cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.18739/a2gq6r37v
title: Wind speed measurements with a 2-dimensional ultrasonic anemometer from the FS Polarstern bow tower, deployed during MOSAiC (Multidisciplinary Drifting Observatory for the Study of Arctic Climate) expedition, Arctic Circle, 2019-2020

description: True and relative wind speed and direction measured from the bow of the research icebreaker FS Polarstern during the 2019-2020 Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) field program. These are minute-averaged values of 1 Hertz (Hz) raw measurements with an RM Young model 86004 heated, 2 Dimensional (2D) ultrasonic anemometer. The measurement location was ~18 meters (m) height on a triangular meteorological tower on the ship's bow, on a horizontal arm extending ~ 1.5m in front of the tower. Sensor heating prevented ice formation in almost all conditions, but there were a few periods of ice build-up in severe freezing rain or fog conditions. The north (N) orientation of the anemometer was in the direction of the ship's bow. True wind speed and direction are computed from relative winds and the ship heading. Due to obstructions from the ship's superstructure, measurements for relative wind directions beyond +/- 130 degrees from the bow are not accurate and subject to high variability. Measurements over the remaining wind sector (+/- 120 deg from the bow) are slightly distorted by the divergence of streamlines over the ship. As a convenience to users, ship navigation parameters (latitude, longitude, speed-over-ground, course-over-ground, and heading) are provided. The archives of ship navigation and meteorological data from PANGEA are the original sources for all navigation parameters (https://doi.org/10.1594/PANGAEA.935221, https://doi.org/10.1594/PANGAEA.935222, https://doi.org/10.1594/PANGAEA.935223, https://doi.org/10.1594/PANGAEA.935224, https://doi.org/10.1594/PANGAEA.935225).
DOI: 10.18739/a2gt5fh0s
title: Arctic chironomid training set from Canada, Greenland, Iceland and Svalbard for estimating paleotemperatures (2022)

description: This dataset includes chironomid species assemblage data and air temperature estimates from 400+ lakes across northern North America, Greenland, Iceland, and Svalbard to inform interpretations of Holocene subfossil chironomid assemblages used in paleolimnological reconstruction. This calibration-set was developed by re-identifying and taxonomically harmonizing chironomids in previously described surface sediment samples, with identifications made at finer taxonomic resolution than in original publications (which are cited in the publication describing this dataset, Medeiros et al. 2022 Quaternary Science Reviews, and should be cited by dataset users). Site summer air temperatures are newly estimated with a consistent method using the WorldClim 2.1 gridded bioclimatic dataset. The large geographic coverage of this dataset is intended to provide climatic analogs for a wide range of Holocene climates in the northwest North Atlantic region and North American Arctic, including Greenland. For many of these regions, modern calibration data for paleoclimate proxies are sparse despite keen interest in paleoclimate reconstructions from high latitudes. Dataset users should consult and cite the following source publication: Medeiros, A.S., Chipman, M., Francis, D.R., Hamerlik, L., Langdon, P., Puleo, P.J.K., Schellinger, G., Steigleder, R., Walker, I.R., Woodroffe, S., and Axford, Y. 2022. A continent-scale chironomid training set for reconstructing arctic temperatures. Quaternary Science Reviews 294, 107728. DOI 10.1016/j.quascirev.2022.107728.
DOI: 10.18739/a2h70823w
title: Thermal state of permafrost in North America - annually observed ground temperatures, 2022

description: This work coordinates data collection using standard equipment and protocols at North American and Russian sites. These data sets provide the baseline to assess the future rates of change in near-surface permafrost temperatures and permafrost boundaries, and to provide spatial data for validation of climate scenario models and temperature reanalysis approaches. The work represents the United States (US) contribution to the ongoing activities of the Global Terrestrial Network for Permafrost that obtains temperatures in a large number of globally distributed monitoring sites in order to provide a snapshot of permafrost temperatures in both time and space. The US National Science Foundation funded this work with award #0520578, #0632400, #0856864, and #1304271.
DOI: 10.18739/a2hd7nt83
title: Healing of cracks in freshwater, saline and sea ice, 2020-2022

