cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.18739/a2xd0r056
title: Optical measurements of light transmittance of the upper water column, United States Coast Guard Cutter (USCGC) Healy, Chukchi Sea to Central Arctic Ocean (2022)

description: The Central Arctic Ocean remains profoundly understudied, particularly with respect to carbon cycling, ecosystem alteration, and associated changes in atmospheric, ice and ocean physics that drive those biological and biogeochemical systems. The region is expected to experience continued marked changes over the coming decades, driven by ongoing climate warming. Yet, because of relatively limited understanding of fundamental characteristics and processes in the region, predicting these changes and their Pan-Arctic linkages remains difficult. The Synoptic Arctic Survey (SAS) is organized around three major research areas: (1) physical drivers of importance to the ecosystem and carbon cycle; (2) the ecosystem response and (3) the carbon cycle. The overarching questions are: “What is the present state, and what are the major ongoing transformations of the Arctic marine system?” The overall objective of this expedition was to quantify the present states of the physical, biological, and biogeochemical systems of the Pacific Arctic (here defined as the Chukchi Sea, Beaufort shelf/slope, Chukchi Borderlands) and Canadian Basin (i.e., the Makarov and Canada basins) during summer 2022." - Cruise Report United States Coast Guard Cutter (USCGC) Healy HLY2202/AWS2022 [Prepared by Carin Ashjian (cashjian@whoi.edu) and the HLY2202 Science Team]. This dataset presents open-ocean (i.e. without the presence of sea ice) upper ocean (~50 meter [m]) optical profiles collected using a Biospherical Compact Optical Profiling System (C-OPS). Eighteen channels (320–780 nanometer [nm]) were measured by upward and downward facing radiometers alongside an upward viewing radiometer at the surface. In addition to the eighteen transmittance channels, subsurface chlorophyll fluorescence and photosynthetic active radiation are provided.
DOI: 10.15468/dl.sfq3us
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
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 "Country is one of (Algeria, Angola, Benin, Botswana, British Indian Ocean Territory, Burkina Faso, Burundi, Cabo Verde, Cameroon, Central African Republic, Chad, Comoros, Congo, Congo, Democratic Republic of the, Côte d’Ivoire, Djibouti, Egypt, Equatorial Guinea, Eritrea, Eswatini, Ethiopia, French Southern Territories, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Lesotho, Liberia, Libya, Madagascar, Malawi, Mali, Mauritania, Mauritius, Mayotte, Morocco, Mozambique, Namibia, Niger, Nigeria, Réunion, Rwanda, Saint Helena, Ascension and Tristan da Cunha, Sao Tome and Principe, Senegal, Seychelles, Sierra Leone, Somalia, South Africa, South Sudan, Sudan, Tanzania, United Republic of, Togo, Tunisia, Uganda, Western Sahara, Zambia, Zimbabwe)"
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 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0016850-250525065834625/datasets/export for details.
DOI: 10.18739/a2xk84s1w
title: On-iceberg autonomous phase-sensitive radar (ApRES) data from 10-day deployment in Sermilik Fjord, Southeast Greenland, 2019

description: Data collection and processing methods are outlined in Schild, K. M., I. Vankova, D. A. Sutherland and K. W. Nicholls (2024), Deriving Iceberg Ablation Rates using an On-Iceberg ApRES, Annals of Glaciology, 65, doi:10.1017/aog.2024.35.
 Paper abstract:
 The increase in iceberg discharge into the polar oceans highlights the importance of understanding how quickly icebergs are deteriorating and where the resulting freshwater injection is occurring. Recent advances in quantifying iceberg deterioration through combinations of modeling, remote sensing, and direct in situ measurements have successfully calculated overall ablation rates, and surface and sidewall ablation; however, in situ measurements of basal melt rates have been difficult to obtain. Radar has successfully measured iceberg thickness, but repeat measurements, which would capture a change in iceberg thickness with time, have not yet been collected. Here we test the applicability of using an on-iceberg autonomous phase-sensitive radar (ApRES) to quantify basal ablation rates of a large (~800 meter [m] long) non-tabular Arctic iceberg during an intensive 2019 summer field campaign in Sermilik Fjord, southeast Greenland. We find that ApRES can be used to measure basal ablation even over a short deployment period (10-days), and also provide a lower bound on sidewall melt. This study fills a critical gap in iceberg research and pushes the limits of field instrumentation.
DOI: 10.7266/n7cj8bjp
title: Dataset for: Trace analysis of surfactants in Corexit oil dispersant formulations and seawater: Seawater sample analysis
DOI: 10.18739/a2xk84s2c
title: Arctic Dynamic Ocean Topography (DOT) Buoy Data, Beaufort Sea & Laptev Sea (2019-2024)

