Distribution, Sources, and Air-Sea Fluxes of Short-Lived Organic Compounds During the O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) Study

一项大型实地考察活动计划于2016年夏季在南半球开展，目的是增进对海气交换过程以及广阔的南大洋对氧气和二氧化碳的吸收的了解。该项目包括测量许多微量气体，以表征和研究海洋生物活动、微量气体通量和碳氧交换之间的关系。这些结果将用于测试一套海洋生物地球化学模型，以提高对这个世界上采样不足但气候重要地区的关键过程和反馈的理解。O2/N2比和CO2空气传播南大洋（ORCAS）野外活动将包括一系列短寿命（即反应性）卤代烃和其他气体的测量，这些气体可能对大气化学产生区域甚至全球影响。例如，溴仿等短寿命溴化合物的排放造成了反应性溴的全球负担，而反应性溴在平流层臭氧损失的化学过程中是重要的。其他活性气体，包括二甲基硫化物和各种有机碘气体，与气溶胶形成过程和非均相化学处理有关。来自海洋表面的有机硝酸盐排放是南大洋大气中活性氧化氮的主要部分。目前对南大洋地区这些活性物质的大气分布和通量的了解是有限的。这项研究将有助于将反应性微量气体交换与碳和氧的基本生物地球化学循环以及详细的遥感海洋特性联系起来。这些结果将有助于提高预测活性微量气体通量的能力，并提高对其在生物地球化学循环和气候变化中的作用的认识。

A large field campaign is being planned for the Southern Hemisphere summer of 2016 to improve understanding of air-sea exchange processes and the uptake of oxygen and carbon dioxide in the vast Southern Ocean. This project includes the measurement of many trace gases to characterize and examine the relationships between biological activity in the ocean, trace gas fluxes, and carbon and oxygen exchanges. The results will be used to test a suite of ocean biogeochemistry models to improve the understanding of key processes and feedbacks in this under sampled yet climatically important region of the world.The O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) field campaign will include the measurement of a range of short-lived (i.e. reactive) halocarbons and other gases that can have both a regional and even global impact on atmospheric chemistry. For example, emissions of short-lived bromine compounds such as bromoform contribute to the global burden of reactive bromine, which is important in the chemistry of ozone loss in the stratosphere. Other reactive gases, including dimethyl sulfide and various organic iodine gases, are related to aerosol formation processes and heterogeneous chemical processing. Organic nitrate emissions from the surface ocean represent a major fraction of reactive oxidized nitrogen in the Southern Ocean atmosphere. Present knowledge of the atmospheric distributions and fluxes of these reactive species in the region of the Southern Ocean is limited. This research will help to link reactive trace gas exchanges to the basic biogeochemical cycles of carbon and oxygen as well as to detailed remotely sensed ocean properties. The results will help advance the ability to predict reactive trace gas fluxes and improve the understanding of their role in biogeochemical cycles and climate change.