description: The combination of a decrease of the ice coverage on the Arctic Ocean, an increase of the amplitude of ocean waves, and damage due to the daily increases and decreases in temperature may lead to the breakup of ice cover. Of interest, therefore, is the strength of ice that was thermally damaged during diurnal temperature cycles. To understand the behavior of ice under these conditions, we conducted new systematic experiments on freshwater and sea ice in the present study, where the ice was cracked by thermal shocking. The cracks initially weakened the ice but within a short period of time, the ice strength returned to its original value. This observation of crack healing is attributed to the formation of a thin liquid water layer on opposing crack surfaces which aid to its freezing as contact is made during warming. The effect of crack healing may help to avoid ice breakup. Sea ice was collected in the Beaufort Sea during winter 2020, while saline ice and freshwater ice were produced in the laboratory.
DOI: 10.18739/a2hh6c72x
title: Annual summer maximum daily counts of adult caribou and muskoxen at the Kangerlussuaq, Greenland, study site 2003-2017

description: These data comprise the annual daily maximum number of adult caribou and muskoxen counted at a long-term study site east of Kangerlussuaq, Greenland, from 2003 through 2017. The data were collected in parallel with long-term continuous observations of plant phenological dynamics, and in concert with annual sampling of tundra vegetation abundance, at the study site. The objectives of the research related to the collection of these data included investigation of the potential contributions of interannual variation in plant green-up timing on population dynamics of caribou and muskoxen at the study site and of effects of variation in large herbivore abundance on tundra vegetation dynamics. The investigators reserve the right to update the dataset in the event that transcription errors or errors of omission are discovered after publication.
DOI: 10.18739/a2hm52m2s
title: Plant community response to warming and herbivory on sub-arctic coastal terraces in Western Alaska, 2015 - 2016

description: To predict future changes in high latitude biomes, it is important to understand how plant communities will respond to increased temperature. Across sub-arctic systems, warming generally increases aboveground biomass in plant communities. Specifically, in arctic graminoid systems, experimental warming has been shown to increase productivity, aboveground biomass and leaf litter production, and stimulate early-season growth. Warming can also decrease species richness, and reduce foliar nitrogen (N) in aboveground biomass over the growing season. Migrating geese are important grazers in arctic and subarctic ecosystems during summer breeding months. Avian herbivores depend on high quality forage (high N) and are often found at high enough densities to impact vegetation communities. Exclosure experiments show that goose herbivory reduces biomass of herbaceous species but increases net above-ground primary production and N concentrations of grazing-tolerant sedges, and sometimes even increases species richness. Goose herbivory also alters plant physiological processes as evidenced by increased N uptake by plants, as well as the biophysical processes that affect N cycling through trampling and fecal deposition. Thus, high-density populations of avian herbivores can have top-down control on their vegetation communities. While increasing global temperatures may increase aboveground biomass and decrease species richness in plant communities, herbivory could potentially mediate, or even reverse, these responses. For example, Post and Pedersen (2008) suggest that herbivory may exacerbate plant response to warming because both effects increase rates of productivity, while simultaneously reducing the effects of warming on aboveground biomass. If the interaction between warming and herbivory causes a shift in plant abundance and community functional groups, this could cascade through the system resulting in changes in nutrient cycling and plant-animal feedbacks. The Yukon-Kuskokwim (Y-K) Delta is one of the largest river deltas in the world and is a globally important breeding area for millions of long-distance migratory waterfowl and shorebird species. The majority of these species nest in high densities close to the ocean among lowland coastal habitat. Geese populations utilize overlapping habitats and shift from more coastal to more interior habitats over the growing season. The expectations for how vegetation responds to increasing temperature and changes in herbivory with climate change will vary for different plant communities. We propose to conduct an experiment that investigates the impact of warming and herbivory on three coastal sub-arctic vegetation communities in the Y-K Delta addressing the following questions: 1) How does warming impact vegetation biomass and community composition; 2) How does herbivory impact species composition and plant functional groups; and 3) How do the different responses to warming and herbivory interact?
DOI: 10.18739/a2ht2gd1h
title: Great Lake Under Ice Remotely Operated Vehicle (ROV) imagery, Near Keweenaw Waterway, Houghton, Michigan, March, 2021

