scholarly journals Laboratory study of heterogeneous ice nucleation in deposition mode of montmorillonite mineral dust particles aged with ammonia, sulfur dioxide, and ozone at polluted atmospheric concentrations

2008 ◽  
Vol 1 (3) ◽  
pp. 135-142 ◽  
Author(s):  
Abdus Salam ◽  
Glen Lesins ◽  
Ulrike Lohmann
Keyword(s):  
Sulfur Dioxide ◽  
Laboratory Study ◽  
Mineral Dust ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Atmospheric Concentrations ◽  
Deposition Mode ◽  
Heterogeneous Ice Nucleation

scholarly journals Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles

2013 ◽  
Vol 13 (17) ◽  
pp. 9097-9118 ◽  
Author(s):  
Z. A. Kanji ◽  
A. Welti ◽  
C. Chou ◽  
O. Stetzer ◽  
U. Lohmann
Keyword(s):  
Mineral Dust ◽  
Active Surface ◽  
Freezing Temperature ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Laboratory Studies ◽  
Ambient Conditions ◽  
First Results ◽  
Deposition Mode ◽  
Heterogeneous Ice Nucleation

Abstract. Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature (T) and relative humidity (RH), as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulfate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long-range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 < T < 263 K. Heterogeneous ice nucleation of untreated kaolinite (Ka) and Arizona Test Dust (ATD) particles is compared to corresponding aged particles that are subjected to ozone concentrations of 0.4–4.3 ppmv in a stainless steel aerosol tank. The portable ice nucleation counter (PINC) and immersion chamber combined with the Zurich ice nucleation chamber (IMCA-ZINC) are used to conduct deposition and immersion mode measurements, respectively. Ice active fractions as well as ice active surface site densities (ns) are reported and observed to increase as a function of decreasing temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. We also present the first results to show a suppression of heterogeneous ice nucleation activity without the condensation of a coating of (in)organic material. In immersion mode, low ozone exposed Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka, whereas high ozone exposed ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder than that of untreated ATD. In deposition mode, low exposure Ka had ice active fractions of an order of magnitude higher than untreated Ka, whereas high ozone exposed ATD had ice active fractions up to a factor of 4 lower than untreated ATD. From our results, we derive and present parameterizations in terms of ns(T) that can be used in models to predict ice nuclei concentrations based on available aerosol surface area.

scholarly journals Chemical processing does not always impair heterogeneous ice nucleation of mineral dust particles

2010 ◽  
Vol 37 (24) ◽  
pp. n/a-n/a ◽  
Author(s):  
Ryan C. Sullivan ◽  
Lorena Miñambres ◽  
Paul J. DeMott ◽  
Anthony J. Prenni ◽  
Christian M. Carrico ◽  
...  
Keyword(s):  
Mineral Dust ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Chemical Processing ◽  
Heterogeneous Ice Nucleation

scholarly journals A laboratory study of the heterogeneous uptake and oxidation of sulfur dioxide on mineral dust particles

2002 ◽  
Vol 107 (D23) ◽  
pp. ACH 16-1-ACH 16-9 ◽  
Author(s):  
C. R. Usher ◽  
H. Al-Hosney ◽  
S. Carlos-Cuellar ◽  
V. H. Grassian
Keyword(s):  
Sulfur Dioxide ◽  
Laboratory Study ◽  
Mineral Dust ◽  
Dust Particles

scholarly journals Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles

2013 ◽  
Vol 13 (4) ◽  
pp. 8701-8767 ◽  
Author(s):  
Z. A. Kanji ◽  
A. Welti ◽  
C. Chou ◽  
O. Stetzer ◽  
U. Lohmann
Keyword(s):  
Organic Compounds ◽  
Mineral Dust ◽  
Freezing Temperature ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Laboratory Studies ◽  
High Exposure ◽  
First Results ◽  
Low Exposure ◽  
Deposition Mode

Abstract. Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature (T) and relative humidity (RH), as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulphate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 < T < 263 K that will represent ageing but not internal mixing with in(organic) compounds. Heterogeneous ice nucleation of untreated kaolinite (Ka) and Arizona Test Dust (ATD) particles is compared to corresponding aged particles that are subjected to ozone exposures of 0.4–4.3 ppmv in a stainless steel aerosol tank. The portable ice nucleation counter (PINC) and immersion chamber combined with the Zurich ice nucleation chamber (IMCA – ZINC) are used to conduct deposition and immersion mode measurements respectively. Ice active fractions as well as ice active surface site densities (ns) are reported and observed to increase as a function of temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. Additionally, these are also the first results to show a suppression of heterogeneous ice nucleation without the condensation of a coating of (in)organic material. In immersion mode, low exposure Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka whereas high exposure ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder than that of untreated ATD. In deposition mode, low exposure Ka had ice active fractions of an order of magnitude higher than untreated Ka, where as high exposure ATD had ice active fractions up to a factor of 4 lower than untreated ATD. Based on our results, we present parameterizations in terms of ns(T) that can represent ice nucleation of atmospherically aged and non-aged particles for both immersion and deposition mode. We find excellent agreement (to within less than a factor of 2) with field measurements when parameterizations derived from our results are used to predict ice nuclei concentrations in the troposphere.

