cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.18739/a2x34ms39
title: RAPID: Impact of Large Scale Greenland Ice Sheet Melting on Glacier Hydrology and Meltwater Geochemistry

description: In 2012, multiple lines of evidence suggest a record release of freshwater from the Greenland ice sheet (GrIS), the largest expanse of glacial ice in the Northern Hemisphere and a major source of meltwater and associated material to the surrounding North Atlantic and Arctic Oceans. Between July 8 and 12, satellite-derived estimates of surface melt increased from 40% to 97% of the ice sheet. This warming received widespread media attention and public interest, yet the scientific community lacks direct observations of meltwater controls on ice sheet movement and meltwater geochemistry for such a large-scale melting event. The overarching goal of this RAPID proposal is to quantify, in short order, the impact of a large-scale melting event on the ice sheet dynamics and meltwater biogeochemistry of a large, land-terminating glacier on the western Greenland margin. RAPID funds will enable the analysis and synthesis of a unique sample set collected during other fieldwork from the Leverett Glacier catchment, a large outlet glacier that discharges through a single proglacial river. Though the focus is on the 2012 episode, the investigators will also analyze samples and GrIS dynamics data from two field seasons (2011- 12), which will aid in interpretation of changes driven by the historic melting event owing to the highly contrasting annual freshwater discharge rates. The investigators will use time-series radiogenic (beryllium-7 and radon-222) and stable isotopes (oxygen and hydrogen), each with unique sources and constant production rates, from the Leverett glacier watershed to differentiate the fractions of meltwater sourced from recent surface snow, glacial ice and delayed flow meltwater. They will also investigate the composition and magnitude of nutrient and metal fluxes released from the subglacial environment and study how these fluxes evolved during July 2012. From 2011-12, parallel ice sheet geophysical data (GPS, satellite imagery) and meltwater biogeochemistry samples (carbon, macro- and micro-nutrients) have been collected by the PI and colleagues from universities in the United Kingdom. The proposed project will fully fund a Ph.D. student, and high school students and undergraduate interns will be recruited to assist with the laboratory aspect of the research. In order to increase the visibility of this project among the general public, the PI and student will co-author an article for the WHOI magazine Oceanus. This publication reaches a wide audience through both print- and web-based editions. Finally, the Ph.D. student will continue to report on the results of this study via an Expedition Blog called "Following the Ice" on Scientific American (http://blogs.scientificamerican.com/expeditions/tag/following-the-ice/).
DOI: 10.18739/a2nk3656p
title: RAPID: Impact of Large Scale Greenland Ice Sheet Melting on Glacier Hydrology and Meltwater Geochemistry

description: In 2012, multiple lines of evidence suggest a record release of freshwater from the Greenland ice sheet (GrIS), the largest expanse of glacial ice in the Northern Hemisphere and a major source of meltwater and associated material to the surrounding North Atlantic and Arctic Oceans. Between July 8 and 12, satellite-derived estimates of surface melt increased from 40% to 97% of the ice sheet. This warming received widespread media attention and public interest, yet the scientific community lacks direct observations of meltwater controls on ice sheet movement and meltwater geochemistry for such a large-scale melting event. The overarching goal of this RAPID proposal is to quantify, in short order, the impact of a large-scale melting event on the ice sheet dynamics and meltwater biogeochemistry of a large, land-terminating glacier on the western Greenland margin. RAPID funds will enable the analysis and synthesis of a unique sample set collected during other fieldwork from the Leverett Glacier catchment, a large outlet glacier that discharges through a single proglacial river. Though the focus is on the 2012 episode, the investigators will also analyze samples and GrIS dynamics data from two field seasons (2011- 12), which will aid in interpretation of changes driven by the historic melting event owing to the highly contrasting annual freshwater discharge rates. The investigators will use time-series radiogenic (beryllium-7 and radon-222) and stable isotopes (oxygen and hydrogen), each with unique sources and constant production rates, from the Leverett glacier watershed to differentiate the fractions of meltwater sourced from recent surface snow, glacial ice and delayed flow meltwater. They will also investigate the composition and magnitude of nutrient and metal fluxes released from the subglacial environment and study how these fluxes evolved during July 2012. From 2011-12, parallel ice sheet geophysical data (GPS, satellite imagery) and meltwater biogeochemistry samples (carbon, macro- and micro-nutrients) have been collected by the PI and colleagues from universities in the United Kingdom. The proposed project will fully fund a Ph.D. student, and high school students and undergraduate interns will be recruited to assist with the laboratory aspect of the research. In order to increase the visibility of this project among the general public, the PI and student will co-author an article for the WHOI magazine Oceanus. This publication reaches a wide audience through both print- and web-based editions. Finally, the Ph.D. student will continue to report on the results of this study via an Expedition Blog called "Following the Ice" on Scientific American (http://blogs.scientificamerican.com/expeditions/tag/following-the-ice/).
DOI: 10.18739/a2hx15r4c
title: RAPID: Impact of Large Scale Greenland Ice Sheet Melting on Glacier Hydrology and Meltwater Geochemistry