description: Ice-water interface is an under sampled region. Instead of using invasive coring and ice-tethered instruments, we are developing navigation algorithms for unmanned underwater vehicles to survey this region autonomous with limited human intervention. For this study, we modified a Blue ROV-2 (Remotely Operated Vehicle) with additional perception sensor and navigation sensors to obtain a better localization and imaging results while surveying the ice from underneath at a standoff distance of about 2 meters. In March 2021, the ROV is deployed through an ice hole to survey the underside of the freshwater ice. The survey transect is about 50 meters long, and the ROV was remotely piloted by the operator to keep about 2 meters from the ice surface. This data set includes the results from our first field tests conducted at the Keweenaw Waterway at Houghton, Michigan in March 2021. The two video footages are recorded using two Forward-Looking Infrared (FLIR) machine vision camera at a baseline of about 9 centimeters (cm). The odometry (ROV trajectory) is processed by applying a Multi-State Constraint Kalman Filter to the measurements from the inertial measurement unit (IMU) and Doppler Velocity Log (DVL). More information about the ROV and the field test could be found in the following paper. For more information about the ROV please refer to the paper "Zhao, L., Zhou, M., Loose, B., Cousens, V.C., and Turrisi, R. (2021). Modifying an Affordable ROV for Under-ice Sensing. OCEANS 2021: San Diego – Porto, 1-5"
DOI: 10.18739/a2j09w57x
title: Shelf-Break Upwelling in the Western Beaufort Sea – Acoustic Doppler Current Profiler (ADCP) Velocity and Backscatter Amplitude collected using the R/V Sikuliaq 300 kHz ADCP, 2018

description: This data set contains processed acoustic Doppler current profiler (ADCP) data collected from the research vessel (R/V) Sikuliaq during August 8 - August 27, 2018 on a cruise to the Western Beaufort Shelf. The data were collected to document water velocities and backscatter during a project focusing on the bio-physical impacts of upwelling along the Beaufort Shelf. Data were collected using the centerboard-mounted 300 kHz ADCP continuously from the start/end port of Nome, Alaska, through Bering Strait and the Chukchi Sea to the working area along the shelf-break approximately north of Nuiqsut, Alaska. Data were processed at the Woods Hole Oceanographic Institution using the University of Hawaii Common Ocean Data Access System (CODAS) ADCP data processing system by Frank Bahr. The data set contains year, decimal date (yearday.time, Jan 1= Day 0, decimal time in GMT) , position (latitude, longitude), and water depth for profiles of velocity (undetided and detided, m/s), percent good, and backscatter amplitude. Data are provided in two formats; one excel file and one text file (tab delimited).
DOI: 10.18739/a2j38kj9r
title: Arctic Alaska Camera Trap Project (Microsoft AI for Earth MegaDetector Evaluation Image Subset), Arctic coastal plain, Alaska, USA, May - September. 2019.

description: Data are available to download at: https://arcticdata.io/data/10.18739/A2J38KJ9R/ The image subset and data provided here are from 20 sampling locations from an ongoing camera trap project (2019-2023) in Arctic Alaska, United States. We used this image set to evaluate a state-of-the-art computer vision model developed by Microsoft AI for Earth named MegaDetector for detecting wildlife in camera trap images. To better understand the utility of automated data processing tools for wildlife camera trap data, we compared image labels (i.e., images with/without animals) assigned manually by human reviewers with those determined using MegaDetector. We found MegaDetector reliably determined the presence or absence of wildlife in camera trap images generated by motion detection camera settings (e.g., ≥95% accuracy), however, performance was substantially poorer for images collected with time-lapse camera settings (e.g., ≤62% accuracy) as compared to human review. Our results highlight the importance of making mindful decisions about how to collect and process camera trap images and the impact those decisions have on the information generated to inform study outcomes. This human-labeled dataset may also be used to evaluate and improve future development of computer vision models for automated image analysis.
DOI: 10.18739/a2j678z16
title: North Pacific and Arctic Marine Vessel Traffic Dataset (2015-2020); 25 Kilometer Resolution.

