Water-column environmental variables and accompanying discrete CTD measurements collected off California and Oregon during NOAA cruise SH-18-12 (USGS field activity 2018-663-FA) from October to November 2018 (ver. 3.0, July 2022)

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Prouty, Nancy G., and Baker, Miranda C., 2021, Water-column environmental variables and accompanying discrete CTD measurements collected off California and Oregon during NOAA cruise SH-18-12 (USGS field activity 2018-663-FA) from October to November 2018 (ver. 3.0, July 2022): data release DOI:10.5066/P99MJ096, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P99MJ096
   • https://www.sciencebase.gov/catalog/item/62a7ac5ad34ec53d2770c81f

   This is part of the following larger work.
   Prouty, Nancy G., and Baker, Miranda C., 2021, CTD profiles and discrete water-column measurements collected off California and Oregon during NOAA cruise SH-18-12 (USGS field activity 2018-663-FA) from October to November 2018 (ver. 3.0, July 2022): data release DOI:10.5066/P99MJ096, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P99MJ096

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -124.9152
   East_Bounding_Coordinate: -119.3453
   North_Bounding_Coordinate: 44.6653
   South_Bounding_Coordinate: 33.1300
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 12-Oct-2018

   Ending_Date: 07-Nov-2018

   Currentness_Reference:

   Ground condition at time data were collected.

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: comma-delimited text
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (161)
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0001. Longitudes are given to the nearest 0.0001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is D_WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      
7. How does the data set describe geographic features?

   A tab-delimited text file with the first line being a header line.

   Output from CO2SYS program and geochemistry lab analyses combined with CTD data from water sample collection (Source: Producer defined.)

   Cruise

   Name of Cruise on which samples and measurements were collected (Source: Producer defined)

   Value	Definition
   SH-18-12	Abbreviation indicating Bell M. Shimada R/V, year and mission number.

   CTD station

   numbered station where CTD measurements were collected (Source: Producer defined.)

   Range of values
   Minimum:	1
   Maximum:	22
   Units:	days

   Site Name

   Site Name where samples were collected (Source: Producer defined.) List of Site names

   Date

   Date [YYYYMMDD] (Source: Producer defined.)

   Range of values
   Minimum:	20181012
   Maximum:	20181107

   Time

   Time (UTC) [HH:MM:SS] (Source: Producer defined.)

   Range of values
   Minimum:	00:00:00
   Maximum:	23:59:59
   Units:	HH:MM:SS
   Resolution:	1

   TimeJ

   Time in Julian Days (Source: Producer defined.)

   Range of values
   Minimum:	285.468436
   Maximum:	311.259419
   Units:	Julian Days
   Resolution:	0.000001

   Temperature

   Temperature in degrees Celsius (Source: Producer defined.)

   Range of values
   Minimum:	4.8869
   Maximum:	19.2192
   Units:	degrees Celsius
   Resolution:	0.0001

   Conductivity

   Conductivity (Source: Producer defined.)

   Range of values
   Minimum:	32900
   Maximum:	45600
   Units:	microsiemens per centimeter
   Resolution:	100

   Pressure

   Pressure (Source: Producer defined.)

   Range of values
   Minimum:	1.504
   Maximum:	617.345
   Units:	decibels
   Resolution:	0.001

   Sbeox0

   Oxygen in milligrams per liter (Source: Producer defined.)

   Range of values
   Minimum:	0.3903
   Maximum:	8.6001
   Units:	milligrams per liter
   Resolution:	0.0001

   Sbeox0PS

   Oxygen in percentage saturation (Source: Producer defined.)

   Range of values
   Minimum:	3.845
   Maximum:	104.553 Attribute_Units_of_Measure: percentage saturation
   Resolution:	0.001

   Turbidity

   Turbidity, (Source: Producer defined.)

   Range of values
   Minimum:	0.0259
   Maximum:	0.5086
   Units:	Nephelometric Turbidity Units
   Resolution:	0.0001

   Fluorescence

   Fluorescence (Source: Producer defined.)

   Range of values
   Minimum:	-0.0397
   Maximum:	4.1578
   Units:	miligrams per cubic meter
   Resolution:	0.0001

   AltM

   meters above seafloor (Source: Producer defined.)

   Range of values
   Minimum:	2.19
   Maximum:	98.87
   Units:	meters
   Resolution:	0.01

   Salinity

   Salinity. Values of -9999 indicate the parameter was not measured (Source: Producer defined.)

