Spatiotemporal changes in aerosol properties by hygroscopic growth and impacts on radiative forcing and heating rates during DISCOVER-AQ 2011

This work focuses on the characterization of vertically resolved aerosol hygroscopicity properties and their direct radiative effects through a unique combination of ground-based and airborne remote sensing measurements during the Column and Vertically Resolved Observations Relevant to Air Quality (...

Full description

Bibliographic Details
Published in:Atmospheric Chemistry and Physics
Main Authors: D. Pérez-Ramírez, D. N. Whiteman, I. Veselovskii, R. Ferrare, G. Titos, M. J. Granados-Muñoz, G. Sánchez-Hernández, F. Navas-Guzmán
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2021
Subjects:
Online Access:https://doi.org/10.5194/acp-21-12021-2021
https://doaj.org/article/2665f9c53fe54265b29df0fdd7a7733c
Description
Summary:This work focuses on the characterization of vertically resolved aerosol hygroscopicity properties and their direct radiative effects through a unique combination of ground-based and airborne remote sensing measurements during the Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) 2011 field campaign in the Baltimore–Washington DC metropolitan area. To that end, we combined aerosol measurements from a multiwavelength Raman lidar located at NASA Goddard Space Flight Center and the airborne NASA Langley High Spectral Resolution Lidar-1 (HSRL-1) lidar system. In situ measurements aboard the P-3B airplane and ground-based Aerosol Robotic Network – Distributed Regional Aerosol Gridded Observational Network (AERONET-DRAGON) served to validate and complement quantifications of aerosol hygroscopicity from lidar measurements and also to extend the study both temporally and spatially. The focus here is on 22 and 29 July 2011, which were very humid days and characterized by a stable atmosphere and increasing relative humidity with height in the planetary boundary layer (PBL). Combined lidar and radiosonde (temperature and water vapor mixing ratio) measurements allowed the retrieval of the Hänel hygroscopic growth factor which agreed with that obtained from airborne in situ measurements and also explained the significant increase of extinction and backscattering with height. Airborne measurements also confirmed aerosol hygroscopicity throughout the entire day in the PBL and identified sulfates and water-soluble organic carbon as the main species of aerosol particles. The combined Raman and HSRL-1 measurements permitted the inversion for aerosol microphysical properties revealing an increase of particle radius with altitude consistent with hygroscopic growth. Aerosol hygroscopicity pattern served as a possible explanation of aerosol optical depth increases during the day, particularly for fine-mode particles. Lidar measurements were used as input to the libRadtran radiative transfer code to ...