Developing and deploying new sensors for in-situ monitoring of clouds

云与太阳辐射和地面辐射相互作用，对气候系统产生相互竞争的加热和冷却效应。云产生降水，从而影响地球表面水的空间分布。云还促进复杂的化学反应，并从空气中去除污染物。需要数据集来捕捉云的微物理特性，即组成粒子的数量、大小和形状，以便正确评估云对地球系统的影响和潜在敏感性。正在建立新的网络来监测云。虽然测量气溶胶粒子和更大的毛毛雨/降水粒子的仪器有许多选择，但缺乏合适的仪器用于对构成地球表面附近云的大部分的液滴进行基于表面的监测。在过去的50年里，云粒子已经使用各种技术进行了测量，包括群体的批量采样和详细的单粒子测量。然而，这些现有的仪器通常被开发用于从高速行进的研究飞行器上操作，其中通过飞行器在空气中的运动提供吸气。这使得其中许多系统不适合地面监测。已经开发了一些地基雾监测系统，但存在数据质量和吸气造成的采样伪影问题。该项目将开发和测试用于地面云监测的新原型传感器。快速原型将使用3D打印和现成的光电元件（二极管激光器，激光驱动器，光学器件，支架）和Arduino型微处理器进行。新的传感器将在实验室中使用经过认证的玻璃校准微球、按需滴加颗粒发生器和使用雾化器系统的多分散颗粒悬浮液进行测试。这些传感器将由霍姆莫斯大气观测站操作，以监测环境云。数值模拟使用米氏散射代码将进行了解新的传感器的响应。博士项目描述和目标本项目将专注于设计，建造和评估新的原型传感器，适用于长期监测环境云中的液滴尺寸分布（直径~2-50）。目标1：对潜在传感器进行财务和业务评估。评估各种传感器配置，包括整体与单个颗粒，照明波长，几何形状，测量原理，例如散射/衍射，抽吸。目标2：原型传感器的设计和构建。设计并构建了原型传感器的光学、电气、机械和数据系统。这包括构建一个数值模型来描述传感器的理论操作。目标3：原型传感器的表征。使用各种系统，如校准微球，纳升按需滴液系统，相互比较米氏散射OPC，如曼彻斯特大学提供的DMT云滴探针。目标4：部署原型传感器。安装和操作由曼彻斯特大学运营的Holme Moss Hilltop大气观测站的原型传感器，以获取真实条件下环境云的数据。目标5：评估传感器性能。数据分析，以确定传感器的实际性能是否满足设计标准。测量原则是否合理？数据是否与云微物理特性的更广泛知识相一致？环境数据是否与校准和其他数据集一致？确定未来对设计的改进。

Clouds interact with solar and terrestrial radiation, which contributes to competing heating and cooling effects on the climate system. Clouds generate precipitation, and so impact on the spatial distribution of water on the Earths surface. Clouds also facilitate complex chemical reactions and remove pollutants from the air. Datasets are required to capture the microphysical properties of clouds, namely the number, size and shape of the constituent particles, in order to correctly assess the impact and potential sensitivities of clouds on the Earth System. New networks are being established to monitor clouds. Whilst there are numerous options for instrumentation for measuring aerosol particles and much larger drizzle/precipitation particles, there is lack of suitable instrumentation for surface-based monitoring of liquid droplets which constitute the majority of clouds near the Earth's surface. PhD Project Methodology Cloud particles have been measured using a variety of techniques over the past 50 years, including bulk sampling of populations, and detailed single particle measurements. However, these existing instruments have generally been developed for operation from research aircraft travelling at high speed, with aspiration provided by the motion of the aircraft through the air. This makes many of these systems unsuitable for ground-based monitoring. Some ground-based fog monitoring systems have been developed, but there are issues over data quality and sampling artefacts resulting from aspiration. This project will develop and test new prototype sensors for surface-based cloud monitoring. Rapid prototyping will be conducted using 3-d printing and off-the-shelf optoelectronic components (diode lasers, laser drivers, optics, mounts) and Arduino-type microprocessors. The new sensors will be tested in the laboratory using certified glass calibration micro-spheres, Drop-on-Demand particle generators, and polydisperse particle suspensions using a nebuliser system. The sensors will be operated from the Holme Moss atmospheric observatory to monitor ambient clouds. Numerical simulations using Mie scattering code will be conducted to understand the response of the new sensors.PhD Project Description & Objectives This project will focus on the design, construction, and evaluation of new prototype sensors suitable for long term monitoring of the droplet size distribution in ambient clouds (diameter ~2-50). Objective 1: Financial and operational assessment of potential sensors. Assess various sensor configurations including bulk vs single particle, illumination wavelength(s), geometry, measurement principle e.g. scattering/diffraction, aspiration.Objective 2: Design and Construction of prototype sensor(s). Design and construct the optical, electrical, mechanical and data system for the prototype sensor. This includes construction of a numerical model to describe the theoretical operation of the sensor.Objective 3: Characterisation of prototype sensor(s). Use a variety of systems such as calibration microspheres, nano-litre Drop-on-Demand systems, intercomparison Mie scattering OPCs such as the DMT Cloud Droplet Probe available from the University of Manchester. Objective 4: Deployment of prototype sensor(s). Install and operate the prototype sensor(s) from the Holme Moss Hilltop Atmospheric Observatory, operated by the University of Manchester, to obtain data from ambient clouds in real-world conditions. Additional deployments may also be possible.Objective 5: Evaluation of sensor performance. Data analysis to establish if the real-world performance of the sensor fulfils design criteria. Are the measurement principles sound? Do data appear consistent with broader knowledge of cloud microphysical properties? Are ambient data consistent with calibrations and other datasets? Identify future improvements to the design.