   Range of values
   Minimum:	32.259
   Maximum:	34.328
   Units:	practical salinity units (PSU)
   Resolution:	0.001

   DepSM

   Depth saltwater from the surface (Source: Producer defined.)

   Range of values
   Minimum:	1.491
   Maximum:	611.778
   Units:	meters
   Resolution:	0.001

   Latitude

   Latitude of sample location (Source: Producer defined.)

   Range of values
   Minimum:	33.1300
   Maximum:	44.6652
   Units:	decimal degrees
   Resolution:	0.0001

   Longitude

   Longitude of sample location (Source: Producer defined.)

   Range of values
   Minimum:	-124.9059
   Maximum:	-119.3454
   Units:	decimal degrees
   Resolution:	0.0001

   Niskin Bottle

   Niskin Bottle Number (Source: Producer defined.)

   Range of values
   Minimum:	1
   Maximum:	12
   Units:	bottle number

   Phosphate

   Dissolved inorganic phosphate concentration. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in inorganic chemistry)

   Range of values
   Minimum:	0.16
   Maximum:	3.40
   Units:	micromole per liter of seawater
   Resolution:	0.01

   Silicate

   Dissolved inorganic silicate concentration. Values of -9999 indicate the parameter was not measured (Source: standard reporting value in inorganic chemistry)

   Range of values
   Minimum:	1.04
   Maximum:	88.17
   Units:	micromole per liter of seawater
   Resolution:	0.01

   Nitrate and Nitrite

   Dissolved inorganic nitrate and nitrite concentration. Values of -9999 indicate the parameter was not measured (Source: standard reporting value in inorganic chemistry)

   Range of values
   Minimum:	0.06
   Maximum:	47.10
   Units:	micromole per liter of seawater
   Resolution:	0.01

   Ammonium

   Dissolved inorganic ammonium concentration. Values of -9999 indicate the parameter was not measured (Source: standard reporting value in inorganic chemistry.)

   Range of values
   Minimum:	<0.019
   Maximum:	0.65
   Units:	micromole per liter of seawater
   Resolution:	0.01

   Total Alkalinity

   Total alkalinity concentration. Values of -9999 indicate the parameter was not measured (Source: standard reporting value in inorganic chemistry)

   Range of values
   Minimum:	2083.97401
   Maximum:	2356.22836
   Units:	micromole per liter of seawater
   Resolution:	0.00001

   Total Alkalinity (STD)

   Standard deviation of Total Alkalinity measurement. Values of -9999 indicate the parameter was not measured (Source: Producer defined.)

   Range of values
   Minimum:	0.03379
   Maximum:	95.90443
   Units:	micromole per liter of seawater
   Resolution:	0.00001

   pH

   The negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions. Values of -9999 indicate the parameter was not measured (Source: Producer defined.)

   Range of values
   Minimum:	6.988469
   Maximum:	7.995355
   Units:	unitless
   Resolution:	0.000001

   Dissolved Inorganic Carbon

   The sum of inorganic carbon species in a solution (carbon dioxide, carbonic acid, bicarbonate anion, and carbonate. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in inorganic chemistry)

   Range of values
   Minimum:	2009.25
   Maximum:	2309.03
   Units:	micromole per kilogram
   Resolution:	0.01

   Dissolved Inorganic Carbon (STD)

   Standard deviation of Dissolved Inorganic Carbon measurement. Values of -9999 indicate the parameter was not measured. (Source: Producer defined.)

   Range of values
   Minimum:	0.01
   Maximum:	49.96
   Units:	micromole per liter of seawater
   Resolution:	0.01

   Calcite Saturation State

   ratio of [CO32-] and [Ca2+] divided by the calcite solubility product (Ksp) assuming the concentration of calcium, [Ca2+] is proportional to the salinity, and the carbonate concentration, [CO32-] was calculated from total alkalinity, pH, and the values of K1 and K2 for carbonic acid from Millero and others (1998) and Dickson and others (1990). Values of -9999 indicate the parameter was not measured. (Source: Calculated with measured salinity, temperature, nutrients, total alkalinity, and pH data using an Excel Workbook Macro translation of the original CO2SYS program (Lewis and Wallace, 1998).)

   Range of values
   Minimum:	0.33
   Maximum:	3.89
   Units:	unitless
   Resolution:	0.01

   Aragonite Saturation State

   ratio of [CO32-] and [Ca2+] divided by the aragonite solubility product (Ksp) assuming the concentration of calcium, [Ca2+] is proportional to the salinity, and the carbonate concentration, [CO32-] was calculated from total alkalinity, pH, and the values of K1 and K2 for carbonic acid from Millero and others (1998) and Dickson and others (1990). Values of -9999 indicate the parameter was not measured. (Source: Calculated with measured salinity, temperature, nutrients, total alkalinity, and pH data using an Excel Workbook Macro translation of the original CO2SYS program (Lewis and Wallace, 1998).)

