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We introduce a density-aided clustering method called Skeleton Clustering that can detect clusters in multivariate and even high-dimensional data with irregular shapes. To bypass the curse of dimensionality, we propose surrogate density measures that are less dependent on the dimension but have intuitive geometric interpretations. The clustering framework constructs a concise representation of the given data as an intermediate step and can be thought of as a combination of prototype methods, density-based clustering, and hierarchical clustering. We show by theoretical analysis and empirical studies that the skeleton clustering leads to reliable clusters in multivariate and high-dimensional scenarios. Supplementary materials for this article are available online.
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This dataset contains data collected during a study "Understanding the development of public data ecosystems: from a conceptual model to a six-generation model of the evolution of public data ecosystems" conducted by Martin Lnenicka (University of Hradec Králové, Czech Republic), Anastasija Nikiforova (University of Tartu, Estonia), Mariusz Luterek (University of Warsaw, Warsaw, Poland), Petar Milic (University of Pristina - Kosovska Mitrovica, Serbia), Daniel Rudmark (Swedish National Road and Transport Research Institute, Sweden), Sebastian Neumaier (St. Pölten University of Applied Sciences, Austria), Karlo Kević (University of Zagreb, Croatia), Anneke Zuiderwijk (Delft University of Technology, Delft, the Netherlands), Manuel Pedro Rodríguez Bolívar (University of Granada, Granada, Spain).
As there is a lack of understanding of the elements that constitute different types of value-adding public data ecosystems and how these elements form and shape the development of these ecosystems over time, which can lead to misguided efforts to develop future public data ecosystems, the aim of the study is: (1) to explore how public data ecosystems have developed over time and (2) to identify the value-adding elements and formative characteristics of public data ecosystems. Using an exploratory retrospective analysis and a deductive approach, we systematically review 148 studies published between 1994 and 2023. Based on the results, this study presents a typology of public data ecosystems and develops a conceptual model of elements and formative characteristics that contribute most to value-adding public data ecosystems, and develops a conceptual model of the evolutionary generation of public data ecosystems represented by six generations called Evolutionary Model of Public Data Ecosystems (EMPDE). Finally, three avenues for a future research agenda are proposed.
This dataset is being made public both to act as supplementary data for "Understanding the development of public data ecosystems: from a conceptual model to a six-generation model of the evolution of public data ecosystems ", Telematics and Informatics*, and its Systematic Literature Review component that informs the study.
Description of the data in this data set
PublicDataEcosystem_SLR provides the structure of the protocol
Spreadsheet#1 provides the list of results after the search over three indexing databases and filtering out irrelevant studies
Spreadsheets #2 provides the protocol structure.
Spreadsheets #3 provides the filled protocol for relevant studies.
The information on each selected study was collected in four categories:(1) descriptive information,(2) approach- and research design- related information,(3) quality-related information,(4) HVD determination-related information
Descriptive Information
Article number
A study number, corresponding to the study number assigned in an Excel worksheet
Complete reference
The complete source information to refer to the study (in APA style), including the author(s) of the study, the year in which it was published, the study's title and other source information.
Year of publication
The year in which the study was published.
Journal article / conference paper / book chapter
The type of the paper, i.e., journal article, conference paper, or book chapter.
Journal / conference / book
Journal article, conference, where the paper is published.
DOI / Website
A link to the website where the study can be found.
Number of words
A number of words of the study.
Number of citations in Scopus and WoS
The number of citations of the paper in Scopus and WoS digital libraries.
Availability in Open Access
Availability of a study in the Open Access or Free / Full Access.
Keywords
Keywords of the paper as indicated by the authors (in the paper).
Relevance for our study (high / medium / low)
What is the relevance level of the paper for our study
Approach- and research design-related information
Approach- and research design-related information
Objective / Aim / Goal / Purpose & Research Questions
The research objective and established RQs.
Research method (including unit of analysis)
The methods used to collect data in the study, including the unit of analysis that refers to the country, organisation, or other specific unit that has been analysed such as the number of use-cases or policy documents, number and scope of the SLR etc.
