Aerosol Properties above SGP Derived from CHARMS Data
Poster PDF
Authors
Richard A. Ferrare — NASA - Langley Research Center
Marian B. Clayton — Science Systems and Applications, Inc. (SSAI)
Tyler Thorsen — NASA - Langley Research Center
Eduard Chemyakin — Science Systems and Applications, Inc.
Sharon P Burton — NASA - Langley Research Center
John E. M. Goldsmith — Sandia National Laboratories
Robert E. Holz — University of Wisconsin/CIMMS
Edwin W. Eloranta — University of Wisconsin
Willem Jacobus Marais — University of Wisconsin - CIMSS
Rob K Newsom — Pacific Northwest National Laboratory
Xu Liu — NASA LANGLEY RESEARCH CENTER
Richard Moore — NASA Langley Research Center
Brent Holben — NASA - Goddard Space Flight Center
Detlef Mueller — Science Systems and Applications, Inc.
Category
ARM field campaigns – Results from recent ARM field campaigns
Description
During the Combined HSRL And Raman lidar Measurement Study (CHARMS), DOE ARM investigated the synergistic use of SGP Raman lidar and High Spectral Resolution Lidar (HSRL) measurements to improve the ARM observational capability of aerosols. The continuous (24/7) operation of these co-located lidars during the ten-week CHARMS mission (mid-July through September 2015) allowed the acquisition of a unique, multiwavelength ground-based lidar dataset for studying the vertical distribution of aerosol properties above the SGP. The ARM SGP Raman lidar measured profiles of aerosol backscatter, extinction and depolarization at 355 nm and profiles of water vapor mixing ratio and temperature. The UW HSRL simultaneously measured profiles of aerosol backscatter, extinction and depolarization at 532 nm and aerosol backscatter at 1064 nm.
We use the lidar profiles of aerosol intensive properties (lidar ratio, depolarization ratio, backscatter color ratio), which provide information about aerosol size, shape and composition, to classify the vertical distribution of aerosols and apportion aerosol optical thickness and extinction to aerosol type. Over the period as a whole, smoke or urban pollution dominates the aerosol extinction and optical thickness. However, on several days a dusty mix of aerosol was observed within the boundary layer as revealed by aerosol depolarization values greater than 0.1. These nonspherical aerosols are likely dust and contain higher fractions of coarse mode aerosols.
We also use the CHARMS multiwavelength lidar backscatter and extinction profiles to derive profiles of aerosol microphysical (e.g. effective radius, concentration, fine mode fraction) properties aloft. Column-averaged comparisons of fine mode effective radius, fine mode fraction, and volume concentration derived from the CHARMS data show generally good agreement with corresponding values derived from AERONET. We study how these retrieved aerosol properties and the aerosol intensive properties described above vary within and above the boundary layer and also how they vary with relative humidity, vertical velocity, and proximity to clouds.
