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| Dataset Title: | [GN01 Dissolved Ba Cd Cu Ga Mn Ni and V] - Dissolved Ba, Cd, Cu, Ga, Mn, Ni, and V concentrations and Ba isotope concentrations from the US GEOTRACES Arctic Expedition (GN01, HLY1502) from August to October 2015 (U.S. Arctic GEOTRACES Study) 
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| Institution: | BCO-DMO (Dataset ID: bcodmo_dataset_772645) |
| Information: | Summary
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| ISO 19115
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Attributes {
s {
CRUISE {
String bcodmo_name "cruise_id";
String description "Cruise identifier: HLY 1502";
String long_name "CRUISE";
String units "unitless";
}
SECT_ID {
String bcodmo_name "cruise_id";
String description "GEOTRACES cruise identifier: GA01";
String long_name "SECT ID";
String units "unitless";
}
GEOTRC_EVENT {
Int16 _FillValue 32767;
Int16 actual_range 6009, 6491;
String bcodmo_name "event";
String description "GEOTRACES Event number";
String long_name "GEOTRC EVENT";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/EVTAGFL/";
String units "unitless";
}
GEOTRC_SAMPNO {
Int16 _FillValue 32767;
Int16 actual_range 10471, 12314;
String bcodmo_name "sample";
String description "GEOTRACES Sample number";
String long_name "GEOTRC SAMPNO";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P02/current/ACYC/";
String units "unitless";
}
STNNBR {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 1, 66;
String bcodmo_name "station";
String description "Station number";
String long_name "STNNBR";
String units "unitless";
}
CASTNO {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 1, 25;
String bcodmo_name "cast";
String description "Cast number";
String long_name "CASTNO";
String units "unitless";
}
latitude {
String _CoordinateAxisType "Lat";
Float64 _FillValue NaN;
Float64 actual_range 60.165, 89.995;
String axis "Y";
String bcodmo_name "latitude";
Float64 colorBarMaximum 90.0;
Float64 colorBarMinimum -90.0;
String description "Latitude North";
String ioos_category "Location";
String long_name "Latitude";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P09/current/LATX/";
String standard_name "latitude";
String units "degrees_north";
}
longitude {
String _CoordinateAxisType "Lon";
Float64 _FillValue NaN;
Float64 actual_range -179.8082, 179.5926;
String axis "X";
String bcodmo_name "longitude";
Float64 colorBarMaximum 180.0;
Float64 colorBarMinimum -180.0;
String description "Longitude East";
String ioos_category "Location";
String long_name "Longitude";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P09/current/LONX/";
String standard_name "longitude";
String units "degrees_east";
}
CTDPRS {
Float32 _FillValue NaN;
Float32 actual_range 1.0, 4287.3;
String bcodmo_name "pressure";
String description "Pressure, from CTD sensor";
String long_name "CTDPRS";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/PRESPR01/";
String units "decibars";
}
depth {
String _CoordinateAxisType "Height";
String _CoordinateZisPositive "down";
Float64 _FillValue NaN;
Float64 actual_range 1.0, 4198.9;
String axis "Z";
String bcodmo_name "depth";
String description "Depth, derived from CTD sensor";
String ioos_category "Location";
String long_name "CTDDEPTH";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P09/current/DEPH/";
String positive "down";
String standard_name "depth";
String units "m";
}
Ga_D_CONC_BOTTLE {
Float32 _FillValue NaN;
Float32 actual_range -999.0, 40.23;
String bcodmo_name "trace_metal_conc";
String description "Dissolved gallium";
String long_name "Ga D CONC BOTTLE";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P03/current/C035/";
String units "picomoles per kilogram (pmol/kg)";
}
QV_WOCEBOTTLE_Ga_D_CONC_BOTTLE {
Int16 _FillValue 32767;
Int16 actual_range -999, 6;
String bcodmo_name "q_flag";
String description "WHP bottle parameter data quality codes";
String long_name "QV WOCEBOTTLE Ga D CONC BOTTLE";
String units "unitless";
}
Ba_D_CONC_BOTTLE {
Float32 _FillValue NaN;
Float32 actual_range 11.87, 86.35;
String bcodmo_name "trace_metal_conc";
