Numerical solution of the light scattering problem for atmospheric ice particles in the infrared range for retrieving the microphysical properties of cirrus clouds

2020 ◽  
Author(s):  
Dmitriy N. Timofeev ◽  
Alexander Konoshonkin ◽  
Natalia Kustova ◽  
Anatoli Borovoi
Keyword(s):  
Light Scattering ◽  
Numerical Solution ◽  
Scattering Problem ◽  
Cirrus Clouds ◽  
Infrared Range ◽  
Microphysical Properties ◽  
Ice Particles

scholarly journals Light Scattering by Particles with Arbitrary Shape in the Vicinity of the Backward Scattering Direction within Geometrical Optics Approximation

2020 ◽  
Vol 237 ◽  
pp. 08012
Author(s):  
Victor Shishko ◽  
Alexander Konoshonkin ◽  
Natalia Kustova ◽  
Anatoli Borovoi ◽  
Dmitry Timofeev
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Light Scattering ◽  
Arbitrary Shape ◽  
Specular Reflection ◽  
Scattering Problem ◽  
Geometrical Optics ◽  
Optical Characteristics ◽  
Ice Particles ◽  
Scattering Light

The work presents the solution for the light scattering problem by arbitrarily-shaped particles in the vicinity of the backward scattering direction. The solution was obtained within the framework of the geometrical optics approximation. The refractive index was equal to 1.3116. It was shown that the general contribution of scattering light for arbitrarily-shaped particles in the vicinity of the backscattering direction consists of the specular reflection of the particles and two types of non-specular optical beams. It is shown that the optical characteristics of the ice particles with arbitrary shapes correspond to experimental data.

scholarly journals PHIPS-HALO: the airborne Particle Habit Imaging and Polar Scattering probe – Part 2: Characterization and first results

2017 ◽  
Author(s):  
Martin Schnaiter ◽  
Emma Järvinen ◽  
Ahmed Abdelmonem ◽  
Thomas Leisner
Keyword(s):  
Light Scattering ◽  
Mixed Phase ◽  
Proper Function ◽  
The Novel ◽  
Scattering Function ◽  
Airborne Particle ◽  
Microphysical Properties ◽  
Ice Particles ◽  
First Results ◽  
Mixed Phase Clouds

Abstract. The novel aircraft optical cloud probe PHIPS-HALO has been developed to establish clarity regarding the fundamental link between the microphysical properties of single atmospheric ice particles and their appropriated angular light scattering function. After final improvements have been implemented to the polar nephelometer part and the acquisition software of PHIPS-HALO, the instrument was comprehensively characterized in the laboratory and was deployed in two aircraft missions targeting cirrus and Arctic mixed-phase clouds. This work demonstrates the proper function of the instrument under aircraft conditions and highlights the uniqueness, quality, and limitations of the data that can be expected from PHIPS-HALO in cloud-related aircraft missions.

scholarly journals Cloud chamber experiments on the origin of ice crystal complexity in cirrus clouds

2015 ◽  
Vol 15 (21) ◽  
pp. 30511-30561 ◽  
Author(s):  
M. Schnaiter ◽  
E. Järvinen ◽  
P. Vochezer ◽  
A. Abdelmonem ◽  
R. Wagner ◽  
...  
Keyword(s):  
Light Scattering ◽  
Cloud Chamber ◽  
Cirrus Clouds ◽  
Atmospheric Conditions ◽  
Ice Crystal ◽  
Ice Clouds ◽  
Spatially Resolved ◽  
Microphysical Properties ◽  
Institute Of Technology ◽  
Low Sensitivity

Abstract. This study reports on the origin of ice crystal complexity and its influence on the angular light scattering properties of cirrus clouds. Cloud simulation experiments were conducted at the AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber of the Karlsruhe Institute of Technology (KIT). A new experimental procedure was applied to grow and sublimate ice particles at defined super- and subsaturated ice conditions and for temperatures in the −40 to −60 °C range. The experiments were performed for ice clouds generated via homogeneous and heterogeneous initial nucleation. Ice crystal complexity was deduced from measurements of spatially resolved single particle light scattering patterns by the latest version of the Small Ice Detector (SID-3). It was found that a high ice crystal complexity is dominating the microphysics of the simulated clouds and the degree of this complexity is dependent on the available water vapour during the crystal growth. Indications were found that the crystal complexity is influenced by unfrozen H2SO4/H2O residuals in the case of homogeneous initial ice nucleation. Angular light scattering functions of the simulated ice clouds were measured by the two currently available airborne polar nephelometers; the Polar Nephelometer (PN) probe of LaMP and the Particle Habit Imaging and Polar Scattering (PHIPS-HALO) probe of KIT. The measured scattering functions are featureless and flat in the side- and backward scattering directions resulting in low asymmetry parameters g around 0.78. It was found that these functions have a rather low sensitivity to the crystal complexity for ice clouds that were grown under typical atmospheric conditions. These results have implications for the microphysical properties of cirrus clouds and for the radiative transfer through these clouds.

