VK-30 — Cirrus Aircraft VK-30

This document presents a research study focused on the linear depolarisation ratio of small cirrus ice crystals, utilizing cloud chamber experiments to investigate the relationship between ice crystal microphysical properties and their optical characteristics. Conducted by a team of researchers from various institutions, the study aims to enhance the understanding of how ice crystal size, shape, and complexity affect the depolarisation signals observed in remote sensing applications. The experiments were carried out under controlled conditions, simulating cirrus temperatures ranging from -75 to -39 °C, and involved a series of 47 cloud experiments. The findings are significant for interpreting lidar measurements and improving optical particle models, particularly for small ice crystals. This research is relevant for atmospheric scientists and those involved in remote sensing of ice clouds.

• The study investigates the linear depolarisation ratio of small cirrus ice crystals at temperatures between -75 °C and -39 °C.
• A total of 47 cloud experiments were conducted to analyze the relationship between ice crystal properties and depolarisation signals.
• Ice crystals larger than 10 μm exhibited depolarisation ratios below 0.3, aligning with polar cirrus observations.
• The research provides new insights into the microphysical properties of ice crystals, which are crucial for accurate remote sensing interpretations.
• The findings highlight the complexity of ice crystal shapes and their impact on lidar measurements.