Oceanic controls on the mass balance of Wilkins Ice Shelf, Antarctica
Oceanic controls on the mass balance of Wilkins Ice Shelf, Antarctica
复制标题
DOI：
10.1029/2011jc007301
复制
发表时间：
2012
影响因子：
--
通讯作者：
L. Padman;D. Costa;M. Dinniman;H. Fricker;M. Goebel;Luis A. Hückstädt;A. Humbert;I. Joughin;J. Lenaerts;S. Ligtenberg;T. Scambos;M. Broeke
中科院分区：
文献类型：
--
作者：
L. Padman;D. Costa;M. Dinniman;H. Fricker;M. Goebel;Luis A. Hückstädt;A. Humbert;I. Joughin;J. Lenaerts;S. Ligtenberg;T. Scambos;M. Broeke
� 0.8 m a � 1 ，由平均基础熔化速率 <wb> = 1.3 � 0.4 m a � 1 驱动。年际变化很大，与表面质量积累和 <wb> 的变化有关。 2000 年左右基础熔化率显着下降，从 1992-2000 年的 1.8 × 0.4 m a × 1 下降到 2001-2008 年的 × 0.75 × 0.55 m a × 1；后一个值对应于近似稳态的冰架质量。 2007-2009 年期间，仪器海豹对海洋温度 T 的观测结果显示，WIS 周围有一个寒冷而深的冬季水晕（WW；T ≈ � 1.6°C）。晕中 WW 的底部为 Ø 170 m，大约是 WIS 的平均冰吃水深度。我们假设 2000 年<wb> 的转变是由冰基和晕中 WW 层底部的相对深度的小扰动（±10-20 m）引起的。我们得出的结论是，像WIS这样的薄冰架的基础融化对上层海洋和沿海过程非常敏感，这些过程比影响乔治六世和松岛冰川等较厚的南极西部冰架基础融化的时间和空间尺度更短。
� 0.8 m a � 1 , driven by a mean basal melt rate of 〈wb〉 = 1.3 � 0.4 m a � 1 . Interannual variability was large, associated with changes in both surface mass accumulation and 〈wb〉. Basal melt rate declined significantly around 2000 from 1.8 � 0.4 m a � 1 for 1992–2000 to � 0.75 � 0.55 m a � 1 for 2001–2008; the latter value corresponding to approximately steady-state ice-shelf mass. Observations of ocean temperature T obtained during 2007–2009 by instrumented seals reveal a cold, deep halo of Winter Water (WW; T ≈ � 1.6°C) surrounding WIS. The base of the WW in the halo is � 170 m, approximately the mean ice draft for WIS. We hypothesize that the transition in 〈wb〉 in 2000 was caused by a small perturbation (� 10–20 m) in the relative depths of the ice base and the bottom of the WW layer in the halo. We conclude that basal melting of thin ice shelves like WIS is very sensitive to upper-ocean and coastal processes that act on shorter time and space scales than those affecting basal melting of thicker West Antarctic ice shelves such as George VI and Pine Island Glacier.