String description "Dissolved barium";
String long_name "Ba D CONC BOTTLE";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P03/current/C035/";
String units "nanomoles per kilogram (nmol/kg)";
}
QV_WOCEBOTTLE_Ba_D_CONC_BOTTLE {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 2, 6;
String bcodmo_name "q_flag";
String description "WHP bottle parameter data quality codes";
String long_name "QV WOCEBOTTLE Ba D CONC BOTTLE";
String units "unitless";
}
Cd_D_CONC_BOTTLE {
Float32 _FillValue NaN;
Float32 actual_range 0.086, 1.087;
String bcodmo_name "trace_metal_conc";
String description "Dissolved cadmium";
String long_name "Cd D CONC BOTTLE";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P03/current/C035/";
String units "nanomoles per kilogram (nmol/kg)";
}
QV_WOCEBOTTLE_Cd_D_CONC_BOTTLE {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 2, 6;
String bcodmo_name "q_flag";
String description "WHP bottle parameter data quality codes";
String long_name "QV WOCEBOTTLE Cd D CONC BOTTLE";
String units "unitless";
}
V_D_CONC_BOTTLE {
Float32 _FillValue NaN;
Float32 actual_range 11.9, 34.19;
String bcodmo_name "trace_metal_conc";
String description "Dissolved vanadium";
String long_name "V D CONC BOTTLE";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P03/current/C035/";
String units "nanomoles per kilogram (nmol/kg)";
}
QV_WOCEBOTTLE_V_D_CONC_BOTTLE {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 2, 6;
String bcodmo_name "q_flag";
String description "WHP bottle parameter data quality codes";
String long_name "QV WOCEBOTTLE V D CONC BOTTLE";
String units "unitless";
}
Ni_D_CONC_BOTTLE {
Float32 _FillValue NaN;
Float32 actual_range 3.04, 10.66;
String bcodmo_name "trace_metal_conc";
String description "Dissolved nickel";
String long_name "Ni D CONC BOTTLE";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P03/current/C035/";
String units "nanomoles per kilogram (nmol/kg)";
}
QV_WOCEBOTTLE_Ni_D_CONC_BOTTLE {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 2, 6;
String bcodmo_name "q_flag";
String description "WHP bottle parameter data quality codes";
String long_name "QV WOCEBOTTLE Ni D CONC BOTTLE";
String units "unitless";
}
Cu_D_CONC_BOTTLE {
Float32 _FillValue NaN;
Float32 actual_range 1.23, 14.02;
String bcodmo_name "trace_metal_conc";
String description "Dissolved copper";
String long_name "Cu D CONC BOTTLE";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P03/current/C035/";
String units "nanomoles per kilogram (nmol/kg)";
}
QV_WOCEBOTTLE_Cu_D_CONC_BOTTLE {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 2, 6;
String bcodmo_name "q_flag";
String description "WHP bottle parameter data quality codes";
String long_name "QV WOCEBOTTLE Cu D CONC BOTTLE";
String units "unitless";
}
Mn_D_CONC_BOTTLE {
Float32 _FillValue NaN;
Float32 actual_range 0.11, 213.81;
String bcodmo_name "trace_metal_conc";
String description "Dissolved manganese";
String long_name "Mn D CONC BOTTLE";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P03/current/C035/";
String units "nanomoles per kilogram (nmol/kg)";
}
QV_WOCEBOTTLE_Mn_D_CONC_BOTTLE {
Byte _FillValue 127;
String _Unsigned "false";
Byte actual_range 2, 6;
String bcodmo_name "q_flag";
String description "WHP bottle parameter data quality codes";
String long_name "QV WOCEBOTTLE Mn D CONC BOTTLE";
String units "unitless";
}
SOURCE {
String bcodmo_name "instrument";
String description "TM = samples from GoFLO bottles on GEOTRACES carousel; s-boat = samples from clean pump ussed aboard small boat; i-hole = samples colelcted under the ice using a clean pump";
String long_name "SOURCE";
String units "unitless";
}
}
NC_GLOBAL {
String access_formats ".htmlTable,.csv,.json,.mat,.nc,.tsv,.esriCsv,.geoJson";
String acquisition_description
"Clean seawater samples were collected using a GEOTRACES CTD referred to as
GT-C/12L GoFlo. For more information, see the cruise report. Additional near
surface samples were collected using either a small boat or through the ice
using Teflon coated Tygon tubing and a trace metal clean pump (IWAKI, model
WMD-30LFY-115).
