20th-century climate change inferred from four long-term point observations of seasonal mass balance
20th-century climate change inferred from four long-term point observations of seasonal mass balance
复制标题
从季节性质量平衡的四个长期点观测推断出的 20 世纪气候变化
作者：
M. Huss;A. Bauder
摘要：从1914年开始，对瑞士克拉登芬（Claridenfirn）和格罗瑟·阿莱奇格莱彻（Grosser Aletschgletscher）和西尔弗瑞特格莱彻（Silvrettagletscher）的两个观测点进行了四个长期季节质量平衡观测序列的汇编。这些数据代表了世界上最长的物质平衡记录。基于温度指数方法的质量平衡模型用于校正不同观测日期和数据缺口的现场数据，并分离积累和消融。均匀化的连续93年时间序列覆盖了20世纪的大部分时间，使我们能够研究冰川质量平衡的时间、区域和高度变化以及气候强迫的变化。一个高海拔站点显示的夏季平衡趋势与位于平衡线附近的三个桩相反。自1975年以来，融冰速率增加了10%(10a)−1个增强的气候强迫期：1943 - 1953年和1987-2007年。尽管与1987年以来的气温相比，20世纪40年代的融化消耗的能量更高。我们发现了冰川表面热收支变化的证据，这对经验温度指数模型中度日因子的长期稳定性具有重要意义。
Abstract Four long-term time series of seasonal mass-balance observations, all starting in 1914, have been compiled for two stakes on Claridenfirn and one stake on Grosser Aletschgletscher and Silvrettagletscher, Switzerland. These data represent the longest records of mass balance worldwide. A mass-balance model based on the temperature-index approach is used to correct field data for varying observation dates and data gaps and to separate accumulation and ablation. The homogenized continuous 93 year time series cover most of the 20th century and enable us to investigate temporal, regional and altitudinal variability in mass balance and changes in the climatic forcing on glaciers. A high-altitude site shows summer balance trends opposite to those at three stakes located near the equilibrium line. Since 1975, melt rates have increased by 10%(10 a) − 1 periods of enhanced climatic forcing are detected: 1943–53 and 1987–2007. The energy consumed for melt was higher in the 1940s despite lower air temperatures compared to the years since 1987. We find evidence for a change in the glacier surface heat budget, which has important implications for the long-term stability of degree-day factors in empirical temperature-index modelling.