml headspace. Samples were preserved by poisoning with 0.133 ml of a saturated HgCl2 solution. Sample bottles were sealed with glass stoppers lightly coated with Apiezon-L grease, and were stored at room temperature (21-25 degrees Celsius) for a maximum of 12 hours prior to analysis. Titrations were carried out in water-jacketed, 250-ml beakers. The beakers were kept at 24.0 minus plus 0.2 degrees Celsius with water from a constant temperature bath. Prior to analysis, samples were placed in the water bath to bring them to the same temperature as the reaction beakers. Seawater samples were dispensed into the water-jacketed beaker using a fixed volume glass syringe. A Metrohm Dosimat 765 was used to deliver acid to the sample beaker in increments of 0.040 ml. The acid titrant used was 0.1 mol/kg HCl prepared in 0.6 mol/kg NaCl background to approximate the ionic strength of seawater (0.7 mol/kg). Instrument control and data acquisition was with custom software developed in Andrew Dickson's laboratory at Scripps Institution of Oceanography and modified by a former employee of the NOAA/PMEL Carbon Group using the National Instruments LabView programming environment. Over the course of the cruise we analyzed over 1,500 samples, including duplicate samples and certified reference materials (CRMs). Typical titrations were completed in 10-14 minutes and required 20-24 acid additions to reach a pH of 3.0. 1,014 values were reported to the database.; 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 24 samples. For this CRM batch, the average offset for system 1 was -0.46 with a standard deviation of 1.04. The average offset for system 2 was -1.16 with a standard deviation of 1.0.; Standardization frequency: All values were directly measured with reference to Certified Reference Material (Dickson, SIO); CRM manufacturer: Andrew Dickson's lab at Scripps Institute of Oceanography; Preservation method: Mercuric Chloride Solution; Preservative volume: 0.12 ml; Preservative correction: The TA values were corrected for dilution by 0.12 ml of saturated HgCl2 used for sample preservation. The total water volume of the sample bottles was 266 ml. The correction factor used for dilution was 1.00045.; TA blank correction: n.a.; Uncertainty: The precision of this method is better than 0.1% and accuracy is 0.1%.; Quality flag convention: TA_QC, 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: Bates, R.G. Determination of pH. Theory and Practice. A Wiley-Interscience Publication, Second Edition. Dickson A.G. (1981). An exact definition of total alkalinity, and a procedure for the estimation of alkalinity and total inorganic carbon from titration data. Deep-Sea Res. 28, 609-623. Dickson A.G. (1992). The development of the alkalinity concept in marine chemistry. Marine chemistry 40:1-21-2, 49-63. Dickson, A. G., Afghan, J. D. and Anderson, G. C. (2003). Reference materials for oceanic CO2 analysis: A method for the certification of total alkalinity. Marine Chemistry 80, 185-197 Gran G. (1952). Determination of the equivalence point in potentiometric titrations. Part II. The analyst, 77, 661-671. Wolf-Gladrow, D.A. et al. (2007). Total alkalinity: The explicit conservative expression and its application to biogeochemical process.; Researcher name: Cynthia Peacock; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Simone Alin.
- Parameter or Variable: CTD pressure; Abbreviation: Press (db); 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/degrees Celsius. Data are acquired at 24 Hz. Discrete pressure data were averaged over an 8-second interval, minus plus 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: Kristene McTaggart; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Gregory C. Johnson.
- Parameter or Variable: CTD temperature, ITS-90 scale; Abbreviation: CTD T degrees Celsius ITS-90; Unit: degrees celsius, ITS-90 scale; 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 35degrees Celsius. The 3plus temperature sensor has a typical accuracy/stability of 0.0002degrees Celsius per month; and resolution of 0.0002degrees Celsius at 24 Hz. Discrete temperature data were averaged over an 8-second interval, minus plus 4 seconds of the sample confirm bit. A uniform viscous heating correction of -0.0006degrees Celsius was applied.; Uncertainty: Calibrations and checks with duplicate sensors suggest uncertainty on the order of minus plus 0.001degrees Celsius. The viscous heating correction results in errors of no more than minus plus 0.00015degrees Celsius for the full range of oceanographic temperature and salinity.; Researcher name: Kristene McTaggart; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Gregory C. Johnson.
- Parameter or Variable: CTD salinity; Abbreviation: CTD Salt; Unit: 1978 Practical Salinity Scale; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Calculated from conductivity measurements.; 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, minus plus 4 seconds of the sample confirm bit. Poor performance by the Autosal made conductivity calibration difficult. An overall linear fit of CTD and bottle data, including a pressure bias, produced the best results using only the data from the last two Autosal runs. The fitting routine recursively throws out data greater than 2.8 standard deviations and returns a single conductivity bias and a conductivity slope for each station. A linear pressure term (modified beta) that is multiplied by CTD pressure and added to conductivity may also be warranted. 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: 94% of points were used in the fit of stations 44-81 with a standard deviation of 0.0071 mS/cm.; Researcher name: Kristene McTaggart; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Gregory C. Johnson.
