DOI: 10.5061/dryad.2280gb5zv
title: Data from: First assessments of trace metal fluxes from the Pacific to the Arctic - high resolution 2021 summer measurements show surprisingly high influence of the Alaskan Coastal Water

description: Trace metals (manganese, iron, nickel, copper, zinc, and cadmium) are
 essential micronutrients for phytoplankton and can be used as tracers of
 oceanic processes. The supply of trace metals to the Western Arctic was
 thought to be dominated by macronutrient-rich Pacific waters entering
 through the Bering Strait and modified by uptake and regeneration on the
 Chukchi Shelf. However, the first high resolution (~6km) trace metal
 measurements in the strait (July 2021) show large variability in trace
 metal concentrations across the strait and a close relationship with
 salinity. The previously unsampled Alaskan Coastal Water has unexpectedly
 high trace metal concentrations, while the macronutrient-rich Anadyr Water
 has surprisingly low trace metal concentrations. We make the first
 estimates of trace metal flux from the Pacific to the Arctic through the
 Bering Strait and find they are elevated despite the comparatively small
 volume transport and, for some metals, exceed the Arctic to Atlantic
 export.
description: Trace metal and macronutrient samples were collected July 10-16,
 2021, from the R/V Norseman II during an annual Bering Strait (BS) mooring
 and hydrographic cruise, which sampled the eastern Bering Strait (eBS) and
 the A3 line (AL) sections at 6-10km resolution. Water was collected using
 an air-diaphragm pump (PTFE, Wilden) with inline filtration (0.2 um,
 Acropak), pumping water from ~5m (“surface”) or ~25-45m depth (“bottom”),
 sufficient resolution to define the strait’s typically two-layer
 stratification (Woodgate et al., 2015). Samples were collected into
 acid-cleaned 250 mL low density polyethylene bottles and acidified to pH
 1.8 following established protocols (Jensen et al., 2020). Additionally,
 filtered macronutrients (nitrate (N), phosphate (P), and silicate (Si))
 samples were taken from the same depths and frozen (-20°C) immediately
 after collection until analysis at the University of Washington Marine
 Chemistry Lab in October 2021, following WOCE/JGOFS protocols (Gordon et
 al., 1993; Knap et al., 1996). Trace metal samples were run using a
 seaFAST-pico and an Element XR ICP-MS at Texas A&M University
 (Jensen et al., 2020). Nutrient data was QA/QCed
 following WOCE/JGOFS protocols by the UW Marine Chem Lab. Trace metal data
 was derived from isotope ratios and standard curve slopes (Jensen et al.,
 2020) and compared to seawater certified reference materials provided by
 the GEOTRACES program (GSP and GSC water). Gordon, L.
 I., J. C. Jennings Jr, A. A. Ross, and J. M. Krest (1993), A suggested
 protocol for continuous flow automated analysis of seawater nutrients
 (phosphate, nitrate, nitrite and silicic acid) in the WOCE Hydrographic
 Program and the Joint Global Ocean Fluxes Study, <em>WOCE
 hydrographic program office, methods manual WHPO</em>(68/91),
 1-52. Jensen, L. T., N. J. Wyatt, W. M. Landing, and J.
 N. Fitzsimmons (2020), Assessment of the stability, sorption, and
 exchangeability of marine dissolved and colloidal metals, <em>Marine
 Chemistry</em>, <em>220</em>, 103754.
 Knap, A., A. Michaels, A. Close, H. Ducklow, and A. Dickson
 (1996), Protocols for the joint global ocean flux study (JGOFS) core
 measurements, <em>JGOFS, Reprint of the IOC Manuals and Guides No.
 29, UNESCO 1994</em>, <em>19</em>.
 Woodgate, R. A., K. M. Stafford, and F. G. Prahl (2015), A
 synthesis of year-round interdisciplinary mooring measurements in the
 Bering Strait (1990–2014) and the RUSALCA years (2004–2011),
 <em>Oceanography</em>, <em>28</em>(3),
 46-67.
