scholarly journals Organic matter matters for ice nuclei of agricultural soil origin

2014 ◽  
Vol 14 (7) ◽  
pp. 9705-9728 ◽  
Author(s):  
Y. Tobo ◽  
P. J. DeMott ◽  
T. C. J. Hill ◽  
A. J. Prenni ◽  
N. G. Swoboda-Colberg ◽  
...  
Keyword(s):  
Organic Matter ◽  
Agricultural Soil ◽  
Source Region ◽  
Ice Nucleation ◽  
Desert Soil ◽  
Composition Analysis ◽  
Ice Nuclei ◽  
Show Evidence ◽  
Dry Heating

Abstract. Heterogeneous ice nucleation is a~crucial process for forming ice-containing clouds and subsequent ice-induced precipitation. The importance for ice nucleation of airborne desert soil dusts composed predominantly of minerals is relatively well understood. On the other hand, the potential influence of agricultural soil dusts on ice nucleation has been poorly recognized, despite recent estimates that they may account for up to ∼25% of the global atmospheric dust load. We have conducted freezing experiments with various dusts, including agricultural soil dusts derived from the largest dust source region in North America. Here we show evidence for the significant role of soil organic matter (SOM) in particles acting as ice nuclei (IN) under mixed-phase cloud conditions. We find that the ice nucleating ability of the agricultural soil dusts is similar to that of desert soil dusts, but is reduced to almost the same level as that of clay minerals (e.g., kaolinite) after either H2O2 digestion or dry heating to 300 °C. In addition, based on chemical composition analysis, we show that organic-rich particles are more important than mineral particles for the ice nucleating ability of the agricultural soil dusts at temperatures warmer than about −36 °C. Finally, we suggest that such organic-rich particles of agricultural origin (namely, SOM particles) may contribute significantly to the ubiquity of organic-rich IN in the global atmosphere.

scholarly journals Organic matter matters for ice nuclei of agricultural soil origin

2014 ◽  
Vol 14 (16) ◽  
pp. 8521-8531 ◽  
Author(s):  
Y. Tobo ◽  
P. J. DeMott ◽  
T. C. J. Hill ◽  
A. J. Prenni ◽  
N. G. Swoboda-Colberg ◽  
...  
Keyword(s):  
Organic Matter ◽  
Agricultural Soil ◽  
Source Region ◽  
Ice Nucleation ◽  
Desert Soil ◽  
Composition Analysis ◽  
Ice Nuclei ◽  
Show Evidence ◽  
Dry Heating

Abstract. Heterogeneous ice nucleation is a crucial process for forming ice-containing clouds and subsequent ice-induced precipitation. The importance for ice nucleation by airborne desert soil dusts composed predominantly of minerals is widely acknowledged. However, the potential influence of agricultural soil dusts on ice nucleation has been poorly recognized, despite recent estimates that they may account for up to 20–25% of the global atmospheric dust load. We have conducted freezing experiments with various dusts, including agricultural soil dusts derived from the largest dust-source region in North America. Here we show evidence for the significant role of soil organic matter (SOM) in particles acting as ice nuclei (IN) under mixed-phase cloud conditions. We find that the ice-nucleating ability of the agricultural soil dusts is similar to that of desert soil dusts, but is clearly reduced after either H2O2 digestion or dry heating to 300 °C. In addition, based on chemical composition analysis, we demonstrate that organic-rich particles are more important than mineral particles for the ice-nucleating ability of the agricultural soil dusts at temperatures warmer than about −36 °C. Finally, we suggest that such organic-rich particles of agricultural origin (namely, SOM particles) may contribute significantly to the ubiquity of organic-rich IN in the global atmosphere.

scholarly journals Investigating the role of dust in ice nucleation within clouds and further effects on regional weather system over East Asia – Part I: model development and validation

2017 ◽  
Author(s):  
Lin Su ◽  
Jimmy C.H. Fung
Keyword(s):  
East Asia ◽  
Source Region ◽  
Model Development ◽  
Ice Nucleation ◽  
Dust Particles ◽  
Weather System ◽  
Microphysics Scheme ◽  
Ice Nuclei ◽  
Cloud Ice ◽  
Ice Water

