Simulation of scattering characteristics of Polar Stratospheric Clouds

Sammanfattning

This thesis uses simulations to study the scattering characteristics of Polar Stratospheric Cloud (PSC) particles. It focuses on lognormal size distributions to see how scattering changes with changes in particle parameters. The simulations are based on the well-established T-matrix method, employing a dependable and proven program to calculate scattering properties. In-situ measurements derived from the literature are utilized to calculate the input parameters for the simulations. By simulating the scattering of the three main types of PSCs (NAT, STS, and ice), parameters were systematically varied to evaluate their influence on the phase function and scattered intensity at key angles, with particular emphasis on 180°, which is relevant for LIDAR observations. The results strongly suggest that the mean radius of the dominant mode has a significant effect on scattering intensity, with a critical threshold for the small mode when it takes over from the large mode. Particle shape and aspect ratio also have significant effects, especially in the backscatter region. The analysis emphasizes the importance of particle size, shape, and distribution properties in determining PSC scattering characteristics, highlighting their importance in both modeling and observational studies. These findings provide valuable insights into how PSCs scatter light, which is important for accurate remote sensing applications.