Water samples were filtered through pre-cleaned, 0.2 \\u00b5m Pall Acropak
Supor filter capsules as described elsewhere (e.g., Cutter et al., 2012; Hatta
et al., 2015). Filtered water was collected in 125 mL HDPE bottles (Nalgene)
that had been precleaned by soaking in hot 1.2 M HCl (reagent grade) for at
least 8 h with subsequent thorough rinsing with ultrapure distilled deionized
water (Barnstead E-pure). Small boat and under-ice samples were first
collected into large acid-washed carboys and subsampled into 125 mL bottles.
Dissolved Ga was determined by isotope dilution ICP-MS using a ThermoFisher
Element 2 operated in low resolution. Samples were concentrated using
Mg(OH)\\u2082 co-precipitation (e.g., Shiller & Bairamadgi, 2006; Zurbrick et
al., 2012). Briefly, in this technique, a small addition (~70 \\u00b5L) of
clean aqueous ammonia is added to the acidified seawater sample (~7.5 mL)
which precipitates a fraction of the dissolved magnesium as the hydroxide,
which in turn, scavenges the gallium from solution. An enriched isotope spike
of known concentration was prepared using purified enriched \\u2077\\u00b9Ga
(99.8%), obtained from Oak Ridge National Laboratories.
Because there is a significant interference of doubly charged
\\u00b9\\u00b3\\u2078Ba with \\u2076\\u2079Ga, the precipitate was washed three
times with a solution of high purity 0.1% NH\\u2084OH to minimize residual Ba.
The precipitate was then dissolved in 550 mL ultrapure 3% HNO3 (Seastar
Chemicals, Baseline) and analyzed in low resolution using a ThermoFinnigan
Element 2 High Resolution Inductively Coupled Plasma Mass Spectrometer (HR-
ICP-MS). Isotopes monitored on the ICP-MS were \\u2076\\u2079Ga, \\u2077\\u00b9Ga,
and \\u00b9\\u00b3\\u2078Ba. A slight correction for residual Ba was made based
on the ratio of responses at masses 69 and 138 to a Ba standard solution.
Because the residual salt content varied from sample to sample, it was not
possible to matrix-match the Ba correction standard. However, typically, this
correction affected the final result by < 2.5 pmol/kg; where higher Ba
corrections were noted, the sample was reprecipitated and re-analyzed because
of concerns about the accuracy of applying the Ba standard correction to
samples of high salt content.
The reagent blank contribution to the dissolved Ga analysis is typically 0.6
pmol/kg and the detection limit (based on 3 times the standard deviation of
the blank) is 0.3 pmol/kg. Repeated runs of US GEOTRACES intercalibration
samples (GS and GD), in-house reference solutions, and cast overlap samples
suggest a precision of \\u00b1 4%; the limit of detection for Ga was 1.5
pmol/kg. Recovery of the method, as determined by repeated analysis of a
spiked and unspiked seawater sample was 100 \\u00b1 7%.
