Ice nucleation activity of iron oxides via immersion freezing and an examination of the high ice nucleation activity of FeO

2021 ◽  
Vol 23 (5) ◽  
pp. 3565-3573
Author(s):  
Esther Chong ◽  
Katherine E. Marak ◽  
Yang Li ◽  
Miriam Arak Freedman
Keyword(s):  
Iron Oxides ◽  
Functional Groups ◽  
Ice Nucleation ◽  
Mechanical Processing ◽  
Immersion Freezing ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

FeO has enhanced ice nucleation activity due to functional groups that are exposed upon mechanical processing.

scholarly journals Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash

2015 ◽  
Vol 15 (13) ◽  
pp. 7523-7536 ◽  
Author(s):  
G. P. Schill ◽  
K. Genareau ◽  
M. A. Tolbert
Keyword(s):  
Volcanic Ash ◽  
Mineral Dust ◽  
Global Climate ◽  
Volcanic Eruptions ◽  
Silica Content ◽  
Ice Nucleation ◽  
Ice Nuclei ◽  
Immersion Freezing ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Ice nucleation of volcanic ash controls both ash aggregation and cloud glaciation, which affect atmospheric transport and global climate. Previously, it has been suggested that there is one characteristic ice nucleation efficiency for all volcanic ash, regardless of its composition, when accounting for surface area; however, this claim is derived from data from only two volcanic eruptions. In this work, we have studied the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman microscopy coupled to an environmental cell. Ash from the Fuego (basaltic ash, Guatemala), Soufrière Hills (andesitic ash, Montserrat), and Taupo (Oruanui eruption, rhyolitic ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. In the present study, we find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice from 225 to 235 K at ice saturation ratios of 1.05 ± 0.01, comparable to the mineral dust proxy kaolinite. Since depositional ice nucleation will be more important at colder temperatures, fine volcanic ash may represent a global source of cold-cloud ice nuclei. For immersion freezing relevant to mixed-phase clouds, however, only the Oruanui ash exhibited appreciable heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

Acidic processing of fly ash: chemical characterization, morphology, and immersion freezing

2018 ◽  
Vol 20 (11) ◽  
pp. 1581-1592 ◽  
Author(s):  
Delanie J. Losey ◽  
Sarah K. Sihvonen ◽  
Daniel P. Veghte ◽  
Esther Chong ◽  
Miriam Arak Freedman
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Chemical Characterization ◽  
Ice Nucleation ◽  
Immersion Freezing ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

The ice nucleation activity of fly ash, a byproduct of coal combustion, depends on its composition.

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.

scholarly journals A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of 17 ice nucleation measurement techniques