description: These data are a spatially explicit representation of monthly shipping intensity in the Pacific Arctic region from January 1, 2015 to December 31, 2020. We calculated shipping intensity based on Automatic Identification System (AIS) data, a type of Global Positioning System (GPS) transmitter required by the International Maritime Organization on all ships over 300 gross tonnes on an international voyage, all cargo ships over 500 gross tonnes, and all passenger ships. We used AIS data received by the exactEarth satellite constellation (64 satellites as of 2020), ensuring spatial coverage regardless of national jurisdiction or remoteness. Our analytical approach converted raw AIS input into monthly raster datasets, separated by vessel type. We first filtered raw AIS messages to remove spurious records and GPS errors, then joined remaining vessel positional records with static messages including descriptive attributes. We further categorized these messages into one of four general ship types (cargo; tanker; fishing; and other). To develop the raster dataset, we created a series of spatially explicit daily vessel tracks according to unique voyages and aggregated tracks by ship type and month. We then created a 25-km raster grid and calculated the total length, in meters, of all vessel tracks within each raster cell. These monthly datasets provide a critical snapshot of dynamic commercial and natural systems in the Pacific Arctic region. Recent declines in sea ice have lengthened the duration of the shipping season and have expanded the spatial coverage of large vessel routes, from the Aleutian Islands through the Bering Strait and into the southern Chukchi Sea. As vessel traffic has increased, so has exposure to the myriad environmental risks posed by large ships, including oil spills, underwater noise pollution, large cetacean ship-strikes, and discharges of pollutants. This dataset provides scientific researchers, local community members, mariners, and decision-makers with a quantitative means to evaluate the distribution and intensity of shipping across space and through time. In addition to these 25-km raster data, we also produced data products in 10-km raster format as well as a 1-km coastal data subset and a hex data set which contains additional attributes (e.g., number of ships, ship speed). To find these products, search for “North Pacific and Arctic Marine Vessel Traffic Dataset” in the Arctic Data Center’s data repository.
DOI: 10.18739/a2j960b5d
title: Walrus teeth as biomonitors of trace elements in Arctic marine ecosystems, 1945-2014

description: Effective biomonitoring requires an understanding of the factors driving concentrations of the substances or compounds of interest in the tissues of studied organisms. Biomonitoring of trace elements, and heavy metals in particular, has been the focus of much research; however, the complex roles many trace elements play in animal and plant tissues can make it difficult to disentangle environmental signals from physiology. This study examined the concentrations of 15 trace elements in the teeth of 122 Pacific walruses (Odobenus rosmarus divergens) to investigate the potential for walrus teeth as biomonitors of trace elements in Arctic ecosystems. Elemental concentrations were measured across cementum growth layer groups (GLGs), thereby reconstructing a lifetime history of element concentrations for each walrus. The locations of GLGs were used to divide trace element time series into individual years, allowing each GLG to be associated with an animal age and a calendar year. The elements studied exhibited a great deal of complexity, reflecting the numerous factors responsible for generating tooth trace element concentrations. Generalized linear mixed models were used to investigate the importance of age and sex in explaining observed variation in trace element concentrations. Some elements exhibited clear physiological signals (particularly zinc, strontium, barium, and lead), and all elements except arsenic varied by age and/or sex. Pearson correlations revealed that elements were more strongly correlated among calendar years than among individual walruses, and correlations of trace elements within individual walruses were generally inconsistent or weak. Plots of average elemental concentrations through time from 1945 – 2014 further supported the correlation analyses, with many elements exhibiting similar patterns across the ~70 year period. Together, these results indicate the importance of physiology in modulating tooth trace element concentrations in walrus tooth cementum, but suggest that many trace elements reflect a record of environmental exposure and dietary intake/uptake.
DOI: 10.18739/a2jh3d41p
title: Water depth, surface elevation, and water temperature of lakes in the Fish Creek Watershed in northern Alaska, USA, 2011-2022

