0000000000345250
AUTHOR
Florian Rubach
Volatility of secondary organic aerosol during OH radical induced ageing
The aim of this study was to investigate oxidation of SOA formed from ozonolysis of <i>&alpha;</i>-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT) in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jülich (FZJ) in Jülich. A fresh SOA was produced from ozonolysis of <i>&alpha;</i>-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in…
Application of an O-ring pinch device as a constant-pressure inlet (CPI) for airborne sampling
We present a novel and compact design of a constant-pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular, the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, in which efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hectopascals. The CPI device can also be used in condensation particle counters (CPCs), cloud condensation nucleus counters (CCNCs), and gas-phase sampling instruments across a wide range of altitudes and inlet pressures. The constant pressure is achieved by changing the inner diameter of a properly scaled O-ring that…
Measurements of aerosol and CCN properties in the Mackenzie River delta (Canadian Arctic) during spring–summer transition in May 2014
Within the framework of the RACEPAC (Radiation–Aerosol–Cloud Experiment in the Arctic Circle) project, the Arctic aerosol, arriving at a ground-based station in Tuktoyaktuk (Mackenzie River delta area, Canada), was characterized during a period of 3 weeks in May 2014. Basic meteorological parameters and particle number size distributions (PNSDs) were observed and two distinct types of air masses were found. One type were typical Arctic haze air masses, termed accumulation-type air masses, characterized by a monomodal PNSD with a pronounced accumulation mode at sizes above 100 nm. These air masses were observed during a period when back trajectories indicate an air mass origin in the north-e…
Optimizing the detection, ablation, and ion extraction efficiency of a single-particle laser ablation mass spectrometer for application in environments with low aerosol particle concentrations
The aim of this study is to show how a newly developed aerodynamic lens system (ALS), a delayed ion extraction (DIE), and better electric shielding improve the efficiency of the Aircraft-based Laser ABlation Aerosol MAss spectrometer (ALABAMA). These improvements are applicable to single-particle laser ablation mass spectrometers in general. To characterize the modifications, extensive size-resolved measurements with spherical polystyrene latex particles (PSL; 150–6000 nm) and cubic sodium chloride particles (NaCl; 400–1700 nm) were performed. Measurements at a fixed ALS position show an improved detectable particle size range of the new ALS compared to the previously used Liu…
Application of an O-ring pinch device as a constant pressure inlet (CPI) for airborne sampling
Abstract. We present a novel and compact design of a constant pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, where efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hPa. The CPI device can also be used in gas phase sampling instruments in a large range of altitude and inlet pressure. The constant pressure is achieved by changing the inner diameter of a properly scaled O-ring that acts as a critical orifice. The CPI control keeps air pressure and thereby mass flow rate (≈ 0.…
Application of an O-ring pinch device as a constant-pressure inlet (CPI) for airborne sampling
We present a novel and compact design of a constant-pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular, the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, in which efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hectopascals. The CPI device can also be used in condensation particle counters (CPCs), cloud condensation nucleus counters (CCNCs), and gas-phase sampling instruments across a wide range of altitudes and inlet pressures. The constant pressure is achieved by changing the inner diameter of a properly scaled O-ring that…
Measurements of aerosol and CCN properties in the Mackenzie River delta (Arctic) during RACEPAC
Within the framework of the RACEPAC (Radiation-Aerosol-Cloud Experiment in the Arctic Circle) project, the Arctic aerosol, arriving at a ground-based station in Tuktoyaktuk (Mackenzie River delta area, Canada), was characterized during a period of 3 weeks in May 2014. Basic meteorological parameters and particle number size distributions (PNSDs) were observed and two distinct types of air masses were found. One type were typical Arctic haze air masses, termed accumulation-type air masses, characterized by a monomodal PNSD with a pronounced accumulation mode at sizes above 100 nm. These air masses were observed during a period when back trajectories indicate an air mass origin in the north-e…
Application of an O-ring pinch device as a constant pressure inlet (CPI) for airborne sampling
We present a novel and compact design of a constant pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, where efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hPa. The CPI device can also be used in gas phase sampling instruments in a large range of altitude and inlet pressure. The constant pressure is achieved by changing the inner diameter of a properly scaled O-ring that acts as a critical orifice. The CPI control keeps air pressure and thereby mass flow rate (≈&thinsp…