An enthalpy formulation for glaciers and ice sheets
An enthalpy formulation for glaciers and ice sheets
复制标题
DOI：
10.3189/2012jog11j088
复制
发表时间：
2012-01-01
影响因子：
3.4
通讯作者：
Blatter, Heinz
中科院分区：
文献类型：
--
作者：
Aschwanden, Andy;Bueler, Ed;Blatter, Heinz
从小山谷冰川到冰原，多热条件在冰川中无处不在。传统的基于温度的“冷冰”模型不能解释这部分内能，即温带冰中液态水的潜热，因此，当温带冰存在时，这种方案不能节约能源。然而，温度和液态水分数是单一焓变量的函数：冷冰的小焓变化是温度的变化，而温带冰的小焓变化是液态水分数的变化。这里描述的统一焓公式在一个单一的节能理论框架中对三维冰流体、地表径流层和冰下水文学层的质量和能量平衡进行了建模。它是在平行冰盖模型中实现的。格陵兰冰盖的结果与冷冰方案的结果进行了比较。本文旨在为冰川学中的焓公式提供一个可访问的基础。
Polythermal conditions are ubiquitous among glaciers, from small valley glaciers to ice sheets. Conventional temperature-based 'cold-ice' models of such ice masses cannot account for that portion of the internal energy which is latent heat of liquid water within temperate ice, so such schemes are not energy-conserving when temperate ice is present. Temperature and liquid water fraction are, however, functions of a single enthalpy variable: a small enthalpy change in cold ice is a change in temperature, while a small enthalpy change in temperate ice is a change in liquid water fraction. The unified enthalpy formulation described here models the mass and energy balance for the three-dimensional ice fluid, for the surface runoff layer and for the subglacial hydrology layer, together in a single energy-conserving theoretical framework. It is implemented in the Parallel Ice Sheet Model. Results for the Greenland ice sheet are compared with those from a cold-ice scheme. This paper is intended to be an accessible foundation for enthalpy formulations in glaciology.