Vegetation Greening Trend in Canada and Alaska: 1984-2012
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.
Please give credit for this item to:
NASA's Scientific Visualization Studio
Papers used in this visualization
Datasets used in this visualization
Landsat Landsat NDVI Trend (1984–2012)ID: 9341984-2012
This research used a nominal peak greenness period, July 1 to August 31, to accommodate tundra of all regions for Landsat data selection. We only considered the terrain-corrected scenes, excluding scenes that have cloud cover more than 80%. As a result, a total of 87,762 Landsat scenes over 1271 Path/Row locations were selected from 1984-2012. Of these, 63% were from Landsat-5, as Landsat-5 provided the only data source for 1984-1998 and continued to acquire data until 2011. This work aims to provide 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.See all pages that use this dataset
Note: While we identify the data sets used in these visualizations, we do not store any further details, nor the data sets themselves on our site.