In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part II: Cirrus Clouds

2006 ◽  
Vol 63 (12) ◽  
pp. 3186-3203 ◽  
Author(s):  
R. Paul Lawson ◽  
Brad Baker ◽  
Bryan Pilson ◽  
Qixu Mo
Keyword(s):  
Particle Size ◽  
Number Concentration ◽  
Cirrus Clouds ◽  
Average Particle ◽  
Cloud Particle ◽  
Microphysical Properties ◽  
Irregular Shapes ◽  
Ice Particles ◽  
Research Aircraft ◽  
Particle Size And Shape

A Learjet research aircraft was used to collect microphysical data, including cloud particle imager (CPI) measurements of ice particle size and shape, in 22 midlatitude cirrus clouds. The dataset was collected while the aircraft flew 104 horizontal legs, totaling over 15 000 km in clouds. Cloud temperatures ranged from −28° to −61°C. The measurements show that cirrus particle size distributions are mostly bimodal, displaying a maximum in number concentration, area, and mass near 30 μm and another smaller maximum near 200–300 μm. CPI images show that particles with rosette shapes, which include mixed-habit rosettes and platelike polycrystals, constitute over 50% of the surface area and mass of ice particles >50 μm in cirrus clouds. Approximately 40% of the remaining mass of ice particles >50 μm are found in irregular shapes, with a few percent each in columns and spheroidal shapes. Plates account for <1% of the total mass. Particles <50 μm account for 99% of the total number concentration, 69% of the shortwave extinction, and 40% of the mass in midlatitude cirrus. Plots and average equations for area versus particle size are shown for various particle habits, and can be used in studies involving radiative transfer. The average particle concentration in midlatitude cirrus is on the order of 1 cm−3 with occasional 10-km averages exceeding 5 cm−3. There is a strong similarity of microphysical properties of ice particles between wave clouds and cirrus clouds, suggesting that, like wave clouds, cirrus ice particles first experience conversion to liquid water and/or solution drops before freezing.

scholarly journals Light Backscattering by Ice Crystals of Cirrus Clouds Within the Physical Optics Approximation

2020 ◽  
Vol 237 ◽  
pp. 08011
Author(s):  
Alexander Konoshonkin ◽  
Anatoli Borovoi ◽  
Natalia Kustova ◽  
Zhenzhu Wang ◽  
Dong Liu ◽  
...  
Keyword(s):  
Light Scattering ◽  
Spatial Orientation ◽  
Scattering Problem ◽  
Cirrus Clouds ◽  
Ice Crystals ◽  
Physical Optics ◽  
Nonspherical Particles ◽  
Physical Optics Approximation ◽  
Computer Resources

Lidar technologies are widely used for retrieving microphysics of cirrus clouds, i.e. sizes, shapes and spatial orientation of ice crystals constituting the clouds. Interpretation of the lidar signals are based on the backscattered light. However, properties of the light backscattered by the ice crystals have not been well known and understood yet. The reason of this is that the problem of light scattering by the ice crystals much larger that incident wavelengths has not been solved satisfactorily yet because of great demands to computer resources. In this contribution we review the physical optics approximation as a prospective method to solve the light scattering problem on large nonspherical particles in lidar application.

scholarly journals PHIPS-HALO: the airborne particle habit imaging and polar scattering probe – Part 2: Characterization and first results

2018 ◽  
Vol 11 (1) ◽  
pp. 341-357 ◽  
Author(s):  
Martin Schnaiter ◽  
Emma Järvinen ◽  
Ahmed Abdelmonem ◽  
Thomas Leisner
Keyword(s):  
Light Scattering ◽  
Mixed Phase ◽  
Proper Function ◽  
The Novel ◽  
Scattering Function ◽  
Airborne Particle ◽  
Microphysical Properties ◽  
Ice Particles ◽  
First Results ◽  
Mixed Phase Clouds

