Blending Land Surface Products for JPSS Mission

A variety of land surface products have been produced from the U.S. JPSS satellite mission since 2012, which have been widely applied for scientific studies on vegetation carbon stock/cycle, water and hydrological cycles, long term trends of global climate, improvement of numerical weather, climate and hydrological predictions, etc. Example societal applications of the satellite land products include agricultural efficiency, surface radiation budget, aviation, wild fire monitoring, flood and drought monitoring, among many others. For instance, vegetation index products help monitor vegetation health, growth patterns, and agricultural management; persistent observations of land surface temperature are pivotal in monitoring heatwave events, and the albedo climatology improves the land surface model running for the weather forecasting services.

While multiple JPSS satellites have been launched and been available in their similar afternoon Sun-synchronous orbits, blending products from those observations may be of great interest, not just because the algorithm benefits from multiple sensor observations for a product, but also because of the operational advantages (i.e. running and keeping one blended product vs. similar products from different satellites). As for an example, impact of the cloud contamination will be significantly reduced in the blended products, such as the land surface albedo and vegetation index, which are based on the visible/infrared measurements. The blended products are also beneficial to the applications of climate study due to its better consistency.

Land product development science team at STAR (the center for SaTellite Applications and Research) of NOAA/NESDIS is responsible for developing, calibrating, and monitoring of JPSS land surface products. Those land products include land surface temperature, land surface emissivity, surface albedo, vegetation index and green vegetation fraction, leaf area index, and surface reflectance. Recently, we conducted experimental study on blending those land surface products from the observations of all the JPSS satellites (currently SNPP, NOAA-20 and NOAA-21). Presented here are the samples of the blended land surface albedo data and blended vegetation index data. The blending algorithms of the two products are described and illustrated, respectively, with scientific analysis. Some issues, concerns and discussions related to the blending process are presented as well.