A finite element sea ice model of the Canadian Arctic Archipelago
A finite element sea ice model of the Canadian Arctic Archipelago
复制标题
加拿大北极群岛的有限元海冰模型
DOI：
10.1007/s10236-010-0356-5
复制
发表时间：
2010
期刊：
影响因子：
2.3
通讯作者：
J. Pietrzak
中科院分区：
文献类型：
--
作者：
A. D. Terwisscha van Scheltinga;P. Myers;J. Pietrzak
加拿大北极群岛（CAA）是由北极狭窄海峡和岛屿组成的复杂区域。它是从北冰洋到拉布拉多海并最终到达大西洋的淡水和海冰运输的重要通道。狭窄的海峡通常在海-冰-海洋耦合模型中被粗略地表示，导致对通过这些海峡的运输的错误描述。非结构化网格是对这个复杂区域进行建模的替代方法，因为它们能够捕获 CAA 的复杂几何形状。这在流场中提供了更高的分辨率，并允许更准确的传输（但不一定是更好的建模）。本文描述了北极地区的有限元海冰模型，并用于估计通过 CAA 的海冰通量。该模型是一个具有弹-粘-塑性流变学的动态-热力学海冰模型，并与板状海洋耦合，其中温度和盐度恢复为气候学，没有速度和表面高度。该模型是根据 NCEP/NARR 再分析数据从 1973 年到 1978 年建立起来的。从 1979 年到 2007 年，该模型是由 NCEP/DoE 再分析数据强制建立的。大尺度海冰特征与观测结果吻合良好。海冰总面积与观测结果非常吻合，并且显示出对北极涛动（AO）的敏感性。对于 1998-2002 年，我们发现对阿德蒙森湾、麦克卢尔海峡和伊丽莎白女王群岛的海冰体积和面积通量的估计与观测结果相当，并且略好于其他模型的估计。对于内雷斯海峡，我们发现由于缺少地形转向对大气强迫场的影响，通量远低于观测值。 1979-2007 年的通量显示出较大的季节性和年际变化，主要由冰速度场的变化以及对 AO 和其他大规模大气变化的敏感性驱动，这表明准确的大气强迫对于 CAA 建模可能至关重要。
The Canadian Arctic Archipelago (CAA) is a complex area formed by narrow straits and islands in the Arctic. It is an important pathway for freshwater and sea-ice transport from the Arctic Ocean to the Labrador Sea and ultimately to the Atlantic Ocean. The narrow straits are often crudely represented in coupled sea-ice–ocean models, leading to a misrepresentation of transports through these straits. Unstructured meshes are an alternative in modelling this complex region, since they are able to capture the complex geometry of the CAA. This provides higher resolution in the flow field and allows for more accurate transports (but not necessarily better modelling). In this paper, a finite element sea-ice model of the Arctic region is described and used to estimate the sea-ice fluxes through the CAA. The model is a dynamic–thermodynamic sea-ice model with elastic–viscous–plastic rheology and is coupled to a slab ocean, where the temperature and salinity are restored to climatology, with no velocities and surface elevation. The model is spun-up from 1973 to 1978 with NCEP/NARR reanalysis data. From 1979 to 2007, the model is forced by NCEP/DoE reanalysis data. The large scale sea-ice characteristics show good agreement with observations. The total sea-ice area agrees very well with observations and shows a sensitivity to the Arctic oscillation (AO). For 1998–2002, we find estimates for the sea-ice volume and area fluxes through Admunsen Gulf, McClure Strait and the Queen Elizabeth Islands that compare well with observation and are slightly better than estimates from other models. For Nares Strait, we find that the fluxes are much lower than observed, due to the missing effect of topographic steering on the atmospheric forcing fields. The 1979–2007 fluxes show large seasonal and interannual variability driven primarily by variability in the ice velocity field and a sensitivity to the AO and other large-scale atmospheric variability, which suggests that accurate atmospheric forcing might be crucial to modelling the CAA.