Evaluation of 1-D EnsVar Retrievals of Aerosol Extinction and PM2.5 using the NASA CATS Lidar and GEOS AGCM
Abstract
Backscatter lidars, such as the NASA Cloud-Aerosol Transport System (CATS) that operated on the International Space Station (ISS) from February 2015 - October 2017 frequently rely on aerosol typing algorithms to assign an extinction-to-backscatter or lidar ratio to derive level 2 aerosol extinction profiles. Using observations of 1064 nm total attenuated backscatter from CATS, we have developed a 1-D ensemble-based variational (1-D EnsVar) technique that uses model priors from the NASA Goddard Earth Observing System (GEOS) atmospheric general circulation model and assimilation system to product vertically resolved speciated aerosol extinction, as well as mass concentration, and provides an alternative approach for deriving aerosol extinction from backscatter lidars. Ensemble perturbations and prior information are derived from NASA Goddard Earth Observing System (GEOS) atmospheric general circulation model and assimilation system which currently assimilates AOT from a number of passive sensors, including MODIS Aqua and Terra from space and surface sunphotometer observations from AERONET. In this work, we assess the performance of our aerosol extinction and mass concentration retrievals by comparing to independent observations of AOT from the spaceborne MISR sensor and surface PM2.5 monitored by the EPA, respectively. Owing to the near-real-time (NRT) data processing capability of CATS, this approach has numerous applications, including providing NRT constraints and initial conditions for air quality forecasting, improve estimates of surface PM2.5 concentrations from passive sensors, and develop lidar data assimilation techniques for use by future spaceborne lidar systems.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A11H2719N
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0319 Cloud optics;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 4275 Remote sensing and electromagnetic processes;
- OCEANOGRAPHY: GENERAL