...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Geophysical Research. Biogeosciences >Seasonal cycles in two regimes of Arctic climate
【24h】

Seasonal cycles in two regimes of Arctic climate

机译：北极气候两个地区的季节性周期

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The annual variability of the Arctic Ocean is characterized by a large seasonal cycle against a background of climatically significant interannual and decadal timescale variations. One of the most significant of these interannual variations is wind-driven motion in the upper Arctic Ocean which alternates between anticyclonic and cyclonic regimes. This study focuses on differences in the seasonal cycle in years attributed to the cyclonic circulation regime (CCR), the anticyclonic circulation regime (ACCR), and the possible impact these seasonal anomalies have on fluctuations occurring over longer durations. Atmospheric, ice, and oceanic observational data and the results of numerical experiments with a coupled sea-ice-ocean model provide evidence that during the ACCR the arctic atmospheric pressure is higher and wind speed is lower compared with the CCR. A mean arctic ACCR winter is colder than a mean CCR winter. When the CCR dominates, precipitation increases over the ocean and decreases over the land. During the CCR, summer wind divergence effectively produces numerous sea-ice openings in the central Arctic Ocean. Repetition of this cyclonic process over several years results in overall thinner ice in the central Arctic, compared with that during the ACCR. Under the CCR, more ice-free summer areas lead to an accumulation of additional heat in the upper ocean, resulting in longer periods of ice melt, increases in fresher water content, and thinner ice. In CCR years both dynamical and thermodynamical factors cause excess ice and freshwater transport through Fram Strait from the Arctic into the Greenland Sea; the water balance in the Arctic Ocean is maintained via an increased inflow of the Atlantic water over the Barents Sea into the Nansen Basin. Finally, we stress that observed modifications of the Arctic Ocean thermohaline structure and Arctic Ocean-North Atlantic interactions in the early 1990s are a manifestation of the cyclonic circulation regime.
机译：北冰洋的年度可变性的特征是，在气候上明显的年际和年代际时标变化的背景下，季节周期较大。这些年际变化中最重要的变化之一是北冰洋上层的风驱动运动，它在反气旋和气旋状态之间交替。这项研究的重点是气旋循环制度（CCR），反气旋循环制度（ACCR）造成的年度季节性周期差异，以及这些季节性异常对较长时期内发生的波动可能产生的影响。大气，冰和海洋观测数据以及采用海冰-海洋耦合模型的数值实验结果提供了证据，表明在ACCR期间，与CCR相比，北极的大气压力更高，风速更低。平均北极ACCR冬季要比平均CCR冬季要冷。当CCR占主导地位时，海洋上的降水增加，陆地上的降水减少。在CCR期间，夏季风的发散有效地在北冰洋中部产生了许多海冰开口。与ACCR期间相比，这种旋风过程重复了数年，导致北极中部的总体冰层变薄。在CCR模式下，夏季无冰的地区增多，导致上层海洋积聚了更多的热量，导致冰融化的时间延长，新鲜水含量增加和冰层变薄。在CCR年中，动力学和热力学因素都导致过多的冰和淡水从弗拉姆海峡从北极进入格陵兰海。北大西洋通过巴伦支海流入南森盆地的流入量增加，从而维持了北冰洋的水平衡。最后，我们强调指出，在1990年代初观察到的北冰洋热盐结构的变化以及北冰洋与北大西洋的相互作用是气旋环流制度的体现。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号