Study’s contributions
The study’s contribution as defined by the authors
Qualitative / quantitative / mixed method
Whether the study uses a qualitative, quantitative, or mixed methods approach?
Availability of the underlying research data
Whether the paper has a reference to the public availability of the underlying research data e.g., transcriptions of interviews, collected data etc., or explains why these data are not openly shared?
Period under investigation
Period (or moment) in which the study was conducted (e.g., January 2021-March 2022)
Use of theory / theoretical concepts / approaches? If yes, specify them
Does the study mention any theory / theoretical concepts / approaches? If yes, what theory / concepts / approaches? If any theory is mentioned, how is theory used in the study? (e.g., mentioned to explain a certain phenomenon, used as a framework for analysis, tested theory, theory mentioned in the future research section).
Quality-related information
Quality concerns
Whether there are any quality concerns (e.g., limited information about the research methods used)?
Public Data Ecosystem-related information
Public data ecosystem definition
How is the public data ecosystem defined in the paper and any other equivalent term, mostly infrastructure. If an alternative term is used, how is the public data ecosystem called in the paper?
Public data ecosystem evolution / development
Does the paper define the evolution of the public data ecosystem? If yes, how is it defined and what factors affect it?
What constitutes a public data ecosystem?
What constitutes a public data ecosystem (components & relationships) - their "FORM / OUTPUT" presented in the paper (general description with more detailed answers to further additional questions).
Components and relationships
What components does the public data ecosystem consist of and what are the relationships between these components? Alternative names for components - element, construct, concept, item, helix, dimension etc. (detailed description).
Stakeholders
What stakeholders (e.g., governments, citizens, businesses, Non-Governmental Organisations (NGOs) etc.) does the public data ecosystem involve?
Actors and their roles
What actors does the public data ecosystem involve? What are their roles?
Data (data types, data dynamism, data categories etc.)
What data do the public data ecosystem cover (is intended / designed for)? Refer to all data-related aspects, including but not limited to data types, data dynamism (static data, dynamic, real-time data, stream), prevailing data categories / domains / topics etc.
Processes / activities / dimensions, data lifecycle phases
What processes, activities, dimensions and data lifecycle phases (e.g., locate, acquire, download, reuse, transform, etc.) does the public data ecosystem involve or refer to?
Level (if relevant)
What is the level of the public data ecosystem covered in the paper? (e.g., city, municipal, regional, national (=country), supranational, international).
Other elements or relationships (if any)
What other elements or relationships does the public data ecosystem consist of?
Additional comments
Additional comments (e.g., what other topics affected the public data ecosystems and their elements, what is expected to affect the public data ecosystems in the future, what were important topics by which the period was characterised etc.).
New papers
Does the study refer to any other potentially relevant papers?
Additional references to potentially relevant papers that were found in the analysed paper (snowballing).
Format of the file.xls, .csv (for the first spreadsheet only), .docx
Licenses or restrictionsCC-BY
For more info, see README.txt
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The empirical quantiles of independent data provide a good summary of the underlying distribution of the observations. For high-dimensional time series defined in two dimensions, such as in space and time, one can define empirical quantiles of all observations at a given time point, but such time-wise quantiles can only reflect properties of the data at that time point. They often fail to capture the dynamic dependence of the data. In this article, we propose a new definition of empirical dynamic quantiles (EDQ) for high-dimensional time series that mitigates this limitation by imposing that the quantile must be one of the observed time series. The word dynamic emphasizes the fact that these newly defined quantiles capture the time evolution of the data. We prove that the EDQ converge to the time-wise quantiles under some weak conditions as the dimension increases. A fast algorithm to compute the dynamic quantiles is presented and the resulting quantiles are used to produce summary plots for a collection of many time series. We illustrate with two real datasets that the time-wise and dynamic quantiles convey different and complementary information. We also briefly compare the visualization provided by EDQ with that obtained by functional depth. The R code and a vignette for computing and plotting EDQ are available athttps://github.com/dpena157/HDts/.