description: We have developed for deployment in ice-covered seas Dynamic Ocean Topography (DOT) Buoys which make precise measurements of sea surface height (SSH) and precipitable water vapor (PWV) content. Our motivation is to improve measurements of DOT, the departure of sea surface height from the height of the geoid time-invariant geopotential surface (e.g., the EGM-2008 model). The spatial gradient of DOT is the sea surface tilt that drives surface geostrophic current. Satellite altimeters such as CryoSat-2, ICESat-2, and SWOT measure DOT, but they require ground truth observations for calibration and validation. These are difficult anywhere, but in ice-covered oceans they have been nonexistent. We have developed the DOT buoys to fill this gap.
 The methodology is in principle very simple, that is to measure the height of a drifting buoy with a precise Global Positioning System (GPS) receiver and the changes in height of the buoy relative to the water surface with a pressure sensor at the bottom of the buoy. The major components of the buoys include the dual channel GPS receiver and the Iridium transmitter receiver, which is used for transmission of the full GPS data including phase of the carrier frequencies. In addition, the buoys have a pressure sensor at the bottom of the buoy hull for determination of the GPS antenna freeboard, tilt and heading sensors, and atmospheric pressure and temperature sensors. To conserve power, we typically sample GPS data at 30-second intervals but on a duty cycle of for example 2 days on and 5-days off. The GPS data have been processed by Bruce Haines at Jet Propulsion Laboratory (JPL) using GYPSY Precise Point Positioning (PPP). The dual frequencies allow determination of the position error due to wet tropospheric delay. PPP uses GPS data from a worldwide array of receivers fixed to bedrock to determine the GPS satellite clock and ephemerae errors that are the other main source of position errors. This results in accuracies of SSH measurement approaching 1-centimeter (cm). The wet tropospheric delay measurement when multiplied by -0.18 is approximately the precipitable water vapor content (PWV) of the atmosphere. All the GPS-derived parameters, the buoy orientation measurements where available, the met measurements, buoy draft pressure, and initial GPSS antenna freeboard, and the constant GPS phase center height above the GPS antenna base are included in the data submission.
DOI: 10.15468/dl.xbuf59
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
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 "Country is one of (American Samoa, Australia, Christmas Island, Cocos (Keeling) Islands, Cook Islands, Fiji, French Polynesia, Guam, Heard Island and McDonald Islands, Kiribati, Marshall Islands, Micronesia (Federated States of), Nauru, New Caledonia, New Zealand, Niue, Norfolk Island, Northern Mariana Islands, Palau, Papua New Guinea, Pitcairn, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu, United States Minor Outlying Islands, Vanuatu, Wallis and Futuna)"
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 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0016851-250525065834625/datasets/export for details.
DOI: 10.18739/a2xp6v547
title: Zooplankton abundance data for 53 micron mesh ring net samples, taken during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAIC) expedition (PS 122), in the central Arctic and Fram Strait, November 2019 - September 2020

description: The Multi-disciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), was conducted from October 2019 to September 2020. The Research Vessel Polarstern was frozen into the ice in the Central Arctic Ocean north of Norway and drifted with the prevailing currents from north to south, traversing multiple Arctic basins and regimes and serving as a floating laboratory for an international, multidisciplinary program focusing on multiple facets of ice, ocean, atmosphere, biogeochemistry, and ecosystem responses to ongoing changing environmental conditions.
 Zooplankton ecology was investigated as part of the ecosystem team program. Abundance data from the area has been limited, particularly for the winter season. Weekly net tows were scheduled with multiple nets (mesh sizes 53, 150 and 1000 microns (µm)) to add to that data.
 This data set contains zooplankton abundance data (individuals per cubic meter) for the 53 µm ring net samples, sampling location and net depth information. Abundant zooplankton were identified to species and stage, including nauplii. Less abundant specimens were identified to subgroup, genus, group or family.
DOI: 10.18739/a2xs5jj9h
title: In Situ Sea Ice Stress Data from the SIDEx (Sea Ice Dynamics Experiment) 2021 Beaufort Sea Field Campaign

