Contrasts in sea ice deformation and production in the Arctic seasonal and perennial ice zones
Contrasts in sea ice deformation and production in the Arctic seasonal and perennial ice zones
复制标题
北极季节性和常年冰区海冰变形和生产的对比
DOI：
10.1029/2005jc003246
复制
发表时间：
2006
影响因子：
--
通讯作者：
R. Kwok
中科院分区：
文献类型：
--
作者：
R. Kwok
[1]使用了四年(1997-2000年)的RADARSAT地球物理处理器系统(RGPS)数据，以对比区域以及季节性(SIZ)和常年(PIZ)冰带的海冰变形和生产。冬季开口处的结冰是季节性的。这些数量的三天估计是在拉格朗日元素内提供的，最初是每侧10公里。在这两个地区都看到了明显的季节性周期，这些估计值在深秋最高，而季节性最低值在仲冬。冬季的地区差异可能高达30%。在空间上，最大的变形出现在阿拉斯加海岸以北的大小。冰的变形和产量都较大：与变形有关的冰产量(∼0.5m)是Piz(∼0.3m)的1.5-2.3倍：这与冰的强度和厚度有关。大气强迫和边界层结构只对季节和年际变化有贡献。冰缝中的季节性冰增长占北冰洋总冰产量的25%-40%。∼对这些估计中的不确定性进行了讨论。就其本身而言，当厚度被扰动时，这种变形-冰产生关系可以被视为负反馈。然而，面对季节性增加和更薄/更弱的冰覆盖，对冰生产的总体影响可能会因水柱的局部不稳定而改变，因为水柱的局部不稳定促进了由于盐水拒绝增加而导致的较暖水的倾覆；以及与海冰中发生的大剪切运动增加有关的跃层上升。结果表明，两个冰区夏季和冬季的辐散与气旋运动的相关性可以忽略不计。
[1] Four years (1997–2000) of RADARSAT Geophysical Processor System (RGPS) data are used to contrast the sea ice deformation and production regionally, and in the seasonal (SIZ) and perennial (PIZ) ice zones. Ice production is of seasonal ice in openings during the winter. Three-day estimates of these quantities are provided within Lagrangian elements initially 10 km on a side. A distinct seasonal cycle is seen in both zones with these estimates highest in the late fall and with seasonal minimums in the midwinter. Regional divergence over the winter could be up to 30%. Spatially, the highest deformation is seen in the SIZ north of coastal Alaska. Both ice deformation and production are higher in the SIZ: deformation-related ice production in the SIZ (∼0.5 m) is 1.5–2.3 times that of the PIZ (∼0.3 m): this is connected to ice strength and thickness. Atmospheric forcing and boundary layer structure contribute to only the seasonal and interannual variability. Seasonal ice growth in ice fractures accounts for ∼25–40% of the total ice production of the Arctic Ocean. Uncertainties in these estimates are discussed. By itself, this deformation-ice production relationship could be considered a negative feedback when thickness is perturbed. However, the overall effect on ice production in the face of increasing seasonal and thinner/weaker ice coverage could be modified by local destabilization of the water column promoting overturning of warmer water due to increased brine rejection; and the upwelling of the pynocline associated with increased occurrence of large shear motion in sea ice. Divergence is shown to be negligibly correlated to cyclonic motion in summer and winter in both ice zones.