Abstract. The novel aircraft optical cloud probe PHIPS-HALO has been developed to establish clarity regarding the fundamental link between the microphysical properties of single atmospheric ice particles and their appropriated angular light scattering function. After final improvements were implemented in the polar nephelometer part and the acquisition software of PHIPS-HALO, the instrument was comprehensively characterized in the laboratory and was deployed in two aircraft missions targeting cirrus and Arctic mixed-phase clouds. This work demonstrates the proper function of the instrument under aircraft conditions and highlights the uniqueness, quality, and limitations of the data that can be expected from PHIPS-HALO in cloud-related aircraft missions.

scholarly journals Cloud chamber experiments on the origin of ice crystal complexity in cirrus clouds

2016 ◽  
Vol 16 (8) ◽  
pp. 5091-5110 ◽  
Author(s):  
Martin Schnaiter ◽  
Emma Järvinen ◽  
Paul Vochezer ◽  
Ahmed Abdelmonem ◽  
Robert Wagner ◽  
...  
Keyword(s):  
Light Scattering ◽  
Cloud Chamber ◽  
Cirrus Clouds ◽  
Small Scale ◽  
Atmospheric Conditions ◽  
Ice Crystal ◽  
Ice Clouds ◽  
Microphysical Properties ◽  
Institute Of Technology ◽  
Low Sensitivity

Abstract. This study reports on the origin of small-scale ice crystal complexity and its influence on the angular light scattering properties of cirrus clouds. Cloud simulation experiments were conducted at the AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber of the Karlsruhe Institute of Technology (KIT). A new experimental procedure was applied to grow and sublimate ice particles at defined super- and subsaturated ice conditions and for temperatures in the −40 to −60 °C range. The experiments were performed for ice clouds generated via homogeneous and heterogeneous initial nucleation. Small-scale ice crystal complexity was deduced from measurements of spatially resolved single particle light scattering patterns by the latest version of the Small Ice Detector (SID-3). It was found that a high crystal complexity dominates the microphysics of the simulated clouds and the degree of this complexity is dependent on the available water vapor during the crystal growth. Indications were found that the small-scale crystal complexity is influenced by unfrozen H2SO4 / H2O residuals in the case of homogeneous initial ice nucleation. Angular light scattering functions of the simulated ice clouds were measured by the two currently available airborne polar nephelometers: the polar nephelometer (PN) probe of Laboratoire de Métérologie et Physique (LaMP) and the Particle Habit Imaging and Polar Scattering (PHIPS-HALO) probe of KIT. The measured scattering functions are featureless and flat in the side and backward scattering directions. It was found that these functions have a rather low sensitivity to the small-scale crystal complexity for ice clouds that were grown under typical atmospheric conditions. These results have implications for the microphysical properties of cirrus clouds and for the radiative transfer through these clouds.

Study of the convergence of the numerical solution of the light scattering problem by atmospheric ice crystals within the physical optics method

2021 ◽  
Author(s):  
Alexander V. Konoshonkin ◽  
Ilia V. Tkachev ◽  
Victor A. Shishko ◽  
Dmitrii N. Timofeev ◽  
Natalia V. Kustova
Keyword(s):  
Light Scattering ◽  
Numerical Solution ◽  
Scattering Problem ◽  
Ice Crystals ◽  
Physical Optics

scholarly journals Algorithm for Solving the Light Scattering Problem for Arbitrary Shaped Ice Particles with Absorption

2020 ◽  
Vol 237 ◽  
pp. 08004
Author(s):  
Timofeev D.N. ◽  
Konoshonkin A.V. ◽  
Kustova N.V. ◽  
Borovoi A.G.
Keyword(s):  
Light Scattering ◽  
Scattering Problem ◽  
Scattering Matrix ◽  
Influence Effect ◽  
Ice Particles ◽  
Scattering Matrices ◽  
Research Show

The work presents the estimation of the absorption influence effect on the light scattering problem for atmospheric ice particles. The calculation of light scattering matrices was performed for two types of particles: the solid hexagonal columns and the arbitrary shaped particles. The range of the size for both types of particles varies from 10 μm to 1000 μm. The results of the research show an insignificant decrease of the value of the M11 element of the light scattering matrix for small-sized particles for all chosen wavelengths (0.355 μm, 0.532 μm, 1.064 μm и 1.6 μm), and a significant decrease for big-sized particles for a 1.6 μm wavelength.

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