Aircraft-based observation of meteoric material in lower stratospheric aerosol particles between 15 and 68°N

Schneider, Johannes; Weigel, Ralf; Klimach, Thomas; Dragoneas, Antonis; Appel, Oliver; Hünig, Andreas; Molleker, Sergej; Köllner, Franziska; Clemen, Hans-Christian; Eppers, Oliver; Hoppe, P.; Hoor, Peter; Mahnke, Christoph; Krämer, M.; Rolf, Christian; Grooß, Jens‐Uwe; Zahn, Andreas; Obersteiner, Florian; Ravegnani, F.; Oulanovsky, Alexei; Schläger, Hans; Scheibe, Monika; Diskin, G. S.; DiGangi, J. P.; Nowak, John B.; Zöger, Martin; Borrmann, Stephan

doi:10.1002/essoar.10501338.1

Cited by 10 publications

(25 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Atmospheric INP measurements showed a significant decrease in hit rate compared to the measurement of the atmospheric aerosol particles without prior ice activation and separation. Thus the hit rate decreased from typical values by 10 -20 % (Köllner, 2020;Schneider et al, 2019) to 0 -2 %.…”

Section: Introductionmentioning

confidence: 93%

“…A detailed description of the CPI that is similar to the one used in the ALABAMA is presented by Molleker et al (2020). Since ALABAMA has been developed particularly for aircraft-based measurements (Schneider et al, 2019;Wendisch et al, 2019;Köllner et al, 2017;Brands et al, 2011), an inlet is required that can quickly adapt to changing atmospheric pressure conditions while still allowing sufficient particle transmission. With the CPI, it is possible to keep the mass flow into the instrument and thus also the pressure within the aerodynamic lens constant.…”

Section: Constant Pressure Inlet and Air Diffusormentioning

confidence: 99%

“…The improved performance of the ALABAMA was further confirmed during aircraft-based measurements. In 2014, the ALABAMA was operated using the setup by Köllner (2020) during the ML-CIRRUS mission (Voigt et al, 2017), whereas in 2018, the ALABAMA was operated with all modifications presented here during the mission CAFE-Africa (Schneider et al, 2019). An increase in the hit rate of about five times was observed in both tropospheric and stratospheric aerosol particle analyses over the entire particle size range (Schneider et al, 2019).…”

Section: Influence Of the Ion Extraction Field Setup On The Mass Specmentioning

confidence: 99%

See 2 more Smart Citations

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

Clemen¹,

Schneider²,

Klimach³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. 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; 150–000 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-type ALS, especially for super-micron particles. At a lens pressure of 2.4 hPa, the new ALS achieves a PSL particle size range from 230 nm to 3240 nm with 50 % detection efficiency and between 350 nm and 2000 nm with 95 % detection efficiency. The particle beam divergence was determined by measuring the detection efficiency at variable ALS positions along the laser cross sections and found to be minimal for PSL at about 800 nm. Compared to measurements of SPMS instruments using Liu-type ALSs, the minimum particle beam divergence is shifted towards larger particle sizes. However, there are no disadvantages compared to the Liu-type lenses for particle sizes down to 200 nm. Improvements achieved by using the DIE and an additional electric shielding could be evaluated by size-resolved measurements of the hit rate, which is the ratio of laser pulses yielding a detectable amount of ions to the total number of emitted laser pulses. In particular, the hit rate for multiply charged particles smaller 500 nm is significantly improved by preventing an undesired deflection of these particles in the ion extraction field. Moreover, it was found that by using the DIE the ion yield of the ablation, ionization and ion extraction process could be increased, resulting in up to seven times higher signal intensities of the cation spectra. The enhanced ion yield results in a larger effective width of the ablation laser beam, which in turn leads to a hit rate of almost 100 % for PSL particles in the size range from 350 nm to 2000 nm. Regarding cubic NaCl particles the modifications of the ALABMA result in a up to two times increased detection efficiency and a up to five times increased hit rate. The need for such instrument modifications arises in particular for measurements of particles that are present in low number concentrations such as ice nucleation particles (INP) in general, but also aerosol particles at high altitudes or in pristine environments. Especially for these low particle number concentrations improved efficiencies help to overcome statistical limitations of single particle mass spectrometer measurements. As an example laboratory INP measurements carried out in this study show that the application of the DIE alone increases the number of INP mass spectra per time unit by a factor of two to three for the sampled substances. Overall, the combination of instrument modifications presented here resulted in an increased measurement efficiency of the ALABAMA for different particle types, particles shapes and for highly charged particles.

show abstract

Section: Introductionmentioning

confidence: 93%

Section: Constant Pressure Inlet and Air Diffusormentioning

confidence: 99%

Section: Influence Of the Ion Extraction Field Setup On The Mass Specmentioning

confidence: 99%

See 1 more Smart Citation

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

Clemen¹,

Schneider²,

Klimach³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…6. In our different approach, a very compact constant-pressure inlet (CPI) setup (without additional pumping or bypass flow) was developed and flight proven for single-particle-type and flashvaporization-type instruments, at altitudes from ground level up to 20 km (e.g., Köllner et al, 2017;Schulz et al, 2018;Höpfner et al, 2019;Dragoneas et al, 2020;Schneider et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Application of an O-ring pinch device as a constant-pressure inlet (CPI) for airborne sampling

et al. 2020

Self Cite

View full text Add to dashboard Cite

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, 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 acts as a critical orifice. The CPI control keeps air pressure and thereby mass flow rate (≈0.1 L min−1) upstream of an aerodynamic lens constant, deviating at most by only ±2 % from a preset value. In our setup, a pressure sensor downstream of the O-ring maintains control of the pinch mechanism via a feedback loop and setpoint conditions are reached within seconds. The device was implemented in a few instruments, which were successfully operated on different research aircraft covering a wide range of ambient pressures, from sea level up to about 55 hPa. Details of operation and the quality of aerosol particle transmission were evaluated by laboratory experiments and in-flight data with a single-particle mass spectrometer.

show abstract

“…In our different approach, a very compact constant pressure inlet (CPI) setup, without additional pumping and a bypass flow was developed and flight proven for single particle and flash-vaporization type instruments, at altitudes from ground level up to 20 km altitude (e.g. Köllner et al, 2017;Schulz et al, 2018;Höpfner et al, 2019;Dragoneas et al, 2020;Schneider et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Application of an O-ring pinch device as a constant pressure inlet (CPI) for airborne sampling

Molleker¹,

Helleis²,

Klimach³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

We present a novel and compact design of a constant pressure inlet (CPI) developed for use in airborne aerosol mass 10 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 (≈0.1 l/min) upstream of an aerodynamic lens constant, deviating at most 15 by only ±2 % from a pre-set value. In our setup a pressure sensor downstream of the O-ring controls the pinch mechanism via a feedback loop and setpoint conditions are reached within seconds. The device was implemented in a few instruments, which were successfully operated on different research aircraft covering a wide range of ambient pressures, from sea level up to about 55 hPa. Details of operation and quality of aerosol particle transmission are evaluated by laboratory experiments and in-flight data with a single particle mass spectrometer.

show abstract

Aircraft-based observation of meteoric material in lower stratospheric aerosol particles between 15 and 68°N

Cited by 10 publications

References 11 publications

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

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

Application of an O-ring pinch device as a constant-pressure inlet (CPI) for airborne sampling

Application of an O-ring pinch device as a constant pressure inlet (CPI) for airborne sampling

Contact Info

Product

Resources

About