description: The Sea Ice Dynamics Experiment (SIDEx) was a field campaign in the Beaufort Sea during February to April 2021. The field experiment was designed to investigate the interaction of ice stress, strain, and fracture over meter-to-kilometer spatial scales as ice fractured and subsequently deformed. Observations were collected in situ at an ice camp, using autonomous buoys, and with remote sensing. Observations were collected over a variety of scales, including scales larger than the target m-km (meter-kilometer) scale. This dataset is one facet of the multi-modal data package collected together in this parent archive.
 This dataset contains stress observations collected in situ at points across the drifting ice floe from 3 March - 20 April 2021. We deployed an array of 31 Geokon Model 4351 stress gages with Campbell CRW3 data loggers and RF407 radios telemetering data during the SIDEx field experiment in a roughly 3x3 km area. We refer to each of these systems as a “Vibrating Wire Stress Gage” (VWSG) system. Data collection occurred once per minute from sensor deployment beginning March 3 through site recovery on April 20. Sensors were installed such that the vibrating wire rosette would be positioned 25 cm (centimeter) beneath the ice surface, by boring a hole approximately 2 cm larger than the sensor cylinder to the appropriate depth. Sensors were then placed, with the orientation mark either toward magnetic north or toward camp (as noted) and the hole was filled with fresh water, and permitted to freeze.
 The sensors consist of a rigid steel cylinder with a rosette of three steel wires strung across its hollow interior. During each sample the wires in the rosette are magnetically plucked and the resonant frequency of each wire is recorded by the CRVW3 logger. Strain on the cylinder causes changes in the tension of the vibrating wires and alters their resonant frequency.
 Primary and secondary principle stresses are calculated using the frequency reading, known material qualities of the sensor itself, and the inclusion factors of the sensor to the ice following the approach of Cox and Johnson 1983 to resolve the stress into primary and secondary principle components and azimuthal angle, relative to true north at 0 degrees. Temperature of the sensor also impacts wire tension and is corrected for using a calibration curve determined from a multi-point calibration of each sensor prior to deployment, as per Geokon’s procedures. A temperature sensor is included in each gage near the rosette.
 Outputs are presented in primary and secondary principle stress, their angle from true north, and the temperature of the stress gage. Information on the ice thickness and type at the deployment sites is included in a separate file. We use the convention that compressive stresses are positive.
DOI: 10.18739/a2xw47z1z
title: Equal Area Scalable Earth Grid (EASE-Grid) Sea Ice Age, Version 4, 1984-2019

description: This data set provides weekly estimates of sea ice age for the Arctic Ocean derived from remotely sensed sea ice motion and sea ice extent. The temporal coverage for this data set is January 1984 through December 2019. For more recent data, see the Quicklook Arctic Weekly Equal Area Scalable Earth Grid (EASE-Grid) Sea Ice Age data product (https://nsidc.org/data/nsidc-0749). The main parameter for this data set is sea ice age, measured in years. Data are provided in georeferenced netCDF (.nc) format. PNG (.png) browse images are also provided. Each netCDF file contains 52 weeks of sea ice ages, coded as integers in a 722 x 722 gridded subset of the 12.5 km Northern Hemisphere EASE-Grid.
 Tschudi, M., W. N. Meier, J. S. Stewart, C. Fowler, and J. Maslanik. 2019. EASE-Grid Sea Ice Age, Version 4. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/UTAV7490FEPB. 16 Nov 2020.
DOI: 10.18739/a2xw47z2f
title: Coastal tundra heath responses to experimental flooding and warming, Yukon-Kuskokwim Delta (western Alaska, United States), 2022-2024

