Abstract
Cirrus clouds contain a large number of irregular small ice crystals. These solid ice crystals cause energy loss and reduce the signal-to-noise ratio at the receiver, causing errors in reception. Considering the random motion and structural diversity of ice particles in cirrus clouds, the discrete dipole approximation method was used to establish sphere-sphere, sphere–ellipsoid, sphere-hexagonal prism, and sphere-hexagonal plate ice particle models. The effects of different agglomerated ice particles on the laser extinction, absorption, and scattering efficiency, as well as the laser intensity and Mueller matrix elements, were analyzed, and the scattering characteristics of agglomerated ice particles in different spatial orientations were preliminarily explored. The results show that the spatial orientation of the clustered particles has great influence on the scattering characteristics. The maximum relative error of the scattering efficiency was 200%, and the maximum relative error value of the elements of the Mueller matrix reaches 800-fold. The results of this study provide theoretical support for further analysis of the scattering characteristics of ice crystal particles with complex agglomeration structures and for further study of the scattering characteristics of randomly moving agglomeration particles in cirrus clouds.
Highlights
To understand the influence of ice crystal particles in cirrus clouds on laser signals, it is necessary to study the scattering characteristics of various complex particles [1,2]
For Θ = 90◦, we understand that the light is still incident in the positive direction on the x-axis, which corresponds to a counterclockwise rotation of the ice particles by 90◦ about the z-axis
When the effective size of the agglomerated ice crystals was increased by 10λ μm from ae f f = λ/10 μm, the extinction, absorption, and scattering efficiencies initially increased and decreased in a wave pattern, the maximum value occurred at ae f f = 1.5λ μm, and the minimum value occurred at ae f f = 8.5λ μm. This is because the scattering effect of the ice crystal particles was the strongest when the size of the ice crystal particles was many times larger than the wavelength of the incident light
Summary
To understand the influence of ice crystal particles in cirrus clouds on laser signals, it is necessary to study the scattering characteristics of various complex particles [1,2]. A single axisymmetric spherical ice crystal particle is taken as the research object to solve the scattering problem of ice crystal particles in cirrus clouds to a certain extent. Xie et al [5] studied the aspect ratio, size, frequency band, and direction of non-spherical single hexagonal prism ice crystal particles in the terahertz frequency band. In 2021, Magee et al [10] developed a cryoencapsulated balloon system to capture ice particles and observe the microscopic morphology of particles via cryoscanning electron microscopy. They found that cirrus clouds are formed from random clumps of amorphous ice crystals of various shapes. Most studies have focused on the agglomeration model of regular ice crystal particles such as spheres, ellipsoids, cylinders, and particles with the same geometric structure, but these studies did not consider the agglomeration of ice crystal particles with different structures and the non-uniformity of the distribution and randomness of the movement of the agglomeration particles
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call