Dissolved Ba was measured using a ThermoFisher Element 2 Inductively Coupled
Plasma Mass Spectrometer (ICP-MS) and the isotope dilution method as described
by Jacquet et al. (2005). Aliquots (50 \\u03bcL) of each sample were spiked
with 25 \\u03bcL of a \\u00b9\\u00b3\\u2075Ba-enriched solution (~170 nM) and then
diluted 30-fold with 0.2 \\u03bcm ultrapure filtered water. A sample of ~93%
enriched \\u00b9\\u00b3\\u2075Ba was obtained from Oak Ridge National
Laboratories for use as the enriched isotope spike. The ICP-MS was operated in
low resolution and both \\u00b9\\u00b3\\u2075Ba and \\u00b9\\u00b3\\u2078Ba were
determined. The samples were bracketed every 10 samples with a blank and the
spike \\u00b9\\u00b3\\u2075Ba solution. The volumes of the spikes, samples and
dilution water were accurately assessed by calibrating each pipette by weight.
The reproducibility error of this method was estimated by comparing samples
collected at the same depths on different casts at the same station. For 12
pairs of these replicate samples, the average absolute deviation of 0.7
nmol/kg or typically 1.5%. Repeated runs of runs of US GEOTRACES
intercalibration samples and in-house reference solutions suggest a similar
precision; the limit of detection for barium was 0.7 nmol/kg. Our precision is
similar to that reported by other labs for Ba (e.g., Jacquet et al., 2005).
Dissolved V, Ni, Cu, Cd and Mn were determined using 14 mL of sample that was
spiked with a mixture of isotopically-enriched Ni-62, Cu-65, Cd-111, and V-50
(Oak Ridge Nat\\u2019l. Labs). Each spike was >90% enriched in the listed
isotopes, except for V-50 (0.25% natural abundance) which was 44.3% enriched.
The sample/spike ratio was chosen so as to have the analytical isotope ratios
approximately the geometric mean of the natural and enriched spike isotope
ratios. Samples were then extracted/pre-concentrated using a SeaFAST system
(Elemental Scientific, Inc.) operated in offline mode. A 10-mL sample loop was
employed and the elution volume was 750 \\u00b5L. A similar online SeaFAST
extraction procedure is described by Hathorne et al. (2012) for rare earth
elements. The extracted samples were subsequently analyzed using a Thermo-
Fisher high resolution ICP-MS with an Apex-FAST high efficiency sample
introduction system with Spiro desolvator (Elemental Scientific, Inc.). All
elements were determined in medium resolution, except Cd which was determined
in low resolution. For Mn-55 the V, Ni, and Cu spikes served as internal
standards. Calibration was checked by analysis of a large-volume composite
North Atlantic surface seawater sample. Spiked (with a natural isotopic
abundance elemental spike) and unspiked aliquots of this sample were analyzed
twice in each analytical run. Ti-47 and Cr-52 were monitored to correct for
any Ti-50 or Cr-50 isobaric interference on V-50; the correction was generally
<1%. Likewise, Mo-98 was monitored to correct for MoO\\u207a interference on Cd
isotopes.
The reproducibility error of this method was estimated by comparing samples
collected at the same depths on different casts at the same station as well as
by repeated measurement of GEOTRACES reference waters and an in-house
standard. Recovery of the method was determined by repeated analysis of a
spiked and unspiked seawater. The recoveries, precisions, and comparisons to
reference waters are shown in Table 1 (see Supplemental Files).";
String awards_0_award_nid "772640";
String awards_0_award_number "OCE-1436312";
String awards_0_data_url "http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1436312";
String awards_0_funder_name "NSF Division of Ocean Sciences";
String awards_0_funding_acronym "NSF OCE";
String awards_0_funding_source_nid "355";
String awards_0_program_manager "Henrietta N Edmonds";
String awards_0_program_manager_nid "51517";
String cdm_data_type "Other";
String comment
"Dissolved Ba, Cd, Cu, Ga, Mn, Ni, and V
Arctic Ocean 2015, GN01 (HLY1502)
PI: Alan M. Shiller (University of Southern Mississippi)
Version date: 2019-07-09";
String Conventions "COARDS, CF-1.6, ACDD-1.3";
String creator_email "info@bco-dmo.org";
String creator_name "BCO-DMO";
String creator_type "institution";
String creator_url "https://www.bco-dmo.org/";
String data_source "extract_data_as_tsv version 2.3 19 Dec 2019";
String date_created "2019-07-09T16:48:17Z";
String date_modified "2020-03-24T16:55:55Z";
String defaultDataQuery "&time<now";
