Variability of Antarctic Bottom Water formation and export from the Weddell Sea

南大洋的大西洋部分（即威德尔海）是向世界大洋提供南极底水的主要来源。由环境变化引起的形成速率变化可以改变经向翻转环流（MOC）的强度和变率，从而影响气候和气候变化。AABW形成过程和AABW形成量的变化也可能影响深海的人为碳吸收。该提案为CASO（南极洲和南大洋气候）框架下的国际极地年（IPY）做出了贡献。CASO旨在了解、解释和预测南极地区的气候变率和变化及其对南极和全球过程的影响。本提案的目的是：•确定威德尔海的AABW地层，特别是评估深水和底水地层的可变性。需要这个时间序列来了解底水形成的可变性与不断变化的环境条件（即冰架退化、加速融化、变暖、变新鲜）之间的联系•确定威德尔海深水和底水（随后的AABW）通过南斯科舍脊和穿过格林威治子午线的出口，以及从东部来源进口的深水及其可变性。•确定向西流入德雷克航道的AABW的路径和体积及其变异性。•确定东南太平洋深坡水（SPDSW）在南极绕极流中的输送和变率及其向南大西洋和威德尔海提供的3-氦。

The Atlantic sector of the Southern Ocean (i.e., the Weddell Sea) is the main supplier for Antarctic Bottom Water (AABW) to the World Ocean. Changes in the formation rate – caused by environmental changes – could modify the strength and variability of the Meridional Overturning Circulation (MOC) and, thus, affect climate and climate change. Changes in the AABW formation process and in the amount of AABW formed might also influence the anthropogenic carbon uptake of the deep ocean. The proposal contributes to the International Polar Year (IPY) in the framework of CASO (Climate in Antarctica and the Southern Ocean). CASO aims to understand, interpret and predict climate variability and change in the southern polar region and its impact on Antarctic and global processes. The aims of this proposal are: • To determine the AABW formation in the Weddell Sea, especially to assess the variability of deep and bottom water formation. This time series is needed to understand links between the variability of bottom water formation and changing environmental conditions (i.e., degradation of ice shelves, enhanced melting, warming, freshening) • To determine the export of Weddell Sea Deep and Bottom Water (subsequently AABW) through the South Scotia Ridge and across the Greenwich Meridian and the import of deep water from easterly sources and their variability. • To determine the pathways and volume of AABW and its variability leaking into Drake Passage towards the west. • To determine the transport and variability of the Southeast Pacific Deep Slope Water (SPDSW) in the Antarctic Circumpolar Current and its supply of 3-helium to the South Atlantic and Weddell Sea.