Co-ordinated Airborne Studies in the Tropics (CAST)

全球鹰独特的研究能力，可以在对流层上层和平流层下层进行超长距离飞行，为推进大气科学提供了一个重大的新机遇。为了响应NERC/STFC/NASA的合作倡议，我们组建了一个经验丰富的英国团队，建议执行一项涵盖基础科学和技术发展的研究计划，通过与全球鹰合作，将从根本上增强我们未来的研究能力。热带对流层顶层(TTL)是化学/气候相互作用的关键区域。在我们已经在这方面做的工作的基础上，我们将与NASA的ATTREX计划合作，通过新的测量和分析来研究太平洋和东南亚的TTL。我们将解决与大气成分、辐射和运输有关的基本问题。TTL控制水蒸气进入平流层的传输，水蒸气是重要的辐射气体；我们将促进对次可见卷云在水蒸气过程中作用的理解。TTL也是寿命非常短的卤素物种进入平流层的主要途径，这些卤素物种代表着未来平流层臭氧演变的巨大不确定性。我们将增进对这些气体的预算以及它们的化学转化和通过TTL的输送的了解，包括对流输送到TTL的作用以及随后从TTL到平流层低层的输送路线。改善这些过程在全球化学/气候模型中的表现是一个关键目标。为了研究这些过程，FAAM BAE-146将于2014年1月/2月部署在关岛。它将与全球鹰协调飞行，后者将在同一时期在西太平洋上空的TTL进行测量。与ATTREX合作任务的所有阶段的详细参与将增强英国未来使用全球鹰进行研究的潜力，包括任务规划和复杂、实时数据分析方法方面的先进能力。飞机测量将结合地面和气球对非常短暂的卤素物种和臭氧的测量，使用一组互补的区域高分辨率模型、全球组成模型和全球卷云模型进行解释。我们将为有效载荷/任务科学家接口开发和测试两个新仪器和新软件，它们非常适合全球鹰的能力。一种新的仪器将允许在TTL中量化亚微米和超微米粒子的重要物理性质，从而获得关于云和辐射的新信息。我们将开发一种新型短波红外光谱仪，利用对流层上层和平流层下层的超长飞行优势，对低层大气中的温室气体(CO2、CH4和H2O)和其他(CO)气体进行遥感测量。这两种仪器都将在CAST中进行飞行测试。

The unique research capability of the Global Hawk, with ultra-long flights possible in the upper troposphere and lower stratosphere, provides a major new opportunity to advance atmospheric science. In response to the NERC/STFC/NASA collaborative initiative, we have assembled an experienced UK team that proposes to execute a research programme covering fundamental science and technology development, which, by working with the Global Hawk, will radically enhance our future research capabilities.The Tropical Tropopause Layer (TTL) is a crucial region for chemistry/climate interactions. Building on work we have already done in this area, we will collaborate with NASA's ATTREX programme to study the TTL over the Pacific Ocean and South East Asia, with new measurements and analysis. We will address fundamental questions related to atmospheric composition, radiation and transport. The TTL controls the transport of water vapour, the crucial radiative gas, into the stratosphere; we will advance understanding of the role of sub-visible cirrus in water vapour processes. The TTL is also the main route by which very short-lived halogen species, which represent a large uncertainty in future stratospheric ozone evolution, enter the stratosphere. We will improve knowledge of the budgets of these gases and of their chemical transformation and transport through the TTL, including the role of convective transport into the TTL and the subsequent routes for transport from the TTL to the lower stratosphere. Improving representation of these processes in global chemistry/climate models is a key aim.In order to study these processes, The FAAM BAe-146 will be deployed in Guam in Jan/Feb 2014. It will fly coordinated flights with the Global Hawk which will making measurements in the same period in the TTL over the West Pacific. Detailed involvement in all phases of the collaborative missions with ATTREX will enhance the UK potential for future research using the Global Hawk, including advanced capability in mission planning and methodologies for complex, real-time data analysis. The aircraft measurements will be interpreted in conjunction with ground-based and balloon-based measurements of very short-lived halogen species and ozone, using a complementary group of regional high resolution models, global composition models and a global cirrus model.We will develop and test two new instruments and new software for the payload/mission-scientist interface, which are ideally suited for the capabilities of the Global Hawk. One new instrument will allow quantification in the TTL of the important physical properties of sub- and super-micron sized particles, allowing new information about clouds and radiation. We will develop a new short-wave IR spectrometer to measure greenhouse (CO2, CH4, and H2O) and other (CO) gases in the lower atmosphere by remote sensing, taking advantage of the very long flights in the upper troposphere and lower stratosphere. Both instruments will be flight-tested in CAST.