Abstract View
Optimizing a Pressure-controlled Inlet (PCI) Coupled with a PM2.5 Lens for Aircraft Measurements with the Aerodyne Aerosol Mass Spectrometer (AMS) in the Lower Stratosphere
DONGWOOK KIM, Pedro Campuzano-Jost, Hongyu Guo, Da Yang, Mark Kanaparthi, Suresh Dhaniyala, Leah Williams, John Jayne, Douglas Worsnop, Jose-Luis Jimenez, CIRES, University of Colorado, Boulder
Abstract Number: 251
Working Group: Instrumentation and Methods
Abstract
Aerosols in the upper troposphere and lower stratosphere (UTLS) are crucial to understanding radiative forcing, ice cloud formation, and ozone chemistry. In-situ aircraft measurements with fast chemical composition sensors are essential to further our understanding of the underlying processes. Mass spectrometers such as the Aerodyne Aerosol Mass Spectrometer (AMS) and several single particle mass spectrometers have been used for these measurements. Such instruments typically use an aerodynamic lens as an inlet that collimates aerosols into a small detection volume over a wide range of particle sizes. However, such lenses depend on a constant upstream pressure to work consistently, and airborne interfaces that provide that (pressure-controlled inlets –PCI-) have historically performed less well at high altitudes. In this study, we are developing and testing a new PCI design coupled with two types of recently developed PM2.5 aerodynamic lenses towards the goal of sampling PM1 aerosols up to ~16 km altitude. We use state-of-the-art fluid dynamic models to inform development and testing. We characterize the transmission efficiency (TE) as a function of particle size over the range of pressures relevant for airborne sampling. As part of this project, a new lens alignment tool and a new particle beam imaging device, based on the Aerodyne aerosol Beam Width Probe (BWP) have been developed and tested. We show the current performance of the new PCI combined with the two different PM2.5 lenses and discuss potential improvements.