Collaborative Research: CLIMODE

0424865智力优势：本过程实验主要研究北大西洋副热带模态水十八度水的形成、演化、储存、扩散及其大规模后果。模态水是海气交换的物理表现，通过连续的冬季暴露，在气候系统中构成长期记忆。目前对这些水域的年更新率及其物理机制的认识不足；从气候学海气通量推断的水团转换似乎与体积分析和估计的耗散过程不相容。据推测，目前的地层速率估计是不准确的，原因是：(i)对海气通量的估计不准确，以及（ii）对海洋侧向作用的了解/表现不佳。通过综合海洋-大气观测和模拟研究，CLIMODE项目（CLIvar模式水动力学实验）将：(i)调查世界海洋中所有亚热带模式水域的共同过程，这些水域位于强纬向流（特别是墨西哥湾流、黑潮延伸、东澳大利亚流、阿古拉斯回流和南极环极流）的赤道方向。（二）重点关注在海气交换中具有重要意义的区域，在分离的墨西哥湾流上发生巨大的海洋到大气的热损失，其通量估算的不确定性很大。（iii）探讨副热带环流边缘冬季对流相关水团的形成、向层状内部的俯冲及其在环流周围的扩散和耗散之间的跨尺度联系。（四）处理目前在气候模式中了解甚少且未充分反映的一个关键过程- -地转涡旋与混合层的相互作用。这是危及当前气候模式的最关键的参数化之一。CLIMODE将提供涡旋和混合层相互作用的现场观测和分析，以支持CLIVAR气候过程小组负责开发/测试参数化的海洋混合。更广泛的影响：CLIMODE将产生广泛的科学影响，因为它直接处理具有气候意义但在气候模式中没有充分体现的海洋现象和大气-海洋耦合。此外，通过对这些过程的气候模式参数化的评估/验证，CLIMODE将产生相当大的社会影响。CLIMODE项目还将有助于参与该研究的几名研究生和博士后的职业发展。在5年的项目中，CLIMODE平均每年将直接资助5名学生和4名博士后。

0424865Intellectual Merit: This process experiment is focused on the formation, evolution, storage, dispersal and large-scale consequences of Eighteen Degree Water, the subtropical mode water of the North Atlantic. Mode waters are a physical manifestation of air-sea exchange that, through successive wintertime exposure, constitute a long-term memory within the climate system. Present understanding of the annual renewal rate of these waters and the responsible physical mechanisms is deficient; water mass transformations inferred from climatological air-sea fluxes appear incompatible with both volumetric analyses and estimated dissipation processes. It is hypothesized that current formation rate estimates are inaccurate due to (i) poorly estimated air-sea fluxes and (ii) poorly understood/represented lateral ocean processes. Through a synthesis of ocean-atmosphere observations and modeling studies, the CLIMODE program (CLIvar MOde water Dynamics Experiment) will: (i) Investigate processes common to all subtropical mode waters in the world ocean, which are found equatorward of strong zonal flows (in particular the Gulf Stream, the Kuroshio Extension, the East Australian Current, the Agulhas Return Current and the Antarctic Circumpolar Current). (ii) Focus on a region of great importance in air-sea exchange huge ocean to atmosphere heat loss occurs over the separated Gulf Stream where uncertainties in flux estimates are large. (iii) Explore the cross-scale connection between water mass formation associated with wintertime convection on the rim of the subtropical gyre, its subduction into the stratified interior, and its dispersal and dissipation around the gyre. (iv) Address a key process that is presently poorly understood and inadequately represented in climate models - the interaction of geostrophic eddies with mixed layers. This is one of the most critical parameterizations that compromises the present generation of climate models. CLIMODE will provide field observations and analysis of the interaction of eddies and the mixed layer, in support of the CLIVAR Climate Process Team in ocean mixing responsible for developing/testing parameterizations. Broader Impact: CLIMODE will have broad scientific impact because it directly addresses oceanic phenomena and atmosphere-ocean coupling that have climatic significance but which are inadequately represented in climate models. Furthermore, through assessment/validation of the climate model parameterizations of these processes, CLIMODE will have considerable societal impact. The CLIMODE project will also contribute to the career advancement of several graduate students and postdoctoral investigators who will participate in the study. On average during the 5 year program, CLIMODE will directly support 5 students and 4 post-docs each year.