近日，英国利兹大学教授Wallis, Benjamin J.及其研究组报道了2014 - 2021年南极半岛西部冰川的普遍季节性加速现象。相关论文于2023年2月27日发表在《自然—地球科学》杂志上。

该研究团队使用Sentinel-1卫星观测，评估了2014年至2021年南极半岛西部105个冰川冰流速度的季节性变化。该研究团队发现夏季冰川的平均加速速率为12.4±4.2%，在季节性最明显的冰川上，最大速度变化可达22.3±3.2%。研究结果表明，在六年的研究期间，南极半岛西部的冰川对冰-海洋-大气系统中的季节性作用力做出响应，表明它们对终端位置、表面融水加上雨水通量和海洋温度的变化很敏感。在测量南极半岛的质量平衡和海平面贡献时，季节速度变化将被考虑在内，并且研究将确定在气候变暖情景下这一以前未记录的信号的未来演变。

据悉，南极冰盖的质量损失主要由冰动力学主导，海洋驱动的融化导致了非支撑和冰流加速。在过去的40年里，研究人员在南极洲测量了长期的冰速变化，然而，对地面冰盖的短期季节性速度变化的观测有限。

附：英文原文

Title: Widespread seasonal speed-up of west Antarctic Peninsula glaciers from 2014 to 2021

Author: Wallis, Benjamin J., Hogg, Anna E., van Wessem, J. Melchior, Davison, Benjamin J., van den Broeke, Michiel R.

Issue&Volume: 2023-02-27

Abstract: Mass loss from the Antarctic Ice Sheet is dominated by ice dynamics, where ocean-driven melt leads to un-buttressing and ice flow acceleration. Long-term ice speed change has been measured in Antarctica over the past four decades; however, there are limited observations of short-term seasonal speed variability on the grounded ice sheet. Here we assess seasonal variations in ice flow speed on 105 glaciers on the west Antarctic Peninsula using Sentinel-1 satellite observations spanning 2014 to 2021. We find an average summer speed-up of 12.4±4.2%, with maximum speed change of up to 22.3±3.2% on glaciers with the most pronounced seasonality. Our results show that over the six-year study period, glaciers on the west Antarctic Peninsula respond to seasonal forcing in the ice–ocean–atmosphere system, indicating sensitivity to changes in terminus position, surface melt plus rainwater flux, and ocean temperature. Seasonal speed variations must be accounted for when measuring the mass balance and sea level contribution of the Antarctic Peninsula, and studies must establish the future evolution of this previously undocumented signal under climate warming scenarios.

DOI: 10.1038/s41561-023-01131-4

Source: https://www.nature.com/articles/s41561-023-01131-4