description: # Data for: First assessments of trace metal fluxes from the Pacific to
 the Arctic - high resolution 2021 summer measurements show surprisingly
 high influence of the Alaskan Coastal Water
 [https://doi.org/10.5061/dryad.2280gb5zv](https://doi.org/10.5061/dryad.2280gb5zv) Oceanographic data for dissolved (filtered to &lt;0.2um) trace metals (Mn, Fe, Cu, Ni, Zn, Cd) and macronutrients (nitrate, phosphate, silicate, ammonium) in seawater. All samples were collected in the Bering Strait (Pacific-Arctic region) between 65 and 69 degrees North on the R/V Norseman II. Sampling took place in July 2021. There are 78 samples in total. Metadata (station name, location, cast, depth, temperature, and salinity) are also included. Temperature and salinity data are derived from concurrent measurements taken with an RBR Concerto CTD. These data are used to assess fluxes of micro and macronutrients from the Pacific to the Arctic Ocean and how that may be changing over time. **Description of the data and file structure** Data is given for 78 discrete samples in an excel workbook. There are 29 columns including data and associated data quality flags. The first row is the parameter (see below) and the second row is the parameter unit (also defined below). All remaining rows are data. Dissolved metal ("dMe") and nutrient samples were taken using an air-powered diaphragm pump deployed over the side                                      Metal and nutrient samples were filtered inline using an Acropak-200 capsule filter (pore size 0.2um) into acid-washed LDPE bottles            Metal samples stored at room temperature and acidified to pH 1.8 with 12M HCl, nutrient samples remained frozen at -20 degC until analysis         Metal data is reported in concentration units of "nanomolar per kilogram" (nmol/kg) = 10^-9 mol/L                                               Nutrient data is reported in concentration units of "micromolar per kilogram" (umol/kg) = 10^-6 mol/L                                                                                Limits of detection: 0.04 nmol/kg (Fe), 0.07 nmol/kg (Zn), 0.01 nmol/kg (Ni), 0.02 nmol/kg (Cu), 0.0001 nmol/kg (Cd), 0.002 nmol/kg (Mn)           Limits of detection:  0.03uM(PO4), 0.45uM(SO4), 0.18uM(NO3), 0.01uM(NO2), 0.09uM(NH4)                                                                                                                                                                                                                                                                                                                                                                                   Column 1, Sample name Column 2, Cast number Column 3, Latitude of station (degrees North) Column 4, Longitude of station (degrees West) Column 5, Depth in seawater(meters) Column 6, Practical salinity (practical salinity units) Column 7, Temperature (degrees Celsius) Column 8, Phosphate (“PO4”)concentration in seawater(umol/kg) Column 9, Phosphate (“PO4”)data quality flag Column 10, Silicate (“SiOH4”) concentration in seawater(umol/kg) Column 11, Silicate (“SiOH4”) data quality flag Column 12, Nitrate (“NO3”) concentration in seawater(umol/kg) Column 13, Nitrate (“NO3”) data quality flag Column 14, Nitrite (“NO2”) concentration in seawater(umol/kg) Column 15, Nitrite (“NO2”) data quality flag Column 16, Ammonium (“NH4”) concentration in seawater(umol/kg) Column 17, Ammonium(“NH4”) data quality flag Column 18, Dissolved iron (“dFe”) concentration in seawater(nmol/kg) Column 19, Dissolved iron (“dFe”) data quality flag Column 20, Dissolved zinc (“dZn”) concentration in seawater(nmol/kg) Column 21, Dissolved zinc (“dZn”) data quality flag Column 22, Dissolved nickel (“dNi”) concentration in seawater(nmol/kg) Column 23, Dissolved nickel (“dNi”) data quality flag Column 24, Dissolved copper (“dCu”) concentration in seawater(nmol/kg) Column 25, Dissolved copper (“dCu”) data quality flag Column 26, Dissolved cadmium (“dCd”) concentration in seawater(nmol/kg) Column 27, Dissolved cadmium (“dCd”) data quality flag Column 26, Dissolved manganese (“dMn”) concentration in seawater(nmol/kg) Column 27, Dissolved manganese (“dMn”) data quality flag No data will be given by "-999" in any cell Data quality flags from SeaDataNet: [https://www.seadatanet.org/Standards/Data-Quality-Control](https://www.seadatanet.org/Standards/Data-Quality-Control)                                                                                            0       No quality control                                                   1       Good value                                                           2       Probably good value                                                  3       Probably bad value                                                   4       Bad value                                                            5       Changed value                                                        6       Below detection limit                                                7       Value in excess                                                      8       Interpolated value                                                   9       Data missing                                                                                                                                                      **Sharing/Access information** More nutrient and hydrographic data included: [https://psc.apl.washington.edu/HLD/Bstrait/bstrait.html](https://psc.apl.washington.edu/HLD/Bstrait/bstrait.html)