Collaborative Research: Carbon System and CFCs in the Southeast Pacific Subantarctic Mode Water/Antarctic Intermediate Water Formation Region

0424744/0424921深厚混合层控制着上层海洋，亚南极模式水和南极中层水在亚南极锋以北的东南太平洋形成。寒冷的厚层具有低盐度和高气体含量，几乎填满了南半球和热带海洋的几乎所有较低温跃层到中等深度。SAMW/AAIW地层对海洋人为二氧化碳的汇有重大影响，其最大的不确定性在中等深度。然而，AAIW可能是唯一一个冬季没有在其主要源头进行研究的中深度、大尺度水团。在这个项目中，来自迈阿密大学罗森斯蒂尔海洋与大气科学学院和加州大学圣地亚哥分校斯克里普斯海洋研究所的研究人员将研究东南太平洋SAMW/AAIW形成的过程。虽然该项目的总体目标是表征东南太平洋形成区SAMW/AAIW厚层的碳和示踪性质，但碳系统参数和氯氟烃(CFCs)的测量也被用于：1)绘制主要SAMW/AAIW形成区冬季碳系统和CFCs性质图；2)将观测到的冬季大气-海洋二氧化碳不平衡与用？C*方法估计的平均不平衡项进行比较；3)研究上层特征(如对流、涡流、交错、洋流)与新形成的SAMW/AAIW深层混合层的碳和示踪特征的可能关系；估计氟氯化碳年龄和局部AAIW形成率，以评估新形成AAIW的平流和混合的相对影响。美国和智利的这一合作成果将填补全球海洋观测中的一个重要而巨大的空白，无论是影响长期气候变化的物理过程，还是管理碳循环的过程。这些成果将广泛传播，以增进对科学和技术的了解，并将用于控制人为二氧化碳向海洋内陆的吸收和运输的过程模型。

ABSTRACTOCE-0424744 / OCE-0424921Deep mixed layers dominate the upper ocean where Subantarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW) are formed in the southeastern (SE) Pacific north of the Subantarctic Front (SAF). The cold thick layers have low salinity and high gas content that fills almost all of the southern hemisphere and tropical oceans at lower thermocline to intermediate depths. SAMW/AAIW formation has a major impact on the oceanic sink for anthropogenic CO2, whose largest uncertainty is at intermediate depths. However, AAIW is probably the only intermediate-depth, large-scale water mass that has not been studied in winter at its major source. In this project, researchers from the University of Miami Rosenstiel School of Marine & Atmospheric Science and the University of California-San Diego Scripps Institute of Oceanography will study the processes responsible for the formation of SAMW/AAIW in the SE Pacific. Though the overall goal of the project is to characterize carbon and tracer properties in the thick SAMW/AAIW layers in the SE Pacific formation region, measurements of carbon system parameters and chlorofluorocarbons (CFCs) also be taken to: 1) map wintertime carbon system and CFC properties in the major SAMW/AAIW formation region; 2) compare the observed wintertime air-sea CO2 disequilibrium to the average disequilibrium terms estimated using the ?C* approach; 3) investigate the possible relationship of upper ocean features (e.g., convection, eddies, interleaving, currents) to the carbon and tracer characteristics of newly formed deep mixed layers of SAMW/AAIW; and 4) estimate CFC ages and a local AAIW formation rate to assess the relative effects of advection versus mixing of newly formed AAIW. The results yielded from this US and Chilean collaboration will fill an important and large gap in global ocean observations, both for physical processes that impact long-term climate change and for processes governing the carbon cycle. The results will be disseminated broadly to enhance scientific and technological understanding and will be available for use in models of processes that control the uptake and transport of anthropogenic CO2 into the ocean interior.