Collaborative Research: Scientific Program Overview--Convective Transport of Active Species in the Tropics (CONTRAST)

该项目将测量北半球冬季西太平洋暖池区域对流层空气团优先输送到平流层下部时，活性化学物质向热带对流层顶过渡层的输送。该区域微量气体及其降解产物的来源、化学演变和输送可对平流层下部的化学性质产生重大影响，但迄今为止，所进行的测量相对较少，因此，我们对相关过程和反馈的理解和预测能力尚不确定。用臭氧探测仪测得的极低的臭氧浓度预计将导致极低水平的OH自由基，从而延长活性气体的寿命，其主要汇是涉及OH的氧化途径。同时发生的深对流和TTL中有机化合物的寿命延长可以显着影响平流层卤素收支。由于该地区的化学和辐射特性是连接大气成分和气候强迫机制的关键因素，因此CONTRAST实验将提供诊断、约束和改进化学气候模型所需的测量结果。一套气体，粒子和气象参数将从NSF GV飞机现场测量和解释，以阐明活跃的对流和远程传输的作用，对热带大气的垂直分辨的化学成分，特别是在海拔地区，占主导地位的对流流出（12-14公里）。此外，还将与计划在同一时间和地理位置进行的另外两项空中研究合作安排和协调，这两项研究是：NASA EV 1项目ATTREX（空中热带对流层顶实验）和欧洲CAST（热带空中协调研究）。借助互补的仪器有效载荷，GV，NASA全球鹰和英国Bae 146的协调飞行将提供对整个大气柱的前所未有的检查，从表面到19公里，在热带西太平洋上空。在BROST主持下的一套独特的基准测量将提高对热带对流输送过程的基本理解，并提高我们模拟热带对流输送作用的能力。深层对流在化学与气候相互作用中的作用。该项目将培训直接参与部署和后续数据分析和建模活动的大气化学学生。将利用网络工具和媒体开展更广泛的教育和外联活动。

This project will measure the transport of reactive chemical species into the tropical Tropopause Transition Layer (TTL) over the Western Pacific warm pool region during boreal winter when tropospheric air masses in this region are preferentially transported into the lower stratosphere. The sources, chemical evolution, and transport of trace gases and their degradation products in this region can substantially impact the chemistry of the lower stratosphere but, to date, relatively few measurements have been made and, consequently, our understanding of and ability to predict the associated processes and feedbacks are uncertain. The extremely low ozone concentrations measured with ozonesondes are expected to result in very low levels of OH radicals and, thus, longer lifetimes for reactive gases whose primary sinks are oxidation pathways involving OH. The simultaneous occurrence of deep convection and prolonged lifetime of organic compounds in the TTL can significantly impact the stratospheric halogen budget. Because the chemical and radiative properties of this region are key factors in the mechanisms that link atmospheric composition and climate forcing, the CONTRAST experiment will provide measurements necessary to diagnose, constrain, and improve chemistry-climate models. A suite of gases, particles, and meteorological parameters will be measured in situ from the NSF GV aircraft and interpreted to elucidate the roles of active convection and long-range transport on the vertically resolved chemical composition of the tropical atmosphere particularly in the altitude region that dominates convective outflow (12-14 km). Moreover, CONTRAST will be scheduled and coordinated in collaboration with two other airborne studies planned for the same time and geographic location: The NASA EV1 project ATTREX (Airborne Tropical Tropopause Experiment) and the European CAST (Coordinated Airborne Studies in the Tropics). With complementary instrument payloads, coordinated flights of the GV, the NASA Global Hawk, and the UK Bae146 will provide an unprecedented examination of the full atmospheric column, from surface to 19 km, over the tropical western Pacific Ocean.The unique suite of benchmark measurements under the auspices of CONTRAST will improve fundamental understanding of convective transport processes in the tropics and our ability to model the role of deep convection in chemistry-climate interactions. The project will train students in atmospheric chemistry who are directly involved in the deployment and subsequent data analysis and modeling activities. Broader education and outreach activities will be developed using web-based tools and media.