scholarly journals The SPectrometer for Ice Nuclei (SPIN): An instrument to investigate ice nucleation

2016 ◽  
Author(s):  
S. Garimella ◽  
T. B. Kristensen ◽  
K. Ignatius ◽  
A. Welti ◽  
J. Voigtländer ◽  
...  
Keyword(s):  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Learning Approach ◽  
Laboratory Measurements ◽  
Ice Nuclei ◽  
Machine Learning Approach ◽  
Optical Particle Counter ◽  
Breakthrough Experiments ◽  
Homogeneous Freezing ◽  
Plate Geometry

Abstract. The SPectrometer for Ice Nuclei (SPIN) is a commercially available ice nuclei counter manufactured by Droplet Measurement Technologies in Boulder, CO. The SPIN is a continuous flow diffusion chamber with parallel plate geometry based on the Zurich Ice Nucleation Chamber and the Portable Ice Nucleation Chamber. This study characterizes and describes the behavior of the SPIN chamber, reports data from laboratory measurements, and quantifies uncertainties associated with the measurements. A machine learning approach for analyzing depolarization data from the SPIN Optical Particle Counter is also presented. Experiments with ammonium sulfate are used to investigate homogeneous freezing and droplet breakthrough, experiments with kaolinite, NX illite, and silver iodide are used to investigate heterogeneous ice nucleation, and results are compared to those from the literature. Overall, we report that the SPIN is able to reproduce previous CFDC ice nucleation measurements.

scholarly journals The SPectrometer for Ice Nuclei (SPIN): an instrument to investigate ice nucleation

2016 ◽  
Vol 9 (7) ◽  
pp. 2781-2795 ◽  
Author(s):  
Sarvesh Garimella ◽  
Thomas Bjerring Kristensen ◽  
Karolina Ignatius ◽  
Andre Welti ◽  
Jens Voigtländer ◽  
...  
Keyword(s):  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Standard Description ◽  
Ice Nuclei ◽  
Machine Learning Approach ◽  
Optical Particle Counter ◽  
Breakthrough Experiments ◽  
Homogeneous Freezing ◽  
Haze Droplets ◽  
Plate Geometry

Abstract. The SPectrometer for Ice Nuclei (SPIN) is a commercially available ice nucleating particle (INP) counter manufactured by Droplet Measurement Technologies in Boulder, CO. The SPIN is a continuous flow diffusion chamber with parallel plate geometry based on the Zurich Ice Nucleation Chamber and the Portable Ice Nucleation Chamber. This study presents a standard description for using the SPIN instrument and also highlights methods to analyze measurements in more advanced ways. It characterizes and describes the behavior of the SPIN chamber, reports data from laboratory measurements, and quantifies uncertainties associated with the measurements. Experiments with ammonium sulfate are used to investigate homogeneous freezing of deliquesced haze droplets and droplet breakthrough. Experiments with kaolinite, NX illite, and silver iodide are used to investigate heterogeneous ice nucleation. SPIN nucleation results are compared to those from the literature. A machine learning approach for analyzing depolarization data from the SPIN optical particle counter is also presented (as an advanced use). Overall, we report that the SPIN is able to reproduce previous INP counter measurements.

scholarly journals Ice nucleation by surrogates for atmospheric mineral dust and mineral dust/sulfate particles at cirrus temperatures

2005 ◽  
Vol 5 (3) ◽  
pp. 3391-3436 ◽  
Author(s):  
C. M. Archuleta ◽  
P. J. DeMott ◽  
S. M. Kreidenweis
Keyword(s):  
Sulfuric Acid ◽  
Relative Humidity ◽  
Mineral Dust ◽  
Aerosol Particles ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Nucleation Behavior ◽  
Ice Nuclei ◽  
Homogeneous Freezing

