NOAA’s Center for Satellite Applications and Research has announced the release of the 2016 update to the Global Surface Type (GST) data, provided by the NOAA/NASA Suomi NPP Visible Infrared Imaging Radiometer Suite (VIIRS).
Updated annually, the GST data product provides users with the most recent information of global land surface type, which may change from year to year as a result of significant natural events (e.g., large scale wildfires) or human activities (e.g., deforestation, urbanization, reforestation, and so on). As such, it is a required input for many land surface models, including numerical weather prediction, climate and hydrological forecasts, studies on natural resources and disaster management.
The VIIRS GST product is generated with the 17-type classification scheme of the International Geosphere-Biosphere Program and is produced at a 1-kilometer spatial resolution based on the previous one or more years of data from VIIRS. The instrument’s surface reflectance, brightness temperature and vegetation index data are vital to creating accurate GST products.
Although land surface type changes occur frequently around the world, some of the changes may take place over a multi-year timescale, whereas others may take place in just a few days. While the VIIRS annual global surface type product may not always capture significant, but short-term surface type changes, it does illustrate their consequences through the detection of such landscape features as burn scars or flooded areas.
For example, the more than 250,000-acre Rim Fire of 2013 resulted in large scale surface type changes in the State of California. As denoted by the red polygon in the graphic below, the GST products generated with 2012 and 2014 VIIRS data show how the surface type of the affected region has surface type changed from woody savanna to shrubland.
The VIIRS Global Surface Type Map—the latest in a series of land cover products of different spatial resolutions and legend definitions that date back to the early 1990s—represents a continuation of NASA and NOAA products created with MODIS-based surface reflectance data and 1 kilometer resolution Advanced Very High Resolution Radiometer data.
The Center for Satellite Applications and Research (STAR) is leading the NOAA-NASA Joint Polar Satellite Systems (JPSS) program efforts to develop, test, validate, and refine the algorithms used to process data from instruments aboard JPSS satellites. STAR-JPSS Surface Type team is tasked with generating the Global Surface Type product annually to provide the most recent land surface type information for users.