CC0 1.0 Universal Public Domain Dedicationhttps://creativecommons.org/publicdomain/zero/1.0/
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The random Lorentz gas (RLG) is a minimal model for transport in disordered media. Despite the broad relevance of the model, theoretical grasp over its properties remains weak. For instance, the scaling with dimension $d$ of its localization transition at the void percolation threshold is not well controlled analytically nor computationally. A recent study [Biroli et al. Phys. Rev. E 103, L030104 (2021)] of the caging behavior of the RLG motivated by the mean-field theory of glasses has uncovered physical inconsistencies in that scaling that heighten the need for guidance. Here, we first extend analytical expectations for asymptotic high-d bounds on the void percolation threshold, and then computationally evaluate both the threshold and its criticality in various d. In high-d systems, we observe that the standard percolation physics is complemented by a dynamical slowdown of the tracer dynamics reminiscent of mean-field caging. A simple modification of the RLG is found to bring the interplay between percolation and mean-field-like caging down to d=3. ... [Read More]
This dataset provides monthly-averaged ocean three-dimensional salinity fluxes on the native Lat-Lon-Cap 90 (LLC90) model grid from the ECCO Version 4 Release 4 (V4r4) ocean and sea-ice state estimate. Estimating the Circulation and Climate of the Ocean (ECCO) ocean and sea-ice state estimates are dynamically and kinematically-consistent reconstructions of the three-dimensional time-evolving ocean, sea-ice, and surface atmospheric states. ECCO V4r4 is a free-running solution of the 1-degree global configuration of the MIT general circulation model (MITgcm) that has been fit to observations in a least-squares sense. Observational data constraints used in V4r4 include sea surface height and model sea level anomaly (SSH) from satellite altimeters [ERS-1/2, TOPEX/Poseidon, GFO, ENVISAT, Jason-1,2,3, CryoSat-2, and SARAL/AltiKa]; sea surface temperature (SST) from satellite radiometers [AVHRR], sea surface salinity (SSS) from the Aquarius satellite radiometer/scatterometer, ocean bottom pressure (OBP) from the GRACE satellite gravimeter; sea ice concentration from satellite radiometers [SSM/I and SSMIS], and in-situ ocean temperature and salinity measured with conductivity-temperature-depth (CTD) sensors and expendable bathythermographs (XBTs) from several programs [e.g., WOCE, GO-SHIP, Argo, and others] and platforms [e.g., research vessels, gliders, moorings, ice-tethered profilers, and instrumented pinnipeds]. V4r4 covers the period 1992-01-01T12:00:00 to 2018-01-01T00:00:00.
U.S. Government Workshttps://www.usa.gov/government-works
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This dataset includes the one-dimensional HEC-RAS water quality model simulation input and output files for two simulation discharges at the Lazy Day (LD) reach on the Big Piney River near St. Robert, Missouri. Simulations were run for environmental DNA (eDNA) sample collection dates on July 07, 2020 and July 23, 2021. For each eDNA collection date, the transport of freshwater mussel eDNA from Cumberlandia monodonta was simulated by specifying eDNA as an arbitrary constituent in the HEC-RAS water quality module and assigning a first order rate of decay. To account for the variation of the eDNA field samples at the upstream boundary condition, as well as the laboratory derived decay constants, we ran three model simulations for each eDNA collection date: a) the mean eDNA concentration at the upstream boundary with the mean decay constant (k), b) the mean eDNA concentration at the upstream boundary plus 1SE with the mean k minus 1SE, and c) the mean eDNA concentration at the upstrea ...
