This data set includes diverse measurements of seawater chemistry along with supplementary conductivity, temperature, depth (CTD); pressure; salinity; potential temperature; and density data from the Arctic Ocean near the North Pole. Measurements were taken from sea ice platforms each April or May from 2000-2005. Investigators used a CTD-O2 system to measure seawater conductivity, temperature, depth, and dissolved oxygen content, and collected Niskin bottle samples for measurements of salinity, oxygen isotope composition, and concentrations of phosphate, silicic acid, nitrate, nitrite, ammonium, and barium. The available in situ dissolved oxygen measurements were collected beginning in 2002.
The North Pole Environmental Observatory (NPEO) is a year-round, automated scientific observatory, deploying various instruments each April in order to learn how the world's northernmost sea helps regulate global climate. It consists of a set of unmanned scientific platforms that record oceanographic, cryospheric, and atmospheric data throughout the year. More information about the project is available at the project Web site, North Pole Environmental Observatory (http://psc.apl.washington.edu/northpole/).
These data are available via FTP.
Falkner, K. K. 2002, updated 2005 and 2006. Seawater chemistry from the North Pole Environmental Observatory, 2000-2005. Boulder, Colorado USA: National Center for Atmospheric Research.
| Category | Description |
|---|---|
| Data format | Tab-delimited ASCII text, Microsoft Word, and PDF |
| Spatial coverage and resolution | Coverage includes the Arctic Ocean near the North Pole. Southernmost latitude: 84.923° N Northernmost latitude: 89.952° N Easternmost longitude: 179.808° E Westernmost longitude: 179.836° W |
| Temporal coverage and resolution | Daily for approximately one week each year from 2000 to 2005 |
| Directories and Files | The data set consists of one directory for each year (NPEOyyyy). The Microsoft Word and PDF files include investigator-provided documentation, graphics, and nutrient sample data. Text files include cast and station information along with CTD data and dissolved oxygen data where applicable. |
| Parameters | Investigators used a CTD-O2 system to measure seawater conductivity, temperature, depth, and dissolved oxygen. They also collected samples in Niskin bottles for measurements of salinity, oxygen isotope composition, and concentrations of phosphate, silicic acid, nitrate, nitrite, ammonium, and barium. |
1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. References and Related Publications
5. Document Information
Kelly K. Falkner
Oregon State University
College of Oceanic and Atmospheric Sciences
104 Ocean Administration Building
Corvallis, OR 97331-5503
USA
James Morison
Polar Science Center, Applied Physics Lab
University of Washington
1013 NE 40th
Seattle, WA 98105-6698
USA
This research was supported by the National Science Foundation (NSF) Office of Polar Programs (OPP) Arctic System Science (ARCSS) Program grants OPP-9910335 and OPP-0352984 to K. Falkner and OPP-9910305 to J. Morison.
The data set consists of one directory for each year named NPEOyyyy, where yyyy represents the year of the deployment.
Generally, the Microsoft Word and PDF files include investigator-provided documentation, graphics, and nutrient sample data. Text files include cast and station information along with CTD data and dissolved oxygen data where applicable. However, slight variations in the structure and content of each data record are apparent from year to year, deployment to deployment.
Southernmost Latitude: 84.923° N
Northernmost Latitude: 89.952° N
Westernmost Longitude: 179.836° W
Easternmost Longitude: 179.808° E
Though data collection sites were not spaced at regular intervals, the researchers did reoccupy NPEO sites visited in previous years. Please consult the investigator-provided documentation in the directory for each deployment to view the station locations. Subsequent information and data profiles for each year can be found on the NPEO Aerial CTD Surveys Web site.
Investigators collected data daily for the duration of each deployment.
