Ice Nucleation Research Paper

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The Significance and Measurement of Ice Nucleating Particles (INPs) in the Atmosphere

Abstract—The paper outlines the significance of ice nucleating particles (INPs) in the atmosphere and collaborative research undertaken and proposed at Leeds University, UK and Addis Ababa University, Ethiopia. Understanding the role of INPs in cloud formation in the troposphere is an essential feature of atmospheric modelling, but is not well researched or understood. It is a branch of atmospheric research that is gaining increasing interest and research funding worldwide. Heterogeneous ice crystal formation in clouds can happen when cloud droplets containing INPs act as surfaces for ice crystal generation and growth. INPs impact cloud properties such as lifetime and whiteness and in turn affect climate. INPs include mineral …show more content…

It is based around a Stirling cryocooler which cools a hydrophobic surface supporting the microlitre droplets. Droplets of microlitre volumes of water from the sampler are cooled down at a controlled rate and their freezing temperatures recorded. This allows determination of the efficiency with which immersed particles nucleate ice. The advantage of using relatively large droplet volumes is that the surface area per droplet is vastly larger than alternative experiments that focus on single aerosol particles or cloud-sized droplets. Droplet freezing experiments tend to have multiple particles suspended in individual water droplets. This increases the probability of observing the effect of less common, but important, high temperature INPs and therefore allows the quantification of their ice nucleation efficiency. The freezing of the droplets is monitored using a digital camera. The set-up is illustrated in Fig. 2 while Fig. 3 shows the progressive freezing of micolitre droplets as the temperature is

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