This model archive contains the data and software application used to develop a two-dimensional hydrodynamic model of a 1.2 kilometer reach of the North Santiam River in Oregon. The Delft3D-Flexible Mesh modeling system was used to simulate flow conditions at a baseflow discharge of 25 cubic meters per second and thus provide spatially distributed predictions of depth and velocity throughout the reach. This model archive consists of four individual components: (1) information on the hydrodynamic model software application; (2) the topographic data used to construct the model grid and field measurements of water depth used to calibrate the model; (3) complete Delft3D model runs, including both the required inputs and the resulting output, for various values of the ks parameter used to represent hydraulic roughness. The model was calibrated by choosing the ks value that minimized the error in model predictions of water depth relative to depth measurements made in the field. A file listing the depth mean error and root-mean-squared error associated with the model run for each of the ks value is provided as a summary of the calibration; and 4) the input parameters used for the final model run used in the main study this model archive is intended to support, along with the final, complete Delft3D model run, including both the required inputs and the resulting output. All of the files listed below are available for download in the "Attached Files" section of this page. 1. The Delft3D hydrodynamic model application can be obtained from Deltares via this link: https://www.deltares.nl/en/software-and-data/products/delft3d-flexible-mesh-suite 2. The topographic data used to construct the model grid are provided in the file "NsrBedLevel.csv" and the field measurements of water depth used for model calibration are provided in the file "NsrDepthData.csv". 3. Complete Delft3D model runs, including both the required inputs and the resulting output, for various values of the ks parameter used to represent hydraulic roughness. These model runs are provided in the files "Calibration_ks_0p09.zip", "Calibration_ks_0p12.zip", "Calibration_ks_0p15.zip", and "Calibration_ks_0p18.zip", which correspond to simulations based on ks values of 0.09, 0.12, 0.15, and 0.18 m, respectively. Each of these zip files contains a *.dsproj project file that can be opened in the Delft3D hydrodynamic model software application. The corresponding *dsproj_data folders have separate subfolders for model input and model output. Please refer to the metadata for further information. The model was calibrated by choosing the ks value that minimized the error in model predictions of water depth relative to depth measurements made in the field. The file "delft3d_Calibration.csv" lists the depth mean error and root-mean-squared error associated with the model run for each of the ks value and is provided as a summary of the calibration. 4. The input parameters used for the final model run used in the main study this model archive is intended to support are provided in the file "Nsr_Delft3D_inputs.csv". The complete Delft3D model for the final run, including both the required inputs and the resulting output, is in the file "Calibration_ks_0p12.zip". In addition, a simple text file "FinalModelOutput.csv" with the output extracted from the Delft3D model run, with columns for the x and y coordinates, u (x-direction) and v (y-direction) velocity vector components, and depths. Units are meters for coordinates and depths and meters per second for velocity vector components.
This dataset provides daily-averaged ocean three-dimensional momentum tendency on the native Lat-Lon-Cap 90 (LLC90) model grid from the ECCO Version 4 Release 4 (V4r4) ocean and sea-ice state estimate. Estimating the Circulation and Climate of the Ocean (ECCO) ocean and sea-ice state estimates are dynamically and kinematically-consistent reconstructions of the three-dimensional time-evolving ocean, sea-ice, and surface atmospheric states. ECCO V4r4 is a free-running solution of the 1-degree global configuration of the MIT general circulation model (MITgcm) that has been fit to observations in a least-squares sense. Observational data constraints used in V4r4 include sea surface height and model sea level anomaly (SSH) from satellite altimeters [ERS-1/2, TOPEX/Poseidon, GFO, ENVISAT, Jason-1,2,3, CryoSat-2, and SARAL/AltiKa]; sea surface temperature (SST) from satellite radiometers [AVHRR], sea surface salinity (SSS) from the Aquarius satellite radiometer/scatterometer, ocean bottom pressure (OBP) from the GRACE satellite gravimeter; sea ice concentration from satellite radiometers [SSM/I and SSMIS], and in-situ ocean temperature and salinity measured with conductivity-temperature-depth (CTD) sensors and expendable bathythermographs (XBTs) from several programs [e.g., WOCE, GO-SHIP, Argo, and others] and platforms [e.g., research vessels, gliders, moorings, ice-tethered profilers, and instrumented pinnipeds]. V4r4 covers the period 1992-01-01T12:00:00 to 2018-01-01T00:00:00.
