Radiative Forcing of Black Carbon Containing Particles from Tethered Balloon Vertical Profiles at the Southern Great Plains Atmospheric Radiation Measurement Site
SUSAN MATHAI, Nurun Nahar Lata, Zezhen Cheng, Fan Mei, Darielle Dexheimer, Swarup China, Claudio Mazzoleni,
Michigan Technological University Abstract Number: 232
Working Group: Carbonaceous Aerosol
AbstractBlack carbon (BC) containing particles affect climate directly by efficiently absorbing solar radiation and indirectly by serving as cloud and ice nuclei as well as by altering surface albedo. However, the light-absorption properties of BC containing particles are highly variable with respect to altitude due to changes in concentrations, physiochemical properties, morphology, and mixing state, leading to large uncertainties in radiative forcing calculation. In this study, we focus on the vertical distribution of BC containing particles and its single particle mixing state at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site. Data and samples were collected during February and April 2022 by deploying instruments onboard an ARM tethered balloon system (TBS). We deployed two micro-aethalometers (AE51 and MA200) to monitor the BC concentration at different altitudes along with a condensation particle counter (CPC) for total particle concentration measurement, and a Portable Optical Particle Spectrometer (POPS, Handix scientific) to monitor the size distribution of the particles. We also deployed an automated Size and Time-resolved Aerosol Collector (STAC) to collect particles at different altitudes. Single particle measurements using multi-modal microscopy and spectroscopy techniques show abundance of carbonaceous and sulfate particles during different events. We use the size distribution and particle concentration measurements from POPS and CPC and the MA200 to estimate the scattering and absorption coefficients at different altitudes. Then we calculated the radiative forcing using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. This study will improve our understanding of radiative forcing from BC particles and their mixing states at different altitudes.