String doi "10.1575/1912/bco-dmo.772645.1";
Float64 Easternmost_Easting 179.5926;
Float64 geospatial_lat_max 89.995;
Float64 geospatial_lat_min 60.165;
String geospatial_lat_units "degrees_north";
Float64 geospatial_lon_max 179.5926;
Float64 geospatial_lon_min -179.8082;
String geospatial_lon_units "degrees_east";
Float64 geospatial_vertical_max 4198.9;
Float64 geospatial_vertical_min 1.0;
String geospatial_vertical_positive "down";
String geospatial_vertical_units "m";
String history
"2024-11-23T17:27:09Z (local files)
2024-11-23T17:27:09Z https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_772645.html";
String infoUrl "https://www.bco-dmo.org/dataset/772645";
String institution "BCO-DMO";
String instruments_0_acronym "ICP Mass Spec";
String instruments_0_dataset_instrument_nid "772656";
String instruments_0_description "An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer.";
String instruments_0_instrument_external_identifier "https://vocab.nerc.ac.uk/collection/L05/current/LAB15/";
String instruments_0_instrument_name "Inductively Coupled Plasma Mass Spectrometer";
String instruments_0_instrument_nid "530";
String instruments_0_supplied_name "ThermoFisher Element 2 ICP-MS";
String instruments_1_acronym "ICP Mass Spec";
String instruments_1_dataset_instrument_nid "772657";
String instruments_1_description "An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer.";
String instruments_1_instrument_external_identifier "https://vocab.nerc.ac.uk/collection/L05/current/LAB15/";
String instruments_1_instrument_name "Inductively Coupled Plasma Mass Spectrometer";
String instruments_1_instrument_nid "530";
String instruments_1_supplied_name "ThermoFinnigan Element 2 High Resolution Inductively Coupled Plasma Mass Spectrometer (HR-ICP-MS)";
String instruments_2_acronym "GO-FLO Teflon TM";
String instruments_2_dataset_instrument_nid "772654";
String instruments_2_description "GO-FLO Teflon-lined Trace Metal free sampling bottles are used for collecting water samples for trace metal, nutrient and pigment analysis. The GO-FLO sampling bottle is designed specifically to avoid sample contamination at the surface, internal spring contamination, loss of sample on deck (internal seals), and exchange of water from different depths.";
String instruments_2_instrument_external_identifier "https://vocab.nerc.ac.uk/collection/L05/current/30/";
String instruments_2_instrument_name "GO-FLO Teflon Trace Metal Bottle";
String instruments_2_instrument_nid "533";
String instruments_2_supplied_name "GT-C/12L GoFlo";
String instruments_3_dataset_instrument_nid "772655";
String instruments_3_description "A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps";
String instruments_3_instrument_name "Pump";
String instruments_3_instrument_nid "726";
String instruments_3_supplied_name "Teflon coated Tygon tubing and a trace metal clean pump (IWAKI, model WMD-30LFY-115)";
String keywords "Ba_D_CONC_BOTTLE, bco, bco-dmo, biological, bottle, castno, Cd_D_CONC_BOTTLE, chemical, conc, cruise, ctddepth, ctdprs, Cu_D_CONC_BOTTLE, data, dataset, dmo, erddap, event, Ga_D_CONC_BOTTLE, geotrc, GEOTRC_EVENT, GEOTRC_SAMPNO, latitude, longitude, management, Mn_D_CONC_BOTTLE, Ni_D_CONC_BOTTLE, oceanography, office, preliminary, QV_WOCEBOTTLE_Ba_D_CONC_BOTTLE, QV_WOCEBOTTLE_Cd_D_CONC_BOTTLE, QV_WOCEBOTTLE_Cu_D_CONC_BOTTLE, QV_WOCEBOTTLE_Ga_D_CONC_BOTTLE, QV_WOCEBOTTLE_Mn_D_CONC_BOTTLE, QV_WOCEBOTTLE_Ni_D_CONC_BOTTLE, QV_WOCEBOTTLE_V_D_CONC_BOTTLE, sampno, sect, SECT_ID, source, stnnbr, v, V_D_CONC_BOTTLE, wocebottle";
String license "https://www.bco-dmo.org/dataset/772645/license";
String metadata_source "https://www.bco-dmo.org/api/dataset/772645";
Float64 Northernmost_Northing 89.995;
String param_mapping "{'772645': {'LATITUDE': 'flag - latitude', 'CTDDEPTH': 'flag - depth', 'LONGITUDE': 'flag - longitude'}}";
String parameter_source "https://www.bco-dmo.org/mapserver/dataset/772645/parameters";
String people_0_affiliation "University of Southern Mississippi";
String people_0_person_name "Alan M. Shiller";
String people_0_person_nid "51611";
String people_0_role "Principal Investigator";
String people_0_role_type "originator";
String people_1_affiliation "Woods Hole Oceanographic Institution";
String people_1_affiliation_acronym "WHOI BCO-DMO";
String people_1_person_name "Shannon Rauch";
String people_1_person_nid "51498";
String people_1_role "BCO-DMO Data Manager";
String people_1_role_type "related";