description: In 2012, multiple lines of evidence suggest a record release of freshwater from the Greenland ice sheet (GrIS), the largest expanse of glacial ice in the Northern Hemisphere and a major source of meltwater and associated material to the surrounding North Atlantic and Arctic Oceans. Between July 8 and 12, satellite-derived estimates of surface melt increased from 40% to 97% of the ice sheet. This warming received widespread media attention and public interest, yet the scientific community lacks direct observations of meltwater controls on ice sheet movement and meltwater geochemistry for such a large-scale melting event. The overarching goal of this RAPID proposal is to quantify, in short order, the impact of a large-scale melting event on the ice sheet dynamics and meltwater biogeochemistry of a large, land-terminating glacier on the western Greenland margin. RAPID funds will enable the analysis and synthesis of a unique sample set collected during other fieldwork from the Leverett Glacier catchment, a large outlet glacier that discharges through a single proglacial river. Though the focus is on the 2012 episode, the investigators will also analyze samples and GrIS dynamics data from two field seasons (2011- 12), which will aid in interpretation of changes driven by the historic melting event owing to the highly contrasting annual freshwater discharge rates. The investigators will use time-series radiogenic (beryllium-7 and radon-222) and stable isotopes (oxygen and hydrogen), each with unique sources and constant production rates, from the Leverett glacier watershed to differentiate the fractions of meltwater sourced from recent surface snow, glacial ice and delayed flow meltwater. They will also investigate the composition and magnitude of nutrient and metal fluxes released from the subglacial environment and study how these fluxes evolved during July 2012. From 2011-12, parallel ice sheet geophysical data (GPS, satellite imagery) and meltwater biogeochemistry samples (carbon, macro- and micro-nutrients) have been collected by the PI and colleagues from universities in the United Kingdom. The proposed project will fully fund a Ph.D. student, and high school students and undergraduate interns will be recruited to assist with the laboratory aspect of the research. In order to increase the visibility of this project among the general public, the PI and student will co-author an article for the WHOI magazine Oceanus. This publication reaches a wide audience through both print- and web-based editions. Finally, the Ph.D. student will continue to report on the results of this study via an Expedition Blog called "Following the Ice" on Scientific American (http://blogs.scientificamerican.com/expeditions/tag/following-the-ice/).
DOI: 10.25413/sun.27437637
title: Participant Study Data for Cardiovascular Metric Estimation with a Developed PPG Device

