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

云层与太阳和地面辐射相互作用，这对气候系统造成了相互竞争的加热和冷却效应。云产生降水，因此影响地球表面水的空间分布。云还促进了复杂的化学反应，并清除了空气中的污染物。为了正确评估云对地球系统的影响和潜在的敏感性，需要数据集来捕捉云的微观物理性质，即组成粒子的数量、大小和形状。正在建立新的网络来监控云。虽然有许多测量气溶胶颗粒和更大的毛毛雨/降水颗粒的仪器可供选择，但缺乏合适的仪器对液滴进行地面监测，这些液滴构成了地球表面附近的大部分云层。博士项目方法论在过去的50年里，使用了各种技术来测量云颗粒，包括对种群进行大量采样，以及详细的单颗粒测量。然而，这些现有的仪器通常是为了在高速飞行的研究飞机上操作而开发的，通过飞机在空中的运动提供吸气。这使得许多这样的系统不适合地面监测。已经开发了一些陆基雾监测系统，但存在数据质量和采样伪影方面的问题。该项目将开发和测试用于地面云监测的新原型传感器。将使用3D打印和现成的光电子元件(二极管激光器、激光驱动器、光学元件、支架)和Arduino类型的微处理器进行快速原型制作。新的传感器将在实验室中使用经过认证的玻璃校准微球、按需滴定粒子发生器和使用雾化器系统的多分散粒子悬浮液进行测试。这些传感器将在霍尔姆·莫斯大气天文台运行，以监测周围的云层。将使用Mie散射程序进行数值模拟，以了解新传感器的响应。PHD项目描述和目标本项目将专注于设计、建造和评估适用于长期监测环境云(直径~2-50)中液滴尺寸分布的新原型传感器。目标1：潜在传感器的财务和业务评估。评估不同的传感器配置，包括散体和单个粒子、照明波长(S)、几何形状、测量原理(例如散射/衍射、吸气)。目标2：传感器原型的设计和构建(S)。设计并搭建了传感器样机的光、电、机、数据系统。这包括建立一个数值模型来描述传感器的理论操作。目标3：传感器原型的特性(S)。使用各种系统，如校准微球、纳米升按需滴定系统、相互比对的Mie散射OPC，如曼彻斯特大学提供的DMT云滴探测器。目标4：原型传感器的布放(S)。安装和操作曼彻斯特大学运营的霍尔姆苔藓山顶大气天文台的原型传感器(S)，以从现实世界条件下的环境云中获取数据。其他部署也是可能的。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。测量原则合理吗？数据看起来是否与更广泛的云微物理属性知识一致？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.