2015 ◽  
Vol 15 (5) ◽  
pp. 2489-2518 ◽  
Author(s):  
N. Hiranuma ◽  
S. Augustin-Bauditz ◽  
H. Bingemer ◽  
C. Budke ◽  
J. Curtius ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Surface Area ◽  
Mineral Dust ◽  
Measurement Techniques ◽  
Ice Nucleation ◽  
Measurement Methods ◽  
Dust Particles ◽  
Immersion Freezing ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Immersion freezing is the most relevant heterogeneous ice nucleation mechanism through which ice crystals are formed in mixed-phase clouds. In recent years, an increasing number of laboratory experiments utilizing a variety of instruments have examined immersion freezing activity of atmospherically relevant ice-nucleating particles. However, an intercomparison of these laboratory results is a difficult task because investigators have used different ice nucleation (IN) measurement methods to produce these results. A remaining challenge is to explore the sensitivity and accuracy of these techniques and to understand how the IN results are potentially influenced or biased by experimental parameters associated with these techniques. Within the framework of INUIT (Ice Nuclei Research Unit), we distributed an illite-rich sample (illite NX) as a representative surrogate for atmospheric mineral dust particles to investigators to perform immersion freezing experiments using different IN measurement methods and to obtain IN data as a function of particle concentration, temperature (T), cooling rate and nucleation time. A total of 17 measurement methods were involved in the data intercomparison. Experiments with seven instruments started with the test sample pre-suspended in water before cooling, while 10 other instruments employed water vapor condensation onto dry-dispersed particles followed by immersion freezing. The resulting comprehensive immersion freezing data set was evaluated using the ice nucleation active surface-site density, ns, to develop a representative ns(T) spectrum that spans a wide temperature range (−37 °C < T < −11 °C) and covers 9 orders of magnitude in ns. In general, the 17 immersion freezing measurement techniques deviate, within a range of about 8 °C in terms of temperature, by 3 orders of magnitude with respect to ns. In addition, we show evidence that the immersion freezing efficiency expressed in ns of illite NX particles is relatively independent of droplet size, particle mass in suspension, particle size and cooling rate during freezing. A strong temperature dependence and weak time and size dependence of the immersion freezing efficiency of illite-rich clay mineral particles enabled the ns parameterization solely as a function of temperature. We also characterized the ns(T) spectra and identified a section with a steep slope between −20 and −27 °C, where a large fraction of active sites of our test dust may trigger immersion freezing. This slope was followed by a region with a gentler slope at temperatures below −27 °C. While the agreement between different instruments was reasonable below ~ −27 °C, there seemed to be a different trend in the temperature-dependent ice nucleation activity from the suspension and dry-dispersed particle measurements for this mineral dust, in particular at higher temperatures. For instance, the ice nucleation activity expressed in ns was smaller for the average of the wet suspended samples and higher for the average of the dry-dispersed aerosol samples between about −27 and −18 °C. Only instruments making measurements with wet suspended samples were able to measure ice nucleation above −18 °C. A possible explanation for the deviation between −27 and −18 °C is discussed. Multiple exponential distribution fits in both linear and log space for both specific surface area-based ns(T) and geometric surface area-based ns(T) are provided. These new fits, constrained by using identical reference samples, will help to compare IN measurement methods that are not included in the present study and IN data from future IN instruments.

scholarly journals Deposition and immersion mode nucleation of ice by three distinct samples of volcanic ash using Raman spectroscopy

2015 ◽  
Vol 15 (2) ◽  
pp. 1385-1420 ◽  
Author(s):  
G. P. Schill ◽  
K. Genareau ◽  
M. A. Tolbert
Keyword(s):  
Volcanic Ash ◽  
Mineral Dust ◽  
Global Climate ◽  
Volcanic Eruptions ◽  
Silica Content ◽  
Ice Nucleation ◽  
Ice Nuclei ◽  
Immersion Freezing ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Ice nucleation on volcanic ash controls both ash aggregation and cloud glaciation, which affect atmospheric transport and global climate. Previously, it has been suggested that there is one characteristic ice nucleation efficiency for all volcanic ash, regardless of its composition, when accounting for surface area; however, this claim is derived from data from only two volcanic eruptions. In this work, we have studied the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman Microscopy coupled to an environmental cell. Ash from the Fuego (basaltic ash, Guatemala), Soufrière Hills (andesitic ash, Montserrat), and Taupo (Oruanui euption, rhyolitic ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. In the present study, we find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice from 225–235 K at ice saturation ratios of 1.05 ± 0.01, comparable to the mineral dust proxy kaolinite. Since depositional ice nucleation will be more important at colder temperatures, fine volcanic ash may represent a global source of cold-cloud ice nuclei. For immersion freezing relevant to mixed-phase clouds, however, only the Oruanui ash exhibited heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

scholarly journals Urediospores of rust fungi are ice nucleation active at > −10 °C and harbor ice nucleation active bacteria

