HALO XCH4 Retrievals During the 2019 ACT-America Campaign

Rory Barton-Grimley,  NASA Langley Research Center,  rory.a.barton-grimley@nasa.gov (Presenter)
Amin Nehrir,  NASA Langley Research Center,  amin.r.nehrir@nasa.gov
Susan Kooi,  SSAI,  susan.a.kooi@nasa.gov
Jim Collins,  SSAI,  james.e.collins@nasa.gov

NASA Langley Research Center has developed the High Altitude Lidar Observatory (HALO) system to address the observational needs of NASA’s carbon cycle, weather, climate, and atmospheric composition focus areas. HALO is a modular and multi-function airborne lidar developed to measure atmospheric H2O and CH4 mixing ratios and aerosol/cloud/ocean optical properties using the Differential Absorption Lidar (DIAL) and High Spectral Resolution Lidar (HSRL) techniques, respectively. HALO serves as an airborne prototype for future space-based DIAL missions. During the summer of 2019 HALO deployed on the NASA C130 aircraft as a part of the final Atmospheric Carbon and Transport America (ACT-America) Earth Venture Suborbital campaign. For the ACT-America campaign HALO employed the DIAL technique at 1645 nm for column and multi-layer measurements of XCH4, and the HSRL technique at 532 nm for retrievals of aerosol extinction, backscatter, and PBL heights. The addition of the HSRL channels provides context to the airborne CH4 DIAL measurements, especially the layered structure of the atmosphere including vertical mixing through PBL height retrievals and provides a critical capability to validate aerosol and cloud induced biases from passive space-borne measurements of column CH4.

In this presentation we will provide a brief overview of the HALO instrument capabilities and present observations of biogenic and anthropogenic emissions over wide range of atmospheric and surface conditions. These observations will be compared to in situ measurements to elucidate the accuracy and precision of the HALO instrument as they pertain to different applications including assessment of top down inventories and chemical transport models, air quality studies, calibration/validation of both operational satellites (e.g.,TropOMI, GOSAT II) and future missions (e.g., MERLIN, GEOCARB). We will end by discussing a cross-cutting space mission concept on a SmallSat platform that pulls heritage from the HALO airborne prototype to allow for high spatial resolution columns of XCH4, distributions of PBL heights, and water vapor/aerosol/cloud profiles.

Poster: Poster_BartonGrimley_0_161_25.pdf 

Presentation Type: Poster

Session: 1.5d Retrieval algorithms and methods for inter-instrument and product Cal/Val

Session Date: Monday (6/14) 12:00 PM