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

正在计划在2016年南半球夏季开展一项大型实地活动，以增进对浩瀚南大洋的海-气交换过程和氧气和二氧化碳吸收的了解。该项目包括测量许多痕量气体，以表征和检查海洋中的生物活动、痕量气体通量以及碳和氧交换之间的关系。结果将用于测试一套海洋生物地球化学模型，以提高对这一采样但气候重要区域的关键过程和反馈的理解。O2/N2比率和二氧化碳气载南大洋(Orcas)实地活动将包括测量一系列短期(即活性)卤化碳和其他气体，这些气体可能对区域乃至全球大气化学产生影响。例如，溴仿等寿命较短的溴化合物的排放造成了全球活性溴的负担，这在平流层臭氧丧失的化学过程中很重要。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。海洋表层排放的有机硝酸盐占南大洋大气中活性氧化氮的很大一部分。目前对这些活性物质在南大洋区域的大气分布和通量的了解有限。这项研究将有助于将活性痕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痕量气体通量的能力，并增进对它们在生物地球化学循环和气候变化中作用的理解。

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.