Accessing BCO-DMO data
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BCO-DMO ERDDAP
Accessing BCO-DMO data |
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| Dataset Title: | [Cr concentration and isotopic composition of Cr(III) and Cr(VI) in the ETNP from RR1804-05 and KM1919-20] - Chromium concentration and isotopic composition of Cr(III) and Cr(VI) in the Eastern Tropical North Pacific from samples collected on R/V Roger Revelle and R/V Kilo Moana in April-May 2018 and Sept- Oct 2019 (Cr Isotope Oceanography of the Eastern Tropical North Pacific Ocean) 
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| Institution: | BCO-DMO (Dataset ID: bcodmo_dataset_925782_v1) |
| Information: | Summary
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Attributes {
s {
Cruise {
String long_name "Cruise";
String units "unitless";
}
Station {
String long_name "Station";
String units "unitless";
}
Latitude {
Float32 actual_range 17.0, 21.8;
String long_name "Latitude";
String units "degrees_north";
}
longitude {
String _CoordinateAxisType "Lon";
Float32 actual_range -110.0, -106.0;
String axis "X";
String ioos_category "Location";
String long_name "Longitude";
String standard_name "longitude";
String units "degrees_east";
}
depth {
String _CoordinateAxisType "Height";
String _CoordinateZisPositive "down";
Int32 actual_range 25, 1000;
String axis "Z";
String ioos_category "Location";
String long_name "Depth";
String positive "down";
String standard_name "depth";
String units "m";
}
CTD_Oxygen {
Float32 actual_range 0.78, 200.85;
String long_name "Ctd_oxygen";
String units "micromoles per kilogram (umol/kg)";
}
dissolved_CrIII {
Float32 actual_range 0.19, 1.66;
String long_name "Dissolved_criii";
String units "nanomoles per kilogram (nmol/kg)";
}
dissolved_d53CrIII {
Float32 actual_range -0.47, 0.52;
String long_name "Dissolved_d53criii";
String units "permil (‰)";
}
measured_CrVI {
Float32 actual_range 0.76, 2.43;
String long_name "Measured_crvi";
String units "nanomoles per kilogram (nmol/kg)";
}
measured_d53CrVI {
Float32 actual_range 1.57, 3.2;
String long_name "Measured_d53crvi";
String units "permil (‰)";
}
calculated_CrVI {
Float32 actual_range 0.9, 3.84;
String long_name "Calculated_crvi";
String units "nanomoles per kilogram (nmol/kg)";
}
calculated_d53CrVI {
Float32 actual_range 0.87, 2.89;
String long_name "Calculated_d53crvi";
String units "permil (‰)";
}
}
NC_GLOBAL {
String cdm_data_type "Other";
String Conventions "COARDS, CF-1.6, ACDD-1.3";
String creator_email "info@bco-dmo.org";
String creator_name "BCO-DMO";
String creator_url "https://www.bco-dmo.org/";
String doi "10.26008/1912/bco-dmo.925782.1";
Float64 Easternmost_Easting -106.0;
Float64 geospatial_lon_max -106.0;
Float64 geospatial_lon_min -110.0;
String geospatial_lon_units "degrees_east";
Float64 geospatial_vertical_max 1000.0;
Float64 geospatial_vertical_min 25.0;
String geospatial_vertical_positive "down";
String geospatial_vertical_units "m";
String history
"2024-10-20T07:51:20Z (local files)
2024-10-20T07:51:20Z https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_925782_v1.html";
String infoUrl "https://www.bco-dmo.org/dataset/925782";
String institution "BCO-DMO";
String license
"The data may be used and redistributed for free but is not intended
for legal use, since it may contain inaccuracies. Neither the data
Contributor, ERD, NOAA, nor the United States Government, nor any
of their employees or contractors, makes any warranty, express or
implied, including warranties of merchantability and fitness for a
particular purpose, or assumes any legal liability for the accuracy,
completeness, or usefulness, of this information.";
String sourceUrl "(local files)";
String summary
"Understanding the cycling of chromium (Cr) and how chromium stable isotopes (δ53Cr) are altered in response to different processes in the modern ocean is important in our interpretation of marine sedimentary δ53Cr records, a promising redox proxy. Therefore, it is crucial to investigate the geochemical processes of Cr in reducing environments such as oxygen deficient zones (ODZs). In this study, we investigated the cycling of Cr in the Eastern Tropical North Pacific (ETNP) ODZ by analyzing the [Cr] and δ53Cr of total dissolved Cr and Cr(III). Our Cr(III) data at two inshore stations shows profile features and Cr reduction isotopic fractionation factor (-1.5‰) similar to an offshore station in a previous study. We also observed significant Cr scavenging signals in the upper 1000 meters (m) throughout the ODZ with an inshore-offshore variability in its magnitude. Specifically, anoxic bottom waters on the continental slope see the greatest Cr scavenging with heaviest δ53Cr (+1.85‰). Our estimates of the scavenged Cr isotopic composition are within error of the anoxic and euxinic marine sedimentary δ53Cr. This implies that the vertical transport of Cr to the seafloor and subsequent diagenesis may not generate significant isotopic fractionation for Cr. This is the first thorough investigation into the Cr cycling in the ETNP ODZ and demonstrated promising usage of marine sedimentary δ53Cr as a redox proxy for ancient oceans.
In the ODZ, oxygen is consumed by degrading sinking particles and reaches extremely low levels (too low to support aerobic life) from 100m to 800m depth. However, microbes that can use other oxidants such as nitrate to metabolize organic carbon live there, and we showed that they also convert soluble anionic chromate Cr(VI) to cationic Cr(III), about half of which is scavenged onto sinking particles and removed to the seafloor. This reduction is accompanied by preferential reduction of light Cr isotopes, so the Cr(III) is 1.3‰ lighter than the source Cr(VI). The removal of part of this light Cr(III) by scavenging leaves the residual total Cr heavier than the source Cr. The analyzed samples listed here were chosen to be from the center and margins of the ETNP ODZ and over extremely reducing continental margin sediments.";
String title "[Cr concentration and isotopic composition of Cr(III) and Cr(VI) in the ETNP from RR1804-05 and KM1919-20] - Chromium concentration and isotopic composition of Cr(III) and Cr(VI) in the Eastern Tropical North Pacific from samples collected on R/V Roger Revelle and R/V Kilo Moana in April-May 2018 and Sept-Oct 2019 (Cr Isotope Oceanography of the Eastern Tropical North Pacific Ocean)";
Float64 Westernmost_Easting -110.0;
}
}
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.