description: With the ongoing advancements of photoplethysmography (PPG) devices for clinical and domestic applications, there exists a distinct lack of publicly available literature addressing the best possible hardware design for these devices. In this project, this question was answered by investigating the hardware design configuration of a PPG device, especially focussing on the light source wavelength, light source brightness, number of light sources, photodetector lens shape, and sensor-to-skin contact pressure. This device was evaluated on the quality of the PPG signals it measures, as well as its ability to accurately estimate the user’s heart rate, blood oxygen saturation, and blood pressure over different skin tones. A participant study was also conducted to collect cardiovascular metric data from 110 participants with varying skin tones, which was used to develop a neural network for blood pressure estimation as well as determine the best hardware configuration of the PPG device. This resulted in the hardware configuration that consisted of a red-and-infrared light-emitting diode (LED) system, a flat lens photodiode, and high sensor-to-skin contact pressure. This configuration was setup with its two red LEDs at a medium level of brightness and four infrared LEDs at a high level of brightness and was primarily used to measure data on the user’s fingertip. The consequent estimations’ mean absolute errors were 3.511 BPM for heart rate, 0.615% for blood oxygen saturation, and 11.279 mmHg for the systolic blood pressure and 6.802 mmHg for the diastolic blood pressure estimations, respectively. Finally, the selected PPG device’s bias to skin tone was determined. It was concluded that the device had very little bias to skin tone, due to it having a 3.817 dB variance over all the skin tones tested. With the successful identification of the most optimal hardware design configuration, future devices are expected to perform with improved accuracy, usability, and versatility in clinical settings. Furthermore, it provides the necessary groundwork for future research to explore additional applications of PPG devices.
DOI: 10.25413/sun.27437637.v1
title: Participant Study Data for Cardiovascular Metric Estimation with a Developed PPG Device

description: With the ongoing advancements of photoplethysmography (PPG) devices for clinical and domestic applications, there exists a distinct lack of publicly available literature addressing the best possible hardware design for these devices. In this project, this question was answered by investigating the hardware design configuration of a PPG device, especially focussing on the light source wavelength, light source brightness, number of light sources, photodetector lens shape, and sensor-to-skin contact pressure. This device was evaluated on the quality of the PPG signals it measures, as well as its ability to accurately estimate the user’s heart rate, blood oxygen saturation, and blood pressure over different skin tones. A participant study was also conducted to collect cardiovascular metric data from 110 participants with varying skin tones, which was used to develop a neural network for blood pressure estimation as well as determine the best hardware configuration of the PPG device. This resulted in the hardware configuration that consisted of a red-and-infrared light-emitting diode (LED) system, a flat lens photodiode, and high sensor-to-skin contact pressure. This configuration was setup with its two red LEDs at a medium level of brightness and four infrared LEDs at a high level of brightness and was primarily used to measure data on the user’s fingertip. The consequent estimations’ mean absolute errors were 3.511 BPM for heart rate, 0.615% for blood oxygen saturation, and 11.279 mmHg for the systolic blood pressure and 6.802 mmHg for the diastolic blood pressure estimations, respectively. Finally, the selected PPG device’s bias to skin tone was determined. It was concluded that the device had very little bias to skin tone, due to it having a 3.817 dB variance over all the skin tones tested. With the successful identification of the most optimal hardware design configuration, future devices are expected to perform with improved accuracy, usability, and versatility in clinical settings. Furthermore, it provides the necessary groundwork for future research to explore additional applications of PPG devices.
DOI: 10.18739/a2d50fz11
title: Late Quaternary Sea Ice History of the Beringian Arctic Gateway

description: Sea ice extent in the Arctic Ocean and its marginal seas is a key component of the coupled ice-atmosphere-ocean system and a driver of meridional ocean circulation, yet information about sea ice conditions in the past is very limited. The goals of this proposed study are two-fold. The first is to use archived surface sediments collected from the Bering and Chukchi Seas to develop quantitative measures of seasonal sea-ice extent and duration. This will be achieved through analysis of diatom morphology, assemblages and the IP25 biomarker of ice-associated diatoms from a suite of over 200 surface sediments collected from the Bering and Chukchi Seas spanning 0-12 months/year of sea ice. The second goal is to apply sea ice reconstructions using the calibrated diatom assemblage methods and IP25 analysis to a suite of six archived cores that form a latitudinal transect through the Bering and Chukchi Seas. The PIs aim to quantitatively reconstruct Late Pleistocene and Holocene seasonal sea ice extent at centennial-scale resolution. These efforts will be corroborated with independent biomarker-based evaluation of surface water temperatures. The successful completion of the project will result in a rich, multi-proxy data set that will be used to evaluate the sea ice and sea surface temperature history of the Bering Strait region. The results of this project will be relevant to global climate modelers as well as paleoecologists, paleoclimatologists, and paleoceanographers interested in regional- to global-scale forcing issues. The broader Arctic science community would benefit from the proxy development proposed. The project would support two full-time graduate students and a summer undergraduate research assistant in each year of the project. The PIs and students will also continue to develop curriculum modules designed to introduce 5th through 8th grade students to the topics of global and Arctic climate, marine sedimentation, ecosystem adaptation to changing environments, and the classification of organisms. The location of the 5 cores are as follows: HLY0202-3JPC: 60.1279N 179.4418W, HLY0202-51JPC: 54.55315N 168.66692W, HLY0202-17JPC: 53.933N 178.69883W, HLY0204-24JPC 73.231N, 167.88235W, HLY0204-28JPC: 73.44836N 167.69124W.
DOI: 10.18739/a28c9r474
title: Sedimetological, geochemical and isotopic evidence from of the Bering and Chukchi Seas during the last deglaciation

