Measurement of Inorganic Bromine during CONTRAST (CONvective TRansport of Active Species in the Tropics)

作为更大规模的CRAST测量活动的一部分，（热带地区活性物质的对流输送）的主要目标是测量活性化学物质进入西太平洋暖池上方的对流层顶过渡层（TTL）的输送，格鲁吉亚理工学院的研究人员将测量一些短寿命的活性溴化合物（BrO，BrCl，Br 2和HOBr的总和），以及过硝酸（HO 2NO 2）。这些分子将被检测和定量使用的化学电离质谱仪（CIMS）在NSF G-V研究飞机飞行期间，在北方冬季，表面对流层的空气质量含有这些活性物质可能会被输送到太平洋暖池上空的TTL低平流层强烈的热带对流高。在这里，它们可能会对平流层下部的化学性质，包括臭氧化学性质产生重大影响。因此，了解TTL中活性卤素和短寿命含卤素物质（如溴碳）的来源、化学环境和丰度将有助于我们了解地球大气中这一未充分研究区域的溴化学。 观察过硝酸，这提供了HOx-NOx自由基反应的约束，将建模光化学提供一个额外的测试，我们的理解TTL光化学如何可能受到热带深对流的影响。对流层上部独特的低臭氧环境预计将导致非常少量的OH自由基，这有望增加活性气体的寿命，其主要损失是通过OH自由基氧化。同时发生的深对流和TTL中有机化合物寿命的延长可能对平流层卤素收支产生重大影响。学生，并提供她的论文研究工作的大部分。此外，一名本科生将提供广泛的研究经验。在设计BARST实验的时间时，考虑到了与计划在同一时间和地理位置进行的两项国际空中研究的合作。这两个项目分别是NASA EV 1项目ATTREX（热带对流层顶空中实验）和欧洲CAST（热带地区协调空中研究）。借助互补的仪器有效载荷，NSF GV，NASA Global Hawk和UK BAE 146的协调飞行将对热带西太平洋从表面到19公里的整个大气柱进行前所未有的检查。

As part of the larger CONTRAST measurement campaign (Convective Transport of Active Species in the Tropics) which has a main objective of measuring the transport of reactive chemical species into the topical Tropopause Transition Layer (TTL) over the western Pacific warm pool, Georgia Tech researchers will measure a number of short lived reactive bromine compounds (BrO, BrCl, the sum of Br2 and HOBr), and also pernitric acid (HO2NO2). These molecules will be detected and quantitated using a chemical ionization mass spectrometer (CIMS) flown on the NSF G-V research aircraft during CONTRAST.During northern winter, surface tropospheric air masses containing these reactive species may be transported by intense tropical convection high into the TTL lower stratosphere over the Pacific warm pool. Here they may substantially impact the chemistry of the lower stratosphere, including its ozone chemistry. Accordingly, knowing the sources, chemical environment and abundance of reactive halogen and short lived halogen containing species such as bromocarbons in the TTL will help inform our understanding of the bromine chemistry of this understudied region of the earth's atmosphere. The observation of pernitric acid, which provides constraint on HOx-NOx radical reactivity, will be modeled photochemically providing an additional test for our understanding of how TTL photochemistry may be impacted by tropical deep convection. The unique low-ozone environments in the upper troposphere are expected to result in very small levels of OH radicals, which can be expected to increase the lifetime of reactive gases whose main loss is through OH radical oxidation. The simultaneous occurrence of deep convection and prolonged lifetime of organic compounds in the TTL can have significant impact on the stratospheric halogen budget.With field work based out of Guam, the project will support one Ph.D. student and provide the bulk of her thesis research work. In addition, one undergraduate student will be provided with an extensive research experience. The timing of the CONTRAST experiment has been designed to take advantage of collaborations with two international airborne studies planned for the same time and geographic location. These are 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 NSF GV, the NASA Global Hawk and the UK BAE146 will provide an unprecedented examination of the full atmospheric column, from surface to 19 km, in the Tropical Western Pacific.