Abstract. This study examines the potential role of some types of mineral dust and mineral dust with sulfuric acid coatings as heterogeneous ice nuclei at cirrus temperatures. Commercially-available nanoscale powder samples of aluminum oxide, alumina-silicate and iron oxide were used as surrogates for atmospheric mineral dust particles, with and without multilayer coverage of sulfuric acid. A sample of Asian dust aerosol particles was also studied. Measurements of ice nucleation were made using a continuous-flow ice-thermal diffusion chamber (CFDC) operated to expose size-selected aerosol particles to temperatures between −45 and −60°C and a range of relative humidity above ice-saturated conditions. Pure metal oxide particles supported heterogeneous ice nucleation at lower relative humidities than those required to homogeneously freeze sulfuric acid solution particles at sizes larger than about 50 nm. The ice nucleation behavior of the same metal oxides coated with sulfuric acid indicate heterogeneous freezing at lower relative humidities than those calculated for homogeneous freezing of the diluted particle coatings. The effect of soluble coatings on the ice activation relative humidity varied with the respective uncoated core particle types, but for all types the heterogeneous freezing rates increased with particle size for the same thermodynamic conditions. For a selected size of 200 nm, the natural mineral dust particles were the most effective ice nuclei tested, supporting heterogeneous ice formation at an ice relative humidity of approximately 135%, irrespective of temperature. Modified homogeneous freezing parameterizations and theoretical formulations are shown to have application to the description of heterogeneous freezing of mineral dust-like particles with soluble coatings.

scholarly journals Ice nucleation by surrogates for atmospheric mineral dust and mineral dust/sulfate particles at cirrus temperatures

2005 ◽  
Vol 5 (10) ◽  
pp. 2617-2634 ◽  
Author(s):  
C. M. Archuleta ◽  
P. J. DeMott ◽  
S. M. Kreidenweis
Keyword(s):  
Sulfuric Acid ◽  
Relative Humidity ◽  
Mineral Dust ◽  
Aerosol Particles ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Nucleation Behavior ◽  
Ice Nuclei ◽  
Homogeneous Freezing

Abstract. This study examines the potential role of some types of mineral dust and mineral dust with sulfuric acid coatings as heterogeneous ice nuclei at cirrus temperatures. Commercially-available nanoscale powder samples of aluminum oxide, alumina-silicate and iron oxide were used as surrogates for atmospheric mineral dust particles, with and without multilayer coverage of sulfuric acid. A sample of Asian dust aerosol particles was also studied. Measurements of ice nucleation were made using a continuous-flow ice-thermal diffusion chamber (CFDC) operated to expose size-selected aerosol particles to temperatures between -45 and -60°C and a range of relative humidity above ice-saturated conditions. Pure metal oxide particles supported heterogeneous ice nucleation at lower relative humidities than those required to homogeneously freeze sulfuric acid solution particles at sizes larger than about 50 nm. The ice nucleation behavior of the same metal oxides coated with sulfuric acid indicate heterogeneous freezing at lower relative humidities than those calculated for homogeneous freezing of the diluted particle coatings. The effect of soluble coatings on the ice activation relative humidity varied with the respective uncoated core particle types, but for all types the heterogeneous freezing rates increased with particle size for the same thermodynamic conditions. For a selected size of 200 nm, the natural mineral dust particles were the most effective ice nuclei tested, supporting heterogeneous ice formation at an ice relative humidity of approximately 135%, irrespective of temperature. Modified homogeneous freezing parameterizations and theoretical formulations are shown to have application to the description of heterogeneous freezing of mineral dust-like particles with soluble coatings.

scholarly journals Condensed-phase biogenic–anthropogenic interactions with implications for cold cloud formation

2017 ◽  
Vol 200 ◽  
pp. 165-194 ◽  
Author(s):  
Joseph C. Charnawskas ◽  
Peter A. Alpert ◽  
Andrew T. Lambe ◽  
Thomas Berkemeier ◽  
Rachel E. O’Brien ◽  
...  
Keyword(s):  
Freezing Temperature ◽  
Organic Aerosol ◽  
Ice Nucleation ◽  
Mixed Phase ◽  
Cloud Formation ◽  
Fossil Fuel Combustion ◽  
Soot Particles ◽  
Ice Nuclei ◽  
Deliquescence Relative Humidity ◽  
Homogeneous Freezing