Heterogeneous ice nucleation of mineral dust particles exposed to ozone

2013 ◽  
Author(s):  
Zamin A. Kanji ◽  
André Welti ◽  
Cédric Chou ◽  
Olaf Stetzer ◽  
Ulrike Lohmann
Keyword(s):  
Mineral Dust ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Heterogeneous Ice Nucleation

Effect of water confinement on heterogeneous ice nucleation

2020 ◽  
Author(s):  
Olli Pakarinen ◽  
Golnaz Roudsari ◽  
Bernhard Reischl ◽  
Hanna Vehkamäki
Keyword(s):  
Active Sites ◽  
Mineral Dust ◽  
Pure Water ◽  
Wedge Angle ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Small Surface ◽  
Surface Features ◽  
Effect Of Water ◽  
Heterogeneous Ice Nucleation

&lt;p&gt;Understanding the formation of ice is of great importance to many fields of science. Sufficiently pure water droplets can remain in the supercooled liquid phase to nearly -40 &amp;#186;C. Crystallization of ice in the atmosphere therefore typically occurs in the presence of ice nucleating particles (INPs), such as mineral dust or organic particles. These can trigger heterogeneous ice nucleation at clearly higher temperatures. Therefore, a better understanding of how the various types of aerosol particles present in the atmosphere affect ice nucleation (IN) in clouds would be an important advance in the field of atmospheric science.&lt;/p&gt;&lt;p&gt;Experiments have shown in great detail what is the IN activity of different types of compounds, and recently also clarified the importance of small surface features such as surface defects, which function as active sites for ice nucleation. On most mineral dust particles, there may be only a few active sites for ice nucleation, typically around defects or pits (Holden et al., 2019). Simulations also showed enhanced ice nucleation efficiency in confined geometry such as wedges or pits (Bi, Cao and Li, 2017).&lt;/p&gt;&lt;p&gt;We systematically study the effect of water confining defects with different surface geometries; pyramidal pits, wedge-shaped cracks and slits with water confined between two parallel walls, using molecular dynamics simulations with both all-atom and monatomic water models, and show that that these defects enhance ice nucleation both at large supercooling and at very low supercooling.&lt;/p&gt;&lt;p&gt;Results of simulations on pyramidal pits on Si (100) surfaces, realizable experimentally, show a clear (&amp;#8710;T &gt; 10 &amp;#186;C) enhancement of ice nucleation compared to the very weakly IN active flat Si (100) or Si (111) surfaces. To show that water confinement can enhance IN also at very low supercooling, at temperatures above &amp;#8722;10 &amp;#186;C, we constructed wedge shaped structures with &amp;#946;-AgI (0001) surface as one of the two side walls, and slit systems by positioning two &amp;#946;-AgI (0001) slabs to mirror each other to cancel the dipole field from the polar surfaces. Depending on the wedge angle or the relation of the width of the gap between two slabs in the slit systems with the thickness of ice bilayers, ice nucleation can be clearly enhanced or hindered. We also clarify the different mechanisms behind IN enhancement at different geometries.&lt;/p&gt;&lt;p&gt;Understanding the enhanced activity at surface features may enable characterization of ice nucleation active sites on some atmospheric particles, creation of IN active sites at otherwise poorly active materials such as silicon, and also enable enhancing very active IN materials such as AgI, to nucleate ice at nearly zero supercooling.&lt;/p&gt;&lt;p&gt;This work was supported by the Academy of Finland Center of Excellence programme (grant no. 307331) and ARKTIKO project 285067 ICINA, by University of Helsinki, Faculty of Science ATMATH project, by the National Center for Meteorology (NCM), Abu Dhabi, UAE, under the UAE Research Program for Rain Enhancement Science, as well as ERC Grant 692891-DAMOCLES. Supercomputing resources were provided by CSC&amp;#8211;IT Center for Science, Ltd, Finland.&lt;/p&gt;

scholarly journals Integrating laboratory and field data to quantify the immersion freezing ice nucleation activity of mineral dust particles