Abstract. The GOCART–Thompson microphysics scheme, which couples the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model and aerosol-aware Thompson microphysics scheme, has been implemented in the Weather Research and Forecast model coupled with Chemistry (WRF-Chem), to quantify and evaluate the effect of dust on the ice nucleation process in the atmosphere by serving as ice nuclei. The performance of the GOCART-Thompson microphysics scheme in simulating the effect of dust in atmospheric ice nucleation is then evaluated over East Asia during spring in 2012, a typical dust-intensive season. Based upon the dust emission reasonably reproduced by WRF-Chem, the effect of dust on atmospheric cloud ice water content is well reproduced. With abundant dust particles serving as ice nuclei, the simulated ice water mixing ratio and ice crystal number concentration increases by one order of magnitude over the dust source region and downwind areas during the investigated period. The comparison with ice water path from satellite observations demonstrated that the simulation of cloud ice profile is substantially improved by applying the GOCART–Thompson microphysics scheme in the simulations. Additional sensitivity experiments are carried out to optimize the parameters in the ice nucleation parameterization in the GOCART–Thompson microphysics scheme, and the results suggest that the calibration factor in the ice nucleation scheme should be set to 3 or 4. Lowering the threshold relative humidity with respect to ice to 100 % for the ice nucleation parameterization leads to further improvement in cloud ice simulation.

scholarly journals Mexican agricultural soil dust as a source of ice nucleating particles

2021 ◽  
Author(s):  
Diana L. Pereira ◽  
Irma Gavilán ◽  
Consuelo Letechipía ◽  
Graciela B. Raga ◽  
Teresa Pi Puig ◽  
...  
Keyword(s):  
Agricultural Soil ◽  
Agricultural Sector ◽  
Agricultural Soils ◽  
Ice Nucleation ◽  
Soil Dust ◽  
High Concentration ◽  
Mineralogical Analysis ◽  
Immersion Freezing ◽  
Mixed Phase Clouds

Abstract. Agricultural soil erosion, both mechanical and eolic, may impact cloud processes as some aerosol particles are able to facilitate ice crystals formation. Given the large agricultural sector in Mexico, this study investigates the ice nucleating abilities of agricultural dust collected at different sites and generated in the laboratory. The immersion freezing mechanism of ice nucleation was simulated in the laboratory via the Universidad Nacional Autónoma de México (UNAM)- Micro Orifice Uniform Deposit Impactor (MOUDI)-Droplet freezing technique (DFT) (UNAM-MOUDI-DFT). The results show that agricultural dust from the Mexican territory promote ice formation in a temperature range from −11.8 ºC to −34.5 ºC, with ice nucleating particle (INP) concentrations between 0.11 L−1 and 41.8 L−1. Furthermore, aerosol samples generated in the laboratory are more efficient than those collected in the field, with T50 values (i.e., the temperature at which 50 % of the droplets freeze) higher by more than 2.9 ºC. The mineralogical analysis indicated a high concentration of feldspars i.e., K-feldspar and plagioclase (> 40 %) in most of the aerosol and soil samples, with K-feldspar significantly correlated with the T50 of particles with sizes between 1.8 µm and 3.2 µm. Similarly, the organic carbon (OC) was correlated with the efficiency of aerosol samples from 3.2 µm to 5.6 µm and 1.0 µm to 1.8 µm. Finally, a decrease in the efficiency as INPs, after heating the samples at 300 ºC for 2 h, evidenced that the organic matter from agricultural soils can influence the role of INPs in mixed-phase clouds.

THE ROLE OF ANTIFREEZE PROTEIN TYPE I IN ICE NUCLEATION INHIBITION

2006 ◽  
Vol 01 (03) ◽  
pp. 271-278 ◽  
Author(s):  
NING DU ◽  
X. Y. LIU ◽  
H. LI ◽  
CHOY LEONG HEW
Keyword(s):  
Antifreeze Proteins ◽  
Antifreeze Protein ◽  
Ice Nucleation ◽  
Type I ◽  
Nucleation Process ◽  
Nucleation Barrier ◽  
Ice Nuclei ◽  
Nucleation Model ◽  
Ice Crystallization

The effect of Antifreeze Protein Type I (AFP I, one type of fish antifreeze protein) on ice crystallization was examined quantitatively based on a "micro-sized ice nucleation" technique. It is found that Antifreeze Proteins can inhibit the ice nucleation process by adsorbing onto both the surface of ice nuclei and that of foreign dusts. This leads to an increase of the ice nucleation barrier and the desolvation kink kinetics barrier. Based on the latest nucleation model, the increases in the ice nucleation barrier and the kink kinetics barrier were measured. This enables us to quantitatively examine the antifreeze mechanism of AFP I.