Anthropogenic and biogenic gas emissions contribute to the formation of secondary organic aerosol (SOA). When present, soot particles from fossil fuel combustion can acquire a coating of SOA. We investigate SOA–soot biogenic–anthropogenic interactions and their impact on ice nucleation in relation to the particles’ organic phase state. SOA particles were generated from the OH oxidation of naphthalene, α-pinene, longifolene, or isoprene, with or without the presence of sulfate or soot particles. Corresponding particle glass transition (Tg) and full deliquescence relative humidity (FDRH) were estimated using a numerical diffusion model. Longifolene SOA particles are solid-like and all biogenic SOA sulfate mixtures exhibit a core–shell configuration (i.e.a sulfate-rich core coated with SOA). Biogenic SOA with or without sulfate formed ice at conditions expected for homogeneous ice nucleation, in agreement with respectiveTgand FDRH. α-pinene SOA coated soot particles nucleated ice above the homogeneous freezing temperature with soot acting as ice nuclei (IN). At lower temperatures the α-pinene SOA coating can be semisolid, inducing ice nucleation. Naphthalene SOA coated soot particles acted as ice nuclei above and below the homogeneous freezing limit, which can be explained by the presence of a highly viscous SOA phase. Our results suggest that biogenic SOA does not play a significant role in mixed-phase cloud formation and the presence of sulfate renders this even less likely. However, anthropogenic SOA may have an enhancing effect on cloud glaciation under mixed-phase and cirrus cloud conditions compared to biogenic SOA that dominate during pre-industrial times or in pristine areas.

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 Feldspar minerals as efficient deposition ice nuclei

2013 ◽  
Vol 13 (22) ◽  
pp. 11175-11185 ◽  
Author(s):  
J. D. Yakobi-Hancock ◽  
L. A. Ladino ◽  
J. P. D. Abbatt
Keyword(s):  
Clay Minerals ◽  
Mojave Desert ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Lower Percentage ◽  
Lead Iodide ◽  
Experimental Procedure ◽  
Ice Nuclei ◽  
Mineral Dusts ◽  
Comparable Activity

Abstract. Mineral dusts are well known to be efficient ice nuclei, where the source of this efficiency has typically been attributed to the presence of clay minerals such as illite and kaolinite. However, the ice nucleating abilities of the more minor mineralogical components have not been as extensively examined. As a result, the deposition ice nucleation abilities of 24 atmospherically relevant mineral samples have been studied, using a continuous flow diffusion chamber at −40.0 ± 0.3 °C and particles size-selected at 200 nm. By focussing on using the same experimental procedure for all experiments, a relative ranking of the ice nucleating abilities of the samples was achieved. In addition, the ice nucleation behaviour of the pure minerals is compared to that of complex mixtures, such as Arizona Test Dust (ATD) and Mojave Desert Dust (MDD), and to lead iodide, which has been previously proposed for cloud seeding. Lead iodide was the most efficient ice nucleus (IN), requiring a critical relative humidity with respect to ice (RHi) of 122.0 ± 2.0% to activate 0.1% of the particles. MDD (RHi) 126.3 ± 3.4%) and ATD (RHi 129.5 ± 5.1%) have lower but comparable activity. From a set of clay minerals (kaolinite, illite, montmorillonite), non-clay minerals (e.g. hematite, magnetite, calcite, cerussite, quartz), and feldspar minerals (orthoclase, plagioclase) present in the atmospheric dusts, it was found that the feldspar minerals (particularly orthoclase) and some clays (particularly kaolinite) were the most efficient ice nuclei. Orthoclase and plagioclase were found to have critical RHi values of 127.1 ± 6.3% and 136.2 ± 1.3%, respectively. The presence of feldspars (specifically orthoclase) may play a significant role in the IN behaviour of mineral dusts despite their lower percentage in composition relative to clay minerals.

scholarly journals Ice cloud processing of ultra-viscous/glassy aerosol particles leads to enhanced ice nucleation ability

2012 ◽  
Vol 12 (18) ◽  
pp. 8589-8610 ◽  
Author(s):  
R. Wagner ◽  
O. Möhler ◽  
H. Saathoff ◽  
M. Schnaiter ◽  
J. Skrotzki ◽  
...  
Keyword(s):  
Glass Transition ◽  
Aerosol Particles ◽  
Ice Nucleation ◽  
Ice Formation ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Ice Cloud ◽  
Ice Nuclei ◽  
Freezing Cycle ◽  
Homogeneous Freezing

