Tidal forcing on sea-ice drift and deformation in the western Weddell Sea in early austral summer, 2004
Tidal forcing on sea-ice drift and deformation in the western Weddell Sea in early austral summer, 2004
复制标题
DOI：
10.1016/j.dsr2.2007.12.026
复制
发表时间：
2008-01-01
影响因子：
3
通讯作者：
Hibler, William D., III
中科院分区：
文献类型：
--
作者：
Heil, Petra;Hutchings, Jennifer K.;Hibler, William D., III
利用来自 24 个流冰浮标的中尺度阵列的现场数据，对 2004 年夏季初威德尔海西部的海冰漂移和变形进行了表征。 2004 年 11 月下旬和 12 月期间，作为 POLarstern 冰站 [ISPOL] 实验的一部分部署的漂流浮标可提供水平 GPS 位置测量，该实验在 2004 年 11 月下旬和 12 月进行了 26 天，具有不同的时间分辨率和空间精度。这些数据构成了中尺度 ISPOL 阵列和两个远程站点的海冰速度和变形测量的基础。对海冰速度的分析揭示了距离小于 70 公里时海冰漂移的相干性；相关长度尺度为60公里。在 ISPOL 阵列的限制内，在较大的间隔处，纬向冰漂移保持相关性，而经向冰漂移则变得不相关。这与冰速的东西梯度一起表明了测深通过潮汐力对局部动力过程的影响。大气强迫也会导致海冰漂移：大约 40% 的海冰速度变化是由风速变化来解释的，这明显低于其他研究发现的该地区冬季的风速变化。已经导出了整个阵列和四个子阵列的海冰变形。尽管在子阵列之间观察到相当大的空间变异性，但冰变形似乎不存在空间尺度依赖性。 ISPOL 阵列的净散度超过 30%，其中散度贡献最大的是整个 ISPOL 阵列的南段和东侧。所有变形参数的时间变化主要由高频（亚日）过程决定，即潮汐强迫和惯性响应。低频（多天）过程，包括大气变化，在 ISPOL 期间迫使海冰变形方面发挥了次要作用。 (C) 2008 Elsevier Ltd. 保留所有权利。
Sea-ice drift and deformation in the western Weddell Sea in early austral summer of 2004 are characterised using in situ data from a meso-scale array of 24 drifting ice buoys. Horizontal GPS-derived position measurements are available from drifting buoys deployed as part of the Ice Station POLarstern [ISPOL] experiment for 26 days during late November and December 2004, at various temporal resolutions and spatial accuracies. These data form the basis for sea-ice velocity and deformation measurements across the meso-scale ISPOL array and at two remote sites. Analysis of the sea-ice velocities reveals coherence for sea-ice drift at separations of less than 70km; and a correlation length scale of 60km. Within the limits of the ISPOL array, at larger separations zonal ice drift remains correlated, while meridional ice drift becomes uncorrelated. This together with the east-west gradient in ice velocities indicates the influence of bathymetry, via tidal forcing, on local dynamic processes. Atmospheric forcing also contributes to the sea-ice drift: about 40% of variability in the sea-ice velocity is explained by changes in wind velocity, which is significantly less than other studies have found for the region during winter. Sea-ice deformation has been derived for the overall array and four sub-arrays. There appeared to be no spatial scale dependency of ice deformation, although considerable spatial variability was observed between sub-arrays. The net divergence of the ISPOL array was in excess of 30%, with the largest contributions to divergence being from the southern section and along the eastern side of the overall ISPOL array. Temporal variability for all deformation parameters is dominated by high-frequency (sub-daily) processes, namely tidal forcing and inertial response. Low-frequency (multiple days) processes, including atmospheric changes, played a secondary role in forcing sea-ice deformation during ISPOL. (C) 2008 Elsevier Ltd. All rights reserved.