Rignot Eric, An Lu, Chauche Nolwenn, Morlighem Mathieu, Jeong Seongsu, Wood Michael, Mouginot Jeremie, Willis Josh K, Klaucke Ingo, Weinrebe Wilhelm, Muenchow Andreas
Department Earth System Science University of California Irvine Irvine CA USA.
Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA.
Geophys Res Lett. 2021 Mar 28;48(6):e2020GL091342. doi: 10.1029/2020GL091342. Epub 2021 Mar 24.
Humboldt Gletscher is a 100-km wide, slow-moving glacier in north Greenland which holds a 19-cm global sea level equivalent. Humboldt has been the fourth largest contributor to sea level rise since 1972 but the cause of its mass loss has not been elucidated. Multi-beam echo sounding data collected in 2019 indicate a seabed 200 m deeper than previously known. Conductivity temperature depth data reveal the presence of warm water of Atlantic origin at 0°C at the glacier front and a warming of the ocean waters by 0.9 ± 0.1°C since 1962. Using an ocean model, we reconstruct grounded ice undercutting by the ocean, combine it with calculated retreat caused by ice thinning to floatation, and are able to fully explain the observed retreat. Two thirds of the retreat are caused by undercutting of grounded ice, which is a physical process not included in most ice sheet models.
洪堡特冰川位于格陵兰岛北部，宽100公里，移动缓慢，其融化量相当于使全球海平面上升19厘米。自1972年以来，洪堡特冰川一直是海平面上升的第四大因素，但导致其质量损失的原因尚未明确。2019年收集的多波束回声测深数据显示，海床比之前所知的深200米。电导率温度深度数据显示，在冰川前沿存在来自大西洋的0°C温水，自1962年以来海水温度上升了0.9±0.1°C。我们使用海洋模型重建了海洋对 grounded ice（此处grounded ice可译为“陆基冰”）的侵蚀，并将其与计算得出的冰变薄至漂浮导致的退缩相结合，从而能够充分解释观测到的退缩现象。三分之二的退缩是由陆基冰被侵蚀造成的，这是大多数冰盖模型中未包含的一个物理过程。
