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Physical-chemical characteristics of the soils and aerosols of Kalmykia
d A e r o s o l Sci. Vol. 30, Suppl. I, pp. $253-$254, 1999 © 1999 Published by Elsevier Science Ltd. All rights reserved Printed in Great Britain 0 0 2 1 - 8 5 0 2 / 9 9 / $ - see front matter
Pergamon
PHYSICAL-CHEMICAL AEROSOLS
CHARACTERISTICS
O F T H E S O I L S AND
OF KALMYKIA
A.V.Andronova, M.A.Iordansky, I.A. Nevsky, J.I. Obvintsev. Karpov Institut of Physical Chemistry, Vorontsovo Pole, 10, Moscow, 103064, Russia KEYWORDS aerosol, desert, dust emission, aerosol properties, environment. The objective of this report is to investigate the processes affecting the dust and salt emission from new desertified regions, and physical-chemical properties of desert aerosol influencing the environment and climate. Complex field experiments have been carried out in the new European desert region (Kalmykian Black Lands) including ground and aircraft measurements in the planetary boundary layer. Field measurements used local probes and remote methods based on optic and acoustic sounding of the atmospheric boundary layer. Analysis of data on aerosol distribution and meteorological data showed the fine particles eroded into the atmosphere due to thermoconvective processes during hot, calm weather with air relative humidity less then 40-50%. Some mechanisms of the submicrometer soil particle emission and the model of aerosol transport in the atmospheric boundary layer are proposed. On the base of the received data the possible scenarios of desertification dynamics in the region and recommendations for reduction of negative consequences of aerosol emissions and desertification processes are considered. The test site for field experiments was defined in the Republic Kalmykia (Russia). Three expeditions have been conducted there. They included the complex measurements of the aerosol characteristics and its spatial-temporal distribution in dependence on the soil and atmosphere state. These works helped to develop the equipment to study thermoconvective liftoff of the aerosol, its transport and the experimental methods to evaluate the emission of the fine particles from desert soils. The measurements of aerosol characteristics were conducted in the surface boundary layer and in the planetary boundary layer by aircraft-laboratory up to altitude of lkm. The data on mass concentration distribution and particle size distribution function have been obtained for size range from 0.005 to 10 ~tm. The comparison of the physical-chemical characteristics of aerosol and soil samples has been conducted. The data on the emission of submicrometer soil aerosol were obtained. It was shown that emission is typical for the arid regions in the hot dry weather and is related to convective processes in the boundary layer. ( Andronova et al., 1998). MEASURING EQUIPMENT AND THE EXPERIMENT STRUCTURE Experimental works allow determining: 1. Microphysical properties of aerosol and soil. 2. Chemical composition of aerosol and soil. 3. Boundary layer characteristics. 4. Lidar measurements of the aerosol layer parameters. 5. Thermovision measurements of the Earth's surface and aerosol systems. I. Study of microphysical properties of aerosol and soil 1. Morphology and unsphericity estimation of aerosol and soil particles. Ground characterization from the point of view of wind and thermal climb efficiency. 2. Determination of aerosol mass and numerical concentration at different altitude above the surface
$253
$254
Abstracts of the 1999EuropeanAerosolConference
a) temporal variability of concentration within the near-the-earth layer. b) extrapolation of altitude profile of concentration. c) characteristic values of concentration for different atmospheric conditions (background, dust emissions). 3. Measurements of particle distributions of optical and aerodynamic sizes. a) characteristic types of size distribution functions for different atmospheric conditions (background, dust). b) 24-hourly variability of distribution function. c) variations of vertical structure of particle size distribution. d) estimation of effective particle sizes by means of optical and radiate measurements. II. Chemical composition of aerosol and soil. 1. Elemental, mineralogical and ionic analysis of aerosol and soil samples as well as their IRspectrometric analysis (if it is possible for different size ranges). 2. Determination of distinctions in space and time variability of aerosol and soil chemical composition. III. Characteristics of the atmosphere. 