Abstract. The ice nucleation potential of airborne glassy aqueous aerosol particles has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 247 and 216 K. Four different solutes were used as proxies for oxygenated organic matter found in the atmosphere: raffinose, 4-hydroxy-3-methoxy-DL-mandelic acid (HMMA), levoglucosan, and a multi-component mixture of raffinose with five dicarboxylic acids and ammonium sulphate. Similar to previous experiments with citric acid aerosols, all particles were found to nucleate ice heterogeneously before reaching the homogeneous freezing threshold provided that the freezing cycles were started well below the respective glass transition temperatures of the compounds; this is discussed in detail in a separate article. In this contribution, we identify a further mechanism by which glassy aerosols can promote ice nucleation below the homogeneous freezing limit. If the glassy aerosol particles are probed in freezing cycles started only a few degrees below their respective glass transition temperatures, they enter the liquid regime of the state diagram upon increasing relative humidity (moisture-induced glass-to-liquid transition) before being able to act as heterogeneous ice nuclei. Ice formation then only occurs by homogeneous freezing at elevated supersaturation levels. When ice forms the remaining solution freeze concentrates and re-vitrifies. If these ice cloud processed glassy aerosol particles are then probed in a second freezing cycle at the same temperature, they catalyse ice formation at a supersaturation threshold between 5 and 30% with respect to ice. By analogy with the enhanced ice nucleation ability of insoluble ice nuclei like mineral dusts after they nucleate ice once, we refer to this phenomenon as pre-activation. We propose a number of possible explanations for why glassy aerosol particles that have re-vitrified in contact with the ice crystals during the preceding homogeneous freezing cycle exhibit pre-activation: they may retain small ice embryos in pores, have footprints on their surface which match the ice lattice, or simply have a much greater surface area or different surface microstructure compared to the unprocessed glassy aerosol particles. Pre-activation must be considered for the correct interpretation of experimental results on the heterogeneous ice nucleation ability of glassy aerosol particles and may provide a mechanism of producing a population of extremely efficient ice nuclei in the upper troposphere.

scholarly journals Kaolinite particles as ice nuclei: learning from the use of different kaolinite samples and different coatings

2014 ◽  
Vol 14 (11) ◽  
pp. 5529-5546 ◽  
Author(s):  
H. Wex ◽  
P. J. DeMott ◽  
Y. Tobo ◽  
S. Hartmann ◽  
M. Rösch ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Succinic Acid ◽  
Freezing Point ◽  
Active Surface ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Rate Coefficients ◽  
Ice Nuclei ◽  
Ability To Act ◽  
Immersion Freezing

Abstract. Kaolinite particles from two different sources (Fluka and Clay Minerals Society (CMS)) were examined with respect to their ability to act as ice nuclei (IN). This was done in the water-subsaturated regime where often deposition ice nucleation is assumed to occur, and for water-supersaturated conditions, i.e., in the immersion freezing mode. Measurements were done using a flow tube (the Leipzig Aerosol Cloud Interaction Simulator, LACIS) and a continuous-flow diffusion chamber (CFDC). Pure and coated particles were used, with coating thicknesses of a few nanometers or less, where the coating consisted of levoglucosan, succinic acid or sulfuric acid. In general, it was found that the coatings strongly reduced deposition ice nucleation. Remaining ice formation in the water-subsaturated regime could be attributed to immersion freezing, with particles immersed in concentrated solutions formed by the coatings. In the immersion freezing mode, ice nucleation rate coefficients jhet from both instruments agreed well with each other, particularly when the residence times in the instruments were accounted for. Fluka kaolinite particles coated with either levoglucosan or succinic acid showed the same IN activity as pure Fluka kaolinite particles; i.e., it can be assumed that these two types of coating did not alter the ice-active surface chemically, and that the coatings were diluted enough in the droplets that were formed prior to the ice nucleation, so that freezing point depression was negligible. However, Fluka kaolinite particles, which were either coated with pure sulfuric acid or were first coated with the acid and then exposed to additional water vapor, both showed a reduced ability to nucleate ice compared to the pure particles. For the CMS kaolinite particles, the ability to nucleate ice in the immersion freezing mode was similar for all examined particles, i.e., for the pure ones and the ones with the different types of coating. Moreover, jhet derived for the CMS kaolinite particles was comparable to jhet derived for Fluka kaolinite particles coated with sulfuric acid. This is suggestive for the Fluka kaolinite possessing a type of ice-nucleating surface feature which is not present on the CMS kaolinite, and which can be destroyed by reaction with sulfuric acid. This might be potassium feldspar.

