Canadian arctic buoy program

加拿大北极群岛(CAA)有望在不久的将来通航。目前的估计是基于大气环流模式(GCM)的模拟结果。然而，GCM的空间分辨率仅允许CAA的粗略表示。为了更好地预测CAA海冰的未来演变，需要更高分辨率的模式。到目前为止，海冰动力学模型已经根据国际北极浮标方案(IABP)在北冰洋的浮标漂移数据进行了校准，但IABP中没有关于CAA的数据。这些模型的校准(以及它们所基于的连续体假设)在高分辨率下是否仍然有效仍然是一个悬而未决的问题。为了解决这一问题，我们在CAA的狭窄通道内进行了现场测量。特别是，我们监测了CAA中海冰变形、内应力和厚度的时间演变。这些测量被用来校准/验证我们小组最近开发的高分辨率海冰模型。该模型的动力学部分采用广义最小残差法(GMRES)求解，并采用线性连续超松弛预条件，以实现有效的长期积分。这一新的实施大大提高了数值效率，并允许在包括CAA和北冰洋在内的一个领域内以高分辨率整合模式。第一次部署于去年10月(2007年)在M‘Clintock海峡以北成功进行，使用Amundsen破冰船上的ArcticNet后勤。

The Canadian Arctic Archipelago (CAA) is expected to become navigable in the near future. Current estimates are based on simulation results from General Circulation Models (GCMs). The spatial resolution of GCMs, however, only allows for a coarse representation of the CAA. Higher resolution models are needed to better predict the future evolution of the sea ice in the CAA. Until now, sea-ice dynamic models have been calibrated against buoy drift data in the Arctic Ocean from the International Arctic Buoy Program (IABP), but no data is present for the CAA in IABP. Whether the calibration of these models (and the continuum assumption upon which they are based), are still valid at high resolution remain an open question. To address this, we make in-situ measurements within the narrow passages of the CAA. In particular, we monitor the temporal evolution of sea-ice deformations, internal stresses and thicknesses in the CAA. These measurements are used to calibrate/validate a high resolution sea-ice model that was recently developed in our group. The dynamical part of this model is solved using the Generalized Minimum Residual method (GMRES), with a line Successive Over-Relaxation preconditioner to allow for efficient long term integrations. This new implementation constitutes a significant improvement in numerical efficiency and allows for the integration of the model at high resolution over a domain including both the CAA and the Arctic Ocean. The first deployment took place successfully last October (2007) north of the M'Clintock Channel using ArcticNet logistics aboard the Amundsen ice breaker.