Collaborative Research: Quantifying the Spatial/Temporal Variability of the Arctic Cold Halocline and Ice-Ocean Interaction

1995年，北极东部的上层海洋特征发生了重大变化。这种变化表现为失去了一个被称为冷盐跃层(CHL)的近地表。如果没有CHL，北极水柱看起来和行为都像南极水柱。局部影响包括可能启动相当大的冬季海洋热通量(15-20W/m2)，并使冬季冰的增长比有CHL的前几年减少70%-80%。目前尚不清楚CHL已经或将缺席多久，尽管它似乎在1999年夏天开始恢复。该项目将检查整个北极地区的CTD站，以量化CHL的强度以及海-冰相互作用的其他季节平均特征(例如，海洋热通量、总体稳定性、冰增长潜力的减少)。量化是通过分析上层海洋综合性质分布，然后生成描述相关物理量的稳健总体性质参数来实现的。该方法最初是为分析南极冰与海洋的相互作用而设计的，但最近表明，它同样适用于北极。一旦应用于北极数据，这些参数将被平均，以提供各种属性的气候。将把这些气候学的空间分布与北极的物理和动力学特性进行比较，以试图确定海冰相互作用的气候学性质与物理/动力学环境之间的关系。然后，将在零星数据覆盖范围允许的范围内应用最优内插方法，以努力确定各种综合属性如何在空间和时间上发生变化。这将提供海冰相互作用的空间/时间分布，用于评估CHL和其他海冰相互作用发生变化的方式。将检查时间变化以寻找周期、趋势或其他连贯模式的证据，正如最近在文献中所建议的那样。考虑到介质的长时间尺度，即使在采样稀少(在空间和时间上)的区域，海洋数据的分析也可能揭示可疑变化的证据，因此对海洋数据的分析是这项工作的理想选择。

There has been a significant change in the upper ocean characteristics of the eastern Arctic in 1995. The change was manifested through the loss of a near-surface layer known as the cold halocline layer (CHL). Without the CHL, the Arctic water column looks and behaves like the Antarctic water column. The local impact involves the likely initiation of considerable winter ocean heat fluxes (15-20 W/m 2 ) and reduction of winter ice growth by 70-80% relative to previous years in which the CHL was present. It is not known how long the CHL did, or will, remain absent, though it appears to begun recovery by summer 1999. This project will examine CTD stations throughout the Arctic region in order to quantify the strength of the CHL as well as other seasonally-averaged characteristics of the ocean-ice interaction (e.g., ocean heat flux, bulk stability, reduction in ice growth potential). The quantification is achieved through analysis of upper ocean integrated property distributions, and then generating robust bulk property parameters describing relevant physical quantities. The methodology was originally designed for analysis of Antarctic ice-ocean interaction, but as recently shown, is equally applicable to the Arctic. Once applied to the Arctic data, the parameters will be averaged to provide climatologies for the various properties. The spatial distribution of these climatologies will be compared to physical and dynamical properties of the Arctic in an attempt to determine the relationship between the climatological nature of the ocean-ice interaction and the physical/dynamical setting. Methods of optimal interpolation will then be applied, to the extent allowed by the sporadic data coverage, in an effort to determine how the various integrated properties have changed through space and time. This will provide spatial/temporal distributions of the ocean-ice interaction that will be used to evaluate the manner in which the CHL and other ocean-ice interactions have changed. The temporal variations will be examined for evidence of cycles, trends, or other coherent patterns, as have been suggested recently in the literature. Analysis of ocean data is ideal for this undertaking given the long time scales of the medium which may reveal evidence of the suspected changes even in sparsely sampled (in space and time) regions.