description: Isotopic, geochemical, and sedimentologic data from 5 marine sediment cores of the Bering and Chukchi Seas. Data includes bulk organic carbon isotopes, nitrogen isotopes, organic carbon, grain size, magnetic susceptibility, density, color, and elemental X-ray fluorescence data.
DOI: 10.18739/a20v89h84
title: Data for: Late Quaternary changes in sediment composition in NE Greenland Fjords, Shelf, and Slope

description: Methods and Data are provided on three sediment properties from a series of Polarstern cores (Hubberten and al., 1995) and on a Jan Mayen core (Husum, 2007). In addition, tables of some aspects of data analysis are also included such as the results of Principal Component Analysis of the mineral weight% data, and the clustering of the grain-size curves (Minasny and McBratney, 2002). Data are also included on the results of a sediment unmixing exercise using the .xls macro program SedUnMixMC. 1) Core location and water depth 2) New radiocarbon dates for cores PS2631, PS2640, and JM07-174GC. 3) Data for color reflectance (CIE*) are listed for cores PS2623, PS2631 and PS2640. 4) Grain-size data from the Malvern laser system are given for cores PS2623, PS2631, PS2640, and PS2641. 5) Mineral weight% data based on quantitative X-ray diffraction analysis (Eberl, 2003) of the &lt; 2 mm sediment are listed for cores PS2623, PS2627, PS2729, PS2630, PS2631, PS2640, and PC2641, and JM07-174GC. 6) Principal component scores for all cores on XRD logratio mineralogy 7) Results of fuzzy clustering of the grain-size % data and the logratio data 8) Results of running SedUnMixMC on the source sediments---the red numbers indicate the fraction associated with that sediment source---ideally should be close to 1.0. 9) Results of the 4 source sediment unmixing analysis using SedUnMixMC (Andrews et al., 2015; Andrews and Eberl, 2012) Methods The color reflectance of dried sediment was measured with an X-Rite spectrophotometer, Model 500 Series, using the CIE* system, with L* a measure of black to white, a* (blue to red) and b* (yellow to green. The prepared dry samples were tapped into a 2.5 cm dia. aluminum XRD holder, overlain by a clear glass slide, and measured. A Pantone Color Chip (4705) was measured repeatedly to evaluate instrument drift. Grain-size analyses were undertaken on sediments from PS2623, PS2631, PS2640, and PS2641 using a Malvern model 2000 laser system for the range 2000 to 0.5 µm. Add 5mL of hydrogen peroxide again and repeat the process. Keep repeating the process until the organic is gone (there is no reaction occurring). When organic is removed and the beakers are cooled a little add 8-10mL of magnesium chloride to each beaker. We employ the quantitative X-ray diffraction method developed by Eberl (2003, 2004). The sediment &lt; 2 mm are spiked by 10% by weight of zincite, milled, and the samples are scanned on a D5000 Siemens X-Ray Diffractometer between 5° and 65° 2-theta with a 0.02° step and a 2-sec count. The resulting 3000 data points are loaded into the Excel macro-program Rockjock v6 (Eberl, 2003) and the weight% of minerals in the sediment mixtures calculated against a suite of 124 "standard" mineral patterns (Eberl, 2003). Finally, the data are normalized to sum to 100%. In this paper we present the results on 8 cores. For PS2641 this included data on both the &lt; 63µm fraction and the &lt; 2mm fraction (0-300 cm).
DOI: 10.18739/a24m91b3c
title: Collaborative Research: Are There Natural Climate Cycles in the Holocene Variations of Arctic Sea Ice and Greenland Icebergs Across the Denmark Strait?

