Temperature and Water Vapor Variability Within and Above the PBL from the Earth Remote Sensing Program of Record

The NASA Decadal Survey Incubation (DSI) is a new program element that was recommended in the 2017 Earth Science Decadal Survey and intended to accelerate readiness of high-priority observables needing science requirements refinement, technology development, and/or other advancements prior to cost-effective flight implementation. One of the targeted observables is the Planetary Boundary Layer (PBL). A PBL study team summarized key findings of a survey of past and current ground, aircraft, and space-based measurements (Teixeira, J. et al. 2021). The PBL Study Report includes a Science and Applications Traceability Matrix (SATM) that highlights the four PBL science goals as well as specific science questions, geophysical variables and measurement requirements, and potential observing technologies to address these requirements. The SATM leads to the following measurement requirements (that can only be satisfied with a combination of different technologies): Vertical resolutions as fine as 100-200 m, Horizontal resolutions as fine as 1 km, Temporal sampling of at least 4 times per day.

This abstract describes results of a task funded at the University of Wisconsin-Madison Space Science and Engineering Center (SSEC) under NASA ROSES-2021 titled, “Refining Planetary Boundary Layer Remote Sensing Requirements Using Merged Orbital and Sub-Orbital and Merged Active and Passive Observations From The Program Of Record (POR)”, R. Knuteson (PI). In this task we select from the POR time periods and locations of interest that characterize the PBL over different global climate regimes with coincident observations of IR soundings and GPS RO profiles. Matchup sets make use of a ray path methodology which collocates the 2-D RO twisted ribbon with 3-D sounding fields from IR sounder POR products. This method is well suited for quantifying the spatial variability along the RO ray path and at the same time the vertical variability along the IR sounding. This variability is both the source of uncertainty in current POR retrievals and the potential source of information for future NASA sensors. We characterize the Horizontal and Vertical scales of temperature and water vapor within and above the PBL for a range of global atmospheric conditions using AIRS L2 and COSMIC wet profiles.

Additionally, recent data from the Space Science and Engineering Center’s (SSEC) Scanning High-Resolution Interferometer Sounder (S-HIS) taken during the AEROMMA field campaign is used to assess finer scale spatial variabilities in radiance than any available satellite sounders can currently provide. This field campaign used aircraft which flew at very low flight levels which enabled the S-HIS to measure high resolution radiation with very small footprints. This data will be leveraged to provide additional assessment on variability within the PBL and of the surface.