A New Concept in Glacier Mass Balance

冰川物质平衡提供了气候和冰川大小和形状变化之间的重要联系。在这里，研究人员提出了物质平衡的新概念，即基准表面的平衡率，它与冰川不断变化的几何形状无关。这是一个为期三年的项目，有两个目标：(1)定义和展示这种新型平衡的重要性，并确定如何在常规质量平衡计划的背景下对其进行测量。(2)完善冰川或冰盖对气候变化的响应理论。第一个目标的动机是，冰川的物质平衡不仅取决于气候，而且取决于冰川表面的几何形状。这是在平衡和气候之间找到联系的一个严重复杂的问题。建议的参考面平衡率与气候直接相关，其测量可能成为正在进行的平衡计划的一部分。第二个目标是确定参考面平衡率的前期工作的结果。对于冰川对气候变化的反应理论的几个扩展来说，这是一个方便的起点。它包括质量平衡对海拔高度和表面三维性质的依赖的影响。要研究的问题包括冰川几何形状对其对气候变化响应的稳定性和大小的影响，在进退过程中观测到的几何不对称的影响，以及从传统的质量平衡速度推断参考面平衡速度的可能性。

Glacier mass balance provides an important link between climate and changes in the size and shape or a glacier. Here the investigators propose a new concept for mass balance, the reference-surface' balance rate, which is independent of the changing geometry of a glacier. This is a three year project with two goals: (1) To define and to show the importance of this new type of balance, and to determine how to measure it within the context of conventional mass balance programs. (2) To improve the theory of the response of a glacier or ice cap to changes in climate. The first goal is motivated by the problem that the mass balance of a glacier depends not only upon climate, but upon the geometry of the glacier surface. This is a serious complication in finding a connection between balance and climate. The proposed reference-surface balance rate is directly connected with climate, and its measurement could become a part of ongoing balance programs. The second goal is an outgrowth of preliminary work on defining the reference-surface balance rate. It is a convenient starting point for several extensions of the theory of the response of a glacier to climate change. It includes the effects of the dependence of mass balance upon elevation and upon the three dimensional nature of the surface. The problems to be studied include the effects of a glacier's geometry on the stability and magnitude of its response to climate change, the effects of observed geometrical asymmetry during advance and retreat, and the possibility of deducing the reference-surface balance rate from conventional mass balance rate.