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- Creator:
- Mason, Lacey A., Riseng, Catherine M., Layman, Andrew J., and Jensen, Robert
- Description:
- Wind exposure is a key physical driver of coastal systems in aquatic environments influencing circulation and wave dynamics. A measure of wind exposure is fetch, the distance over which wind can travel across open water. In large lake systems, such as the Laurentian Great Lakes, estimating fetch has proved to be difficult due to their vast size and complex topobathymetry. Here we describe the development of two spatially discrete indicators of exposure to provide a more accurate indicator of influence of wind exposure in the nearshore of the Laurentian Great Lakes. We summarized wind data from offshore buoys and leveraged existing tools to calculate effective fetch and relative exposure index (effective fetch scaled by mean wind speed) at a 30 m grid cell resolution. We validated these models by comparing our exposure maps to the U.S. Army Corps of Engineers Wave Information Studies models and found general agreement. These exposure maps are available for public download for the years 2004-2014.
- Keyword:
- GLAHF, Great Lakes, waves, fetch, REI, wind exposure, and geospatial
- Discipline:
- Science
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- Creator:
- Azari, A. R.
- Description:
- ABSTRACT: We present a statistical study of interchange injections in Saturn's inner and middle magnetosphere focusing on the dependence of occurrence rate and properties on radial distance, partial pressure, and local time distribution. Events are evaluated from over the entirety of the Cassini mission’s equatorial orbits between 2005 and 2016. We identified interchange events from CHarge Energy Mass Spectrometer (CHEMS) H+ data using a trained and tested automated algorithm, which has been compared with manual event identification for optimization. We provide estimates of interchange based on intensity, which we use to investigate current inconsistencies in local time occurrence rates. This represents the first automated detection method of interchange, estimation of injection event intensity, and comparison between interchange injection survey results. We find the peak rates of interchange occur between 7 - 9 Saturn radii and that this range coincides with the most intense events as defined by H+ partial particle pressure. We determine that nightside occurrence dominates as compared to the dayside injection rate, supporting the hypothesis of an inversely dependent instability growth rate on local Pedersen ionospheric conductivity. Additionally, we observe a slight preference for intense events on the dawn side, supporting a triggering mechanism related to large-scale injections from downtail reconnection. Our observed local time dependence paints a dynamic picture of interchange triggering due to both the large-scale injection driven process and ionospheric conductivity. Within this repository we provide a readme file (description of data file and usage) and the event list provided as a .txt file. The event list includes start and stop times, comparison to previous surveys, and the average location of events identified. Additional formats are available on request. , Further details on this method can be found in "Interchange Injections at Saturn: Statistical Survey of Energetic H+ Sudden Flux Intensifications" by Azari et al., 2018 in the Journal of Geophysical Research: Space Physics. https://doi.org/10.1029/2018JA025391. , and Curation notes: The files 'events_CORRECTED.txt' and 'readme_UPDATED.rtf' were added to this record July 31 and August 7, 2018 and supersede the previous data file 'events.txt' and readme file 'readme.rtf'. The file 'events.txt' uploaded May 9, 2018 should not be used, as this file contains a duplication error where the last column, InAllSurveys, is incorrectly presented as a duplicate of the column InAnySurvey. 'readme_UPDATED.rtf' contains additional context and updated references to the new data file.
- Keyword:
- Planetary Science, Automated Event Detection, Space Physics, Magnetospheric Physics, Interchange Injections, and Saturn
- Discipline:
- Science
-
- Creator:
- Tye, Alexander R, Wolf, Aaron S, and Niemi, Nathan A
- Description:
- Detrital zircon age distributions provide robust insights into past sedimentary systems, but these age distributions are often complex and multi-peaked, with sample sizes too small to confidently resolve population distributions. This limited sampling hinders existing quantitative methods for comparing detrital zircon age distributions, which show systematic dependence on the sizes of compared samples. The proliferation of detrital zircon studies motivates the development of more robust quantitative methods. We present the first attempt, to our knowledge, to infer probability model ensembles (PMEs) for samples of detrital zircon ages using a Bayesian method. Our method infers the parent population age distribution from which a sample is drawn, using a Monte Carlo approach to aggregate a representative set of probability models that is consistent with the constraints that the sample data provide. Using the PMEs inferred from sample data, we develop a new estimate of correspondence between detrital zircon populations called Bayesian Population Correlation (BPC). Tests of BPC on synthetic and real detrital zircon age data show that it is nearly independent from sample size bias, unlike existing correspondence metrics. Robust BPC uncertainties can be readily estimated, enhancing interpretive value. When comparing two partially overlapping zircon age populations where the shared proportion of each population is independently varied, BPC results conform almost perfectly to expected values derived analytically from probability theory. This conformity of experimental and analytical results permits direct inference of the shared proportions of two detrital zircon age populations from BPC. We provide MATLAB scripts to facilitate the procedures we describe.