1. Content and variability of atmospheric ions. 2. Estimation of electric conditions of air. 3. Estimation of aerosol generation ability of the atmosphere. IV. Lidar measurements. 1. Investigations of aerosol layers structure and their geometric sizes. 2. Investigations of aerosol concentration variations within the layer. V. Thermovision measurements. 1. Investigations of variations of the Earth's surface temperature. 2. Investigations of temperature fields within aerosol emissions. VI. Weather conditions analysis. 1. Data on temperature, wind speed and direction, relative humidity of air and pressure as well as meteorological range of vision in the region under study during experimental works. 2. Description of air mass transport and salt-dust emissions formation. Granulometrik analisis show that Kalmykian soils contain significant fraction of fine particles with sizes less than 3 ktm. Obviously, this fraction is main source of the fine aerosol emitted during hot dry weather. Mineral composition was tested for fractions: less than l~m, 1-5 ktm and 5-10~m. Mineral composition of particles with size less than l~tm is multi-component. Two phases prevail: hydro-mica (-41%) and smectite (-47%) phases. About 12% of the mass are kaolinite and chloride. During Kalmykian expeditions the measurements of aerosol mass and particle concentration were performed continuously by nephelometers and counters, discretely by aspirate and aspiration-free samplers, and by weight method. The instrumental complex applied for these measurements covers aerosol size range from 0.005 to 20 ~tm: electrostatic analyzer (0.005-1.0 ktm), nephelometer and laser analyzer (0.1-5.0 ~m), impactor (0.01-10.0~tm). On the base of the field measurements the mechanisms of the particle lift-off in dependence on meteorological conditions were studied. The main emission mechanisms were related to the local circulation in the boundary layer caused by the surface temperature heterogeneity and relief. Intensive emission takes place in the dust column and vortex. The important peculiarity of this emission is that particles have sizes less than 3-5 ~tm. They have a long lifetime in the atmosphere and can be transported far away to long distances. A.V.Andronova et al., (1998) Investiganions of prpcesses of salt-dust transfer from newlydrained territories. Experimental stady. In Collection: Natural and antropogenic aerosol. Ed. by L.S.Ivlev. St-p. Pp414-446. (in Russ).
Pergamon
PHYSICAL-CHEMICAL AEROSOLS
CHARACTERISTICS
O F T H E S O I L S AND
OF KALMYKIA
A.V.Andronova, M.A.Iordansky, I.A. Nevsky, J.I. Obvintsev. Karpov Institut of Physical Chemistry, Vorontsovo Pole, 10, Moscow, 103064, Russia KEYWORDS aerosol, desert, dust emission, aerosol properties, environment. The objective of this report is to investigate the processes affecting the dust and salt emission from new desertified regions, and physical-chemical properties of desert aerosol influencing the environment and climate. Complex field experiments have been carried out in the new European desert region (Kalmykian Black Lands) including ground and aircraft measurements in the planetary boundary layer. Field measurements used local probes and remote methods based on optic and acoustic sounding of the atmospheric boundary layer. Analysis of data on aerosol distribution and meteorological data showed the fine particles eroded into the atmosphere due to thermoconvective processes during hot, calm weather with air relative humidity less then 40-50%. Some mechanisms of the submicrometer soil particle emission and the model of aerosol transport in the atmospheric boundary layer are proposed. On the base of the received data the possible scenarios of desertification dynamics in the region and recommendations for reduction of negative consequences of aerosol emissions and desertification processes are considered. The test site for field experiments was defined in the Republic Kalmykia (Russia). Three expeditions have been conducted there. They included the complex measurements of the aerosol characteristics and its spatial-temporal distribution in dependence on the soil and atmosphere state. These works helped to develop the equipment to study thermoconvective liftoff of the aerosol, its transport and the experimental methods to evaluate the emission of the fine particles from desert soils. The measurements of aerosol characteristics were conducted in the surface boundary layer and in the planetary boundary layer by aircraft-laboratory up to altitude of lkm. The data on mass concentration distribution and particle size distribution function have been obtained for size range from 0.005 to 10 ~tm. The comparison of the physical-chemical characteristics of aerosol and soil samples has been conducted. The data on the emission of submicrometer soil aerosol were obtained. It was shown that emission is typical for the arid regions in the hot dry weather and is related to convective processes in the boundary layer. ( Andronova et al., 1998). MEASURING EQUIPMENT AND THE EXPERIMENT STRUCTURE Experimental works allow determining: 1. Microphysical properties of aerosol and soil. 2. Chemical composition of aerosol and soil. 3. Boundary layer characteristics. 