String project "U.S. GEOTRACES Arctic,GEOTRACES Arctic Methane V Ba Ga";
String projects_0_acronym "U.S. GEOTRACES Arctic";
String projects_0_description
"Description from NSF award abstract:
In pursuit of its goal \"to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions\", in 2015 the International GEOTRACES Program will embark on several years of research in the Arctic Ocean. In a region where climate warming and general environmental change are occurring at amazing speed, research such as this is important for understanding the current state of Arctic Ocean geochemistry and for developing predictive capability as the regional ecosystem continues to warm and influence global oceanic and climatic conditions. The three investigators funded on this award, will manage a large team of U.S.scientists who will compete through the regular NSF proposal process to contribute their own unique expertise in marine trace metal, isotopic, and carbon cycle geochemistry to the U.S. effort. The three managers will be responsible for arranging and overseeing at-sea technical services such as hydrographic measurements, nutrient analyses, and around-the-clock management of on-deck sampling activites upon which all participants depend, and for organizing all pre- and post-cruise technical support and scientific meetings. The management team will also lead educational outreach activities for the general public in Nome and Barrow, Alaska, to explain the significance of the study to these communities and to learn from residents' insights on observed changes in the marine system. The project itself will provide for the support and training of a number of pre-doctoral students and post-doctoral researchers. Inasmuch as the Arctic Ocean is an epicenter of global climate change, findings of this study are expected to advance present capability to forecast changes in regional and globlal ecosystem and climate system functioning.
As the United States' contribution to the International GEOTRACES Arctic Ocean initiative, this project will be part of an ongoing multi-national effort to further scientific knowledge about trace elements and isotopes in the world ocean. This U.S. expedition will focus on the western Arctic Ocean in the boreal summer of 2015. The scientific team will consist of the management team funded through this award plus a team of scientists from U.S. academic institutions who will have successfully competed for and received NSF funds for specific science projects in time to participate in the final stages of cruise planning. The cruise track segments will include the Bering Strait, Chukchi shelf, and the deep Canada Basin. Several stations will be designated as so-called super stations for intense study of atmospheric aerosols, sea ice, and sediment chemistry as well as water-column processes. In total, the set of coordinated international expeditions will involve the deployment of ice-capable research ships from 6 nations (US, Canada, Germany, Sweden, UK, and Russia) across different parts of the Arctic Ocean, and application of state-of-the-art methods to unravel the complex dynamics of trace metals and isotopes that are important as oceanographic and biogeochemical tracers in the sea.";
String projects_0_end_date "2017-06";
String projects_0_geolocation "Arctic Ocean; Sailing from Dutch Harbor to Dutch Harbor";
String projects_0_name "U.S. Arctic GEOTRACES Study";
String projects_0_project_nid "638812";
String projects_0_start_date "2014-07";
String projects_1_acronym "GEOTRACES Arctic Methane V Ba Ga";
String projects_1_description
"NSF Award Abstract:
In this project, an investigator participating in the 2015 U.S. GEOTRACES Arctic expedition will make measurements of methane, a dissolved trace gas, as well as the dissolved trace elements of gallium, barium, and vanadium in the Arctic Ocean. In common with other multinational initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. Some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. The trace elements and gas measured as part of this project will be used as tracers for a variety of processes such as river and atmospheric inputs to the Arctic Ocean, as well as circulation in the region. The knowledge and experience gained from this project will be incorporated into courses in oceanography and marine chemistry, as well as be shared through public outreach activities. The project will support the scientific training of a graduate student.
