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Data release associated with the report "Trends in satellite-derived phenology in grasslands and shrublands of Southern Colorado Plateau Network parks" (2003-2022)

Published by National Park Service | Department of the Interior | Metadata Last Checked: January 25, 2026 | Last Modified: 2025-01-24T00:00:00Z
This dataset accompanies the report "Trends in satellite-derived phenology in grasslands and shrublands of Southern Colorado Plateau Network parks". The report examines daily satellite-derived vegetation index data from 2002-2022 for 12 study areas in 6 parks of the Southern Colorado Plateau Network. Data were derived from MODIS sensors onboard the Aqua and Terra satellites, using the MOD09GQ product for reflectance data and the MOD09GA product for quality screening of individual pixel values (Collection #6). Detailed processing steps are described in Norris 2020. Broadly, the processing steps were: 1) Satellite reflectance data for individual pixels within the target study areas were screened to retain only high-quality values. 2) Normalized Difference Vegetation Index (NDVI) was calculated for those values. 3) A 15-day median-smooth was applied to each pixel's complete time series 4) Median-smoothed values were only retained if there were at least three high-quality contributing values. 5) Linear interpolation filled in values across missing days. Files include: 1) Daily time series for each contributing pixel of each of the 12 study areas. This dataset includes all individual pixel locations (latitude-longitude). 2) Daily time series for the median value across all study area pixels. 3) Yearly peak values and dates-of-peak for each study area. 4) Results of daily-ranked trend analysis 5) Climate normal values for study areas from PRISM 30-year climate normals (1991-2020) 6) Historical seasonal climate values for study areas from nClimGrid data from 1940-2022.

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