description: This set of eleven lakes located in the Fish Creek Watershed in northern Alaska have been monitored for varying periods of time starting as early as 2011 as part of the Fish Creek Watershed Observatory (http://www.fishcreekwatershed.org/) and in coordination with several NSF supported projects. Lakes were primarily selected for long-term monitoring because of interest in water supply for industrial activities and corresponding ecosystem services along with dynamics related to climate change and variability. These data include basic lake attributes of water surface elevation and water temperature at the lake bed of interest to studies of water balance, aquatic habitat, and permafrost stability. In some cases, additional data or studies have been completed on some of these lakes which are reported separately in other datasets or scientific papers or reports.
DOI: 10.18739/a2jm23h40
title: Spatial extent of southeast Greenland firn aquifers detected by airborne radars, 1993-2018

description: Surface melt produces more mass loss than any other process on the Greenland Ice Sheet. In some regions of Greenland with high summer surface melt and high winter snow accumulation, the warm porous firn of the percolation zone can retain liquid meltwater through the winter. These regions of water-saturated firn, which may persist for longer than one year, are known as firn aquifers, commonly referred to as perennial firn aquifers. We use airborne ice-penetrating radar data from the Center for Remote Sensing of Ice Sheets (CReSIS) to document the extent of four firn aquifers in the Helheim, Ikertivaq, and Køge Bugt glacier basins. We select these sites because they have more than six repeat radar flight lines from 1993 to 2018. Our observations reveal decadal-scale expansion and interannual variability of the firn aquifers in response to high-melt years and decreasing cold content of the firn. This dataset contains detections of the four firn aquifers from the CReSIS Accumulation Radar data, collected from 2010 to 2018, and Radar Depth Sounder data, collected from 1993 to 2018. We use an open-source radar processing and interpretation toolbox to pick the detected firn aquifers in the data. The file all_detections.csv contains the latitude and longitude of the repeat radar flight lines, and the latitude and longitude of all detections of the four firn aquifers. Additionally, the associated collection year of the radar data is included. The other files contain the same data but broken into four individual files, one for each firn-aquifer site that was analyzed.
DOI: 10.18739/a2k35mf90
title: Wildfire effects on aquatic chemistry (Yukon Kuskokwim Delta, Alaska), 2015-2019

description: Data from this study originate from the NSF (National Science Foundation) Polaris Project. The Polaris Project integrates scientific research in the Arctic-boreal region with education and outreach, with a primary focus on engaging and inspiring the next generation of scientists. The overarching scientific issue that drives the Polaris Project is the vulnerability and fate of ancient carbon stored in perennially frozen ground, permafrost. Although extensive permafrost thaw is expected to occur across the northern permafrost region this century, large uncertainties remain in the timing, magnitude, and form of carbon that will be released. Participants of the Polaris Project conducted field research in the Yukon-Kuskokwim Delta (YKD), collaborating to make fundamental scientific discoveries related to the transformation and fate of thawed permafrost carbon, and implications for global climate. This data set includes aquatic chemistry data from expeditions to the YKD during 2015–2019. Parameters measured include water temperature, pH, dissolved oxygen, conductivity, dissolved organic and inorganic carbon, nitrogen species, phosphorous, greenhouse gases, stables isotopes of carbon and water, optical properties of water, and fluxes of methane and carbon dioxide made in the field. These data were compiled and underwent quality assurance / quality control specifically for the scientific objectives of the manuscript published by Zolkos et al. (2022). Consequently, this dataset contains a modified version of Polaris Project YKD aquatic chemistry data previously published for 2015–2016 (http://doi.org/10.18739/A22804Z8M) and 2017 (http://doi.org/10.18739/A23775V7T). Data from 2018–2019 were not previously published. Therefore, users interested in the original datasets for 2015–2017 are encouraged to access them via the provided links, while users interested in the data and metadata specific to the associated manuscript by Zolkos et al. are encouraged to use this companion dataset.