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

目前正在计划于2016年南半球夏季开展一项大型实地活动，以增进对海气交换过程以及广阔南大洋氧气和二氧化碳吸收情况的了解。该项目包括测量许多痕量气体，以确定和研究海洋生物活动、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地球化学模型，以提高对世界上这一采样不足但气候重要的地区的关键过程和反馈的理解。O2/N2比率和CO2空中南大洋（ORCAS）现场活动将包括测量一系列短暂的（即反应性）卤烃和其他可能对大气化学产生区域甚至全球影响的气体。例如，溴仿等寿命短的溴化合物的排放增加了全球活性溴的负担，而活性溴在平流层臭氧损失的化学过程中非常重要。其他反应性气体，包括二甲基硫醚和各种有机碘气体，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。目前对南大洋区域这些活性物种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，并提高对它们在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.