Remote Control of Filchner-Ronne Ice Shelf Melt Rates by the Antarctic Slope Current
Remote Control of Filchner-Ronne Ice Shelf Melt Rates by the Antarctic Slope Current
复制标题
南极坡流对菲尔希纳-龙冰架融化速率的远程控制
作者：
Bull C
最近对Filchner伦讷冰架（FRIS）系统的研究表明，威德尔海东南部沿岸流的重新定向可能导致一种状态变化，其中温暖的改良环极深水的入侵导致基底融化率大幅增加。到目前为止，工作主要集中在如何增加修改环极深水穿越大陆架断裂直接导致热驱动的变化融化在冰架腔。在这项研究中，我们介绍了威德尔海区域海洋模式配置与静态冰架。我们评估了参考模拟雷达观测融化，并发现模拟和观察到的平均熔化率之间的良好协议。我们分析了28个敏感性实验，模拟了南极斜坡流的远程水属性的变化对FRIS基底融化的影响。我们发现，远程盐度的变化准线性地调制平均FRIS净融化率。远程温度的变化使FRIS净熔融速率呈二次变化。在盐度和温度扰动下，响应是快速和短暂的，恢复时间尺度为5-15年，取决于扰动的大小/类型。我们表明，这两种类型的扰动导致大陆架上的不同变化，并最终不同的因素调制FRIS腔的融化速率。我们讨论了这些结果，是相关的海洋后报模拟，海平面和融化速率预测的FRIS。
Recent work on the Filchner‐Ronne Ice Shelf (FRIS) system has shown that a redirection of the coastal current in the southeastern Weddell Sea could lead to a regime change in which an intrusion of warm Modified Circumpolar Deep Water results in large increases in the basal melt rate. Work to date has mostly focused on how increases in the Modified Circumpolar Deep Water crossing the continental shelf break leads directly to heat driven changes in melting in the ice‐shelf cavity. In this study, we introduce a Weddell Sea regional ocean model configuration with static ice shelves. We evaluate a reference simulation against radar observations of melting, and find good agreement between the simulated and observed mean melt rates. We analyze 28 sensitivity experiments that simulate the influence of changes in remote water properties of the Antarctic Slope Current on basal melting in the FRIS. We find that remote changes in salinity quasi‐linearly modulate the mean FRIS net melt rate. Changes in remote temperature quadratically vary the FRIS net melt rate. In both salinity and temperature perturbations, the response is rapid and transient, with a recovery time‐scale of 5–15 years dependent on the size/type of perturbation. We show that the two types of perturbations lead to different changes on the continental shelf, and that ultimately different factors modulate the melt rates in the FRIS cavity. We discuss how these results, are relevant for ocean hindcast simulations, sea level, and melt rate projections of the FRIS.