Background
The Planetary Boundary Layer (PBL) is the interface between the Earth’s surface and lowermost 2-3 km atmosphere. Knowing its highly dynamic properties is vital to understand the diurnal, seasonal, and climate-scale variations of Earth’s atmospheric processes and is key to cloud formation and pollution dispersal. Both hyperspectral sounders and Global Navigation Satellite Systems (GNSS)-Radio Occultations (RO) measure atmospheric temperature and moisture. Combining hyperspectral sounder data with GNSS-RO data into a merged global product will advance PBL process science and will improve weather forecasting applications. The 2017 Decadal Survey identified PBL as an Instrument Incubator Program activity that seeks to identify and develop new technology to improve our understanding of the exchanges between the biosphere and the atmosphere, and likewise the air-sea exchanges of chemical and energy fluxes. The Satellite Needs Working Group (SNWG)-PBL activity will provide a needed low-resolution dataset with current capabilities for requesting agencies as new technical capabilities mature.