4. Lidar measurements of the aerosol layer parameters. 5. Thermovision measurements of the Earth's surface and aerosol systems. I. Study of microphysical properties of aerosol and soil 1. Morphology and unsphericity estimation of aerosol and soil particles. Ground characterization from the point of view of wind and thermal climb efficiency. 2. Determination of aerosol mass and numerical concentration at different altitude above the surface
$253
$254
Abstracts of the 1999EuropeanAerosolConference
a) temporal variability of concentration within the near-the-earth layer. b) extrapolation of altitude profile of concentration. c) characteristic values of concentration for different atmospheric conditions (background, dust emissions). 3. Measurements of particle distributions of optical and aerodynamic sizes. a) characteristic types of size distribution functions for different atmospheric conditions (background, dust). b) 24-hourly variability of distribution function. c) variations of vertical structure of particle size distribution. d) estimation of effective particle sizes by means of optical and radiate measurements. II. Chemical composition of aerosol and soil. 1. Elemental, mineralogical and ionic analysis of aerosol and soil samples as well as their IRspectrometric analysis (if it is possible for different size ranges). 2. Determination of distinctions in space and time variability of aerosol and soil chemical composition. III. Characteristics of the atmosphere. 1. Content and variability of atmospheric ions. 2. Estimation of electric conditions of air. 3. Estimation of aerosol generation ability of the atmosphere. IV. Lidar measurements. 1. Investigations of aerosol layers structure and their geometric sizes. 2. Investigations of aerosol concentration variations within the layer. V. Thermovision measurements. 1. Investigations of variations of the Earth's surface temperature. 2. Investigations of temperature fields within aerosol emissions. VI. Weather conditions analysis. 1. Data on temperature, wind speed and direction, relative humidity of air and pressure as well as meteorological range of vision in the region under study during experimental works. 2. Description of air mass transport and salt-dust emissions formation. Granulometrik analisis show that Kalmykian soils contain significant fraction of fine particles with sizes less than 3 ktm. Obviously, this fraction is main source of the fine aerosol emitted during hot dry weather. Mineral composition was tested for fractions: less than l~m, 1-5 ktm and 5-10~m. Mineral composition of particles with size less than l~tm is multi-component. Two phases prevail: hydro-mica (-41%) and smectite (-47%) phases. About 12% of the mass are kaolinite and chloride. During Kalmykian expeditions the measurements of aerosol mass and particle concentration were performed continuously by nephelometers and counters, discretely by aspirate and aspiration-free samplers, and by weight method. The instrumental complex applied for these measurements covers aerosol size range from 0.005 to 20 ~tm: electrostatic analyzer (0.005-1.0 ktm), nephelometer and laser analyzer (0.1-5.0 ~m), impactor (0.01-10.0~tm). On the base of the field measurements the mechanisms of the particle lift-off in dependence on meteorological conditions were studied. The main emission mechanisms were related to the local circulation in the boundary layer caused by the surface temperature heterogeneity and relief. Intensive emission takes place in the dust column and vortex. The important peculiarity of this emission is that particles have sizes less than 3-5 ~tm. They have a long lifetime in the atmosphere and can be transported far away to long distances. A.V.Andronova et al., (1998) Investiganions of prpcesses of salt-dust transfer from newlydrained territories. Experimental stady. In Collection: Natural and antropogenic aerosol. Ed. by L.S.Ivlev. St-p. Pp414-446. (in Russ).