M2TCNPLTM (or tavgC_3d_ltm_Np) is a 3-dimensional monthly data collection for climatological long term mean and standard deviation representing the interannual variability on a monthly timescale, derived from monthly Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) datasets. V2 of this data collection is calculated with data from January 1991 to December 2020. In contrast, V1, the original version, is computed with data from an earlier 30-year time of 1981-2010.This collection consists of meteorological diagnostics at 12 vertical pressure levels (e.g.,850 hPa, 500hPa, and 200 hPa), such as air temperature, wind components, and both relative and specific humidity. MERRA-2 is the latest version of global atmospheric reanalysis for the satellite era produced by the NASA Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980-present, with a latency of ~3 weeks after the end of the previous month.Data Reprocessing: Please check “Records of MERRA-2 Data Reprocessing and Service Changes”, linked from the “Documentation” tab on this page. Note that a reprocessed data filename is different from the original filename.MERRA-2 Mailing List: Sign up to receive information on reprocessing of data, changes to tools and services, as well as data announcements from GMAO. Contact the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov) to be added to the list.Questions: If you have a question, please read the "MERRA-2 File Specification Document'', “MERRA-2 Data Access – Quick Start Guide”, and FAQs linked from the ”Documentation” tab on this page for more information. If these documents do not answer your question, you may post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov).
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In this article, we consider sufficient dimension folding for the regression mean function when predictors are matrix- or array-valued. We propose a new concept named central mean dimension folding subspace and its two local estimation methods: folded outer product of gradients estimation (folded-OPG) and folded minimum average variance estimation (folded-MAVE). We establish the asymptotic properties for folded-MAVE. A modified BIC criterion is used to determine the dimensions of the central mean dimension folding subspace. We evaluate the performances of the two local estimation methods by simulated examples and demonstrate the efficacy of folded-MAVE in finite samples. And in particular, we apply our methods to analyze a longitudinal study of primary biliary cirrhosis. Supplementary materials for this article are available online.
Attribution-ShareAlike 3.0 (CC BY-SA 3.0)https://creativecommons.org/licenses/by-sa/3.0/
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Dataset will be under an embargo until June 1, 2021. Data to accompany Rajala, K., M. G. Sorice, and V. Thomas. 2020. The meaning(s) of place: Identifying the structure of sense of place across a social-ecological landscape in the journal, People and Nature. Details on sampling, data management, and data analysis are detailed in the journal article including extensive supplemental materials provided at the journal's website. Because the article is freely available (i.e., open access), the details are not replicated here. Files: padata - a csv file that includes the composite dependent variable, place attachment, and 38 other meanings. pavars – a csv file that contains the names of each variable in the dataset with a brief label.
Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
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Additional file 2. R Code. All of the R scripts used for the analysis in “Analyzing health insurance coverage using the 2015 planningdatabase†section.
The Modern Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) contains a wealth of information that can be used for weather and climate studies. By combining the assimilation of observations with a frozen version of the Goddard Earth Observing System (GEOS), a global analysis is produced at an hourly temporal resolution spanning from January 1980 through present (Gelaro et al., 2017). It can be difficult to parse through a multidecadal dataset such as MERRA-2 to evaluate the interannual variability of weather that occurs on a daily timescale, let alone determine the occurrence of an extreme weather event. This data collection is a climatological long term mean and standard deviation representing the interannual variability on a monthly timescale. Find the product File Specific, Readme, References, and data tools under "Documentation" tab. Sign up for the MERRA-2 mailing list to receive announcements on the latest data information, tools and services that become available, data announcements from GMAO MERRA-2 project and more! Contact the GES DISC User Services (gsfc-dl-help-disc@mail.nasa.gov) to be added to the list.
Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
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The data files in this collection are associated with the paper "Universal Non-Debye Scaling in the Density of States of Amorphous Solids", A. Poncet, P. Charbonneau, E. I. Corwin, G. Parisi, and F. Zamponi, PRL, 2016. They include .dat, .pdf, .gnu, .eps and .gle files with associated raw data and generating scripts to allow for replication of the figures. At the jamming transition, amorphous packings are known to display anomalous vibrational modes with a density of states (DOS) that remains constant at low frequency. The scaling of the DOS at higher packing fractions remains, however, unclear. One might expect to find simple Debye scaling, but recent results from effective medium theory and the exact solution of mean-field models both predict an anomalous, non-Debye scaling. Being mean-field solutions, however, these solutions are only strictly valid in the limit of infinite spatial dimension, and it is unclear what value they have for finite-dimensional systems. Here, we study packings of soft spheres in dimensions 3 through 7 and find, away from jamming, a universal non-Debye scaling of the DOS that is consistent with the mean-field predictions. We also consider how the soft mode participation ratio converges to the mean-field prediction as dimension increases. ... [Read More]
The Modern Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) contains a wealth of information that can be used for weather and climate studies. By combining the assimilation of observations with a frozen version of the Goddard Earth Observing System (GEOS), a global analysis is produced at an hourly temporal resolution spanning from January 1980 through present (Gelaro et al., 2017). It can be difficult to parse through a multidecadal dataset such as MERRA-2 to evaluate the interannual variability of weather that occurs on a daily timescale, let alone determine the occurrence of an extreme weather event. This data collection is a climatological long term mean and standard deviation representing the interannual variability on a monthly timescale.
Find the product File Specific, Readme, References, and data tools under "Documentation" tab.
Sign up for the MERRA-2 mailing list to receive announcements on the latest data information, tools and services that become available, data announcements from GMAO MERRA-2 project and more! Contact the GES DISC User Services (gsfc-help-disc@lists.nasa.gov) to be added to the list.
Attribution-NonCommercial-ShareAlike 4.0 (CC BY-NC-SA 4.0)https://creativecommons.org/licenses/by-nc-sa/4.0/
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This data includes validation of the reliability and validity of two self-designed scales, namely the Marriage and Childbearing Meaning Scale and the Marriage and Childbearing Intention Scale, both of which contain two dimensions. The Marriage and Childbearing Meaning Scale includes dimensions of marriage and fertility, while the Marriage and Childbearing Intention Scale includes dimensions of marriage and fertility. Two scales each have 20 questions, and we also collected demographic variables of gender and age.
M2TMNPQDT (or tavgM_3d_qdt_Np) is a 3-dimensional monthly mean data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of assimilations of moist tendencies on the 42 pressure levels, such as tendency of ice (or liquid) water due to dynamics, total ice (or liquid) water tendency due to moist, total specific humidity analysis tendency, and specific humidity tendency due to moist. The information on the pressure levels can be found in the section 4.2 of the MERRA-2 File Specification document. The collection also includes variance of certain parameters.MERRA-2 is the latest version of global atmospheric reanalysis for the satellite era produced by NASA Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980-present with the latency of ~3 weeks after the end of a month. Data Reprocessing: Please check “Records of MERRA-2 Data Reprocessing and Service Changes” linked from the “Documentation” tab on this page. Note that a reprocessed data filename is different from the original file.MERRA-2 Mailing List: Sign up to receive information on reprocessing of data, changing of tools and services, as well as data announcements from GMAO. Contact the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov) to be added to the list.Questions: If you have a question, please read "MERRA-2 File Specification Document", “MERRA-2 Data Access – Quick Start Guide”, and FAQs linked from the ”Documentation” tab on this page. If that does not answer your question, you may post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov).
This dataset provides monthly-averaged ocean three-dimensional salinity fluxes on the native Lat-Lon-Cap 90 (LLC90) model grid from the ECCO Version 4 Release 4 (V4r4) ocean and sea-ice state estimate. Estimating the Circulation and Climate of the Ocean (ECCO) ocean and sea-ice state estimates are dynamically and kinematically-consistent reconstructions of the three-dimensional time-evolving ocean, sea-ice, and surface atmospheric states. ECCO V4r4 is a free-running solution of the 1-degree global configuration of the MIT general circulation model (MITgcm) that has been fit to observations in a least-squares sense. Observational data constraints used in V4r4 include sea surface height and model sea level anomaly (SSH) from satellite altimeters [ERS-1/2, TOPEX/Poseidon, GFO, ENVISAT, Jason-1,2,3, CryoSat-2, and SARAL/AltiKa]; sea surface temperature (SST) from satellite radiometers [AVHRR], sea surface salinity (SSS) from the Aquarius satellite radiometer/scatterometer, ocean bottom pressure (OBP) from the GRACE satellite gravimeter; sea ice concentration from satellite radiometers [SSM/I and SSMIS], and in-situ ocean temperature and salinity measured with conductivity-temperature-depth (CTD) sensors and expendable bathythermographs (XBTs) from several programs [e.g., WOCE, GO-SHIP, Argo, and others] and platforms [e.g., research vessels, gliders, moorings, ice-tethered profilers, and instrumented pinnipeds]. V4r4 covers the period 1992-01-01T12:00:00 to 2018-01-01T00:00:00.
