Towards a new generation of atmospheric vertical profiling

这是英国气象局观测方法部门和曼彻斯特大学联合提出的一项建议，目的是利用垂直廓线仪器的组合，为约束和初始化精细天气预报模式生成新的测量方法。它建立在建议者之间的长期合作基础上，该合作源于位于阿伯里斯特威斯Capel Dewi的NERC MST雷达设施。这产生了关于风、湍流和大气结构的信息，而后者才是这里感兴趣的。晴空雷达回波是湿度和温度梯度的函数，为从雷达回波中得出这些变量的轮廓提供了可能性。最近D.Hooper(Ral)对云雷达和甚高频雷达的比较表明，云和降水都会影响雷达的测量。这表明，雷达可能被用来获取有关云结构的信息，而胡珀博士是本项目的合作者。该博士项目的总体目标如下：a)确定影响MST雷达回波功率的因素，并建立一个将回波功率与大气参数联系起来的定量模型，考虑到无线电物理学的基本原理和现有的测量数据库；b)利用a)的结果，利用雷达和辅助数据得出温度和湿度分布。C)确定可以从雷达得出哪些关于云结构的定量信息d)将这些结果推广到超高频剖面图雷达e)评估如何利用这些信息来约束数值模式该项目的初步计划是利用在MST雷达站进行辅助剖面图测量时的现有数据。这为将雷达测量与其他仪器联系起来并发展假说提供了一个起点。稍后，我们计划操作一系列剖面仪-微波辐射计、云雷达、超高频雷达、Ceileter和激光雷达-这将为解决这个问题提供新的和强大的攻击。这些活动将在活动的基础上进行：该项目每年进行一次为期四周的活动，无线电探空仪提供温度和湿度的“地面真实”轮廓。通过仔细的校准，湿度和温度廓线的恢复将为数值模式的初始化和约束提供良好的数据集。学生将在实验工作的基础上，在康诺利博士的指导下，模拟测量地点附近的云场。我们将选择数值实验来评估所得到的廓线对云场模拟的影响。目前曼彻斯特在COPS财团资助下的工作正在为这样的研究做准备。在该项目接近尾声时，将进行进一步的数值试验，以评估所得出的轮廓对气象局预报模式初始化的影响。这项工作将在JCMM in Reding进行，Gaffard博士与数据同化小组的同事有密切联系。因此，学生还将获得在现代预测模型中使用测量方法的经验。因此，学生将获得现场工作和操作最先进的垂直剖面设备的培训。将有相当数量的数据处理，这将需要发展优秀的IT技能，以及无线电物理和大气物理的理论工作，以正确解释测量结果。最后，学生将获得最先进的大气数值模式的经验。这名学生将常驻曼彻斯特，接受由地球、大气和环境科学学院提供的正常学生培训计划。除了大气物理学和动力学的讲座，还有一个技能培训计划，用http://tinyurl.com/3brne3和http://tinyurl.com/3eylkm.描述

This is a joint proposal between the Observing Methods section of the Met Office and the University of Manchester to exploit combinations of vertical profiling instruments, generating new measurements for constraining and initialising fine-scale weather forecasting models. It builds on a long-standing collaboration between the proposers, arising from the NERC MST radar facility at Capel Dewi, Aberystwyth. This yields information on winds, turbulence and atmospheric structure, and it is the latter that is of interest here. Clear-air radar echoes are a function of humidity and temperature gradients, offering the potential for deriving profiles of these variables from the radar echoes. Recent comparison by D. Hooper (RAL) between a cloud radar and the VHF radar has shown that clouds as well as precipitation affect the radar measurements. This suggests that the radar may be used to derive information on cloud structure, and Dr. Hooper is a collaborator in the present project. The overall aims of this PhD project are as follows: a) establish the factors that influence the echo power of the MST radar and develop a quantitative model relating the echo power to atmospheric parameters, taking into account the fundamentals of radio physics and the existing measurement data base b) use the results of a) to derive temperature and humidity profiles using the radar and ancillary data. c) establish what quantitative information on cloud structure may be derived from the radar d) extend these results to UHF profiling radars e) evaluate how this information may be used to constrain numerical models The initial plan for the project is to exploit the existing data when ancillary profiling measurements were made at the MST radar site. This provides a starting point to relate the radar measurements to other instruments and develop hypotheses. Later, we plan to operate a cluster of profiling instruments - microwave radiometer, cloud radar, UHF radar, ceilometer and lidar - which will provide a novel and powerful assault on the problem. These will be operated on a campaign basis: one campaign of four weeks per year of the project with radiosondes providing 'ground truth' profiles of temperature and humidity. With careful calibration, the retrieval of humidity and temperature profiles will provide an excellent dataset for initialisation and constraining of numerical models. The student will build on the experimental work by simulating a cloud field in the vicinity of the measurement site, under the guidance of Dr Connolly. The numerical experiments will be chosen to evaluate the impact of the derived profiles on the simulation of a cloud field. Current work at Manchester under the aegis of the COPS consortium grant is preparing the ground for such studies. Towards the end of the project further numerical experiments will be conducted to evaluate the impact of the derived profiles on the initialisation of the Met Office forecast model. This work will be conducted at JCMM in Reading where Dr Gaffard has close links with colleagues in the Data Assimilation Group. Thus the student will also gain experience in the way measurements are used with a modern forecasting model. The student will thus obtain training in field work and operating state-of-the-art vertical profiling equipment. There will be a considerable amount of data handling, for which excellent IT skills will need to be developed, and theoretical work in radio physics and atmospheric physics to interpret the measurements properly. Finally, the student will gain experience with state-of-the-art numerical models of the atmosphere. The student will be based at Manchester and undergo the normal programme of student training provided by the School of Earth, Atmospheric and Environmental Sciences. As well as lectures in atmospheric physics and dynamics, there is a programme of skills training described in http://tinyurl.com/3brne3 and http://tinyurl.com/3eylkm.