description: Historical observations and theory suggest the importance of the extent and duration of drift ice on the Climate System through changes in the Hemispheric albedo and the impact of freshwater export from the Arctic Ocean and Greenland Ice Sheet on the Thermohaline Circulation. Funds are provided to develop 50-100 yr resolution records of changes in sea ice export from the Arctic Ocean and iceberg transport from tidewater ice streams of NE Greenland that reach the Denmark Strait and to develop a detailed history of ice-rafted debris (IRD) over the last 12,000 cal yr BP. Denmark Strait is believed to be a critical area for study as it lies at the boundary between the southward export of Polar and Arctic waters and the northwestern limb of the North Atlantic Drift in the form of the Irminger Current. The research will explore a sources-to-sink model along the ENE/E Greenland shelf and across the Denmark Strait using sediment characteristics to document spatial and temporal changes in composition in a series of well-dated, high-resolution cores from either side of the Denmark Strait and along the NE Greenland shelf. This information will be used to infer changes in the transport of sea ice through the Denmark Strait. Given the ongoing observations of changing sea ice character in the Arctic, changes in the flux of sea ice into the Greenland-Norwegian Seas and the North Atlantic Ocean, and possible acceleration of ice loss from the Greenland Ice Sheet through iceberg calving, a better understanding of how these processes varied in the past will help inform projections of future climate variations. This project will develop data sets that contribute to that understanding.
DOI: 10.18739/a2w37kw32
title: IPY: Microbial winter survival physiology: a driver on microbial community composition and carbon cycling

description: Arctic landscapes are changing rapidly. The "greening" and "shrubification" of the Arctic drive climate feedbacks (via albedo and energy exchange) as well as affecting human activities directly. Vegetation change, however, is driven belowground by nutrient availability, a result of microbial feedbacks that also have independent effects on the climate system (e.g. CO2 and CH4 emissions). The microbial system, therefore, plays a key role in regulating the functioning of the overall Arctic System. As organisms migrate and spread across the Arctic, the processes they regulate migrate with them. Predicting changes in the pattern of tundra biogeochemistry therefore requires understanding the factors that regulate the distribution and functioning of key groups of microbes. Are bacteria and fungi regulated simply by the chemical substrates available to them, and thus by plant distribution? Or alternatively, are microbes independently regulated by the challenges of tolerating the freezing conditions of winter? What are microbial adaptations to low temperature, and what are their ecological consequences? These are interesting questions for basic microbial ecology, but are also important in the context of the changing Arctic. The core hypotheses of this project are: 1) the distribution of specific microbial groups is controlled primarily by plant community composition, but 2) the challenge of acclimating to winter requires changes in membrane composition, cryoprotectants, and freeze-tolerance proteins that involve physiological costs to microbes that have important implications for overall ecosystem function. Hypotheses will be tested by analyzing patterns of microbial distribution and physiology across toposequences in Alaska (low Arctic) and Greenland (high Arctic), capturing latitude and plant community variation. Seasonal changes (pre- and post-freeze, pre- and post-thaw) will be assessed by using clone library and quantitative genetic analyses (QPCR) to evaluate microbial community composition. Microbial membrane chemistry (phospholipids) and cryoprotectants (amino acids, trehalose, polyols) will be assessed by chemical analyses. Shifts in protein production patterns, including anti-freeze proteins, chaperones, and others will be assessed using proteomic techniques. This work will be supported by laboratory studies evaluating specific aspects of freezing stress: rate, temperature, and duration. It will be integrated with other studies on pan-Arctic microbial population dynamics by collaboration with the ICSU MERGE network. This will be the first ever study on how stress physiology regulates microbial distributions.