High-latitude regions have been warming rapidly since the last century, at a rate higher than the global average. At continental scales, satellite data since the 1980s have indicated increased vegetation productivity (greening) across northern high latitudes, and a productivity decline (browning) for certain areas of undisturbed boreal forest of Canada and Alaska. These remote sensing results have been corroborated by in-situ evidence. This research provides a spatially complete view of the vegetation greenness change for all of Canada and Alaska by calculating per-pixel NDVI trend from all available 1984-2012 peak-summer Landsat-5 and -7 surface reflectance data. By incorporating observations from overlapping scenes, researchers obtained up to 160 valid NDVI values for certain areas from this 29-year period, establishing the mid-Summer greenness trend. This animation shows the resulting greenness trend over Canada and Alaska with special attention focused on the regions of Quebec and northern Alaska.
from NASA's Scientific Visualization Studio: Most Recent Items http://ift.tt/1Zll9BX
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