- Keyword:
- provenance, statistics, zircon, Bayesian, detrital, and density estimation
- Citation to related publication:
- A.R. Tye, A.S. Wolf, N.A. Niemi, Bayesian population correlation: A probabilistic approach to inferring and comparing population distributions for detrital zircon ages, Chemical Geology, Volume 518, 2019, Pages 67-78, ISSN 0009-2541, https://doi.org/10.1016/j.chemgeo.2019.03.039
- Discipline:
- Science
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- Creator:
- Ozturk, Dogacan
- Description:
- The global magnetosphere-ionosphere-thermosphere (M-I-T) system is intrinsically coupled and susceptible to external drivers such as solar wind dynamic pressure enhancements. In order to understand the large-scale dynamic processes in the M-I-T system due to the compression from the solar wind, the 17 March 2015 sudden commencement was studied in detail using global numerical models. This data set is comprised of the simulation data generated from these models. and NOTE: The following changes were made to this dataset on March 28, 2018. First, two mp4 files were added. Second, the symbol representing "degree" was not rendering properly in the README file. The symbols were removed and replaced with the word "degree". Third, the metadata in the "methodology" and "description" fields were revised for content and clarity. On April 16, 2018 a citation to the corresponding article was added to the metadata record.
- Keyword:
- MHD model, BATS'R'US, and GITM
- Citation to related publication:
- Ozturk, D. S., Zou, S., Ridley, A. J., & Slavin, J. A. (2018). Modeling study of the geospace system response to the solar wind dynamic pressure enhancement on 17 March 2015. Journal of Geophysical Research: Space Physics, 123, 2974–2989. https://doi.org/10.1002/2017JA025099
- Discipline:
- Science
-
- Creator:
- Johnson, Jena E.
- Description:
- Note: The "Readme_Metadata" file was updated on March 15, 2018 to include a citation to the related article making use of this data and was reformatted to be presented as a pdf file rather than as a docx file. and This data set is comprised of synchrotron-based X-ray transmission and absorption spectroscopy data as well as X-ray diffraction patterns that were performed to characterize the best-preserved examples of nanoscale iron silicate mineral inclusions from 2.5 billion-year-old Banded Iron Formations (BIFs) and ferruginous cherts.
- Keyword:
- Precambrian banded iron formations and nanoparticle inclusions of iron silicates in chert
- Citation to related publication:
- Johnson, J. E., Muhling, J. R., Cosmidis, J., Rasmussen, B. & Templeton, A. S. (2018). Low-Fe(III) Greenalite Was a Primary Mineral from Neoarchean Oceans. Geophysical Research Letters, 45. https://doi.org/10.1002/2017GL076311
- Discipline:
- Science
-
- Creator:
- Flanner, Mark
- Description:
- Greenhouse gas (GHG) additions to Earth’s atmosphere initially reduce global outgoing longwave radiation (OLR), thereby warming the planet. In select environments with temperature inversions, however, increased GHG concentrations can actually increase local OLR. Negative top-of-atmosphere and effective radiative forcing (ERF) from this situation give the impression that local surface temperatures could cool in response to GHG increases. Here we consider an extreme scenario in which GHG concentrations are increased only within the warmest layers of winter near-surface inversions of the Arctic and Antarctic. We find, using a fully coupled Earth system model, that the underlying surface warms despite the GHG addition exerting negative ERF and cooling the troposphere in the vicinity of the GHG increase. This unique radiative forcing and thermal response is facilitated by the high stability of the polar winter atmosphere, which inhibits thermal mixing and amplifies the impact of surface radiative forcing on surface temperature. These findings also suggest that strategies to exploit negative ERF via injections of short-lived GHGs into inversion layers would likely be unsuccessful in cooling the planetary surface. and Note: A revised data description file was added to this work on April 11, 2018 containing additional information about the data set than was provided in the original description. Additional keywords and a full citation to the related article were added as well.
- Keyword:
- climate, greenhouse gas, polar inversion layers, radiative forcing (and/or effective radiative forcing), and MODTRAN simulation
- Discipline:
- Science
-
- Creator:
- Forrest, Stephen R., Panda, Anurag, Qu, Yue, Che, Xiaozhou, Coburn, Caleb, and Burlingame, Quinn
- Description:
- Mathematica Diffusion Simulation: Programmed by Coburn, Caleb. Simulation of diffusion in organic heterostructures, including least square fits and statistical goodness of fit analysis. Used to calculate fits to transient data in Fig 1, 3 and Extended Data Fig.2. Example data file included for download Matlab Montecarlo simulation: Programmed by Coburn, Caleb. Montecarlo simulation of charge diffusion on a cubic lattice to determine lateral diffusion length as a function of barrier height, assuming thermionic emission over the barrier. Matlab 2D Diffusion Simulation:Programmed by Coburn, Caleb. Modified from BYU Physics 430 Course Manual. Simulates diffusion around a film discontinuity, such a cut. Used to generate fits to Extended Data Fig. 1
- Keyword:
- Organic semiconductors and Charge diffusion
- Citation to related publication:
- Burlingame, Q., Coburn, C., Che, X., Panda, A., Qu, Y., & Forrest, S. R. (2018). Centimetre-scale electron diffusion in photoactive organic heterostructures. Nature, 554(7690), 77-80. https://doi.org/10.1038/nature25148
- Discipline:
- Science
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- Creator:
- Blesh, Jennifer and King, Alison E.