Role of soil organic matter in a desert soil on plant response to silver, tungsten, cobalt, and lead

1977 ◽  
Vol 8 (9) ◽  
pp. 719-725 ◽  
Author(s):  
E. M. Romney ◽  
A. Wallace ◽  
R. Wood ◽  
A. M. El‐Gazzar ◽  
J. D. Childress ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Plant Response ◽  
Desert Soil

scholarly journals Biological residues define the ice nucleation properties of soil dust

2011 ◽  
Vol 11 (18) ◽  
pp. 9643-9648 ◽  
Author(s):  
F. Conen ◽  
C. E. Morris ◽  
J. Leifeld ◽  
M. V. Yakutin ◽  
C. Alewell
Keyword(s):  
Organic Matter ◽  
Agricultural Land ◽  
Size Fraction ◽  
Ice Nucleation ◽  
Soil Dust ◽  
Ice Nuclei ◽  
Mineral Dusts ◽  
Nucleation Activity ◽  
Micro Organisms ◽  
Ice Nucleation Activity

Abstract. Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nucleation sites per unit mass active in the immersion freezing mode at −12 °C than montmorillonite, the nucleation properties of which are often used to represent those of mineral dusts in modelling studies. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

scholarly journals Biological residues define the ice nucleation properties of soil dust

2011 ◽  
Vol 11 (6) ◽  
pp. 16585-16598 ◽  
Author(s):  
F. Conen ◽  
C. E. Morris ◽  
J. Leifeld ◽  
M. V. Yakutin ◽  
C. Alewell
Keyword(s):  
Organic Matter ◽  
Agricultural Land ◽  
Size Fraction ◽  
Ice Nucleation ◽  
Global Climate Models ◽  
Soil Dust ◽  
Ice Nuclei ◽  
Nucleation Activity ◽  
Micro Organisms ◽  
Ice Nucleation Activity

Abstract. Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nuclei per unit mass active in the immersion freezing mode at −12 °C than montmorillonite, the most efficient pure clay mineral. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

scholarly journals Microbiology and atmospheric processes: the role of biological particles in cloud physics

2007 ◽  
Vol 4 (6) ◽  
pp. 1059-1071 ◽  
Author(s):  
O. Möhler ◽  
P. J. DeMott ◽  
G. Vali ◽  
Z. Levin
Keyword(s):  
Cloud Condensation Nuclei ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Cloud Formation ◽  
Bacterial Cells ◽  
Biological Particles ◽  
Ice Nuclei ◽  
Potential Impact ◽  
The Impact

Abstract. As part of a series of papers on the sources, distribution and potential impact of biological particles in the atmosphere, this paper introduces and summarizes the potential role of biological particles in atmospheric clouds. Biological particles like bacteria or pollen may be active as both cloud condensation nuclei (CCN) and heterogeneous ice nuclei (IN) and thereby can contribute to the initial cloud formation stages and the development of precipitation through giant CCN and IN processes. The paper gives an introduction to aerosol-cloud processes involving CCN and IN in general and provides a short summary of previous laboratory, field and modelling work which investigated the CCN and IN activity of bacterial cells and pollen. Recent measurements of atmospheric ice nuclei with a continuous flow diffusion chamber (CFDC) and of the heterogeneous ice nucleation efficiency of bacterial cells are also briefly discussed. As a main result of this overview paper we conclude that a proper assessment of the impact of biological particles on tropospheric clouds needs new laboratory, field and modelling work on the abundance of biological particles in the atmosphere and their CCN and heterogeneous IN properties.

scholarly journals Microbiology and atmospheric processes: the role of biological particles in cloud physics

2007 ◽  
Vol 4 (4) ◽  
pp. 2559-2591 ◽  
Author(s):  
O. Möhler ◽  
P. J. DeMott ◽  
G. Vali ◽  
Z. Levin
Keyword(s):  
Cloud Condensation Nuclei ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Cloud Formation ◽  
Bacterial Cells ◽  
Biological Particles ◽  
Ice Nuclei ◽  
Potential Impact ◽  
The Impact

Abstract. As part of a series of papers on the sources, distribution and potential impact of biological particles in the atmosphere, this paper introduces and summarizes the potential role of biological particles in atmospheric clouds. Biological particles like bacteria or pollen may be active as both cloud condensation nuclei (CCN) and heterogeneous ice nuclei (IN) and thereby can contribute to the initial cloud formation stages and the development of precipitation through giant CCN and IN processes. The paper gives an introduction to aerosol-cloud processes like CCN and IN in general and provides a short summary of previous laboratory, field and modelling work investigating the CCN and IN activity of bacterial cells and pollen. Recent measurements of atmospheric ice nuclei with a continuous flow diffusion chamber (CFDC) and of the heterogeneous ice nucleation efficiency of bacterial cells are also briefly discussed. As a main result of this overview paper we conclude that a proper assessment of the impact of biological particles on tropospheric clouds needs new laboratory, field and modelling work investigating the abundance of biological particles in the atmosphere and their CCN and heterogeneous IN properties.

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