Influence of Free-tropospheric Aerosol at the Boundary Layer in Remote Marine Environment

 

Authors


Daniel Veghte — Pacific Northwest National Laboratory
Johannes Weiss — Lawrence Berkeley National Laboratory
Jay Tomlin — Purdue University
Ryan Moffet — Sonoma Technology Inc.
Daniel Knopf — Stony Brook University
Shira Raveh — Weizmann Institute of Science
Mary Gilles — Lawrence Berkeley National Laboratory
Jian Wang — Washington University in St. Louis
Alexander Laskin — Purdue University

Category

General topics – Aerosols

Description

After emission of atmospheric particles in the planetary boundary layer, they often transported into the free troposphere. However, under certain meteorological conditions atmospheric particles can be entrained into the boundary layer and impact the cloud formation potential of particles in the boundary layer. This process potentially impact the cloud condensation nuclei budget in the marine boundary layer. Atmospheric particles were collected during the Aerosol and Cloud Experiment in the Eastern North Atlantic (ACE-ENA) field study, onboard the ARM aerial facility platform (G-1 aircraft) at varying altitudes in the remote region of the Azores archipelago. Samples were collected using a custom built time-resolved aerosol collector that can autonomously collect particles on substrates for predetermined times. In this study we investigate the entrainment of free tropospheric aerosol into the boundary layer by investigating the physicochemical properties of boundary layer and free-tropospheric aerosol. To this end, multi-modal chemical imaging of particles was performed using complementary capabilities of electron microscopy and scanning transmission X-ray microscopy. Additionally, particles were investigated by in-situ electron microscopy to determine volatility and water uptake on a single particle basis. Results reveal presence of substantial fraction of carbonaceous and sulfate aerosol, while relatively minor contribution from sea-spray aerosol in the boundary layer, suggesting that boundary layer aerosol may influence from free troposphere.