description: While the Arctic warms rapidly, several coastal tundra regions face increasing threats from altered flooding regimes. Yet, how flooding shapes coastal tundra ecosystems remains largely unknown. We experimentally examined how increased tidal flooding, under both ambient and elevated temperatures, influences key drivers of ecosystem functioning: micro-environment, vegetation, and organic matter decomposition. Data were collected across three summers (2022-2024) in a low-Arctic coastal tundra heath of the Yukon-Kuskokwim Delta (Alaska) – one of the largest high-latitude riverine deltas in North America. In May 2022, soon after snowmelt, we selected seven blocks within the focal tundra heath. Each block contained six plots, for a total of 42 plots. Plots within blocks were randomly assigned to a factorial combination of experimental monthly tidal floods (three levels: no-flooding, low-severity flooding, and high-severity flooding) and experimental warming (two levels: ambient and higher temperatures). We focused on three response categories: (1) micro-environmental changes, including air and soil temperatures, soil active layer thickness, redox potential, salinity, potential of hydrogen (pH), and chemistry; (2) vegetation responses, such as aboveground community composition and biomass, plant height, and root production; and (3) responses of organic matter decomposition (mass loss, decomposition rate, and stabilization factor).
DOI: 10.18739/a2z31nq9w
title: Mooring data from Harrison Bay, Alaska, August-September 2022

description: Six small coastal moorings were deployed in Harrison Bay for approximately 30 days between early August and early September. Two moorings were outfitted with Nortek Aquadopps and optical backscatter sensors and the remainder were outfitted with RBR sensors which recorded some combination of salinity, temperature, pressure, and turbidity. All sensors were mounted within approximately 0.5 meters (m) of the bed to capture boundary-layer dynamics. Turbidity values were converted to total suspended solids concentrations. Wave parameters (significant wave height, peak wave period, and wave direction) were post-processed from Aquadopp data. Shear velocities (used in sediment-transport research) were calculated from current and wave data at the sites where Aquadopps were mounted. Data have been used in support of a publication, "Summertime sediment convergence on the Alaskan Beaufort Shelf and implications for ice rafting."
DOI: 10.15468/dl.rttnpu
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
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 "Country is one of (Åland Islands, Albania, Andorra, Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czechia, Denmark, Estonia, Faroe Islands, Finland, France, Germany, Gibraltar, Greece, Guernsey, Holy See, Hungary, Iceland, Ireland, Isle of Man, Italy, Jersey, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Moldova, Republic of, Monaco, Montenegro, Netherlands, North Macedonia, Norway, Poland, Portugal, Romania, Russian Federation, San Marino, Serbia, Slovakia, Slovenia, Spain, Svalbard and Jan Mayen, Sweden, Switzerland, Ukraine, United Kingdom of Great Britain and Northern Ireland)"
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 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0016852-250525065834625/datasets/export for details.
DOI: 10.18739/a2z60c41r
title: Enzyme activities and nutrient dynamics in arctic soil (2021-2023)