   Range of values
   Minimum:	0.21
   Maximum:	2.51
   Units:	unitless
   Resolution:	0.01

   Fraction Modern

   Fraction modern is a measurement of the deviation of the delta-Carbon-14/delta-Carbon-12 ratio of a sample from modern carbon (Stuiver and Polach, 1977). Values of -9999 indicate the parameter was not measured. (Source: defined in Stuiver and Polach (1977))

   Range of values
   Minimum:	0.8628
   Maximum:	1.0193
   Units:	unitless
   Resolution:	0.0001

   Fraction Modern (error)

   Fraction modern (error) is a measurement of the deviation of the delta-Carbon-14/delta-Carbon-12 ratio of a sample from modern carbon (Stuiver and Polach, 1977). Values of -9999 indicate the parameter was not measured. (Source: defined in Stuiver and Polach (1977))

   Range of values
   Minimum:	0.0019
   Maximum:	0.003
   Units:	unitless
   Resolution:	0.0001

   Conventional Radiocarbon Age

   Conventional Radiocarbon Age calculated using the radiocarbon decay equation (Stuiver and Polach, 1977). Values of -9999 indicate the parameter was not measured. (Source: defined in Stuiver and Polach (1977))

   Range of values
   Minimum:	10
   Maximum:	1190
   Units:	years
   Resolution:	5

   Conventional Radiocarbon Age (error)

   Standard error for Conventional Radiocarbon Age. Values of -9999 indicate the parameter was not measured. (Source: Producer defined.)

   Range of values
   Minimum:	15
   Maximum:	25
   Units:	years
   Resolution:	1

   delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-0.53
   Maximum:	1.18
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   Delta-C-14

   The relative difference between the absolute international standard (base year 1950) and sample activity corrected for age and delta-Carbon-13. Values of -9999 indicate the parameter was not measured. (Source: defined in Stuiver and Polach (1977))

   Range of values
   Minimum:	-145.66
   Maximum:	10.24
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   Entity_and_Attribute_Overview: The first line of the tab-delimited text file is a header line.
   Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Nancy G. Prouty
   • Miranda C. Baker
2. Who also contributed to the data set?
   Sarah Merolla, Carina Fish, Chelsey Souza (U.C. Davis), Nissa Kreisler (Humboldt State)
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?

   nutrients (source 1 of 4)

   University of California at Santa Barbara, Marine Science Institute, 2019, Seawater nutrient analyses.

   Online Links:

   • http://msi.ucsb.edu/services/analytical-lab/seawater-nutrients-fia

   Type_of_Source_Media: seawater lab samples
   Source_Contribution:

   Flow injection analysis for dissolved nutrient (nitrate, ammonium, phosphate, and silicate) concentrations.

   pH and total alkalinity (source 2 of 4)

   University of California at Davis, Bodega Marine Lab, 2019, Seawater carbonate chemistry analysis.

   Online Links:

   • https://marinescience.ucdavis.edu/bml/about

   Type_of_Source_Media: seawater lab samples
   Source_Contribution:

   pH was determined Spectrophotometrically; Total alkalinity was determined by means of automated Gran titration on a Metrohm 809 Titrando (Dickson et al. 2007).

   dissolved inorganic radiocarbon (source 3 of 4)

   National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility, 2019, Seawater radiocarbon analysis.

   Online Links:

   • https://www.whoi.edu/nosams/Submitting_Guidelines

   Type_of_Source_Media: seawater lab samples
   Source_Contribution:

   An accelerator mass spectrometer (AMS) was used to measure inorganic radiocarbon

   CTD data (source 4 of 4)

   U.S. Geological Survey, 2020, CTD profile measurements collected off California and Oregon during NOAA cruise SH-18-12 (USGS field activity 2018-663-FA) from October to November 2018.

   Online Links:

   • https://doi.org/10.5066/P99DIQZ5

   Type_of_Source_Media: CTD measurements
   Source_Contribution:

   CTD measurements at particular depths were appended to the Niskin bottle water sample data

2. How were the data generated, processed, and modified?

   Date: 08-Nov-2018 (process 1 of 5)

   Water samples were collected using a Niskin bottle rosette apparatus at different depths throughout the water column. Simultaneous conductivity, salinity, and depth (CTD) data were collected with a SeaBird SBE-9 CTD profiler at each Niskin bottle sample depth. The latitude and longitude were updated in v2.0 to correct values from v1.0.

