Transformational Science with the WindMapper Mission Concept

WindMapper is a NASA Earth System Explorers class mission concept dedicated to the retrieval of accurate, vertically-resolved, global winds from the surface to the tropopause, yielding breakthrough observations to reveal the mechanisms driving societally impactful weather events. The three-year on-orbit mission would conduct transformational new science using a train of three, identical small spacecraft (s/c) each hosting the same three instruments: a hyperspectral imaging sounder (MISTiC), a mid-IR stereo imaging system (CMIS), and a GNSS occultation and reflectometry package (OREO). The mission addresses the Earth Science Decadal Survey targeted observable (TO) of tropospheric winds (TO-4) and partially addresses ocean surface winds (TO-11). Both TOs are identified as “most important” across numerous Decadal Survey (DS) Science Objectives. Crucially, WindMapper will close the tropospheric wind observation gap (Fig. 1) that has been a barrier to scientific advancement in numerous areas covering atmospheric dynamics, atmospheric transport, and Earth system modeling and prediction.

WindMapper is a distributed observing system (DOS) that yields a unique, scientifically rich set of coincident datasets. Three identical S/C in high inclination sun synchronous orbits, separated by ~15 min, and following the same ground track (Fig. 2), provide the time-change of instrument observables needed to track the movement of atmospheric water vapor features and clouds from which atmospheric motion vectors (AMVs) are retrieved. Data from each of the observatories are used together, in coordination, to obtain these measurements. WindMapper geophysical data products include: 1) AMVs from hyperspectral water vapor and clouds (MISTiC); 2) Stereo-optical cloud AMVs (CMIS); 3) Ocean surface wind speed (OREO reflectometry); 4) Stereo cloud top height and cloud top vertical velocity (CMIS); 5) Stereo PBL height estimates from low clouds (CMIS), all-sky water vapor (OREO radio occultation) and water vapor profiles (MISTiC); 6) Temperature profiles (MISTiC), and soil moisture and inland water surface area (OREO reflectometry). All of these products are provided at a cadence of 12 hours or less covering 90% of the planet.

Notably, the coincident and contemporaneous retrievals of the WindMapper geophysical variables enable transformational science connecting the independently determined kinematic (wind) and thermodynamic (temperature and moisture) fields into a single, physically consistent picture of the atmospheric system. WindMapper focuses on the precursor mechanisms responsible for extreme moisture transport weather events and helps to improve their representation in models of Earth’s changing climate system. Atmospheric rivers (ARs) and monsoon disturbances (MDs) are end members of extratropical and tropical systems, respectively, that epitomize extreme moisture transport driven by complex atmospheric dynamics and thermodynamics. Because of the importance of ARs and MDs to water resources and because of the simultaneous hazards that they produce, WindMapper further focuses on two objectives: 1) Discover, identify, and quantify the relative importance of the mechanisms responsible for the genesis and evolution of atmospheric rivers and monsoon disturbances; and 2) Fill the mid-tropospheric gap in vertically-resolved wind observations, quantify the corresponding improvement in atmospheric analyses, and quantify the sensitivity of Earth System models to such observations. WindMapper data can also be used to investigate numerous other phenomena of high scientific and societal interest.

The WindMapper mission concept is presented along with an overview of the spacecraft and instruments. Examples of data expected from detailed observing system simulation experiments, pseudo-observing system experiments, and simulated retrievals are presented and discussed in the context of specific WindMapper scientific and numerical weather prediction investigations that will answer some of the most fundamental and outstanding questions about atmospheric rivers and monsoon disturbances.