Observing greenhouse gases and aerosols in Los Angeles using CLARS-FTS and OCO-3
Abstract
Observing greenhouse gases (GHGs) from space over megacities such as Los Angeles (LA) is challenging due to the large biases in GHG retrievals caused by aerosol scattering. We explore the potential of a "divide and conquer" strategy to mitigate this issue using a full physics retrieval algorithm developed for the California Laboratory for Atmospheric Remote Sensing - Fourier Transform Spectrometer (CLARS-FTS) that accounts for aerosol scattering. Aerosol optical depth (AOD) and aerosol layer height (ALH) are first retrieved using a spectral-sorting method (Zeng et al., 2020). Then, the retrieved AOD and ALH and their associated uncertainties are utilized to provide a strong constraint in the full physics retrieval algorithm to retrieve the GHGs. Further, we apply the same strategy to the Orbiting Carbon Observatory (OCO-3) Snapshot Area Map observations over LA, which are collected from neighboring scans taken over LA. The GHG and aerosol retrievals from both instruments (performed using the same retrieval algorithm and laboratory spectroscopic data) will be compared. CLARS and OCO-3 share a common goal of mapping GHGs over LA and have similar measurement characteristics in terms of their large range of scattering angles. In addition, we will obtain single scattering albedo information, enabling identification of aerosol composition. Results from this effort will shed light on how aerosol scattering (and the related optical properties and aerosol composition) affects the remote sensing retrieval of GHGs in megacities.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA222.0003C
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0480 Remote sensing;
- BIOGEOSCIENCES;
- 1615 Biogeochemical cycles;
- processes;
- and modeling;
- GLOBAL CHANGE