Aerosol Optical Thickness: Organic Composition, Associated Particle Water, and Aloft Extinction
Over the contiguous United States, the strongest remotely sensed aerosol optical thickness (AOT) is observed in the east, where aerosol liquid water (ALW) and extinction per unit PM2.5 dry mass are highest. Positive associations between ALW due to sulfate and nitrate with remotely sensed AOT offer a contributing explanation for geospatial patterns in AOT seasonality. We seek here to further resolve patterns in ALW-AOT relationships by investigating organic mass (OM) fractionation, converted from organic carbon (OC) measurements using regionally specific OM:OC ratios, and the associated impacts on ALW. ALW is integrated from the surface through the boundary layer and estimated from measured particle chemical composition using ISORROPIAv2.1 and κ-Kohler theory at eight Interagency Monitoring of PROtected Visual Environments (IMPROVE) sites in areas of contrasting AOT seasonality. Two groups of four sites each, clustered by chemical climatology, are compared to AOT derived from the Moderate Resolution Imaging Spectroradiometer and vertically resolved extinction retrieved from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) from 2007 to 2016. Estimated ALW within the planetary boundary layer differs between the regions. Spatial patterns and vertical profiles are qualitatively similar to CALIPSO patterns. However, inclusion of volatility-based organic speciation from routine surface networks and the associated ALW do not improve correlation with satellite-derived AOT. CALIPSO-measured extinction is enhanced above the PBL and may partly explain discrepancies. This work is suggestive that the effects of intrinsic physicochemical properties are remotely sensed, but approaches to link AOT to current surface measurements are limited in detail and their ability to assess aloft phenomena.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of California, Irvine, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER); National Science Foundation (NSF)
- Grant/Contract Number:
- AC02-06CH11357; AGS-1242155; AGS-1445831
- OSTI ID:
- 1509998
- Journal Information:
- ACS Earth and Space Chemistry, Vol. 3, Issue 3; ISSN 2472-3452
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data
Final DOE-ASR Report for the Project “Advancing our Understanding and the Remote Sensing of Ice Clouds”