M2TMNPUDT (or tavgM_3d_udt_Np) is a 3-dimensional monthly mean data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of assimilations of wind tendencies on 42 pressure levels, such as total eastward (or northward) wind analysis tendency, tendency of eastward (or northward) wind due to dynamics, and tendency of eastward (or northward) wind due to turbulence. The information on the pressure levels can be found in the section 4.2 of the MERRA-2 File Specification document. The collection also includes variance of certain parameters.MERRA-2 is the latest version of global atmospheric reanalysis for the satellite era produced by NASA Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980-present with the latency of ~3 weeks after the end of a month. Data Reprocessing: Please check “Records of MERRA-2 Data Reprocessing and Service Changes” linked from the “Documentation” tab on this page. Note that a reprocessed data filename is different from the original file.MERRA-2 Mailing List: Sign up to receive information on reprocessing of data, changing of tools and services, as well as data announcements from GMAO. Contact the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov) to be added to the list.Questions: If you have a question, please read "MERRA-2 File Specification Document", “MERRA-2 Data Access – Quick Start Guide”, and FAQs linked from the ”Documentation” tab on this page. If that does not answer your question, you may post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov).
This dataset provides monthly-averaged ocean three-dimensional potential temperature fluxes on the native Lat-Lon-Cap 90 (LLC90) model grid from the ECCO Version 4 Release 4 (V4r4) ocean and sea-ice state estimate. Estimating the Circulation and Climate of the Ocean (ECCO) ocean and sea-ice state estimates are dynamically and kinematically-consistent reconstructions of the three-dimensional time-evolving ocean, sea-ice, and surface atmospheric states. ECCO V4r4 is a free-running solution of the 1-degree global configuration of the MIT general circulation model (MITgcm) that has been fit to observations in a least-squares sense. Observational data constraints used in V4r4 include sea surface height and model sea level anomaly (SSH) from satellite altimeters [ERS-1/2, TOPEX/Poseidon, GFO, ENVISAT, Jason-1,2,3, CryoSat-2, and SARAL/AltiKa]; sea surface temperature (SST) from satellite radiometers [AVHRR], sea surface salinity (SSS) from the Aquarius satellite radiometer/scatterometer, ocean bottom pressure (OBP) from the GRACE satellite gravimeter; sea ice concentration from satellite radiometers [SSM/I and SSMIS], and in-situ ocean temperature and salinity measured with conductivity-temperature-depth (CTD) sensors and expendable bathythermographs (XBTs) from several programs [e.g., WOCE, GO-SHIP, Argo, and others] and platforms [e.g., research vessels, gliders, moorings, ice-tethered profilers, and instrumented pinnipeds]. V4r4 covers the period 1992-01-01T12:00:00 to 2018-01-01T00:00:00.
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We introduce a density-aided clustering method called Skeleton Clustering that can detect clusters in multivariate and even high-dimensional data with irregular shapes. To bypass the curse of dimensionality, we propose surrogate density measures that are less dependent on the dimension but have intuitive geometric interpretations. The clustering framework constructs a concise representation of the given data as an intermediate step and can be thought of as a combination of prototype methods, density-based clustering, and hierarchical clustering. We show by theoretical analysis and empirical studies that the skeleton clustering leads to reliable clusters in multivariate and high-dimensional scenarios. Supplementary materials for this article are available online.