2015 ◽  
Vol 15 (1) ◽  
pp. 393-409 ◽  
Author(s):  
P. J. DeMott ◽  
A. J. Prenni ◽  
G. R. McMeeking ◽  
R. C. Sullivan ◽  
M. D. Petters ◽  
...  
Keyword(s):  
Mineral Dust ◽  
Order Approximation ◽  
Ice Nucleation ◽  
Calibration Factor ◽  
Dust Particles ◽  
Single Type ◽  
Aerosol Layer ◽  
Atmospheric Measurements ◽  
Immersion Freezing ◽  
Nucleation Activity

Abstract. Data from both laboratory studies and atmospheric measurements are used to develop an empirical parameterization for the immersion freezing activity of natural mineral dust particles. Measurements made with the Colorado State University (CSU) continuous flow diffusion chamber (CFDC) when processing mineral dust aerosols at a nominal 105% relative humidity with respect to water (RHw) are taken as a measure of the immersion freezing nucleation activity of particles. Ice active frozen fractions vs. temperature for dusts representative of Saharan and Asian desert sources were consistent with similar measurements in atmospheric dust plumes for a limited set of comparisons available. The parameterization developed follows the form of one suggested previously for atmospheric particles of non-specific composition in quantifying ice nucleating particle concentrations as functions of temperature and the total number concentration of particles larger than 0.5 μm diameter. Such an approach does not explicitly account for surface area and time dependencies for ice nucleation, but sufficiently encapsulates the activation properties for potential use in regional and global modeling simulations, and possible application in developing remote sensing retrievals for ice nucleating particles. A calibration factor is introduced to account for the apparent underestimate (by approximately 3, on average) of the immersion freezing fraction of mineral dust particles for CSU CFDC data processed at an RHw of 105% vs. maximum fractions active at higher RHw. Instrumental factors that affect activation behavior vs. RHw in CFDC instruments remain to be fully explored in future studies. Nevertheless, the use of this calibration factor is supported by comparison to ice activation data obtained for the same aerosols from Aerosol Interactions and Dynamics of the Atmosphere (AIDA) expansion chamber cloud parcel experiments. Further comparison of the new parameterization, including calibration correction, to predictions of the immersion freezing surface active site density parameterization for mineral dust particles, developed separately from AIDA experimental data alone, shows excellent agreement for data collected in a descent through a Saharan aerosol layer. These studies support the utility of laboratory measurements to obtain atmospherically relevant data on the ice nucleation properties of dust and other particle types, and suggest the suitability of considering all mineral dust as a single type of ice nucleating particle as a useful first-order approximation in numerical modeling investigations.

scholarly journals Heterogeneous ice nucleation on dust particles sourced from nine deserts worldwide – Part 2: Deposition nucleation and condensation freezing

2019 ◽  
Vol 19 (2) ◽  
pp. 1059-1076 ◽  
Author(s):  
Yvonne Boose ◽  
Philipp Baloh ◽  
Michael Plötze ◽  
Johannes Ofner ◽  
Hinrich Grothe ◽  
...  
Keyword(s):  
Active Sites ◽  
Mineral Dust ◽  
Atmospheric Transport ◽  
Chemical Imaging ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Full Potential ◽  
Nucleation Behavior ◽  
Crystal Water ◽  
Desert Dust

Abstract. Mineral dust particles from deserts are amongst the most common ice nucleating particles in the atmosphere. The mineralogy of desert dust differs depending on the source region and can further fractionate during the dust emission processes. Mineralogy to a large extent explains the ice nucleation behavior of desert aerosol, but not entirely. Apart from pure mineral dust, desert aerosol particles often exhibit a coating or are mixed with small amounts of biological material. Aging on the ground or during atmospheric transport can deactivate nucleation sites, thus strong ice nucleating minerals may not exhibit their full potential. In the partner paper of this work, it was shown that mineralogy determines most but not all of the ice nucleation behavior in the immersion mode found for desert dust. In this study, the influence of semi-volatile organic compounds and the presence of crystal water on the ice nucleation behavior of desert aerosol is investigated. This work focuses on the deposition and condensation ice nucleation modes at temperatures between 238 and 242 K of 18 dust samples sourced from nine deserts worldwide. Chemical imaging of the particles' surface is used to determine the cause of the observed differences in ice nucleation. It is found that, while the ice nucleation ability of the majority of the dust samples is dominated by their quartz and feldspar content, in one carbonaceous sample it is mostly caused by organic matter, potentially cellulose and/or proteins. In contrast, the ice nucleation ability of an airborne Saharan sample is found to be diminished, likely by semi-volatile species covering ice nucleation active sites of the minerals. This study shows that in addition to mineralogy, other factors such as organics and crystal water content can alter the ice nucleation behavior of desert aerosol during atmospheric transport in various ways.

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