scholarly journals Ice nucleation of ammonia gas exposed montmorillonite mineral dust particles

2007 ◽  
Vol 7 (14) ◽  
pp. 3923-3931 ◽  
Author(s):  
A. Salam ◽  
U. Lohmann ◽  
G. Lesins
Keyword(s):  
Room Temperature ◽  
Mineral Dust ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Experimental Conditions ◽  
Activation Temperature ◽  
Ammonia Gas ◽  
Ice Nuclei ◽  
Gas Exposure

Abstract. The ice nucleation characteristics of montmorillonite mineral dust aerosols with and without exposure to ammonia gas were measured at different atmospheric temperatures and relative humidities with a continuous flow diffusion chamber. The montmorillonite particles were exposed to pure (100%) and diluted ammonia gas (25 ppm) at room temperature in a stainless steel chamber. There was no significant change in the mineral dust particle size distribution due to the ammonia gas exposure. 100% pure ammonia gas exposure enhanced the ice nucleating fraction of montmorillonite mineral dust particles 3 to 8 times at 90% relative humidity with respect to water (RHw) and 5 to 8 times at 100% RHw for 120 min exposure time compared to unexposed montmorillonite within our experimental conditions. The percentages of active ice nuclei were 2 to 8 times higher at 90% RHw and 2 to 7 times higher at 100% RHw in 25 ppm ammonia exposed montmorillonite compared to unexposed montmorillonite. All montmorillonite particles are more efficient as ice nuclei with increasing relative humidities and decreasing temperatures. The activation temperature of montmorillonite exposed to 100% pure ammonia was 15°C higher than for unexposed montmorillonite particles at 90% RHw. In the 25 ppm ammonia exposed montmorillonite experiments, the activation temperature was 10°C warmer than unexposed montmorillonite at 90% RHw. Degassing does not reverse the ice nucleating ability of ammonia exposed montmorillonite mineral dust particles suggesting that the ammonia is chemically bound to the montmorillonite particle. This is the first experimental evidence that ammonia gas exposed montmorillonite mineral dust particles can enhance its activation as ice nuclei and that the activation can occur at temperatures warmer than –10°C where natural atmospheric ice nuclei are very scarce.

scholarly journals On the ice nucleation spectrum

2011 ◽  
Vol 11 (11) ◽  
pp. 29601-29646 ◽  
Author(s):  
D. Barahona
Keyword(s):  
Surface Composition ◽  
Ice Nucleation ◽  
Atmospheric Modeling ◽  
Cloud Formation ◽  
Volume Distribution ◽  
Ice Crystal ◽  
Ice Nuclei ◽  
New Formulation ◽  
Homogeneous Freezing ◽  
Heterogeneous Ice Nucleation

Abstract. This work presents a novel formulation of the ice nucleation spectrum, i.e. the function relating the ice crystal concentration to cloud formation conditions and aerosol properties. The new formulation relies on a statistical view of the ice nucleation process and explicitly accounts for the dependency of the ice crystal concentration on temperature, supersaturation, cooling rate, and particle size, and, in the case of heterogeneous ice nucleation, on the distributions of particle area and surface composition. The new formulation is used to generate ice nucleation parameterizations for the homogeneous freezing of cloud droplets and the heterogeneous deposition ice nucleation on dust and soot ice nuclei. For homogeneous freezing, it was found that by increasing the dispersion in the droplet volume distribution the fraction of supercooled droplets in the population increases. For heterogeneous ice nucleation it was found that ice nucleation on efficient ice nuclei (IN) shows features consistent with the singular hypothesis (characterized by a lack of temporal dependency of the ice nucleation spectrum) whereas less efficient IN tend to display stochastic behavior. Analysis of empirical nucleation spectra suggested that inferring the aerosol heterogeneous ice nucleation properties from measurements of the onset supersaturation and temperature may carry significant error as the variability in ice nucleation properties within the aerosol population is not accounted for. This work provides a simple and rigorous ice nucleation framework were theoretical predictions, laboratory measurements and field campaign data can be reconciled, and that is suitable for application in atmospheric modeling studies.

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