Data collection dates:
| Year | Start Date | End Date |
| 2000 | April 21 | April 28 |
| 2001 | April 9 | April 14 |
| 2002 | April 23 | April 28 |
| 2003 | May 6 | May 9 |
| 2004 | April 26 | April 29 |
| 2005 | April 25 | April 28 |
Investigators used a CTD-O2 system to measure seawater conductivity, temperature, depth, and dissolved oxygen content. They also collected Niskin samples for measurements of salinity, oxygen isotope composition, and concentrations of phosphate, silicic acid, nitrate, nitrite, ammonia, and barium. The available in situ dissolved oxygen measurements were collected beginning in 2002.
| Parameter | Unit |
| pressure | decibar (dbar) |
| temperature | degrees Celsius (°C) |
| conductivity | siemens per meter (S/m) |
| depth | meters (m) |
| salinity | practical salinity units (psu) |
| dissolved oxygen | milliliters per liter (ml/L) |
| oxygen concentration | millimoles per cubic meter (mmol/m3) |
| barium concentration | nanomolar (nM) |
| phosphate concentration | micromolar (µM) |
| silicic acid concentration | micromolar (µM) |
| nitrate concentration | micromolar (µM) |
| nitrite concentration | micromolar (µM) |
| ammonium concentration | micromolar (µM) |
| del18O (oxygen isotope) | standard mean ocean water (SMOW) |
Investigators calculated oxygen saturation using in situ temperature and salinity values and recorded it in units of milliliters per liter (ml/L). Temperatures recorded in "T90 degrees C" refer to the International Temperature Scale of 1990.
The sample data below is from the file wpcSt89-90w.txt, and can be found in the NPEO2004 directory.
| Scan # | pressure dbar |
in situ temperature T90 degrees C |
conductivity S/m |
Oxygen voltage |
depth m |
potential temperature T90 degrees C |
salinity psu |
sigma- theta |
Oxygen ml/L |
Oxygen- saturation |
Oxygen mmol/m3 |
| 465 | 1.175 | -1.734 | 2.508 | 2.823 | 1.162 | -1.734 | 31.550 | 25.375 | 8.649 | 8.634 | 386.3 |
| 466 | 1.276 | -1.735 | 2.507 | 2.823 | 1.262 | -1.735 | 31.538 | 25.365 | 8.650 | 8.635 | 386.3 |
| 467 | 1.393 | -1.735 | 2.506 | 2.822 | 1.378 | -1.735 | 31.533 | 25.361 | 8.646 | 8.635 | 386.1 |
| 468 | 1.528 | -1.735 | 2.506 | 2.823 | 1.512 | -1.735 | 31.530 | 25.359 | 8.646 | 8.636 | 386.1 |
| 469 | 1.681 | -1.735 | 2.506 | 2.822 | 1.663 | -1.735 | 31.530 | 25.358 | 8.646 | 8.636 | 386.1 |
| 470 | 1.853 | -1.735 | 2.506 | 2.822 | 1.833 | -1.735 | 31.529 | 25.358 | 8.642 | 8.636 | 386.0 |
| 471 | 2.042 | -1.735 | 2.506 | 2.819 | 2.020 | -1.735 | 31.529 | 25.358 | 8.651 | 8.636 | 386.4 |
| 472 | 2.244 | -1.734 | 2.506 | 2.821 | 2.220 | -1.734 | 31.529 | 25.358 | 8.642 | 8.636 | 386.0 |
| 473 | 2.456 | -1.735 | 2.506 | 2.821 | 2.430 | -1.735 | 31.529 | 25.358 | 8.643 | 8.636 | 386.0 |
| 474 | 2.678 | -1.734 | 2.506 | 2.819 | 2.649 | -1.734 | 31.529 | 25.358 | 8.643 | 8.636 | 386.0 |
| 475 | 2.906 | -1.734 | 2.506 | 2.818 | 2.875 | -1.734 | 31.528 | 25.357 | 8.648 | 8.636 | 386.2 |
Data are available from NCAR.
Culbertson, C. H., and S. Huang. 1987. Automated amperometric oxygen titration. Deep-Sea Research 34:875-880.
Dickson, A. G. 1994. Determination of dissolved oxygen in sea water by Winkler titration. WOCE Hydrographic Program, Operations and Methods Manual. 11. Loose-leaf, Woods Hole, Mass.
