Exploring the Trade Space for Measurements of the Global Planetary Boundary Layer

The atmospheric planetary boundary layer (PBL) serves as the interface region between the atmosphere and the underlying surface and modulates nearly all surface – atmosphere mass and energy exchanges. Despite its importance, there are no systematic global observations of the complex three-dimensional (3D) thermodynamic structure of the PBL. This presentation will describe a current effort that seeks to evaluate measurements capable of characterizing the thermodynamic structure of the PBL for a diverse set of regions and climateological conditions. This project conducts a set of observing system simulation experiments (OSSEs) that are designed to quantify the trades among various instrument types and orbit configurations. In contrast to OSSEs that quantify the impact of candidate observations on a weather forecast, our study examines the ability of various measurement combinations to meet specific PBL science objectives. In so doing, we combine observing system simulation tools developed at the Jet Propulsion Laboratory (JPL), NASA Langley Research Center (LaRC), and NASA Goddard Global Modeling and Assimilation Office (GMAO). We use the Global Earth Observing System (GEOS) nature run (G5NR) as context, as the two-year integration contains a wide range of large scale and relatively coarse resolution dynamic and thermodynamic states. High resolution atmospheric state data is provided by a library of existing large eddy simulations produced at JPL and Colorado Stateu University for a range of different PBL environments (marine, continental, stratocumulus topped, shallow convective, deep convective, etc).

Instruments that are considered include: differential absorption lidar (DIAL; NASA LaRC), differential absorption radar (DAR; JPL), thermodynamic sounding (JPL), and Global Navigation Satellite System (GNSS) radio occultation (JPL). The NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST)-funded parallel OSSE (ParOSSE) toolkit is used to rapidly explore the measurement trade space and to identify combinations of various instruments that meet PBL mission objectives. An orbit simulator also developed under ESTO AIST funding (the Tradespace Analysis Toolkit for Constellations; TAT-C) is used to assess the effectiveness of various orbit and swath configurations for PBL science and applications objectives. This presentation will demonstrate the tools that are already in place and will show the results from the first set of PBL measurement design experiments.