scholarly journals Automated Continuous-Flow Thermal-Diffusion-Chamber Type Ice Nucleus Counter

SOLA ◽  
2011 ◽  
Vol 7 ◽  
pp. 29-32 ◽  
Author(s):  
Atsushi Saito ◽  
Masataka Murakami ◽  
Toyoaki Tanaka
Keyword(s):  
Thermal Diffusion ◽  
Continuous Flow ◽  
Diffusion Chamber ◽  
Nucleus Counter

An improved continuous-flow condensation nucleus counter for use in the stratosphere

1983 ◽  
Vol 14 (3) ◽  
pp. 387-391 ◽  
Author(s):  
James Charles Wilson ◽  
Edmund D. Blackshear ◽  
Jong Ho Hyun
Keyword(s):  
Continuous Flow ◽  
Condensation Nucleus ◽  
Nucleus Counter ◽  
Flow Condensation

scholarly journals Manchester Ice Nucleus Counter (MINC) measurements from the 2007 International workshop on Comparing Ice nucleation Measuring Systems (ICIS-2007)

2011 ◽  
Vol 11 (1) ◽  
pp. 53-65 ◽  
Author(s):  
H. M. Jones ◽  
M. J. Flynn ◽  
P. J. DeMott ◽  
O. Möhler
Keyword(s):  
International Workshop ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Concentric Cylinder ◽  
Measuring Systems ◽  
Colorado State University ◽  
Ice Nuclei ◽  
Nucleus Counter ◽  
First Results ◽  
Order Of Magnitude

Abstract. An ice nucleus counter was developed and constructed to enable investigation of potential ice nucleating materials. The Manchester Ice Nucleus Chamber (MINC) is a concentric-cylinder continuous flow diffusion chamber (CFDC). A full explanation of the MINC instrument is given here, along with first results and a comparison to an established instrument of similar design (Colorado State University CFDC) during sampling of common ice nucleating aerosols at the 2007 International workshop on Comparing Ice nucleation Measuring Systems (ICIS-2007). MINC and CSU-CFDC detected the onset of ice nucleation under similar conditions of temperature and supersaturation for several different types of ice nuclei. Comparisons of the ratio of ice nuclei to total aerosol concentrations as a function of supersaturation with respect to water (SSw) showed agreement within one order of magnitude. Possible reasons for differences between the two instruments relating to differences in their design are discussed, along with suggestions to future improvements to the current design.

scholarly journals Results from the University of Toronto continuous flow diffusion chamber (UT-CFDC) at the international workshop for comparing ice nucleation measuring systems (ICIS 2007)

2010 ◽  
Vol 10 (9) ◽  
pp. 20857-20886 ◽  
Author(s):  
Z. A. Kanji ◽  
P. J. DeMott ◽  
O. Möhler ◽  
J. P. D. Abbatt
Keyword(s):  
Continuous Flow ◽  
International Workshop ◽  
Measurement Techniques ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Ice Formation ◽  
Aerosol Sample ◽  
Measuring Systems ◽  
University Of Toronto ◽  
The University

Abstract. The University of Toronto continuous flow diffusion chamber (UT-CFDC) was used to study heterogeneous ice nucleation at the International Workshop on Comparing Ice Nucleation Measuring Systems (ICIS 2007) which also represented the 4th ice nucleation workshop, on 14–28 September 2007. One goal of the workshop was to inter-compare different ice nucleation measurement techniques using the same aerosol sample source and preparation method. The aerosol samples included four types of desert mineral dust, graphite soot particles, and live and dead bacterial cells (Snomax®). This paper focuses on the UT-CFDC results, with a comparison to techniques of established heritage including the Colorado State CFDC and the AIDA expansion chamber. Good agreement was found between the different instruments with a few specific differences attributed to the variation in how onset of ice formation is defined between the instruments. It was found that when efficiency of ice formation is based on the lowest onset relative humidity, Snomax® particles were most efficient followed by the desert dusts and then soot. For all aerosols, deposition mode freezing was only observed for T < 245 K except for the dead bacteria where freezing occurred below water saturation as warm as 263 K.

scholarly journals Comparing contact and immersion freezing from continuous flow diffusion chambers

2016 ◽  
Author(s):  
Baban Nagare ◽  
Claudia Marcolli ◽  
André Welti ◽  
Olaf Stetzer ◽  
Ulrike Lohmann
Keyword(s):  
Residence Time ◽  
Continuous Flow ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Freezing Process ◽  
Electrical Mobility ◽  
Cloud Droplets ◽  
Immersion Freezing ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Ice nucleating particles (INPs) in the atmosphere are responsible for glaciating cloud droplets between 237 K and 273 K. Different mechanisms of heterogeneous ice nucleation can compete under mixed-phase cloud conditions. Contact freezing is considered relevant because higher ice nucleation temperatures than for immersion freezing for the same INPs were observed. It has limitations because its efficiency depends on the number of collisions between cloud droplets and INPs. This study compares immersion and contact freezing efficiencies of three different INPs. The contact freezing data was obtained with the ETH CoLlision Ice Nucleation CHamber (CLINCH) using 80 μm diameter droplets which can interact with INPs for residence times of 2 s and 4 s in the chamber. The contact freezing efficiency was calculated by estimating the number of collisions between droplets and particles. Theoretical formulations of collision efficiencies gave too high freezing efficiencies for all investigated INPs, namely AgI particles with 200 nm electrical mobility diameter, 400 and 800 nm diameter ATD and kaolinite particles. Comparison of freezing efficiencies by contact and immersion freezing is therefore limited by the accuracy of collision efficiencies. The concentration of particles was 1000 cm−3 for ATD and kaolinite and 500, 1000, 2000 and 5000 cm−3 for AgI. For concentrations < 5000 cm−3, the droplets collect only one particle on average during their time in the chamber. For ATD and kaolinite particles, contact freezing efficiencies at 2 s residence time were smaller than at 4 s, which is in disagreement with a collisional contact freezing process but in accordance with contact freezing insideout or immersion freezing. For best comparison with contact freezing results, immersion freezing experiments of the same INPs were performed with the continuous flow diffusion chamber IMCA/ZINC for 3 s residence time. In IMCA/ZINC, each INP is activated into a droplet in IMCA and provides its surface for ice nucleation in the ZINC chamber. The comparison of contact and immersion freezing results did not confirm a general enhancement of freezing efficiency for contact compared with immersion freezing experiments. For AgI particles the onset of heterogeneous freezing in CLINCH was even shifted to lower temperatures compared with IMCA/ZINC. For ATD, freezing efficiencies for contact and immersion freezing experiments were similar. For kaolinite particles, contact freezing became detectable at higher temperatures than immersion freezing. Using contact angle information between water and the INP, it is discussed how the position of the INP in or on the droplets may influence its ice nucleation activity.

Sign in / Sign up

Export Citation Format

Share Document