A Highly Modular Systems Model For Integrated Assessment Of Aircraft Emissions

研究背景经济发展、全球联系日益密切以及机票价格持续下降，使得航空旅行成为所有运输方式中增长最快的部门。虽然平均而言，过去40年来，航空业的燃油效率显著提高，但旅行需求的强劲增长抵消了每飞行旅客公里燃油使用量的相关下降。因此，二氧化碳和其他温室气体及其前体的排放量继续强劲增加。鉴于预期需求将进一步增长，主流技术提高燃油效率的潜力下降将导致排放量进一步强劲增长。这些增长趋势需要仔细分析，以确定各种政策工具(经济措施、飞机技术、空中交通业务)对环境和航空运输系统的潜在影响。为了应对这些趋势，美国和欧洲在过去几年里建立了几个重要的研究计划，旨在生成现在和未来的全球空中交通排放分布。与此同时，大气科学家的工作在很大程度上独立于出行需求建模人员和工程师。不出所料，这些孤立的努力在对飞机排放进行综合评估时造成了一些困难。目的和目标拟议的研究旨在超越这些孤立的努力，建立一套松散联系的模型，能够进行综合政策分析。高度模块化的系统将允许为其他研究小组、政府和行业轻松交换和测试不同的模型组件。拟议的模式系统的一些组成部分已经作为独立的飞机运行、当地空气质量和全球大气模式运行，需要进行修改才能在整个模式系统中发挥作用。其他模块需要新开发。其中包括航空运输需求模块，它模拟现有和未来的客运和货运量水平及其全球分布，以及机场活动模块，它模拟起飞和降落的航班延误。飞机技术模块模拟了与预测的运输需求相关的飞机燃料使用和排放。然后，沿着各自飞行轨迹估计的飞机排放量被输入当地空气污染和全球大气模型，以研究区域和全球环境影响。拟议的模式系统将在剑桥大学新成立的航空与环境研究所的综合评估工作中发挥核心作用。潜在的应用和好处拟议的模式系统提供了广泛的综合政策分析，范围从经济措施(例如引入各种类型的税收)到技术措施(例如氮氧化物排放量较低的新发动机)到操作措施(例如改变飞行路线和巡航高度)及其对全球和当地大气的影响。与上述现有的孤立努力相比，综合评估所需的所有学科的内部能力提供了多种优势。这些措施包括在模型组件之间纳入反馈以更好地了解权衡和制定最佳政策的可能性，增强建模小组之间的信息流(与数据需求、质量和格式、研究方法等相关)，以及政府和行业对政策分析请求的快速响应时间。

Context of researchEconomic development, increasing global linkages, and continuously declining airfares have made air travel the sector of fastest growth amongst all transportation modes. Although, on average, aviation has become significantly more fuel-efficient over the last 40 years, the associated decline in fuel use per passenger-kilometer flown has been more than offset by the strong growth in travel demand. As a result, emissions of carbon dioxide and other greenhouse gases and precursors have continued to increase strongly. In light of the expected further growth in demand, the declining potential of mainstream technologies for increasing fuel efficiency will lead to a further strong growth in emissions. These growth trends require careful analysis to determine the potential implication of various policy tools (economic measures, aircraft technology, air traffic operation) on the environment and air transport system. In response to these trends, several important research programs, aiming at generating global air traffic emission distributions today and for the future were established during the past years both in the United States and Europe. At the same time, atmospheric scientists have been working largely independent from travel demand modelers and engineers. Not surprisingly, these isolated efforts create a number of difficulties when conducting integrated assessment of aircraft emissions.Aims and objectives The proposed research aims to go beyond these isolated efforts and build a set of loosely connected models, capable of performing integrated policy analysis. The highly modular system will allow to easily exchange and test different model components for other research groups, government, and industry. Some components of the proposed model system are already operational as independent aircraft movement, local air quality, and global atmospheric models and need to be modified to function within the overall model system. Other modules need to be newly developed. Among those are an Air Transport Demand Module, which simulates the existing and projects future levels of passenger and freight traffic and its global distribution, and an Airport Activity Module, which simulates flight delays for take-offs and landings. Aircraft fuel use and emissions associated with the predicted transport demand are simulated by an Aircraft Technology Module. The estimated aircraft emissions along the respective flight trajectories are then fed into local air pollution and global atmospheric models to study regional and global environmental impacts. The proposed model system would play a central role in the integrated assessment work of the newly founded Institute for Aviation and the Environment (IAE) at the University of Cambridge. Potential applications and benefitsThe proposed model system offers a wide range of integrated policy analyses, ranging from economic measures (e.g. the introduction of various types of taxes) over technology measures (e.g. new engines with lower nitrogen oxide emissions) to operational measures (e.g. change in flight routings and cruise altitude) and their global and local atmospheric impacts. Compared to the existing isolated efforts described above, the in-house capability of all disciplines required for integrated assessment offers multiple advantages. These range from the possibility of including feedbacks between the model components to better understand trade-offs and develop optimum policies, enhanced information flow between modeling groups (associated with data needs, quality, and formats, research methods, etc.), and quick response time for policy analysis requests from government and industry.