2013 ◽  
Vol 13 (8) ◽  
pp. 4223-4233 ◽  
Author(s):  
C. E. Morris ◽  
D. C. Sands ◽  
C. Glaux ◽  
J. Samsatly ◽  
S. Asaad ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Rust Fungi ◽  
Plant Diseases ◽  
Ice Nuclei ◽  
Ice Nucleators ◽  
The Usa ◽  
Immersion Freezing ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause illustrate the important role of rainfall in their life history. Based on this insight we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections of 7 species of weeds in France, from coffee in Brazil and from field and greenhouse-grown wheat in France, the USA, Turkey and Syria. Immersion freezing was used to determine freezing onset temperatures and the abundance of ice nuclei in suspensions of washed spores. Microbiological analyses of spores from France, the USA and Brazil, and subsequent tests of the ice nucleation activity of the bacteria associated with spores were deployed to quantify the contribution of bacteria to the ice nucleation activity of the spores. All samples of spores were ice nucleation active, having freezing onset temperatures as high as −4 °C. Spores in most of the samples carried cells of ice nucleation-active strains of the bacterium Pseudomonas syringae (at rates of less than 1 bacterial cell per 100 urediospores), but bacterial INA accounted for only a small fraction of the INA observed in spore suspensions. Changes in the INA of spore suspensions after treatment with lysozyme suggest that the INA of urediospores involves a polysaccharide. Based on data from the literature, we have estimated the concentrations of urediospores in air at cloud height and in rainfall. These quantities are very similar to those reported for other biological ice nucleators in these same substrates. However, at cloud level convective activity leads to widely varying concentrations of particles of surface origin, so that mean concentrations can underestimate their possible effects on clouds. We propose that spatial and temporal concentrations of biological ice nucleators active at temperatures > −10 °C and the specific conditions under which they can influence cloud glaciation need to be further evaluated so as to understand how evolutionary processes could have positively selected for INA.

scholarly journals Seasonal ice nucleation activity of water samples from alpine rivers and lakes in Obergurgl, Austria

2021 ◽  
pp. 149442
Author(s):  
Philipp Baloh ◽  
Regina Hanlon ◽  
Christopher Anderson ◽  
Eoin Dolan ◽  
Gernot Pacholik ◽  
...  
Keyword(s):  
Water Samples ◽  
Ice Nucleation ◽  
Rivers And Lakes ◽  
Nucleation Activity ◽  
Alpine Rivers ◽  
Ice Nucleation Activity

scholarly journals Effects of atmospheric conditions on ice nucleation activity of <i>Pseudomonas</i>

2012 ◽  
Vol 12 (22) ◽  
pp. 10667-10677 ◽  
Author(s):  
E. Attard ◽  
H. Yang ◽  
A.-M. Delort ◽  
P. Amato ◽  
U. Pöschl ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Acidic Ph ◽  
Bacterial Cells ◽  
Atmospheric Conditions ◽  
Ice Nucleation Protein ◽  
Ice Melt ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i) acidic pH (ii) NO2 and O3 exposure and (iii) UV-A exposure on the ice nucleation activity (INA) of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

scholarly journals Ice nucleation activity identified in some phytopathogenic Fusarium species

2005 ◽  
Vol 77 (2) ◽  
pp. 83-92 ◽  
Author(s):  
C. Richard ◽  
J.-G. Martin ◽  
S. Pouleur
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Species ◽  
Freezing Temperature ◽  
Ice Nucleation ◽  
Free Living ◽  
Factors Affecting ◽  
Pure Cultures ◽  
Nucleation Activity ◽  
Ice Nucleation Activity ◽  
Positive Controls

In order to know which species of Fusarium are ice nucleating and to determine the factors affecting their pathogenicity, ice nucleation activity (INA) was examined in Fusarium oxysporum, F. sporotrichioides, and F. tricinctum. Positive controls (lna+) used were F. acuminatum and F. avenaceum. The test for fungal INA was done with a simple and rapid tube nucleation assay. Twelve out of the 42 F. oxysporum isolates, and 8 out of 14 F. tricinctum isolates were lna+. No INA was detected in F sporotrichioides. In this test the threshold freezing temperature tended to increase with culture age, reaching a peak of -1°C in a few samples, which is as high as the warmest INA reported for bacteria, and higher than the INA detected in pure cultures of free-living fungi, lichen fungi, lichen algae and cyanobacteria. This is the first report of INA for F oxysporum.

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