The tracers to be measured as part of this study, methane, gallium, barium, and vanadium, will provide important information about oceanic circulation and water inputs to the Arctic. Gallium is likely to prove a sensitive tracer for Atlantic versus Pacific water components in the western Arctic Ocean, an issue of interest in circulation studies and also relevant to projections of the stability of methane hydrates on the Arctic shelves. Barium is of interest because it has been shown to be an indicator of fluvial inputs and contributions to the halocline. This is pertinent to understanding upper ocean circulation in the Arctic as well as to freshwater contributions to the Atlantic Meridional Overturning Circulation. For vanadium, the large proportion of shelf area in the Arctic makes this an ideal region to examine whether shelf sediment uptake determines surface ocean vanadium depletion. For methane, Arctic waters are a significant source of this Greenhouse Gas to the atmosphere and global change is likely exacerbating its release. Determination of the methane distribution will therefore be of interest in and of itself, although it is also a potentially valuable indicator of interactions with the shelf as well as of river inputs. Overall, results from this study will lead to an increased understanding of key ocean biogeochemical and physical processes including cross margin exchange of materials, sources of water in the Arctic Ocean, and fluxes of methane to the atmosphere.";
String projects_1_end_date "2018-12";
String projects_1_geolocation "Arctic Circle";
String projects_1_name "GEOTRACES Arctic Section: Methane, vanadium, barium, and gallium as process indicators in the Arctic Ocean";
String projects_1_project_nid "772641";
String projects_1_start_date "2015-01";
String publisher_name "Biological and Chemical Oceanographic Data Management Office (BCO-DMO)";
String publisher_type "institution";
String sourceUrl "(local files)";
Float64 Southernmost_Northing 60.165;
String standard_name_vocabulary "CF Standard Name Table v55";
String subsetVariables "CRUISE,SECT_ID";
String summary "Dissolved Ba, Cd, Cu, Ga, Mn, Ni, and V concentration data from the US GEOTRACES Arctic Expedition (GN01, HLY1502) from August to October 2015. Clean seawater samples were collected using a GEOTRACES CTD referred to as GT-C/12L GoFlo. Additional near surface samples were collected using either a small boat or through the ice using Teflon coated Tygon tubing and a trace metal clean pump (IWAKI, model WMD-30LFY-115).";
String title "[GN01 Dissolved Ba Cd Cu Ga Mn Ni and V] - Dissolved Ba, Cd, Cu, Ga, Mn, Ni, and V concentrations and Ba isotope concentrations from the US GEOTRACES Arctic Expedition (GN01, HLY1502) from August to October 2015 (U.S. Arctic GEOTRACES Study)";
String version "1";
Float64 Westernmost_Easting -179.8082;
String xml_source "osprey2erddap.update_xml() v1.3";
}
}
Data Access Protocol (DAP) and its
selection constraints.
The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.
Tabledap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/pmelTaoDySst.htmlTable?longitude,latitude,time,station,wmo_platform_code,T_25&time>=2015-05-23T12:00:00Z&time<=2015-05-31T12:00:00Z
Thus, the query is often a comma-separated list of desired variable names,
followed by a collection of
constraints (e.g., variable<value),
each preceded by '&' (which is interpreted as "AND").
For details, see the tabledap Documentation.