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    • ABoVE: NDVI Trends across Alaska and Canada from Landsat, 1984-2012

    Metadata Updated: December 6, 2023

    This dataset provides the summer NDVI trend and trend significance for the period 1984-2012 over Alaska and Canada. The NDVI were calculated per-pixel from all available peak-summer 30-m Landsat 5 and 7 surface reflectance data for the period. NDVI time series were assembled for each 30-m land location (i.e., non-water, non-snow), from observations that were unaffected by clouds as indicated by data-quality masks and following additional processing to remove anomalous NDVI values. A simple linear regression via ordinary least squares was applied to the per-pixel NDVI time series. The slope of the regression was taken as the annual NDVI trend (unit NDVI change per year) and is reported in the "trend" data files. A Student's t-test was used to assess the significance of the trend and the per-pixel significance is reported in the "trend_sig" data files. A significant positive slope indicates a greening trend, and a significant negative slope indicates a browning trend.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Created Date December 1, 2022
    Metadata Updated Date December 6, 2023

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Graphic Preview

    Figure 1: NDVI trends derived from 30-m Landsat NDVI times series for 1984-2012 for Canada and Alaska (Ju and Masek, 2016).

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date December 1, 2022
    Metadata Updated Date December 6, 2023
    Publisher ORNL_DAAC
    Maintainer
    Identifier C2162131333-ORNL_CLOUD
    Data First Published 2019-03-14
    Language en-US
    Data Last Modified 2023-06-12
    Category ABoVE, geospatial
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Metadata Catalog ID https://data.nasa.gov/data.json
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Citation Ju, J., and J.G. Masek. 2018. ABoVE: NDVI Trends across Alaska and Canada from Landsat, 1984-2012. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1576
    Graphic Preview Description Figure 1: NDVI trends derived from 30-m Landsat NDVI times series for 1984-2012 for Canada and Alaska (Ju and Masek, 2016).
    Graphic Preview File https://daac.ornl.gov/ABOVE/guides/Vegetation_greenness_trend_Fig1.png
    Harvest Object Id aea35974-f8b4-45fb-809e-3cb8c251b6c2
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://doi.org/10.3334/ORNLDAAC/1576
    Metadata Type geospatial
    Old Spatial -169.97 41.61 -50.17 80.51
    Program Code 026:001
    Source Datajson Identifier True
    Source Hash 0d072144633cc52b804f66fa6a47d339e8ac7c1835e1da57831f52bc8c711343
    Source Schema Version 1.1
    Spatial
    Temporal 1984-01-01T00:00:00Z/2012-12-31T23:59:59Z

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