- Parameter or Variable: Bottle salinity; Abbreviation: bot salt; Unit: 1978 Practical Salinity Scale; Observation type: Profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Calculated from conductivity measurements.; Sampling instrument: 250 ml Kimax bottle; Analyzing instrument: Guildline Autosal, model 8400B salinometer (S/N 68807); Detailed sampling and analyzing information: Sample salinity measurements were made using Guildline 8400B Autosal salinometer s/n 68807 set up in a temperature-controlled space on the ship (i.e. walk-in refrigerator). The Autosal bath temperature was set to 24degrees Celsius. Ambient temperature was also set to 24degrees Celsius and unfortunately was not monitored. Ambient temperature should have been set to 23 degrees Celsius and recorded with a logging thermometer. Power to the Autosal was conditioned through a UPS to reduce noise in the readings. An Ocean Scientific Instruments interface box and software were used to capture readings and compute an averaged value of salinity. Samples were collected from most casts, at least one from the deepest Niskin and likely a second one from the surface mixed layer. Samples were collected in 200 ml Kimax high-alumina borosilicate bottles, sealed with custom clear plastic inserts and Nalgene caps, and externally rinsed with fresh water to reduce salt contamination. Salinity samples were allowed to equilibrate in temperature for a minimum of 12 hours before run in groups of about 34 samples over 6 days. Samples were sorted deep to shallow before each run. A bottle of sub-standard seawater (expired batch P147) was flushed ten times through the conductivity cell before a bottle of standard seawater (batch P152) was measured for calibration purposes. Each water sample was flushed through the cell four times before taking the first reading. After waiting five seconds, six seconds of data were averaged for one reading of the conductivity ratio. Three ratios were averaged for one salinity value calculated for each water sample. At the end of the run, a second bottle of standard seawater was measured. A dilute solution of Triton-X surfactant was flushed through the cell at the end of each session, followed by 400 ml is distilled water. Distilled water remained in the cell when not in use. AOML program correct_autosal_drift_v4.m was used to apply a linear fit with time over the run to determine a slope and an offset subsequently applied to the samples run. Runs were appended and resorted by station/sample number. A total of 152 sample salinity measurements were made during this cruise.; Quality flag convention: Bot_Salt_QC, 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: Kristene McTaggart; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Gregory C. Johnson.
- Parameter or Variable: CTD oxygen; Abbreviation: CTD OXY (umol/kg); Unit: micromol/kg; Observation type: profile; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; 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 the single oxygen sensor used during this cruise.; Uncertainty: 87% of points were used in the fit with a standard deviation of 2.3527 umol/kg.; Researcher name: Kristene McTaggart; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; PI: Gregory C. Johnson.
- Parameter or Variable: bottle dissolved oxygen; Abbreviation: Bot O2 (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: 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. 615 discrete oxygen samples were run to validate sensor O2 observations on the CTD package.; Quality flag convention: Bot_O2_QC, 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: Colleen Wall; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: Orthosilicic acid; Abbreviation: Silicate 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: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 (trade mark) components were used for silicic acid, nitrate plus nitrite, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were generally analyzed within a few hours of their collection. Samples were kept refrigerated until they were 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.; 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: 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: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 (trade mark) components were used for silicic acid, nitrate plus nitrite, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were generally analyzed within a few hours of their collection. Samples were kept refrigerated until they were 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.; 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: 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: Alpkem RFA 300; Detailed sampling and analyzing information: Alpkem RFA 300 (trade mark) components were used for silicic acid, nitrate plus nitrite, and nitrite. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were generally analyzed within a few hours of their collection. Samples were kept refrigerated until they were 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.; 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: 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: Alpkem RFA 300; Detailed sampling and analyzing information: Technicon AutoAnalyzer II (trade mark) components were used to measure phosphate and ammonium. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were generally analyzed within a few hours of their collection. Samples were kept refrigerated until they were 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.; Researcher name: Joe Jennings; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: ammonia; Abbreviation: Ammonia 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: Alpkem RFA 300; Detailed sampling and analyzing information: Technicon AutoAnalyzer II (trade mark) components were used to measure phosphate and ammonium. All five of the macronutrients are analyzed simultaneously. Nutrient samples were collected in 30 ml HDPE bottles and were generally analyzed within a few hours of their collection. Samples were kept refrigerated until they were 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.; Researcher name: Joe Jennings; Researcher institution: Oregon State University, College of Earth, Ocean, and Atmospheric Sciences; PI: Burke Hales.
- Parameter or Variable: chlorophyll concentration in sea water; Abbreviation: Chlorophyll a concentration ug/L; Unit: microgram per liter; In-situ / Manipulation / Response variable: In-situ observation; Measured or calculated: Measured; Sampling instrument: Niskin Bottle; Analyzing instrument: Turner Designs Fluorometer; Detailed sampling and analyzing information: 100 ml was filtered from water samples that were collected at the surface, the depth of the chlorophyll maximum, and at 30 m for extracted Chlorophyll-a. Chlorophyll-a is extracted from glass-fiber filters in 90% acetone then analyzed using a Turner Designs Fluorometer. 132 values were reported to the database.; Researcher name: Tracy Shaw; Researcher institution: Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration, William T Peterson .
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