description: This study was conducted to investigate how nutrient dynamics and microbial and plant enzyme activities vary across arctic tundra hillslopes with changing precipitation and temperature events. Samples were collected during the plant-growing season between 2021 and 2023 in two different hillslope positions with contrasting pH and different glaciation histories (older acidic tundra and younger non-acidic tundra areas). Study plots were established in both areas along hillslope transects characterized by increasing soil moisture from top to bottom. Three replicate 5 meter (m) x 5m plots were established in each the dry, mesic, and hydric sites to collect soil, plant and porewater samples for nutrient and enzyme assays.
 Freshly collected soil samples from all plots were separately extracted with water, 0.5M NaHCO3 (Olsen), or 0.5M K2SO4 to determine extractable nutrient concentrations. Enzyme assays were also performed on freshly collected soils. Hydrolytic enzyme activities were determined fluorometrically and oxidative enzyme activities were determined colorimetrically. Hydrolytic enzyme activities were also assayed fluorometrically on freshly collected live roots irrespective of plant species from each site and zone.
 To determine mobile nutrient concentrations in soil, porewater samples were collected from each site using 10 centimeter (cm) rhizon samplers (dry and mesic) and custom-made perforated strong Teflon tubes (commonly known as sippers) with variable lengths based on intended depths. Porewater samples were collected from different soil depths (0cm for surface water, 5cm, 10cm, 20cm) during 2021 and 2022 plant-growing seasons. In 2023, porewater samples were collected from different soil horizons – O horizon, A horizon, and O/A horizon. Porewater samples were acidified or frozen (based on analytical needs) immediately after collection to preserve for later measurements of carbon and nutrients, and metal concentrations.
 Additionally, to determine how nutrients move downslope at our sites, we setup one transect per area, comprised of 13 approximately equally spaced sampling points, starting at the dry sites at the tops of the hillslopes, through the mid- and downslopes (i.e., mesic and hydric zones, respectively). Soil porewater was collected from these transect locations as described above. Furthermore, anion and cation exchange resin strips were installed at each transect point and left in soils over summers (June/July-August) or winters (August-June/July) as measures of cumulative soil nutrient availability. Upon collection, resin strips were extracted with 2M KCl, and the extracts were frozen and later analyzed for inorganic nitrogen and phosphorus.
DOI: 10.18739/a2zc7rw7f
title: eXpendable Conductivity Temperature Depth (XCTD) profiles of temperature and salinity from Sermilik Fjord during September 2012

description: Seven temperature and salinity profiles from Sermilik Fjord in Southeast Greenland. The profiles were collected using Sippican XCTD-1 eXpendable Conductivity Temperature Depth (XCTD) probes deployed from a helicopter. The profiles were collected on September 14 2012 in the ice mélange region of the Helheim Glacier/Sermilik Fjord system. The profiles were manually examined, quality controlled, and are provided as 2-meter (m) depth bin averaged profiles. The collection of these XCTD profiles was done concurrently with a shipboard survey of Sermilik Fjord from September 15 - 20 2012. The shipboard CTD data are provided separately. These data were collected as part of a long-term project to monitor Sermilik Fjord to determine what water masses flow into and out of the fjord; in particular, if warm, Atlantic water from the Irminger Sea penetrates into the fjord and how freshwater from ice melt is diluted and transported out of the fjord. Observations have been collected in the fjord since 2008.
DOI: 10.18739/a2zg6g886
title: Relative cover of vegetation from a small mammal experiment from summer 2018 and 2019 near Nome Alaska

description: We conducted a manipulative experiment to quantify the impact of small mammal herbivores on the plant community of the tundra at three sites near Nome, Alaska. At each site we set up grazing fences in July of 2018 to simulate different levels of small mammal herbivore (vole and lemming) activity. Each site had 3 treatment plots and a control plot: 1) Exclosure treatments (EX) were 8 meter (m) x 8m square mesh fences 2) control plots (CT) were 8m x 8m unfenced plots marked with pin flags at corners 3) press treatments (PR) were 20m x 20m square mesh fences stocked with 4 tundra voles (Microtus oeconomus) every summer and 4) pulse treatments (PU) where we stocked the fence with 4 voles in 2018 and then removed and excluded voles in 2019. At each site in each plot we collected relative abundance of plant species and ground cover in 8 1 square meter (m2) plots once each year.
DOI: 10.18739/a2zp3w26f
title: Soundscape Ecology to Assess Environmental and Anthropogenic Controls on Wildlife Behavior: Environmental Data (Northeastern Alaska and Northwestern Canada, 2017-2023)

description: This project used cutting-edge soundscape observations and analyses to quantify the influence of changing environmental dynamics and increasing anthropogenic activity on the behavior and phenology of migratory caribou, waterfowl, and songbird communities in Arctic-boreal Alaska and northwestern Canada. We used acoustic and camera-trap monitoring methods to evaluate wildlife responses in novel and non-invasive ways across broad spatial ranges during crucial seasons. Our study combined field observations, modeling, and analyses included (1) soundscape measurements, (2) camera-trap observations, (3) automated soundscape analyses, (4) analyses of camera-trap caribou observations, (5) high-resolution modeling of environmental variables, and (6) statistical analyses of wildlife occupancy, diversity, and phenology. This “Environmental Data” dataset package describes and includes the high-resolution environmental variables used in this study.