Trends in annual start of vegetation growing season 2000-2016, version 1, Mar. 2019

The raster file is the temporal trend in the start of the vegetation growing season. The start of growing season dataset is based on the time series of the Plant Phenology Index (PPI) derived from the MODIS BRDF-Adjusted Reflectance product (MODIS MCD43 NBAR). The PPI index is optimized for efficient monitoring of vegetation phenology and is derived from the source MODIS data using radiative transfer solutions applied to the reflectance in visible-red and near infrared spectral domains. The start of season dataset is based on calculating the start of the growing season from the annual PPI temporal curve using the TIMESAT software. Change in the start of growing season was then calculated after fitting a linear trend and extracting the slope of the trend. Negative values refer to earlier start of the vegetation growing season, whereas positive values refer to later start of the vegetation growing season.