An assessment of Southern Ocean water masses and sea ice during 1988-2007 in a suite of interannual CORE-II simulations
An assessment of Southern Ocean water masses and sea ice during 1988-2007 in a suite of interannual CORE-II simulations
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DOI：
10.1016/j.ocemod.2015.07.022
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发表时间：
2015-10-01
期刊：
影响因子：
3.2
通讯作者：
Yeager, Stephen G.
中科院分区：
文献类型：
--
作者：
Downes, Stephanie M.;Farneti, Riccardo;Yeager, Stephen G.
我们在一套 15 个全球海冰模型中描述了南大洋水团结构和海冰的表征，这些模型采用协调海冰参考实验第二阶段 (CORE-II) 协议运行。主要重点是当前（1988-2007）模式和中间水域的表示，从而构建冬季和夏季混合层深度的分析；温度、盐度和位涡结构；以及海冰分布的时间变化。我们还考虑了同一 20 年期间的年际变化。对模型之间以及可用的基于观测的分析进行了比较。CORE-II 模型表现出相对于南大洋观测的一些偏差，包括低估了 3 月份模式和中间水团的模型平均混合层深度（与更大的海洋表面热量增益相关），以及 9 月份的高估（与更大的高纬度海洋热损失和更北的冬季海冰范围相关）。此外，这些模型的冷水、淡水/暖水和咸水柱偏差集中在南纬 50 度附近。在 1933 年至 2007 年期间，CORE-II 模型始终模拟海冰浓度、表面淡水通量、混合层深度和 200-700 海洋热含量的空间变化趋势。特别是，大部分南极大陆架周围的海冰覆盖范围减少，导致近地表水域冷却和清新。混合层的浅滩与表面浮力增益的增加有关，但太平洋除外，海冰也有影响。尽管 CORE-II 大气状态相同，但这些模型在混合层深度和海冰 20 年趋势的空间格局方面存在分歧。 (C) 2015 Elsevier Ltd. 保留所有权利，
We characterise the representation of the Southern Ocean water mass structure and sea ice within a suite of 15 global ocean-ice models run with the Coordinated Ocean-ice Reference Experiment Phase II (CORE-II) protocol. The main focus is the representation of the present (1988-2007) mode and intermediate waters, thus framing an analysis of winter and summer mixed layer depths; temperature, salinity, and potential vorticity structure; and temporal variability of sea ice distributions. We also consider the interannual variability over the same 20 year period. Comparisons are made between models as well as to observation-based analyses where available.The CORE-II models exhibit several biases relative to Southern Ocean observations, including an underestimation of the model mean mixed layer depths of mode and intermediate water masses in March (associated with greater ocean surface heat gain), and an overestimation in September (associated with greater high latitude ocean heat loss and a more northward winter sea-ice extent). In addition, the models have cold and fresh/warm and salty water column biases centred near 50 degrees S. Over the 1933-2007 period, the CORE-II models consistently simulate spatially variable trends in sea-ice concentration, surface freshwater fluxes, mixed layer depths, and 200-700 in ocean heat content. In particular, sea-ice coverage around most of the Antarctic continental shelf is reduced, leading to a cooling and freshening of the near surface waters. The shoaling of the mixed layer is associated with increased surface buoyancy gain, except in the Pacific where sea ice is also influential. The models are in disagreement, despite the common CORE-II atmospheric state, in their spatial pattern of the 20-year trends in the mixed layer depth and sea-ice. (C) 2015 Elsevier Ltd. All rights reserved,