Falkner, K. K., R. W. MacDonald, E. C. Carmack, and T. Weingartner. 1994. The potential of barium as a tracer of Arctic water masses. In The polar oceans and their role in shaping the global environment, edited by O. M. Johannessen, R. D. Muench, and J. E. Overland. Vol. 85 of Geophysical Monograph Series. Washington DC: 63-76.
Fofonoff, N. P., and R. C. J.Millard. 1983. Algorithms for computation of fundamental properties of seawater. In UNESCO Technical Papers in Marine Science. Endorsed by UNESCO/SCOR/ICES/IAPSO Joint Panel on Oceanographic Tables and Standards and SCOR Working Group 51. Paris. 44: 53.
Gordon, L. I., J. J. C. Jr., A. A. Ross, and J. M. Krest. 1994. A suggested protocol for continuous flow automated analysis of seawater nutrients (phosphate, nitrate, nitrite and silicic acid) in the WOCE Hydrophobic Program and the Joint Global Ocean Fluxes Study. In WOCE Operations Manual, Vol. 3: The Observational Program, Section 3.1: WOCE Hydrographic Program, Part 3.1.3: WHP Operations and Methods. 52 loose-leaf, Woods Hole, Mass.
Gorshkov, S. G. 1978. Arctic Ocean. Vol 3 of World Ocean Atlas. Oxford: Pergamon Press (in Russian).
Guay, C. K., and K. K. Falkner. 1998. A survey of dissolved barium in the estuaries of major Arctic rivers and adjacent seas. Continental Shelf Research 18 (8): 859-882.
Jakobsson, M. N. Z., N. Z. Cherkis, J. Woodward, and R. Macnab. 2000. New grid of Arctic bathymetry aids scientists and mapmakers. Eos, Transactions, American Geophysical Union 81 (9).
Jones, E. P., J. H. Swift, L. G. Anderson, M. Lipizer, G. Civitarese, K. K. Falkner, G. Kattner, F. McLaughlin, and J. Olafsson. 2003. Tracing Pacific water in the North Atlantic Ocean. Journal of Geophysical Research 108(C4), 3116, doi:10.1029/2001JC001141.
Jones, E. P., and L. G. Anderson. 1986. On the origin of the chemical properties of the Arctic Ocean halocline. Journal of Geophysical Research 91 (C9): 10,759-10,767.
Jones, E. P., L. G. Anderson, and J. H. Swift. 1998. Distribution of Atlantic and Pacific waters in the upper Arctic Ocean: Implications for circulation. Geophysical Research Letters 25 (6): 765-768.
Knapp, G. P., M. C. Stalcup, and R .J. Stanley. 1989. Dissolved oxygen measurements in sea water at the Woods Hole Oceanographic Institution. Technical Report, WHOI-89-23. Woods Hole, Massachusetts: Woods Hole Oceanographic Institution. 13 pp.
Morison, J. H., K. Aagaard, K. K. Falkner, K. Hatakeyama, R. Moritz, J. E. Overland, D. Perovich, K. Shimada, M. Steele, T. Takizawa, and R. Woodgate. 2002. The North Pole Environmental Observatory delivers early results. Eos, Transactions, American Geophysical Union 83(33), 360–361.
Owens, W. B., and R. C. J. Millard. 1985. A new algorithm for CTD oxygen calibrations. Journal of Physical Oceanography 15:621-631.
Weiss, R. F. 1970. The solubility of nitrogen, oxygen, and argon in water and seawater. Deep-Sea Research 17:721-735.
The following acronyms are used in this document:
ARCSS: Arctic System Science
CTD: Conductivity Temperature Depth
CFS: Canadian Forces Station
FTP: File Transfer Protocol
IAPSO: International Association for the Physical Science of the
Oceans
JGOFS: Joint Global Ocean Flux Study
NCAR: National Center for Atmospheric Research
NPEO: North Pole Environmental Observatory
OPP: Office of Polar Programs
PDF: Portable Document Format
PSU: Practical Salinity Units
RFA: Rapid Flow Analyzer
SCICEX: Scientific Ice Expeditions
SMOW: Standard Mean Ocean Water
URL: Uniform Resource Locator
WOCE: World Ocean Circulation
Experiment
July 2002
September 2005
September 2006