- Description:
- This dataset contains three data files used in: King, A.E. and J. Blesh, 2017. Crop rotations for increased soil carbon: perenniality as a guiding principle. Ecological Applications. There are also three corresponding metadata files. The file “CRMA 2017 Main.csv” contains data for the control and treatment rotations used to construct pairwise comparisons for meta-analysis, response ratios calculated for soil organic carbon concentration, and change in carbon input. The dataset also includes management, soil, and other environmental characteristics for each site. The file “CRMA 2017 Diversity x Nitrogen.csv” contains data used to test whether N fertilizer inputs mediated the effect of functional diversity on SOC concentrations. The file “CRMA Annual grain.csv” contains data used to test for effects of crop rotation species diversity (one vs. two species, or two vs. three species) on SOC concentrations and C input (i.e., for the “grain-only” rotations). The dataset also includes management, soil, and other environmental characteristics for each site. The corresponding metadata files: “CRMA 2017 Main_metadata.csv”, “CRMA 2017 Diversity x Nitrogen_metadata.csv”, and “CRMA Annual grain _metadata.csv” provide a detailed description of all variables in each dataset. Note: On Jan 12, 2018 the following information was added to the three metadata files: the name of the data file the metadata refers to, an explanation as to the meaning of blank cells in the data file, a full citation to the paper where the author describes her findings and contact information for the author.
- Keyword:
- soil carbon, functional diversity, meta-analysis, cropping system, and student-friendly
- Discipline:
- Science
-
- Creator:
- Steiner, Allison and Kawecki, Stacey
- Description:
- WRF-Chem model
- Keyword:
- aerosols and weather
- Citation to related publication:
- Kawecki, S., Steiner, A.L., 2018. The Influence of Aerosol Hygroscopicity on Precipitation Intensity During a Mesoscale Convective Event. Journal of Geophysical Research: Atmospheres 123, 424–442. https://doi.org/10.1002/2017JD026535
- Discipline:
- Science
-
- Creator:
- Engel, Daniel D. , Evans, Mary Anne, Low, Bobbi S., and Schaeffer, Jeff
- Description:
- This dataset was compiled as an attempt to understand how natural resource managers and research ecologists in the Great Lakes region integrate the ecosystem services (ES) paradigm into their work. The following text is the adapted abstract from a thesis associated with this data. Ecosystem services, or the benefits people obtain from ecosystems, have gained much momentum in natural resource management in recent decades as a relatively comprehensive approach to provide quantitative tools for improving decision-making and policy design. However, to date we know little about whether and how natural resource practitioners, from natural resource managers to research ecologists (hereafter managers and ecologists respectively), have adopted the ES paradigm into their respective work. Here, we addressed this knowledge gap by asking managers and ecologists about whether and how they have adopted the ES paradigm into their respective work. First, we surveyed federal, state, provincial and tribal managers in the Great Lakes region about their perception and use of ES as well as the relevance of specific services to their work. Although results indicate that fewer than 31% of the managers said they currently consider economic values of ES, 79% of managers said they would use economic information on ES if they had access to it. Additionally, managers reported that ES-related information was generally inadequate for their resource management needs. We also assessed managers by dividing them into identifiable groups (e.g. managers working in different types of government agencies or administrative levels) to evaluate differential ES integration. Overall, results suggest a desire among managers to transition from considering ES concepts in their management practices to quantifying economic metrics, indicating a need for practical and accessible valuation techniques. Due to a sample of opportunity at the USGS Great Lakes Science Center (GLSC), we also evaluated GLSC research ecologists’ integration of the ES paradigm because they play an important role by contributing requisite ecological knowledge for ES models. Managers and ecologists almost unanimously agreed that it was appropriate to consider ES in resource management and also showed convergence on the high priority ES. However, ecologists appeared to overestimate the adequacy of ES-related information they provide as managers reported the information was inadequate for their needs. This divergence may reflect an underrepresentation of ecological economists in this system who can aid in translating ecological models into estimates of human well-being. As a note, the dataset for the research ecologists has had some data removed as it could be considered personally identifiable information due to the small sample size in that population. The surveys associated with both datasets have also been included in PDF format. Curation Notes: Three files were added to the data set on Dec 21, 2017. Two csv files: "Ecosystem services and Research Ecologists - Data Index.csv" and "Ecosystem services and Research Managers - Data Index.csv" and one text file: "Ecosystem Services Adoption Readme.txt". The file names of the original four files were altered to replace an ampersand with the word "and".
- Keyword:
- Research Ecologist, Decision-Making, Ecosystem Services, Natural Resource Management, Paradigm Adoption, and Ecological Economics
- Citation to related publication:
- Engel, D.D., Evans, M.A., Low, B.S., Schaeffer, J. (2017) “Understanding Ecosystem Services Adoption by Natural Resource Managers and Research Ecologists.” Journal of Great Lakes Research, 43(3), 169-179. https://doi.org/10.1016/j.jglr.2017.01.005
- Discipline:
- Science and Social Sciences