   Date: 24-Apr-2019 (process 2 of 5)

   Seawater samples were analyzed by several different labs (see Sources) for different variables. Data from all seawater lab analyses were combined into a single document. Calcite and aragonite saturation states were calculated using an Excel Workbook Macro translation of the original CO2SYS program (Lewis and Wallace, 1998; Pierrot and others, 2006). -9999 cell value indicates no data (for example, where water was not sampled, or a water sample was not analyzed for a particular variable). Data sources used in this process:

   • nutrients
   • pH and total alkalinity
   • dissolved inorganic radiocarbon

   Data sources produced in this process:

   • lab data

   Date: 16-Apr-2020 (process 3 of 5)

   CTD data and water column variables were combined based on depths into a single document (SH-18-12_BTL_CTD_data.csv). Data sources used in this process:

   • lab data
   • CTD data

   Date: 02-Sep-2021 (process 4 of 5)

   Corrected the lat/lon coordinates for CTD measurements collected on October 18, 2018. No other data were changed. Version 1.0 data available upon request.

   Date: Jul-2022 (process 5 of 5)

   This data release supersedes version 2.0, published in September 2021 at https://doi.org/10.5066/P99DIQZ5. Versioning details are documented in the accompanying VersionHistory_P99MJ096.txt file. For the revision, an attribute column header in the water-column environmental variable data file (SH-18-12_BTL_CTD_v.2.0_data.csv) was revised to accurately report ammonium not ammonia. No data values were changed, nor were any changes made in the accompanying CTD data (SH-18-12_raw_CTD.zip). Metadata files for both data files were revised to reflect the new doi number, URLs, download links, and PIDs. The metadata available from a harvester may supersede metadata bundled within a download file. Users are advised to compare the metadata dates to determine which metadata file is most recent.

3. What similar or related data should the user be aware of?
   Lewis, E., and Wallace, W.R., 1998, Program developed for CO2 system calculations.

   Online Links:

   • http://cdiac.ornl.gov/oceans/co2rprt.html

   Stuiver, M., and Polach, H.A., 1977, Discussion reporting of 14C data.

   Online Links:

   • https://doi.org/10.1017/S0033822200003672

   Dickson, A.G., 1990, Thermodynamics of the dissociation of boric acid in synthetic seawater from 273.15 to 318.15 K.

   Online Links:

   • https://doi.org/10.1016/0198-0149(90)90004-F

   Dickson, A.G., Sabine, C.L., and Christian, J.R., 2007, A guide to best practices for ocean CO2 measurements.

   Millero, F.J., Lee, K., and Roche, M., 1998, Distribution of alkalinity in the surface waters of the major oceans.

   Online Links:

   • https://doi.org/10.1016/S0304-4203(97)00084-4

   Pierrot, D., Lewis, E., and Wallace, D.W.R., 2006, MS Excel program developed for CO2 system calculations.

   Online Links:

   • https://doi.org/10.3334/CDIAC/otg.CO2SYS_XLS_CDIAC105a

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   All geochemistry data were calibrated against known standards
2. How accurate are the geographic locations?
   A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. The horizontal accuracy is based on ship’s position using the navigations system; MX420 DGPS (Differential GPSP) with an accuracy of 1 m.
3. How accurate are the heights or depths?
   A formal accuracy assessment of the vertical positional information in the data set has not been conducted. Depth was determined using a SeaBird CTD digiquartz pressure sensor with a stated accuracy of 0.015%.
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the metadata for each part of this data release carefully for additional details. Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the metadata for each part of this data release carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   No formal logical accuracy tests were conducted.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? These data are available in a text file (SH_18_12_CTD_BTLDATA_v3.0.txt) which contains seawater carbonate analysis and CTD data for all collected water samples.
3. What legal disclaimers am I supposed to read?
   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	ASCII text file in format tab-delimited text (version 14.7.7) Size: 0.041
     Network links:	https://www.sciencebase.gov/catalog/file/get/62a7ac5ad34ec53d2770c81f https://www.sciencebase.gov/catalog/item/62a7ac5ad34ec53d2770c81f https://doi.org/10.5066/P99MJ096

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?
   These data can be viewed with any text editor software.

Who wrote the metadata?

Dates:

Last modified: 13-Jul-2022

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)